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REVIEWED BLD BLD2024-0958+Calculations+7.23.2024_9.27.55_AM+4394479BLD2024-0958 0 u N N 0 L to RECEIVED Jul 24 2024 CITY OF EDMONDS DEVELOPMENT SERVICES DEPARTMENT I. L. GROSS STRUCTURAL ENGINEERS .............................................. REVIEWED BY CITY OF EDMONDS BUILDING DEPARTMENT ............................................... Thomson Veiguth Residence New Deck Edmonds, WA Calculations for Permit Review June 24, 2024 Design Criteria 2021 International Building Code 2016 ASCE 7 Seismic analysis I = 1.0 Ss= 132% S i = 47% Sys= 106% SDI= 47% R = 6.5 Seismic Design Category D Live Loads Roof 25 psf snow Residential 40 psf Dead Loads Deck Framing Composite Deck 6 psf Framing 3 psf Thomson Velguth Residence Deck 6811 164th PL SW Edmonds, WA Wind analysis Wind Speed (V3s) mph 100 Exposure B Importance Factor I = 1.0 Topographic Factor Kzt = 1.0 2" Diameter Extra Strong Pipe Pile Capacity = 6 tons/pile OEOTECH CONSULTANTS, INC_ Kerry Thomson and Kurt Velguth 6811 — 164th Place Southwest Edmonds, Washington 98026 via email: thomson. kerry(a)gmail. com & vetquth(@Vahoo.com Subject: Transmittal Letter — Geotechnical Engineering Study Proposed Deck and Landscaping Project 6811 — 164th Place Southwest Edmonds, Washington Greetings: 2401 1 Oth Ave E Seattle, Washington 98102 (425)747-5618 December 21, 2023 J N 23322 Attached to this transmittal letter is our geotechnical engineering report for the proposed deck and landscaping project in Edmonds. The scope of our services consisted of exploring site surface and subsurface conditions, and then developing this report to provide recommendations for general earthwork, Geologically Hazardous Area considerations, and design considerations for foundations, retaining walls, subsurface drainage, and temporary excavations. This work was authorized by your acceptance of our proposal, P-11479, dated September 6, 2023. The attached report contains a discussion of the study and our recommendations. Please contact us if there are any questions regarding this report, or for further assistance during the design and construction phases of this project. Respectfully submitted, GEOTECH CONSULTANTS, INC. I)- 7&- Adam S. Moyer Geotechnical Engineer cc: Studio 342 Landscape Architecture — Chad Wichers via email: chad(a)studio342.com ASM/DRW:kg GEOTECH CONSULTANTS, INC. GEOTECHNICAL ENGINEERING STUDY Proposed Deck and Landscaping Project 6811 — 1641" Place Southwest Edmonds, Washington This report presents the findings and recommendations of our geotechnical engineering study for the site of the proposed deck and landscaping project to be located in Edmonds. We were provided with a preliminary site plan of the proposed project and a topographic map of the property. Studio 342 developed the preliminary site plan, which is dated August 1, 2023; the topographic survey was developed by Site Surveying, Inc. and dated June 14, 2022. Based on this site plan, we understand that a new deck is proposed that will wrap around the north and west sides of the residence; the proposed deck will extend to the top of, or slightly onto the top of the steep slopes that descend to the northern and southwestern from the residence. Based on the provided plans, the new deck will extend approximately 16 to 17 feet north and west of the residence footprint. New stairs will descend west off of the deck to give access to the lawn below. A relatively level yard area currently extends west of the residence, along the top of a narrow east - west knoll feature; steep slopes drop from the edges of the knoll to both the north and southwest. We understand this area will be re -landscaped along the top of the knoll feature. This landscaping will generally consist of reconfiguring the shape of the yard, installing a small firepit and seating area, and planting some small trees. If the scope of the project changes from what we have described above, we should be provided with revised plans in order to determine if modifications to the recommendations and conclusions of this report are warranted. SITE CONDITIONS SURFACE The Vicinity Map, Plate 1, illustrates the general location of the site in the northern end of Edmonds. The 0.56-acre property is roughly triangular in shape, with a width of approximately 300 feet along its southern property line. Between the northern property corner and the center of the southern property line, the site has a width of approximately 130 feet. The northwest and northeast property lines have lengths of 187 and 195 feet respectively. A short narrow panhandle extends east from the southeast corner of the property to the southern end of 164th Place Southwest to the east. Residential properties containing single-family residences surround the remainder of the subject site, with the exception of the very southwest site corner, which abuts the North Meadowdale Road right-of-way. A two-story residence is located in the southeast corner of the property, which has a lowest finished floor elevation of 435.2 feet. The eastern end of the house contains an attached two -car garage, while the remainder of the house overlies a crawlspace. A concrete driveway spans between the garage and 164th Place Southwest. The ground surfaces slopes gently downwards to the west around the residences, such that the first floor on the western end of the house is elevated approximately 5 to 6 feet above the surrounding grade. A small concrete patio and wooden deck extends north of the house, and abuts the top of a steep slope that descends to the north-northwest (discussed further below); the deck also wraps around the northwest corner of the house. West of GEOTECH CONSULTANTS, INC. Thomson & Velguth J N 23322 December 21, 2023 Page 2 the house is the top of an approximately 30-foot wide, grass -covered knoll, that slopes gently downwards to the west approximately 80 to 90 feet from the edge of the western deck. The remainder of the property is generally covered with tall evergreen trees and underbrush consisting of ivy, ferns, and bushes. As discussed above, existing development on the property is located along the top of a knoll feature that slopes gently downwards to the west across the property. The ground surface slopes gently downwards from 164th Place Southwest, along the concrete driveway to and around the perimeter of the house. A grass lawn area continues to slope gently downwards to the west from the house. However, the ground surface slopes steeply downwards and away to the north-northwest and to the south-southwest from the northern and southern sides of the development and western knoll. Based on the provided topographic survey of the property, the northern steep slope has an overall inclination of 35 percent over a height of up to 22 feet on the property. However, the upper 10 to 18 feet of the slope has an inclination of 42 percent, while the remaining lower portion of the slope has an inclination of 25 to 26 percent. This slope continues onto the northeastern and northwestern adjacent properties. The southwestern slope descending from the knoll has a height of 15 to 32 feet on the property, at an inclination ranging from 35 to 38 percent. However, the top of the slope off the southwest corner of the house appears to have been oversteepened with fill soils placed overtop of the original ground surface when the property was originally developed; because of this, the upper 10 to 11 feet of the slope has an inclination of 43 percent. Portions of the subject site would be classified as Geologically Hazardous Areas per chapter 23.80 of the City of Edmonds Code (ECDC). Based on the provided topographic survey of the property, the upper approximately 10 to 18 feet of the northern, western, and southwestern slopes that drop away from the developed portion of the property have inclinations greater than 40 percent, and thus is considered Landslide Hazard Areas under the ECDC. However, we did not observe any indications of instability of the steep slopes on the property. In addition, any portion of the site that is greater than 15 percent is considered an Erosion Hazard Area per ECDC 23.80. SUBSURFACE The subsurface conditions were explored by drilling four test borings and excavating two test holes at the approximate locations shown on the Site Exploration Plan, Plate 2. Our exploration program was based on the proposed construction, anticipated subsurface conditions and those encountered during exploration, and the scope of work outlined in our proposal. The test borings were drilled on October 4, 2023 using a small track -mounted, hollow -stem auger drill. Samples were taken at approximate 2.5- to 5-foot intervals with a standard penetration sampler. This split -spoon sampler, which has a 2-inch outside diameter, is driven into the soil with a 140-pound hammer falling 30 inches. The number of blows required to advance the sampler a given distance is an indication of the soil density or consistency. A geotechnical engineer from our staff observed the drilling process, logged the test borings, and obtained representative samples of the soil encountered. The Test Boring Logs are attached as Plates 3 through 6. The test holes were excavating by a geotechnical engineer from our staff on October 4, 2023 using hand auger equipment. The Test Hole Logs are attached to this report as Plate 7. GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 Soil Conditions J N 23322 Page 3 The test borings and test holes conducted on the property encountered 6 inches to 5.5 feet of loose to medium -dense silty sand fill soils and native weathered silty sand overtop of very dense silty sand with gravel beneath the subject site. The underlying very dense silty sand soil was deposited and compressed by glaciers during the last glaciation period and are referred to geologically as glacial till. The test borings with the hand -carried Acker drill reached auger refusal in the very dense glacial till at depths of 7.2 to 11.3 feet below the ground surface. A discussion of each test boring and test hole is given below: • Test Boring 1 was conducted on the knoll west of the residence, and encountered the very dense glacial till approximately 0.5 feet beneath the ground surface. • Near the northwest corner of the proposed deck, Test Boring 2 encountered 5.5 feet of loose silty sand fill soils, directly overlying the very dense glacial till. The glacial till extended to the maximum -explored depth of 11.3 feet. • Test Boring 3 was conducted near the southwestern corner of the new deck and encountered 5 feet of loose to medium -dense native silty sand overtop of the very dense glacial till. • Test Boring 4 encountered very dense glacial till below 6 inches of topsoil off of the northeast corner of the house. The test boring was terminated 7.2 feet below grade due to auger refusal. • Test Hole 1 was conducted near the top of the northern steep slope, near the north- northwest portion of the proposed deck. Approximately 5.5 feet of loose sand fill soils were encountered overlying the remnant topsoil layer. Native weathered silty sand was revealed beneath the old topsoil layer. The test hole was terminated at a depth of 6.1 feet due to refusal on cobbles. • Near the toe of the northern steep slope, Test Hole 2 encountered 3 feet of loose sand fill soils overlying the native weathered silty sand. The test hole was terminated due to refusal on cobbles within the weathered silty sand at a depth of 3.5 feet. No obstructions were revealed by the explorations. However, debris, buried utilities, and old foundation and slab elements are commonly encountered on sites that have had previous development. Our explorations encountered cobbles within the glacial till; cobbles and boulders are often found in soils that have been deposited by glaciers or fast-moving water. Groundwater Conditions No groundwater seepage was observed in our subsurface explorations. The test borings and test holes were left open for only a short time period. Therefore, the seepage levels on the logs represent the location of transient water seepage and may not indicate the static groundwater level. It should be noted that groundwater levels vary seasonally with rainfall and other factors. We anticipate that groundwater could be found in the looser near -surface soils, perched on top of the underlying denser glacial till. The stratification lines on the logs represent the approximate boundaries between soil types at the exploration locations. The actual transition between soil types may be gradual, and subsurface conditions can vary between exploration locations. The logs provide specific subsurface information only at the locations tested. If a transition in soil type occurred between samples in the borings, the depth of the transition was interpreted. The relative densities and moisture descriptions indicated on GEOTECH CONSULTANTS, INC. Thomson & Velguth J N 23322 December 21, 2023 Page 4 the test boring and test hole logs are interpretive descriptions based on the conditions observed during drilling and excavation. SEISMIC CONSIDERATIONS In accordance with the International Building Code (IBC), the site class within 100 feet of the ground surface is best represented by Site Class Type C (Very Dense Soil and Soft Rock). As noted in the USGS website, the mapped spectral acceleration value for a 0.2 second (Ss) and 1.0 second period (Si) equals 1.32g and 0.47g, respectively. The IBC and ASCE 7 require that the potential for liquefaction (soil strength loss) during an earthquake be evaluated for the peak ground acceleration of the Maximum Considered Earthquake (MCE), which has a probability of occurring once in 2,475 years (2 percent probability of occurring in a 50-year period). The MCE peak ground acceleration adjusted for site class effects (FPGA) equals 0.68g. The soils beneath the site are not susceptible to seismic liquefaction under the ground motions of the MCE because of their dense nature and the absence of near -surface groundwater. Sections 1803.5 of the IBC and 11.8 of ASCE 7 r design parameters (seismic surcharge for retaining potential effects of the Design Earthquake. The Earthquake is defined in Section 11.2 of ASCE 7 acceleration, or 0.46g. SLOPE STABILITY ANALYSIS equire that other seismic -related geotechnical wall design and slope stability) include the peak ground acceleration for the Design as two-thirds (2/3) of the MCE peak ground We conducted a slope stability analysis of the northern steep slope on the subject site. The cross- section we used for the analysis is through approximately the tallest section of the steep slope off of the northwest corner of the proposed new deck. The analysis was done with the assistance of a computer program Slope/W, which is developed by GeoStudio. Slope stability is essentially governed by the topography of the area being analyzed, the delineation of each soil layer, and the geotechnical parameters of each soil layer. The main geotechnical parameters of each soil are the internal angle of friction and the cohesion. Analyses have been completed for both static and dynamic conditions; a seismic coefficient has been included in the dynamic analysis as noted further in this section. Based on the test borings and test holes conducted on the property, we have used three soil layers to model the slope: an upper thin layer of loose silty sand fill soils, overlying a thin layer of medium - dense silty sand (weathered glacial till), overlying very dense glacial till. Appendix A attached to the end of this report includes the cross section, with the soil parameters used (density, internal angle of friction, cohesion) for each of the soil layers. Typically for slope stability, the peak ground acceleration is equal to 2/3rds of the MCE; as noted above, the MCE is a very low probability earthquake event with a theoretical 2% potential of occurring in 50 years, or a one-in-2,475-years event. Thus, peak ground acceleration is 0.45g. Therefore, the coefficient used in the seismic slope analysis is 0.23g, which is one-half the peak seismic force (as is typical for seismic slope stability analyses). GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 The analysis indicated that the slope has the minimum required safety factor CONCLUSIONS AND RECOMMENDATIONS GENERAL J N 23322 Page 5 s THIS SECTION CONTAINS A SUMMARY OF OUR STUDY AND FINDINGS FOR THE PURPOSES OF A GENERAL OVERVIEW ONLY. MORE SPECIFIC RECOMMENDATIONS AND CONCLUSIONS ARE CONTAINED IN THE REMAINDER OF THIS REPORT. ANY PARTY RELYING ON THIS REPORT SHOULD READ THE ENTIRE DOCUMENT. The subject site is generally underlain at relatively shallow depths by very competent, dense to very dense glacial till soil; it has a high internal strength and therefore is not susceptible to deep-seated instability. The test borings and test holes conducted for this study encountered approximately 1 to 5.5 feet of loose silty sand fill soils and loose native weathered silty sand overlying the glacial till. As noted above, the stability of the glacial till soil in sloping conditions is adequate on the property. However, the loose soils above potentially are susceptible to movement based the safety factors needed for stability analysis. This report discusses, amongst other things, the project and its relationship to slope stability. The recommendations presented in this report are intended to: 1) prevent the proposed new deck and landscaping project from adversely impacting the stability of the steep slopes on the site and the adjoining properties and 2) protect the proposed development from damage in the event of potential future shallow soil movement on the steep slope downslope of the new deck and landscaping. An expanded discussion regarding the Geologically Hazardous Areas (Erosion Hazard Areas and Landslide Hazard Areas) on and near the property, the associated buffers and setbacks, and their impacts on the proposed development is included in the following section of this report. The proposed new deck will wrap around the northern and western perimeters of the residence and extend to the top of, or slightly onto the top of the adjacent steep slopes that descend the north and southwest. The competent dense glacial till was encountered approximately 1 to 6 feet beneath the ground surface in the area of the proposed new deck. Although the glacial till soils that comprise the core of the slope are not susceptible to deep-seated movement, the loose near -surface soils are prone to settlement, creep, and shallow movement on the steep slope. Therefore, we recommend the proposed deck be supported on small -diameter pipe piles driven into the glacial till that comprises the core of the adjacent steep slopes. This will allow for the loads of the decks to extend into the stable glacial till and not rely on the loose upper soils for any vertical or lateral support. The use of pipe piles will also greatly limit the amount of excavation and disturbance as compared to a standard footing foundation (which would have to extend as much as 6 feet below the ground surface). The northern and western sides of the residence have very limited access for construction equipment. Therefore, we anticipate the deep foundations will need to be installed using hand - carried equipment. Two -inch -diameter pipe piles can be installed using a pneumatic jackhammer or 140-pound Rhino hammer. Each of the isolated deck columns should contain a minimum of three piles, with one being vertical and the other two driven at a 1:5 (Horizontal:Vertical) batter downslope. Additional recommendations and clarifications for these piles is given in a subsequent section of this report. GEOTECH CONSULTANTS, INC. Thomson & Velguth J N 23322 December 21, 2023 Page 6 We anticipate very minimal excavations and disturbance will be required to construct the piles foundation system to support the proposed deck. However, any excess soil created during the excavations for the project should not be placed on or near a steep slope; this may require these soils to be exported from the site. We also understand that the existing yard area on top of the gently -sloped knoll west of the house will be slightly reconfigured with new landscaping installed around the lawn. A new fire pit and seating area are proposed west and east of the reconfigured lawn, respectively. We anticipate these seating areas will be constructed with pervious stone and gravel surfaces. The development is early in the planning stages; however, we anticipate the new landscaping will be surficial and will not include any significant earthwork or grading. Any structural fill for the landscaping project will need to be retained by an engineered retaining wall that bears directly on the dense glacial till. The test boring completed in this area on the western knoll encountered very dense glacial till within about 6 inches of the ground surface. The fine-grained, moisture sensitive nature of the onsite soils makes them very difficult to adequately recompact and reuse as structural fill. Therefore, we believe exporting the onsite soils and importing select granular material for structural fill will be necessary for the project. The glacial till encountered underlying the site is essentially impervious and will not accommodate stormwater infiltration. Any water that percolates through the loose upper soils will become perched above the relatively impervious underlying glacial till and migrate downslope toward the steep slopes to the north and southwest. Increasing the potential for shallow perched groundwater can adversely impact slope stability. Therefore, it is our opinion that onsite dispersion or concentrated infiltration of collected stormwater is not appropriate for the subject site. All collected stormwater should be tightlined to an approved off -site stormwater discharge system. If precipitation can flow through the deck, it will not be necessary to collect the water and tightline it away from the slope. Where the subject site is steeper than 15 percent, it is considered an Erosion Hazard Area per the ECDC 23.80.020.A.1 because of the silty sand soils (mapped as Everett gravelly sandy loam by the USDA Natural Resources Conservation Service) underlying the property. However, we point out that potential erosion hazards on sites such as this only occur during construction when the existing vegetation is removed and prior to placing buildings, and hardscaping and landscaping features. Thus, during construction, erosion control measures are needed to mitigate the potential for erosion. For this project, we recommend that a silt fence will be needed around the downslope sides of any cleared areas. Existing ground cover should be left in place wherever possible to minimize the amount of exposed soil. Rocked staging areas and construction access roads should be provided to reduce the amount of soil or mud carried off the property by trucks and equipment. Wherever possible, the access roads should follow the alignment of planned pavements. Trucks should not be allowed to drive off of the rock -covered areas. Cut slopes and soil stockpiles should be covered with plastic during wet weather. Following clearing or rough grading, it may be necessary to mulch or hydroseed bare areas that will not be immediately covered with landscaping or an impervious surface. On most construction projects, it is necessary to periodically maintain or modify temporary erosion control measures to address specific site and weather conditions. Geotech Consultants, Inc. should be allowed to review the final development plans to verify that the recommendations presented in this report are adequately addressed in the design. Such a plan review would be additional work beyond the current scope of work for this study, and it may include revisions to our recommendations to accommodate site, development, and geotechnical constraints that become more evident during the review process. GEOTECH CONSULTANTS, INC. Thomson & Velguth A 23322 December 21, 2023 Page 7 We recommend including this report, in its entirety, in the project contract documents. This report should also be provided to any future property owners so they will be aware of our findings and recommendations. INFORMATION WITH REGARDS TO ECDC 23.08. The following information is with regards to ECDC 23.08. We have listed the specific requested information noted in this chapter of the ECDC, followed by our responses to the requested information in italics. Per ECDC 23.80.050.A-C A. Preparation by a Qualified Professional. A critical areas report for assessing a potential geologically hazardous area shall be prepared by a geologist licensed in the state of Washington, with experience analyzing geologic, hydrologic, and ground water flow systems, and who has experience preparing reports for the relevant type of hazard. If mitigation measures are necessary, the report detailing the mitigation measures and design of the mitigation shall be prepared by an engineer licensed in the state of Washington, with experience stabilizing slopes with similar geotechnical properties. Critical areas studies and reports on geologically hazardous areas shall be subject to independent review pursuant to ECDC 23.40.090(B). This report is stamped by a professional geotechnical engineer. B. Area Addressed in Critical Areas Report. The following areas shall be addressed in a critical areas report for geologically hazardous areas: 1. The project area of the proposed activity; and 2. All geologically hazardous areas within 200 feet of the project area or that have the potential to be affected by the proposal. Steep slopes with an inclination of at least 40 percent (potential Landslide Hazard Areas) with heights of 10 to 18 feet are located on the northern, western, and southwestern portions of the subject site. These steep slopes continue onto the neighboring properties to the northwest, northeast, and south, and generally slope downwards away from the subject site. Also as noted in this report, all slopes on the site and surrounding properties that are steeper than 15 percent are also considered Erosion Hazard Areas. C. Geological Hazards Assessment. A geology hazard assessment report for a geologically hazardous area shall include a field investigation and contain an assessment of whether or not each type of geologic hazard identified in ECDC 20.80.020 is present or not present and if development of the site will increase the risk of landslides or erosion on or off the site. Geotechnical reports shall be prepared, stamped and signed by a qualified professional. These reports must: 1. Be appropriate for the scale and scope of the project. We believe this report is appropriate for the scale and scope of this project. 2. Include a discussion of all geologically hazardous areas on the site and any geologically hazardous areas off site potentially impacted by the proposed project. If the affected area extends beyond the subject property, the geology hazard assessment may utilize existing data sources pertaining to that area. As discussed above, there are several steep slopes located downslope of the proposed development on the subject site; these steep slope GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 J N 23322 Page 8 (potential Landslide Hazard Areas) continue onto the neighboring properties. Based on our site explorations, these slopes are comprises of very dense glacial till which is not susceptible to deep-seated movement. In our opinion, the proposed geologically hazardous areas on and off the subject site will not be adversely impacted by the proposed development. As discussed earlier, all portions of the site that are steeper than 15 percent are considered an Erosion Hazard Area of the ECDC. The portions of the subject site steeper than 15 percent are currently covered with scattered mature trees and underbrush; the proposed development area is covered with landscaping and hardscaping. In our opinion, the erosion hazard of the subject site is currently negligible because of this. However, the minimal excavations necessary for the proposed project may temporarily increase the erosion potential if suitable erosion control measures are not installed. We expect the project will include a suitable temporary erosion and sedimentation control (TESC) plan to address this. Following construction, we expect all temporary disturbance areas will be adequately reestablished with appropriate permanent landscaping/hardscaping to allow the site to return to a negligible erosion hazard. 3. Clearly state that the proposed project will not decrease slope stability or pose an unreasonable threat to persons or property either on or off site and provide a rationale as to those conclusions based on geologic conditions and interpretations specific to the project. In our opinion, the project will not decrease slope stability or pose an unreasonable threat to persons or property on or off site because: 1) the proposed deck will be supported on pipe piles embedded into the competent, very dense glacial till that comprises the core of the adjacent steep slope on the site, 2) the use of pipe piles will prevent the new deck from placing a surcharge load onto the loose near -surface soils on the steep slope, 3) the removal of the existing deck (on shallow footings bearing on the loose near -surface soils) will remove load from the top of the steep slope and actually improve the slope stability. 4. Provide adequate information to determine compliance with the requirements of this chapter. We believe this report provides this information. 5. Generally follow the guidelines set forth in the Washington State Department of Licensing Guidelines for Preparing Engineering Geology Reports in Washington (2006). In some cases, such as when it is determined that no landslide or erosion risk is present, a full report may not be necessary to determine compliance with this chapter, and in those cases a letter or abbreviated report may be provided. This report is stamped by a licensed geotechnical engineer, and thus we believe the guidelines are followed. 6. If a landslide or erosion hazard is identified, provide minimum setback recommendations for avoiding the landslide or erosion hazard, other recommendations for site development so that the frequency or magnitude of landsliding or erosion on or off the site is not altered, and recommendations consistent with ECDC 23.80.060 and 23.80.070. In our professional opinion, no setbacks are needed from either the Landslide Hazard Areas (steep slopes) or the Erosion Hazard Areas, provided the recommendations in this report are followed and appropriate permanent erosion control measures (vegetation) are installed after construction. In our opinion, provided the recommendations presented in this report are followed, the frequency or magnitude of landsliding or erosion on or off the site will not be altered. Information regarding ECDC 23.80.060 and 070 are included below. GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 J N 23322 Page 9 Per ECDC 23.80.050.F, additional Technical Information Requirements for Projects within Erosion and Landslide Hazard Areas. In addition to the basic critical areas report requirements for geologically hazardous areas provided in subsections (A) through (E) of this section, technical information for any development within earth subsidence and landslide hazard areas shall meet the requirements of Chapter 19.10 ECDC and include the following information at a minimum: 1. Site Plan. The critical areas report shall include a copy of the site plan for the proposal showing: a. The height of slope, slope gradient, and cross-section of the project area. The height of the slope and slope gradients are shown on Plate 2 of this report. A cross section is included within the slope stability analysis in Appendix A. b. The location of springs, seeps, or other surface expressions of ground water on or within 200 feet of the project area or that have the potential to be affected by the proposal. We did not observe any locations of seeps or springs. c. The location and description of surface water runoff features. We are unaware of any surface water runoff features on the subject site. 2. Hazards Analysis. The hazards analysis component of the critical areas report shall specifically include: a. A description of the extent and type of vegetative cover. It is described in the Surface section of this report. b. A description of subsurface conditions based on data from site -specific explorations. Described in the Subsurface section of this report. c. Descriptions of surface and ground water conditions, public and private sewage disposal systems, fills and excavations, and all structural improvements. These are discussed earlier in this report. d. An estimate of slope stability and the effect construction and placement of structures will have on the slope over the estimated life of the structure. Based on the slope stability analysis noted earlier in this report, the subject site is underlain by glacial till and is not susceptible to deep-seated movement. However, as with any steep slope in the Puget Sound region, there is always the potential for movement of the loose near -surface soils in a "skin slide". This most commonly occurs are extended periods of heavy precipitation. Supporting the proposed deck on pipe piles embedded into the dense glacial till that comprises the core of the slope is intended to prevent the proposed development from impacting the stability of the steep slope. In fact, removing the loads from the existing deck (which is supported on shallow footings bearing on the loose near -surface soils) will actually increase the stability of the adjacent steep slopes on the property. e. An estimate of the bluff retreat rate or an estimate of the percent risk of landslide area expansion that recognizes and reflects potential catastrophic events such as seismic activity or a 100-year storm event. The slope stability has taken into account the catastrophic seismic event; in our opinion, the proposed development will not increase the risk of the Landslide Hazard Areas on the subject site or neighboring properties. As discussed above, the possibility of soil movement during a 100-year storm event will only GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 J N 23322 Page 10 potentially include the looser, weathered, near surface soil (a mudslide). The recommendations presented in this report are intended to protect the proposed development from damage in the event of foreseeable future shallow soil movement on the steep slope downslope of the new deck and landscaping. Consideration of the run -out hazard of landslide debris and/or the impacts of landslide run - out on downslope properties. As with any steep slope in the Puget Sound Area, landslides can occur during times of significant precipitation and potentially during large seismic events. These types of landslides occur in the loose shallow soils above the glacial till that comprises the core of the steep slopes onsite. However, it is our opinion that the proposed development will not change this potential from occurring in relation to the existing conditions. g. A study of slope stability including an analysis of proposed cuts, fills, and other site grading. A slope stability analysis is provided in this report. h. Recommendations for building siting limitations. The proposed new deck and landscaping project will generally be located within the existing developed portion of the property. This area is generally gently to moderately sloped, and located upslope of the steep slopes on the property. It is our opinion that the siting of the proposed new deck and landscaping improvements is very suitable. An analysis of proposed surface and subsurface drainage, and the vulnerability of the site to erosion. The subject site is currently covered with native vegetation, landscaping, and hardscaping, and there is negligible erosion potential at the site. The minimal excavations for the proposed site improvements will temporarily increase the erosion potential if suitable erosion control measures are not installed. The recommendations presented in this report are intended to minimize the amount of site disturbance. We expect the project plans will include suitable erosion control measures, and thus potential erosion can be suitably controlled during construction. Following construction, permanent landscaping/hardscaping will be installed. If the deck uses flow -through materials, such as gapped decking boards, it is not necessary to collect the precipitation falling on the deck. Any stormwater collected from the proposed deck footprint will be properly directed away from the top of the steep slope to the stormwater drainage system. 3. Geotechnical Engineering Report. The technical information for a project within a landslide hazard area shall include a geotechnical engineering report prepared by a licensed engineer that presents engineering recommendations for the following: a. Parameters for design of site improvements including appropriate foundations and retaining structures. These should include allowable load and resistance capacities for bearing and lateral loads, installation considerations, and estimates of settlement performance. These are in this report. b. Recommendations for drainage and subdrainage improvements. These are noted in the report. c. Earthwork recommendations including clearing and site preparation criteria, fill placement and compaction criteria, temporary and permanent slope inclinations and protection, and temporary excavation support. These are included in this report. GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 J N 23322 Page 11 d. Mitigation of adverse site conditions including slope stabilization measures and seismically unstable soils, if appropriate. Removing the existing deck loads from the loose soils along the top of the steep slope and constructing the new deck on pipe piles embedded into the dense core of the slope is intended to improve the stability of the Landslide Hazard Areas on the property. Per ECDC 23.80.060.A, alterations of geologically hazardous areas or associated buffers may only occur for activities that: Will not increase the threat of the geological hazard to adjacent properties beyond predevelopment conditions. It is our professional opinion that this project will not increase the threat of the geological hazard areas to adjacent properties beyond the predevelopment conditions. 2. Will not adversely impact other critical areas. It is our professional opinion that this project will not impact other critical areas. 3. Are designed so that the hazard to the project is eliminated or mitigated to a level equal to or less than predevelopment conditions. The intent of the recommendations presented in this report is that the hazard to the project is mitigated to a level equal to or less than the existing conditions. 4. Are certified as safe as designed and under anticipated conditions by a qualified engineer or geologist, licensed in the state of Washington. The stamping geotechnical engineer certifies that recommendations presented in this report are intended such that the proposed development may be designed as safe under the anticipated conditions. Per ECDC 23.80.070, activities on sites containing erosion or landslide hazards shall meet the requirements of ECDC 23.80.060 (as noted in the previous section above) and the specific following requirements: Minimum Building Setback. The minimum setback shall be the distance required to ensure the proposed structure will not be at risk from landslides for the life of the structure, considered to be 120 years, and will not cause an increased risk of landslides taking place on or off the site. A setback shall be established from all edges of landslide hazard areas. The size of the setback shall be determined by the director consistent with recommendations provided in the geotechnical report to eliminate or minimize the risk of property damage, death, or injury resulting from landslides caused in whole or part by the development, based upon review of and concurrence with a critical areas report prepared by a qualified professional. It is our opinion that the proposed new deck and landscaping project does not require a setback from the Erosion Hazard Areas or Landslide Hazard Areas, and that the project will not increase the risk of landslides taking place on or off the site, provided the recommendations presented in this report are followed. 2. Buffer Requirements. A buffer may be established with specific requirements and limitations, including but not limited to, drainage, grading, irrigation, and vegetation. Buffer requirements shall be determined by the director consistent with recommendations provided in the geotechnical report to eliminate or minimize the risk of property damage, death, or injury resulting from landslides caused in whole or part by activities within the buffer area, based upon review of and concurrence with a critical areas report prepared by a qualified professional. We do not believe that a buffer is necessary from the onsite Erosion Hazard GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 J N 23322 Page 12 Areas or Landslide Hazard Areas because of the very dense glacial till core of the steep slopes, and because we did not observe any indications of instability of these slopes. 3. Alterations of an erosion or landslide hazard area, minimum building setback and/or buffer may only occur for activities for which a hazards analysis is submitted and certifies that: a. The alteration will not increase surface water discharge or sedimentation to adjacent properties beyond predevelopment conditions. It is our opinion that the proposed alterations will not increase surface water discharge or sedimentation to adjacent properties beyond the existing conditions, provided the recommendations presented in this report are followed. 4. Design Standards within Erosion and Landslide Hazard Areas. Development within an erosion or landslide hazard area and/or buffer shall be designed to meet the following basic requirements unless it can be demonstrated that an alternative design that deviates from one or more of these standards provides greater long-term slope stability while meeting all other provisions of this title. The requirement for long-term slope stability shall exclude designs that require regular and periodic maintenance to maintain their level of function. The basic development design standards are: a. The proposed development shall not decrease the factor of safety for landslide occurrences below the limits of 1.5 for static conditions and 1.2 for dynamic conditions. If stability at the proposed development site is below these limits, the proposed development shall provide practicable approaches to reduce risk to human safety and improve the factor of safety for Iandsliding. In no case shall the existing factor of safety be reduced for the subject property or adjacent properties. As previously discussed in this report, the proposed development will not decrease the factor of safety for landslide occurrences below their existing conditions. The slope stability analysis attached to this report shows the steep slope has safety factors of at least 1.5 and 1.2 in static and dynamic conditions with regards to deep-seated soil movement. b. Structures and improvements shall be clustered to avoid geologically hazardous areas and other critical areas. The proposed new deck and landscaping will generally be located within the existing developed portion of the property, which is located upslope of the steep slopes on the property. c. Structures and improvements shall minimize alterations to the natural contour of the slope, and foundations shall be tiered where possible to conform to existing topography. We understand the proposed site improvements will minimize alterations to the existing site contours. d. Structures and improvements shall be located to preserve the most critical portion of the site and its natural landforms and vegetation. As discussed above, the proposed deck and landscaping improvements for this development will almost entirely be located outside (upslope) of the steep slopes on the previously developed, moderately sloped portions of the site. e. The proposed development shall not result in greater risk or a need for increased buffers on neighboring properties. It is our opinion that the proposed development shall not result in greater risk or a need for increased buffers on neighboring properties. GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 J N 23322 Page 13 f. The use of retaining walls that allow the maintenance of existing natural slope area is preferred over graded artificial slopes. We understand that if any minor grading occurs, that small landscaping retaining walls will be used. g. Development shall be designed to minimize impervious lot coverage. We understand that is the case. PIPE PILES As discussed above, we recommend the proposed new deck be supported on a deep foundation system consisting of pipe piles driven into the very dense underlying glacial till. A 2-inch-diameter pipe pile driven with a minimum 90-pound jackhammer or a 140-pound Rhino hammer to a final penetration rate of 1-inch or less for one minute of continuous driving may be assigned an allowable compressive load of 3 tons. Extra -strong steel pipe should be used. The site soils are not highly organic, and are not located near salt water. As a result, they do not have an elevated corrosion potential. Considering this, it is our opinion that standard "black" pipe can be used, and corrosion protection, such as galvanizing, is not necessary for the pipe piles. Subsequent pipe sections should be connected together using threaded or slip couplers, or by welding. If slip couplers are used, they must fit snugly into the ends of the pipes. This can require that shims or beads of welding flux be applied to the couplers. Pile caps and grade beams should be used to transmit loads to the piles. As discussed in the General section, we recommend each isolated deck column contain a minimum of three piles, with one pile installed vertically and the two other piles driven at a 1:5 (Horizontal:Vertical) batter downslope. Lateral loads are typically resisted by passive earth pressure acting on the vertical, embedded portions of the foundation. However, because the ground surfaces slopes downwards away from the proposed deck, no passive earth pressure should be used for lateral resistance. Due to their small diameter, the lateral capacity of vertical pipe piles is negligible. The lateral capacity of a battered pile is equal to one-half of the lateral component of the allowable compressive load. The allowable vertical capacity of battered piles does not need to be reduced if the piles are battered steeper than 1:5 (Horizontal:Vertical). LANDSCAPING RETAINING WALLS Landscaping retaining walls can be supported on conventional footings bearing directly on the undisturbed, dense glacial till beneath the site. We recommend that continuous footings have minimum widths of 16 inches. Exterior footings should also be bottomed at least 18 inches below the lowest adjacent finish ground surface for protection against frost and erosion. The local building codes should be reviewed to determine if different footing widths or embedment depths are required. Footing subgrades must be cleaned of loose or disturbed soil prior to pouring concrete. Depending upon site and equipment constraints, this may require removing the disturbed soil by hand. An allowable bearing pressure of 2,000 pounds per square foot (psf) is appropriate for footings supported directly on the dense glacial till. GEOTECH CONSULTANTS, INC. Thomson & Velguth J N 23322 December 21, 2023 Page 14 Retaining walls backfilled on only one side should be designed to resist the lateral earth pressures imposed by the soil they retain. The following recommended parameters are for walls that restrain level backfill: PARAMETER Active Earth Pressure * VALUE 35 pcf Passive Earth Pressure 200 pcf Coefficient of Friction 0.50 Soil Unit Weight 130 pcf Where: pcf is Pounds per Cubic Foot, and Active and Passive Earth Pressures are computed using the Equivalent Fluid Pressures. * For a restrained wall that cannot deflect at least 0.002 times its height, a uniform lateral pressure equal to 10 psf times the height of the wall should be added to the above active equivalent fluid pressure. This applies only to walls with level backfill. The design values given above do not include the effects of any hydrostatic pressures behind the walls and assume that no surcharges, such as those caused by slopes, vehicles, or adjacent foundations will be exerted on the walls. If these conditions exist, those pressures should be added to the above lateral soil pressures. Where sloping backfill is desired behind the walls, we will need to be given the wall dimensions and the slope of the backfill in order to provide the appropriate design earth pressures. The surcharge due to traffic loads behind a wall can typically be accounted for by adding a uniform pressure equal to 2 feet multiplied by the above active fluid density. Heavy construction equipment should not be operated behind retaining and foundation walls within a distance equal to the height of a wall, unless the walls are designed for the additional lateral pressures resulting from the equipment. The values given above are to be used to design only permanent foundation and retaining walls that are to be backfilled, such as conventional walls constructed of reinforced concrete or masonry. It is not appropriate to use the above earth pressures and soil unit weight to back -calculate soil strength parameters for design of other types of retaining walls, such as soldier pile, reinforced earth, modular or soil nail walls. We can assist with design of these types of walls, if desired. The values for friction and passive resistance are ultimate values and do not include a safety factor. Restrained wall soil parameters should be utilized the wall and reinforcing design for a distance of 1.5 times the wall height from corners or bends in the walls, or from other points of restraint. This is intended to reduce the amount of cracking that can occur where a wall is restrained by a corner. Wall Pressures Due to Seismic Forces Per IBC Section 1803.5.12, a seismic surcharge load need only be considered in the design of walls over 6 feet in height. A seismic surcharge load would be imposed by adding a uniform lateral pressure to the above -recommended active pressure. The recommended seismic surcharge pressure for this project is 9H pounds per square foot (psf), where H is the design retention height of the wall. Using this increased pressure, the safety factor against sliding and overturning can be reduced to 1.2 for the seismic analysis. GEOTECH CONSULTANTS, INC. Thomson & Velguth December 21, 2023 Retainin_q Wall Backfill J N 23322 Page 15 Backfill placed behind retaining or foundation walls should be coarse, free -draining structural fill containing no organics. This backfill should contain no more than 5 percent silt or clay particles and have no gravel greater than 4 inches in diameter. The percentage of particles passing the No. 4 sieve should be between 25 and 70 percent. Drainage composite similar to Miradrain 6000 should be placed against the backfilled retaining walls. The drainage composites should be hydraulically connected to the foundation drain system. Free -draining backfill should be used for the entire width of the backfill where seepage is encountered. For increased protection, drainage composites should be placed along cut slope faces, and the walls should be backfilled entirely with free -draining soil. The purpose of these backfill requirements is to ensure that the design criteria for a retaining wall are not exceeded because of a build-up of hydrostatic pressure behind the wall. Also, subsurface drainage systems are not intended to handle large volumes of water from surface runoff. The top 12 to 18 inches of the backfill should consist of a compacted, relatively impermeable soil or topsoil, or the surface should be paved. The ground surface must also slope away from backfilled walls at one to 2 percent to reduce the potential for surface water to percolate into the backfill. Water percolating through pervious surfaces (pavers, gravel, permeable pavement, etc.) must also be prevented from flowing toward walls or into the backfill zone. Foundation drainage and waterproofing systems are not intended to handle large volumes of infiltrated water. The compacted subgrade below pervious surfaces and any associated drainage layer should therefore be sloped away. Alternatively, a membrane and subsurface collection system could be provided below a pervious surface. It is critical that the wall backfill be placed in lifts and be properly compacted, in order for the above -recommended design earth pressures to be appropriate. The recommended wall design criteria assume that the backfill will be well -compacted in lifts no thicker than 12 inches. The compaction of backfill near the walls should be accomplished with hand - operated equipment to prevent the walls from being overloaded by the higher soil forces that occur during compaction. The section entitled General Earthwork and Structural Fill contains additional recommendations regarding the placement and compaction of structural fill behind retaining and foundation walls. Footing drains should be used at the base of all earth -retaining walls. These drains should be surrounded by at least 6 inches of 1-inch-minus, washed rock that is encircled with non- woven, geotextile filter fabric (Mirafi 140N, Supac 4NP, or similar material). At its highest point, a perforated pipe invert should be at least 6 inches below the downslope grade. Weep holes (2-inch-diameter holes at 6-foot centers) should be installed through the base of the retaining walls as an outlet from the footing drain. EXCAVATIONS AND SLOPES Temporary excavation slopes should not exceed the limits specified in local, state, and national government safety regulations. Also, temporary cuts should be planned to provide a minimum 2 to 3 feet of space for construction of foundations, walls, and drainage. Temporary cuts to a maximum overall depth of about 4 feet may be attempted vertically in unsaturated soil, if there are no indications of slope instability. However, vertical cuts should not be made near property boundaries, GEOTECH CONSULTANTS, INC. Thomson & Velguth J N 23322 December 21, 2023 Page 16 or existing utilities and structures. Unless approved by the geotechnical engineer of record, it is important that vertical cuts not be made at the base of sloped cuts. Based upon Washington Administrative Code (WAC) 296, Part N, the loose near -surface soils at the subject site would generally be classified as Type B. Therefore, temporary cut slopes greater than 4 feet in height should not be excavated at an inclination steeper than 1:1 (Horizontal:Vertical), extending continuously between the top and the bottom of a cut. The above -recommended temporary slope inclinations are based on the conditions exposed in our explorations, and on what has been successful at other sites with similar soil conditions. It is possible that variations in soil and groundwater conditions will require modifications to the inclination at which temporary slopes can stand. Temporary cuts are those that will remain unsupported for a relatively short duration to allow for the construction of foundations, retaining walls, or utilities. Temporary cut slopes should be protected with plastic sheeting during wet weather. It is also important that surface runoff be directed away from the top of temporary slope cuts. Cut slopes should also be backfilled or retained as soon as possible to reduce the potential for instability. Please note that sand or loose soil can cave suddenly and without warning. Excavation, foundation, and utility contractors should be made especially aware of this potential danger. These recommendations may need to be modified if the area near the potential cuts has been disturbed in the past by utility installation, or if settlement -sensitive utilities are located nearby. Water should not be allowed to flow uncontrolled over the top of any temporary or permanent slope. All permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve the stability of the surficial layer of soil. Any disturbance to the existing slope outside of the building limits may reduce the stability of the slope. Damage to the existing vegetation and ground should be minimized, and any disturbed areas should be revegetated as soon as possible. Soil from the excavation should not be placed on the slope, and this may require the off -site disposal of any surplus soil. GENERAL EARTHWORK AND STRUCTURAL FILL All building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and other deleterious material. The stripped or removed materials should not be mixed with any materials to be used as structural fill, but they could be used in non-structural areas, such as landscape beds. Structural fill is defined as any fill, including utility backfill, placed under, or close to, a building, or in other areas where the underlying soil needs to support loads. All structural fill should be placed in horizontal lifts with a moisture content at, or near, the optimum moisture content. The optimum moisture content is that moisture content that results in the greatest compacted dry density. The moisture content of fill is very important and must be closely controlled during the filling and compaction process. As discussed in the General section, the on -site soils are not suitable for reuse as structural fill, due to its moisture sensitivity and high fines content. Fills placed on sloping ground should be keyed into the dense glacial till. This is typically accomplished by placing and compacting the structural fill on level benches that are cut into the competent soils. The allowable thickness of the fill lift will depend on the material type selected, the compaction equipment used, and the number of passes made to compact the lift. The loose lift thickness should not exceed 12 inches, but should be thinner if small, hand -operated compactors are used. We recommend testing structural fill as it is placed. If the fill is not sufficiently compacted, GEOTECH CONSULTANTS, INC. Thomson & Velguth J N 23322 December 21, 2023 Page 17 it should be recompacted before another lift is placed. This eliminates the need to remove the fill to achieve the required compaction. The following table presents recommended levels of relative compaction for compacted fill: Beneath slabs or 95% walkways Filled slopes and 90% behind retaining walls 95% for upper 12 inches of Beneath pavements subgrade; 90% below that level Where: Minimum Relative Compaction is the ratio, expressed in percentages, of the compacted dry density to the maximum dry density, as determined in accordance with ASTM Test Designation D 1557-91 (Modified Proctor). Structural fill that will be placed in wet weather should consist of a coarse, granular soil with a silt or clay content of no more than 5 percent. The percentage of particles passing the No. 200 sieve should be measured from that portion of soil passing the three -quarter -inch sieve. LIMITATIONS The conclusions and recommendations contained in this report are based on site conditions as they existed at the time of our exploration and assume that the soil and groundwater conditions encountered in the test borings and test holes are representative of subsurface conditions on the site. If the subsurface conditions encountered during construction are significantly different from those observed in our explorations, we should be advised at once so that we can review these conditions and reconsider our recommendations where necessary. Unanticipated conditions are commonly encountered on construction sites and cannot be fully anticipated by merely taking samples in test borings or test holes. Subsurface conditions can also vary between exploration locations. Such unexpected conditions frequently require making additional expenditures to attain a properly constructed project. It is recommended that the owner consider providing a contingency fund to accommodate such potential extra costs and risks. This is a standard recommendation for all projects. The recommendations presented in this report are directed toward the protection of only the proposed deck from damage due to slope movement. Predicting the future behavior of steep slopes and the potential effects of development on their stability is an inexact and imperfect science that is currently based mostly on the past behavior of slopes with similar characteristics. Landslides and soil movement can occur on steep slopes before, during, or after the development of property. The owner of any property containing, or located close to steep slopes must ultimately accept the possibility that some slope movement could occur, resulting in possible loss of ground or damage to the facilities around the proposed deck. This report has been prepared for the exclusive use of Kerry Thomson and Kurt Velguth and their representatives, for specific application to this project and site. Our conclusions and recommendations are professional opinions derived in accordance with our understanding of current local standards of practice, and within the scope of our services. No warranty is expressed GEOTECH CONSULTANTS, INC. Thomson & Velguth J N 23322 December 21, 2023 Page 18 or implied. The scope of our services does not include services related to construction safety precautions, and our recommendations are not intended to direct the contractor's methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. Our services also do not include assessing or minimizing the potential for biological hazards, such as mold, bacteria, mildew and fungi in either the existing or proposed site development. ADDITIONAL SERVICES In addition to reviewing the final plans, Geotech Consultants, Inc. should be retained to provide geotechnical consultation, testing, and observation services during construction. This is to confirm that subsurface conditions are consistent with those indicated by our exploration, to evaluate whether earthwork and foundation construction activities comply with the general intent of the recommendations presented in this report, and to provide suggestions for design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. However, our work would not include the supervision or direction of the actual work of the contractor and its employees or agents. Also, job and site safety, and dimensional measurements, will be the responsibility of the contractor. During the construction phase, we will provide geotechnical observation and testing services when requested by you or your representatives. Please be aware that we can only document site work we actually observe. It is still the responsibility of your contractor or on -site construction team to verify that our recommendations are being followed, whether we are present at the site or not. The following plates are attached to complete this report: Plate 1 Vicinity Map Plate 2 Site Exploration Plan Plates 3 - 6 Test Boring Logs Plate 7 Test Hole Logs Appendix A Slope Stability Analysis We appreciate the opportunity to be of service on this project. Please contact us if you have any questions, or if we can be of further assistance. _ Jim _, ASM/DRW:kg Respectfully submitted, GEOTECH CONSULTANTS, INC. J)� � � 7 A - Adam S. Moyer Geotechnical Engineer D. Robert Ward, P.E. Principal 03 GEOTECH CONSULTANTS, INC. NORTH Edmond,. GEOTECH CONSULTANTS, INC. 1' --Me Sdowdal e 1 Beach P� o f 1 / 1 - SITE ��--7 ity Park f i 1 t t ti r I r1 I LI I I I �i f (Source: Snohomish County Assessor) VICINITY MAP 6811 - 164th Place Southwest Edmonds, Washington Job Date: Plate: 23322 1 Dec.2023 1 1 NORTH Legend: ra Test Boring Location 0 Test Hole Location Slope Stability Analysis Cross Section GEOTECH CONSULTANTS, INC. SITE EXPLORATION PLAN 6811 - 164th Place Southwest Edmonds, Washington Job Date: Plate: 23322 1 Dec. 2023 No Scale 1 2 BORING 1 5 10 0 co 4" 2" C 1f Description Topsoil over: Gray, gravelly, silty SAND with occasional cobbles, fine to medium -grained, cemented, moist, very dense (Glacial Till) 12■ 3 11 1 * Test boring was terminated at 7.4 feet on October 4, 2023 due to refusal. * No groundwater was encountered during drilling. GEOTECH CONSULTANTS, INC. TEST BORING LOG 6811 - 164th Place Southwest Edmonds, Washington Job Date: Logged by: Plate: 23322 1 Dec.2023 1 ASM 1 3 BORING 2 5 10 15 0 co 13 77 50/0" 50/6" 50/3" Description Brown, silty SAND with gravel, fine-grained, dry, loose (FILL) FILL 1 - becomes brown to dark brown 2 Light brown, silty SAND with gravel and occasional cobbles, fine to medium -grained, moist, medium -dense becomes gray, cemented, very dense (Glacial Till) 3 I sM 5 ■I I * Test boring was terminated at 11.3 feet on October 4, 2023 due to refusal. * No groundwater was encountered during drilling. GEOTECH CONSULTANTS, INC. TEST BORING LOG 6811 - 164th Place Southwest Edmonds, Washington Job Date: Logged by: Plate: 23322 1 Dec.2023 1 ASM 1 4 BORING 3 5 10 0 co cn Description Brown, silty SAND with gravel and occasional roots, fine to medium - grained, moist, loose - becomes medium dense gM - becomes gray -brown with rust mottling 2 I I - becomes gray, cemented, very dense (Glacial Till) 3 11 1 * Test boring was terminated at 7.4 feet on October 4, 2023 due to refusal. * No groundwater was encountered during drilling. GEOTECH CONSULTANTS, INC. TEST BORING LOG 6811 - 164th Place Southwest Edmonds, Washington Job Date: Logged by: Plate: 23322 1 Dec.2023 1 ASM 1 5 BORING 4 5 10 0 co Description Topsoil over: Gray gravelly silty SAND with occasional cobbles, fine to medium -grained, moist, very dense (Glacial Till) 63 1 1 11 sM 3" 12■ 3 mi: i * Test boring was terminated at 7.2 feet on October 4, 2023 due to refusal. * No groundwater was encountered during drilling. GEOTECH CONSULTANTS, INC. TEST BORING LOG 6811 - 164th Place Southwest Edmonds, Washington Job Date: Logged by: Plate: 23322 1 Dec.2023 1 ASM 1 6 TEST HOLE 1 Depth (Feet) Soil Description 0.0 — 5.5 Dark brown SAND with silt, gravel, cobbles, organics, and occasional pieces of Glacial Till, fine to coarse -grained, moist, loose FILL 5.5 — 6.0 Topsoil 6.0 — 6.1 Light brown, silty SAND with gravel and cobbles, fine to medium -grained, moist, loose SM Test Hole was terminated at 6.1 feet on October 4, 2023 due to refusal on cobbles. No groundwater seepage was encountered in the test hole. No caving was observed during excavation. TEST HOLE 2 Depth (Feet) I Soil Description 0.0 — 3.0 Dark brown SAND with silt, gravel, cobbles, and organics, fine-grained, moist, loose [FILL] 3.0 — 3.5 Light brown, silty SAND with gravel and cobbles, moist, loose [SM] Test Hole was terminated at 3.5 feet on October 4, 2023 due to refusal. No groundwater seepage was encountered in the test hole. No caving was observed during excavation. *NOTE — Letters in brackets [ ] denote the USCS soil classification. GEOTECH CONSULTANTS, INC. TEST HOLE LOG 6811 - 164th Place Southwest Edmonds, Washington Job Date: Logged by: Plate: 23322 1 Dec.2023 I ASM Appendix A Materials ❑ Loose Silty Sand FILL ❑ Very Dense GLACIAL TILL ❑ Medium -Dense Silty SAND Name: Loose Silty Sand FILL Unit Weight: 120 pcf Cohesion': 0 psf Phi': 28 ° Name: Very Dense GLACIAL TILL Unit Weight: 135 pcf Cohesion': 100 psf Phi': 42 ° Name: Medium -Dense Silty SANC Unit Weight: 130 pcf Cohesion': 50 psf Phi': 34 ° 0 10 20 30 40 50 60 70 80 90 Distance (ft) J N 23322 Slope Stability Analysis Cross Section 460 450 440 430 420 C O co 410 > N W 400 390 380 370 100 110 120 130 140 150 Materials ❑ Loose Silty Sand FILL ❑ Very Dense GLACIAL TILL ❑ Medium -Dense Silty SAND Name: Loose Silty Sand FILL Unit Weight: 120 pcf Cohesion': 0 psf Phi': 28 ° Name: Very Dense GLACIAL TILL Unit Weight: 135 pcf Cohesion': 100 psf Phi': 42 ° Name: Medium -Dense Silty SAN[ Unit Weight: 130 pcf Cohesion': 50 psf Phi': 34 ° J N 23322 Slope Stability Analysis Static 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 v Distance (ft) W Static Static Report generated using GeoStudio 2012. Copyright © 1991-2016 GEO-SLOPE International Ltd. File Information File Version: 8.15 Title: 23322 Slope Stability Analysis Created By: Adam Moyer Last Edited By: Adam Moyer Revision Number: 23 Date: 12/19/2023 Time: 11:26:19 PM Tool Version: 8.15.6.13446 File Name: 23322 Slope Stability Analysis.gsz Directory: C:\Users\AdamM\Geotech Consultants\Shared Documents - Documents\2023 Jobs\23322 Thomson - Velguth (DRW)\ Last Solved Date: 12/19/2023 Last Solved Time: 11:26:25 PM Project Settings Length(L) Units: Feet Time(t) Units: Seconds Force(F) Units: Pounds Pressure(p) Units: psf Strength Units: psf Unit Weight of Water: 62.4 pcf View: 2D Element Thickness: 1 Analysis Settings Static Kind: SLOPE/W Method: Morgenstern -Price Settings Side Function Interslice force function option: Half -Sine PWP Conditions Source: (none) Slip Surface Direction of movement: Right to Left Use Passive Mode: No Slip Surface Option: Entry and Exit Critical slip surfaces saved: 1 Resisting Side Maximum Convex Angle: 1 ° file:///C/... OJobs/23322%20Thomson%20-%20Velguth%20(DRV)/23322°/o20slope%20stability%20analysis%20-%20static%20report.html[12/19/2023 11:31:03 PM] Static Driving Side Maximum Convex Angle: 5 ° Optimize Critical Slip Surface Location: No Tension Crack Tension Crack Option: (none) F of S Distribution F of S Calculation Option: Constant Advanced Number of Slices: 30 F of S Tolerance: 0.001 Minimum Slip Surface Depth: 0.1 ft Search Method: Root Finder Tolerable difference between starting and converged F of S: 3 Maximum iterations to calculate converged lambda: 20 Max Absolute Lambda: 2 Materials Loose Silty Sand FILL Model: Mohr -Coulomb Unit Weight: 120 pcf Cohesion': 0 psf Phi': 28 ° Phi-B: 0 ° Very Dense GLACIAL TILL Model: Mohr -Coulomb Unit Weight: 135 pcf Cohesion': 100 psf Phi': 42 ° Phi-B: 0 ° Medium -Dense Silty SAND Model: Mohr -Coulomb Unit Weight: 130 pcf Cohesion': 50 psf Phi': 34 ° Phi-B: 0 ° Slip Surface Entry and Exit Left Projection: Range Left -Zone Left Coordinate: (0.5, 403.06818) ft Left -Zone Right Coordinate: (35, 410) ft Left -Zone Increment: 20 Right Projection: Range Right -Zone Left Coordinate: (90.5, 429) ft Right -Zone Right Coordinate: (102.47167, 429) ft file:///C/... OJobs/23322%20Thomson%20-%20Velguth%20(DRV)/23322°/o20slope%20stability%20analysis%20-%20static%20report.html[12/19/2023 11:31:03 PM] Static Right -Zone Increment: 20 Radius Increments: 20 Slip Surface Limits Left Coordinate: (0, 403) ft Right Coordinate: (150, 431.5) ft Points X (ft) Y (ft) Point 1 0 403 Point 2 11 404.5 Point 3 35 410 Point 4 41.5 412 Point 5 74 425 Point 6 77 426.5 Point 7 80 428 Point 8 92 429 Point 9 103.5 429 Point 10 136 431.5 Point 11 147.5 431.5 Point 12 150 431.5 Point 13 80 422.5 Point 14 80 417 Point 15 74 419 Point 16 35 407 Point 17 35 406.5 Point 18 0 370 Point 19 150 370 Point 20 90.5 429 Point 21 j 35 402 Point 22 1 0 398 Regions Material Points Area (ft2) Region 1 Very Dense GLACIAL TILL 18,22,21,15,13,20,8,9,10,11,12,19 7,105.5 Region 2 Loose Silty Sand FILL 2,3,4,5,6,7,20,13,15,16 265.13 Region 3 Medium -Dense Silty SAND 2,1,22,21,15,16 276.75 Current Slip Surface Slip Surface: 5,293 F of S: 2.684 Volume: 322.64959 ft' Weight: 39,540.075 I bs file:///C/... OJobs/23322%2OThomson%20-%2OVelguth%20(DRW)/23322°/o20slope%20stability%20analysis%20-%20static%20report.html[12/19/2023 11:31:03 PM] Static Resisting Moment: 3,643,772.6 Ibs-ft Activating Moment: 1,357,893.7 Ibs-ft Resisting Force: 32,163.951 Ibs Activating Force: 11,985.338 Ibs F of S Rank (Analysis): 1 of 9,261 slip surfaces F of S Rank (Query): 1 of 9,261 slip surfaces Exit: (21.268237, 406.85314) ft Entry: (90.5, 429) ft Radius: 104.73065 ft Center: (25.957283, 511.47876) ft Slip Slices X (ft) Y (ft) PWP Base Normal Stress Frictional Strength Cohesive Strength (psf) (psf) (psf) (psf) Slice 1 22.41255 406.81438 0 36.724673 19.526855 0 Slice 2 24.701177 406.7619 0 107.86569 57.353204 0 Slice 3 26.989805 406.75946 0 173.59002 92.299453 0 Slice 4 29.278432 406.80705 0 233.23093 124.01108 0 Slice 5 31.567059 406.90474 0 286.19339 152.17173 0 Slice 6 33.855686 407.05268 0 331.99532 176.52504 0 Slice 7 35.319425 407.1679 0 361.14513 192.02427 0 Slice 8 36.615709 407.29651 0 401.7157 270.96066 50 Slice 9 38.569425 407.51495 0 450.82804 304.08735 50 Slice 40.523142 407.77066 0 493.29369 332.73079 50 10 Slice 42.705735 408.1032 0 545.66618 368.05648 50 11 Slice 45.117204 408.52294 0 605.57878 408.46804 50 12 Slice 47.528674 409.00113 0 654.86959 441.71512 50 13 Slice 49.940143 409.5386 0 693.91729 468.05312 50 14 Slice 52.351613 410.1363 0 723.28055 487.85889 50 15 Slice 54.763082 410.79529 0 743.636 501.58882 50 16 Slice 57.095766 411.49121 0 763.16936 687.16078 100 17 Slice 59.349664 412.2213 0 766.06467 689.76772 100 18 Slice 61.603562 413.00839 0 761.72783 685.86282 100 19 Slice 63.857459 413.85385 0 750.77929 676.00471 100 20 Slice 66.111357 414.75922 0 733.75633 660.67717 100 21 Slice 68.365255 415.7262 0 711.08717 640.26577 100 22 23Ce 70.619153 416.75668 0 683.07095 615.03984 100 file:///C/... OJobs/23322%2OThomson%20-%2OVelguth%20(DRV)/23322°/o20slope%20stability%20analysis%20-%20static%20report.html[12/19/2023 11:31:03 PM] Static Slice 72 873051 417.85275 0 649.86214 585.1385 100 24 Slice 75.5 419.22298 0 622.81346 560.78375 100 25 Slice 78.5 420.89861 0 599.46126 539.75734 100 26 Slice 81.05 422.41824 0 531.83713 478.86831 100 27 Slice 83.15 423.75231 0 421.92486 379.90285 100 28 Slice 85.25 425.15808 0 305.33711 274.92677 100 29 Slice 87.35 426.63913 0 180.75281 162.75056 100 30 Slice 89.45 428.19947 0 46.651027 42.004774 100 31 file:///C/... OJobs/23322%2OThomson%20-%2OVelguth%20(DRV)/23322°/o20slope%20stability%20analysis%20-%20static%20report.html[12/19/2023 11:31:03 PM] Materials ❑ Loose Silty Sand FILL ❑ Very Dense GLACIAL TILL ❑ Medium -Dense Silty SAND Name: Loose Silty Sand FILL Unit Weight: 120 pcf Cohesion': 0 psf Phi': 28 ° Name: Very Dense GLACIAL TILL Unit Weight: 135 pcf Cohesion': 100 psf Phi': 42 ° Name: Medium -Dense Silty SAN[ Unit Weight: 130 pcf Cohesion': 50 psf Phi': 34 ° J N 23322 Slope Stability Analysis Seismic 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 v Distance (ft) W Seismic Seismic Report generated using GeoStudio 2012. Copyright © 1991-2016 GEO-SLOPE International Ltd. File Information File Version: 8.15 Title: 23322 Slope Stability Analysis Created By: Adam Moyer Last Edited By: Adam Moyer Revision Number: 23 Date: 12/19/2023 Time: 11:26:19 PM Tool Version: 8.15.6.13446 File Name: 23322 Slope Stability Analysis.gsz Directory: C:\Users\AdamM\Geotech Consultants\Shared Documents - Documents\2023 Jobs\23322 Thomson - Velguth (DRW)\ Last Solved Date: 12/19/2023 Last Solved Time: 11:26:28 PM Project Settings Length(L) Units: Feet Time(t) Units: Seconds Force(F) Units: Pounds Pressure(p) Units: psf Strength Units: psf Unit Weight of Water: 62.4 pcf View: 2D Element Thickness: 1 Analysis Settings Seismic Kind: SLOPE/W Method: Morgenstern -Price Settings Side Function Interslice force function option: Half -Sine PWP Conditions Source: (none) Slip Surface Direction of movement: Right to Left Use Passive Mode: No Slip Surface Option: Entry and Exit Critical slip surfaces saved: 1 Resisting Side Maximum Convex Angle: 1 ° file:///C/... obs/23322%20Thomson%20%20Velguth%20(DRW)/23322%20slope%20stability%20analysis%20-0/o20seismic%20report.html[12/19/2023 11:31:19 PM] Seismic Driving Side Maximum Convex Angle: 5 ° Optimize Critical Slip Surface Location: No Tension Crack Tension Crack Option: (none) F of S Distribution F of S Calculation Option: Constant Advanced Number of Slices: 30 F of S Tolerance: 0.001 Minimum Slip Surface Depth: 0.1 ft Search Method: Root Finder Tolerable difference between starting and converged F of S: 3 Maximum iterations to calculate converged lambda: 20 Max Absolute Lambda: 2 Materials Loose Silty Sand FILL Model: Mohr -Coulomb Unit Weight: 120 pcf Cohesion': 0 psf Phi': 28 ° Phi-B: 0 ° Very Dense GLACIAL TILL Model: Mohr -Coulomb Unit Weight: 135 pcf Cohesion': 100 psf Phi': 42 ° Phi-B: 0 ° Medium -Dense Silty SAND Model: Mohr -Coulomb Unit Weight: 130 pcf Cohesion': 50 psf Phi': 34 ° Phi-B: 0 ° Slip Surface Entry and Exit Left Projection: Range Left -Zone Left Coordinate: (0.5, 403.06818) ft Left -Zone Right Coordinate: (35, 410) ft Left -Zone Increment: 20 Right Projection: Range Right -Zone Left Coordinate: (85.5, 428.52381) ft Right -Zone Right Coordinate: (102.47167, 429) ft file:///C/... obs/23322%20Thomson%20 "/o20Velguth%20(DRW)/23322%20slope%20stability%20analysis%20-0/o20seismic%20report.html[12/19/2023 11:31:19 PM] Seismic Right -Zone Increment: 20 Radius Increments: 20 Slip Surface Limits Left Coordinate: (0, 403) ft Right Coordinate: (150, 431.5) ft Seismic Coefficients Horz Seismic Coef.: 0.228 Points X (ft) Y (ft) Point 1 0 403 Point 2 11 404.5 Point 3 35 410 Point 4 41.5 412 Point 5 74 425 Point 6 77 426.5 Point 7 80 428 Point 8 92 429 Point 9 103.5 429 Point 10 136 431.5 Point 11 147.5 431.5 Point 12 150 431.5 Point 13 80 422.5 Point 14 80 417 Point 15 74 419 Point 16 35 407 Point 17 35 406.5 Point 18 0 370 Point 19 150 370 Point 20 90.5 429 Point 21 35 402 Point 22 0 398 Regions Material Points Area (ftz) Region 1 Very Dense GLACIAL TILL 18,22,21,15,13,20,8,9,10,11,12,19 7,105.5 Region 2 Loose Silty Sand FILL 2,3,4,5,6,7,20,13,15,16 265.13 Region 3 Medium -Dense Silty SAND 2,1,22,21,15,16 276.75 Current Slip Surface file:///C/... obs/23322%20Thomson%20%20Velguth%20(DRW)/23322%20slope%20stability%20analysis%20-0/o20seismic%20report.html[12/19/2023 11:31:19 PM] Seismic Slip Surface: 3,970 F of S: 1.233 Volume: 296.68988 ft' Weight: 36,236.487 Ibs Resisting Moment: 2,322,356.1 Ibs-ft Activating Moment: 1,882,734.6 Ibs-ft Resisting Force: 22,441.155 Ibs Activating Force: 18,196.39 Ibs F of S Rank (Analysis): 1 of 9,261 slip surfaces F of S Rank (Query): 1 of 9,261 slip surfaces Exit: (16.118825, 405.67306) ft Entry: (85.5, 428.52381) ft Radius: 97.504221 ft Center: (22.528742, 502.96636) ft Slip Slices PWP Base Normal Stress Frictional Strength Cohesive Strength X (ft) Y (ft) (psf) (psf) (psf) (psf) Slice 1 17.201477 405.61382 0 38.369194 20.401263 0 Slice 2 19.366781 405.51945 0 113.07027 60.120529 0 Slice 3 21.66198 405.47354 0 200.75414 135.41038 50 Slice 4 24.087074 405.48214 0 283.15154 190.98812 50 Slice 5 26.512169 405.5511 0 356.65143 240.56443 50 Slice 6 28.937264 405.68056 0 419.27033 282.80141 50 Slice 7 31.362358 405.87075 0 469.32635 316.56462 50 Slice 8 33.787453 406.12203 0 505.65179 341.06644 50 Slice 9 36.083333 406.41508 0 539.67855 364.01778 50 Slice 38.25 406.74417 0 572.4689 386.13515 50 10 Slice 40.416667 407.12336 0 593.4346 400.27669 50 11 Slice 42.682586 407.57541 0 615.57757 415.21231 50 12 Slice 45.047758 408.10599 0 637.84502 430.2319 50 13 Slice 47.41293 408.6989 0 648.22452 437.23296 50 14 Slice 49.778102 409.35531 0 648.4123 437.35962 50 15 Slice 52.143275 410.07658 0 640.13339 431.77543 50 16 Slice 54.508447 410.86422 0 624.99055 421.56145 50 17 Slice 56.873619 411.71996 0 604.35519 407.64272 50 18 Slice 59.238791 412.64573 0 579.30087 390.74337 50 19 Slice 61.603963 413.64372 0 550.57295 371.36614 50 20 Slice 63.969135 414.71638 0 518.58463 349.78975 50 file:///C/... obs/23322%20Thomson%20%20Velguth%20(DRW)/23322%20slope%20stability%20analysis%20-0/o20seismic%20report.html[12/19/2023 11:31:19 PM] Seismic 21 Slice 66.334307 415.86646 0 483.42915 326.07708 50 22 Slice 68.699479 417.09708 0 444.89921 300.08831 50 23 Slice 70.911549 418.32139 0 423.59233 225.22804 0 24 Slice 72 970516 419.53224 0 394.43463 209.72461 0 25 Slice 75.5 421.1255 0 365.25272 194.20832 0 26 Slice 78.5 423.14823 0 332.6892 176.89398 0 27 Slice 81.375 425.2411 0 241.25532 128.27773 0 28 Slice 84.125 427.40296 0 84.722623 45.047818 0 29 file:///C/... obs/23322%20Thomson%20 "/o20Velguth%20(DRW)/23322%20slope%20stability%20analysis%20-0/o20seismic%20report.html[12/19/2023 11:31:19 PM] Thomson Velguth Residence Fu (double) 2x12 pt df #2 BUJ DECK WEIGHT 6811 164th PL SW Edmonds, WA 98026 0 A;jr landscape architecture p o b o x 9 7 2 e d m o n d s • w a s h i n g t o n • 98020 p h o n e/ f a x •( 2 o 6) 5 4 5- 0 3 4 2 w w w s t u d i o 3 4 20 c o m project number: 20221005 drawn: CSW checked: Studio 342 date issue / revision 07.30.22 Schematic Design 08.01.23 Pre-app 05.20.24 Deck Permit JOIST & DECKING LAYOUT 0 2 4 8 SCALE: 1 /4" = 1'-0" L � J NORTH L-2.1 © Studio 342 Landscape Architecture, LLC 6/24/24, 10:59 AM ATC Hazards by Location A This is a beta release of the new ATC Hazards by Location website. Please contact us with feedback. O The ATC Hazards by Location website will not be updated to support ASCE 7-22. Find out why. nTCHazards by Location Search Information Address: 6811 164th PI SW, Edmonds, WA98026, USA Coordinates: 47.8495724,-122.3260796 Elevation: 438It Ti mestamp: 2024-06-24T17:58:44.604Z Hazard Type: Seismic Reference Document: ASCE7-16 Risk Category: II Site Class: C on tot Ma sville Mt. rY- Baker Snoqualmie Wh 438 ft -ett National Forest Wana O _ t Edmonds© �J ilympic M onal Park t Shoreline of Seattle oRedmon O Gei Bremerton RentoMap data 02024 Google, Report a map error MCER Horizontal Response Spectrum Design Horizontal Response Spectrum Sa(g) Sa(g) 1.50 1.00 0.80 1.00 0.60 0.40 0.50 0.20 0.00 0.00 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Period (s) 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Period (s) Basic Parameters Name Value Description SS 1.324 MCER ground motion (period=0.2s) St 0.471 MCER ground motion (period=1.Os) SMS 1.589 Site -modified spectral acceleration value SM1 0.706 Site -modified spectral acceleration value SDS 1.059 Numeric seismic design value at 0.2s SA SDI 0.471 Numeric seismic design value at 1.0s SA Additional Information Name Value Description SDC D Seismic design category Fa 1.2 Site amplification factor at 0.2s Fv 1.5 Site amplification factor at 1.0s CRS 0.903 Coefficient of risk (0.2s) CRI 0.894 Coefficient of risk (1.0s) PGA 0.569 MCEG peak ground acceleration FPGA 1.2 Site amplification factor at PGA PGAM 0.683 Site modified peak ground acceleration TL 6 Long -period transition period (s) SsRT 1.324 Probabilistic risk -targeted ground motion (0.2s) SsUH 1.466 Factored uniform -hazard spectral acceleration (2 % probability of exceedance in 50 years) SsD 3.002 Factored deterministic acceleration value (0.2s) S1 RT 0.471 Probabilistic risk -targeted ground motion (1.0s) S1 UH 0.526 Factored uniform -hazard spectral acceleration (2 % probability of exceedance in 50 years) https://hazards.atcouncil.org/#/seismic?lat=47.8495724&ing=-l22.3260796&address=6811 164th PI SW%2C Edmonds%2C WA98026%2C USA 1/2 6/24/24, 10:59AM ATC Hazards by Location S1 D 1.316 Factored deterministic acceleration value (1.0s) PGAd 1.074 Factored deterministic acceleration value (PGA) The results indicated here DO NOT reflect any state or local amendments to the values or any delineation lines made during the building code adoption process. Users should confirm any output obtained from this tool with the local Authority Having Jurisdiction before proceeding with design. Please note that the ATC Hazards by Location website will not be updated to support ASCE 7-22. Find out why. Disclaimer Hazard loads are provided by the U.S. Geological Survey Seismic Design Web Services. While the information presented on this website is believed to be correct, ATC and its sponsors and contributors assume no responsibility or liability for its accuracy. The material presented in the report should not be used or relied upon for any specific application without competent examination and verification of its accuracy, suitability and applicability by engineers or other licensed professionals. ATC does not intend that the use of this information replace the sound judgment of such competent professionals, having experience and knowledge in the field of practice, nor to substitute for the standard of care required of such professionals in interpreting and applying the results of the report provided by this website. Users of the information from this website assume all liability arising from such use. Use of the output of this website does not imply approval by the governing building code bodies responsible for building code approval and interpretation for the building site described by latitude/longitude location in the report. https://hazards.atcouncil.org/#/seismic?lat=47.8495724&ing=-l22.3260796&address=6811 164th PI SW%2C Edmonds%2C WA98026%2C USA 2/2 Seismic Design Thomson Velguth Residence Deck Internation Building Code Section 1613 ASCE7 Chapter 12 Maximum Considered Earthquake Spectral Response Acceleration Parameters Interpolate Fv Ss= 132% SpS= 106% Fa= 1.2 per Table 11.4-1 S1 Fv S1 = 47% Sp,= 47% Fv= 1.5 per Table 11.4-2 0.4 1.5 0.5 1.5 Site Class C assumed MCE 47% 1.5 Section 1613 Design Spectral Response Acceleration Parameters (IBC 1613.2.1) 5% damped design Approximate Fundamental Period Where: Ct = 0.02 Hn = 8 x= 0.75 General Resonse Spectrum To = 0.2* SDADS = 0.09 sec Ts = SpI/SpS = 0.44 sec TL = 6 sec figure 22-12 Sa= 4.916635 1 1.4-5 if T,To Sa= 1.06 if To<T<Ts Sa= 4.950778 1 1.4-6 if Ts<T<TL Sa= 312.2318 1 1.4-7 if T>TL Sa= 1.0592 Importance Factor Seismic Use Group= Seismic Design Category IBC Building Classification: T = Ct(hn)Ax T = 0.095 sec 'OK, no increase' (ASCE7 12.8.2.1) table 12.8-2 (ASCE 11.4.8) Exception #2 (ASCE7 1 1.4.5) Design Response Spectrum 1.4 1.2 1n 0 1 0 0.8 v 0.6 0.4 N O 0.2 C N v 0 0 02 0.4 0.6 0.8 1 12 1.4 A u Period T d a U) C Table 11.6-1 D Table 11.6-2 Regular Building Ss = 1.059 (ASCE-7 Table 9.1.3) (ASCE-7 Table 11.6) (ASCE7 12.3.2) Seismic Design Equivalent Lateral Force Procedure (ASCE 7 section 12.8) Requirements to use the Equivalent Lateral Force Procedure: Regular Building T < 3.5 Ts okay Building Type Cantilevered Column Sys R= 1.5 no = 1.5 CD = 1.5 Seismic Base Shear V = Cs W Cs = SDs Cs = 0.706 R/I but need not be greater than, Cs = SDI For 1<I1 = 3.301 T(R/1) Cs = SDI TL For T>TL = 208.155 T 2 (R/1) Cs max= 3.301 but shall not be less than: Cs = .044*SDS/(R/le) Cs min= 0.0049 Cs = 0.5*Sd 1 /(R/le) Therefore: CS = 0.706 W Total W = 11.0 kips V = 7.8 kips Redudancy Factor Thomson Velguth Residence Deck (ASCE7 Table 12.2.1) (ASCE7 Eq 12.8-1) (ASCE7 Eq 12.8-2) 1 (ASCE7 Eq 12.8-3) (ASCE7 Eq 12.8-4) E = r Eh + Ev (ASCE7 EQ 12.3.4) where r = 1.3 unless criteria of table 12.3-3 are met for SDC D,E,F r = 1.0 for Seismic Design Categories A,B,C Therefore: r = 1.30 E = 10.10 kips Building Weight Roof 11.00 k Deck = 9 lost Total Deck Wt 1 1.0 SEISMIC DISTRIBUTION STRENGTH / LRFD ALLOW. STRESS DESIGN level W h Wh Wh (kips) (ft) (kip-ft) E Wh story shear E (kips) (kips) story shear E (kips) (kips) Deck 11.0 17.5 192.5 1.00 10.10 10.10 7.21 7.21 BASE I I Klps I Y2.5 Seismic Force per sf = 7.21/1231 ==>5.9 psf Thomson Velguth Residence (18) 44 pt df #2 post w/ footing (typ.) - located C C C'. C C'. °ISMIG FORGE = 30l SF X 9 PSF = 18111 LB/ (6) OLUMNS = 302 LB COLUMN CK GALL f=LAN 1/4"J = It 6811 164th PL SW Edmonds, WA 98026 ft 0 oud.U0, 141EW landscape architecture Q3 . :0 p o b o x 9 7 2 e d m o n d s • w a s h i n g t o n • 98020 p h o n e/ f a x •( 2 o 6) 5 4 5- 0 3 4 2 w w w s t u d i o 3 4 20 c o m project number: 20221005 drawn: CSW checked: Studio 342 date issue / revision 07.30.22 Schematic Design 08.01.23 Pre-app 05.20.24 Deck Permit POST & BEAM LAYOUT I ^� 0 2 4 8 L J L-2.0 SCALE:1/4 = 1 -0 NORTH © Studio 342 Landscape Architecture, LLC Project Title: Engineer: Project ID: Project Descr: Building Code Information Governing Code : IBC 2021, ASCE 7-16, AISC 360-16, NDS 2018, ACI 318-19, TMS 402-16 City Jurisdiction : City of Edmonds Contact Name Alternate Contact Building Official Address : , Edmonds, WA Phone : Fax : eMail : Notes : Project File: TV Deck.ec6 Project Information Project Title : Thomson Velguth Residence Deck Description : New Deck I.D. : Address : 6811 164th Place West, Edmonds, WA 98026 Project Leader : VM Phone : 425-640-7333 Fax : Project Notes Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck eMail : victorm@ilgross.com Project File: TV Deck.ec6 Multiple Simple Beam LIC# : KW-06016108, Build:20.24.03.04 Description : New Deck Framing Wood Beam Design: New Deck Joists Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Project File: TV Deck.ec6 Calculations per NDS 2018, IBC 2021, ASCE 7-16 BEAM Size: 2x8, Sawn, Braced @ 1/3 Points Using Allowable Stress Design with IBC 2021 Load Combinations, Major Axis Bending Wood Species: Hem -Fir Wood Grade: No.2 Fb - Tension 850.0 psi Fc - Prll 1,300.0 psi Fv 150.0 psi Ebend- xx 1,300.0 ksi Density 26.840 pcf Fb - Compr 850.0 psi Fc - Perp 405.0 psi Ft 525.0 psi Eminbend - xx 470.0 ksi Applied Loads Beam self weight calculated and added to loads Unif Load: D = 0.0080, L = 0.060 k/ft, Trib= 1.0 ft Design Summary Max fb/Fb Ratio = 0.565 : 1 D(0.0080) L(0.060) fb : Actual : 511.59 psi at 4.000 ft in Span # 1 Fb: Allowable: 904.83 psi x x Load Comb: +D+L * 2x8 Max fv/FvRatio = 0.275 : 1 8.0 ft fv : Actual : 32.97 psi at 0.000 ft in Span # 1 Fv: Allowable: 120.00 psi Load Comb: +D+L Max Deflections Max Reactions (k) D Lr L a W E H Transient Downward 0.090 in Total Downward 0.105 in Left Support 0.04 0.24 Ratio 1069 Ratio 916 Right Support 0.04 0.24 LC: L Only LC: +D+L Transient Upward 0.000 in Total Upward 0.000 in Ratio 9999 Ratio 9999 LC: LC: Wood Beam Design: FB-1A Calculations per NDS 2018, IBC 2021, ASCE 7-16 BEAM Size: 6x12, Sawn, Braced @ 1/4 Points Using Allowable Stress Design with IBC 2021 Load Combinations, Major Axis Bending Wood Species: Hem -Fir Wood Grade: No.2 Fb - Tension 850.0 psi Fc - Prll 1,300.0 psi Fv 150.0 psi Ebend- xx 1,300.0 ksi Density 26.840 pcf Fb - Compr 850.0 psi Fc - Perp 405.0 psi Ft 525.0 psi Eminbend - xx 470.0 ksi Applied Loads Beam self weight calculated and added to loads Unif Load: D = 0.0060, L = 0.060 k/ft, Trib= 3.80 ft Unif Load: D = 0.0060, L = 0.060 k/ft, 10.0 to 13.50 ft, Trib= 3.640 ft Design Summary Max fb/Fb Ratio = 0.567. 1 D o.0228o L o.228o D 0.02184 L(0.2184) fb : Actual : 385.01 psi at 5.500 ft in Span # 2 Fb: Allowable: 678.61 psi ON" Load Comb: +D+L+H, LL Comb Run (*L*) 6x12 6x12 6x12 Max fv/FvRatio = 0.262 : 1 fv : Actual : 31.48 psi at 10.047 ft in Span # 2 Fv: Allowable: 120.00 psi Load Comb: +D+L+H, LL Comb Run (*LL) Max Reactions (k) D Lr L s W E H Left Support 0.27 1.90 Right Support 0.36 2.71 2.50 ft 11.0 ft Max Deflections Transient Downward 0.085 in Ratio 1546 - Only, LL Comb Run (*L* Transient Upward -0.062 in Ratio 966 - Only, LL Comb Run (*L* 2.50 ft Total Downward 0.094 in Ratio 1403 )+L+H, LL Comb Run (*L* Total Upward -0.067 in Ratio 898 )+L+H, LL Comb Run (*L* Multiple Simple Beam LIC# : KW-06016108. Build:20.24.03.04 Wood Beam Design: FB-1 Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Project File: TV Deck.ec6 Calculations per NDS 2018, IBC 2021, ASCE 7-16 BEAM Size: W2, Sawn, Braced @ 1/4 Points Using Allowable Stress Design with IBC 2021 Load Combinations, Major Axis Bending Wood Species: Hem -Fir Wood Grade: No.2 Fb - Tension 850.0 psi Fc - Prll 1,300.0 psi Fv 150.0 psi Ebend- xx 1,300.0 ksi Density 26.840 pcf Fb - Compr 850.0 psi Fc - Perp 405.0 psi Ft 525.0 psi Eminbend - xx 470.0 ksi Applied Loads Beam self weight calculated and added to loads Unif Load: D = 0.00550, L = 0.060 k/ft, Trib= 6.70 ft Design Summary Max fb/Fb Ratio = 0.972. 1 D(0.03685) L(0.4020) fb : Actual : 659.64 psi at 5.500 ft in Span # 2 Fb: Allowable: Load Comb: 678.61 psi +D+L+H, LL Comb Run ('L') 6x12 6x12 6x12 Max fv/FvRatio = 0.512 : 1 2.50 ft 11.0 ft 2.50 ft fv : Actual : 61.49 psi at 11.000 ft in Span # 2 Fv: Allowable: 120.00 psi Load Comb: +D+L+H, LL Comb Run ('LL) Max Deflections Max Reactions (k) D Lr L s W E H Transient Downward 0.148 in Total Downward 0.161 in Left Support 0.39 3.33 Ratio 893 Ratio 819 Right Support 0.39 3.33 - Only, LL Comb Run ('L' )+L+H, LL Comb Run ('L' Transient Upward -0.106 in Total Upward -0.115 in Ratio 564 Ratio 522 - Only, LL Comb Run ('L' )+L+H, LL Comb Run ('L' Wood Beam Design: FB-2 Calculations per NDS 2018, IBC 2021, ASCE 7-16 BEAM Size: W2, Sawn, Braced @ 1/4 Points Using Allowable Stress Design with IBC 2021 Load Combinations, Major Axis Bending Wood Species: Hem -Fir Wood Grade: No.2 Fb - Tension 850.0 psi Fc - Prll 1,300.0 psi Fv 150.0 psi Ebend- xx 1,300.0 ksi Density 26.840 pcf Fb - Compr 850.0 psi Fc - Perp 405.0 psi Ft 525.0 psi Eminbend - xx 470.0 ksi Applied Loads Beam self weight calculated and added to loads Unif Load: D = 0.0060, L = 0.060 k/ft, Trib= 5.50 ft Design Summary Max fb/Fb Ratio = 0.984 : 1 fb : Actual : 667.78 psi at 6.000 ft in Span # 1 Fb: Allowable: 678.50 psi Load Comb: +D+L+H Max fv/FvRatio = 0.376 : 1 fv : Actual : 45.15 psi at 11.080 ft in Span # 1 Fv: Allowable: 120.00 psi Load Comb: +D+L+H Max Reactions (k) g Lr L s w E Left Support 0.27 1.98 Right Support 0.27 1.98 LC: L Only Transient Upward 0.000 in Ratio 9999 LC: LC: +D+L+H Total Upward 0.000 in Ratio 9999 LC: Multiple Simple Beam LIC# : KW-06016108. Build:20.24.03.04 Wood Beam Design: FB-3 with Stair Loadinq Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Project File: TV Deck.ec6 Calculations per NDS 2018, IBC 2021, ASCE 7-16 BEAM Size: 4x12, Sawn, Braced @ 1/4 Points Using Allowable Stress Design with IBC 2021 Load Combinations, Major Axis Bending Wood Species: Hem -Fir Wood Grade: No.2 Fb - Tension 850.0 psi Fc - Prll 1,300.0 psi Fv 150.0 psi Ebend- xx 1,300.0 ksi Density 26.840 pcf Fb - Compr 850.0 psi Fc - Perp 405.0 psi Ft 525.0 psi Eminbend - xx 470.0 ksi Applied Loads Beam self weight calculated and added to loads Unif Load: D = 0.0060, L = 0.060 k/ft, Trib= 6.170 ft Design Summary Max fb/Fb Ratio = 0.407. 1 fb : Actual : 303.22 psi at 3.000 ft in Span # 1 Fb: Allowable: 745.78 psi Load Comb: +D+L+H Max fv/FvRatio = 0.274 : 1 fv : Actual : 32.85 psi at 5.080 ft in Span # 1 Fv: Allowable: 120.00 psi Load Comb: +D+L+H Max Reactions (k) D Lr L s W E Left Support 0.13 1.11 Right Support 0.13 1.11 LC: L Only Transient Upward 0.000 in Ratio 9999 LC: LC:+D+L+H Total Upward 0.000 in Ratio 9999 LC: Wood Beam Design: FB-4 with Stair Loadinq Calculations per NDS 2018, IBC 2021, ASCE 7-16 BEAM Size: 4x12, Sawn, Braced @ 1/4 Points Using Allowable Stress Design with IBC 2021 Load Combinations, Major Axis Bending Wood Species: Hem -Fir Wood Grade: No.2 Fb - Tension 850.0 psi Fc - Prll 1,300.0 psi Fv 150.0 psi Ebend- xx 1,300.0 ksi Density 26.840 pcf Fb - Compr 850.0 psi Fc - Perp 405.0 psi Ft 525.0 psi Eminbend - xx 470.0 ksi Applied Loads Beam self weight calculated and added to loads Unif Load: D = 0.0060, L = 0.060 k/ft, Trib= 2.50 ft Unif Load: D = 0.0060, L = 0.060 k/ft, 0.0 to 3.0 ft, Trib= 4.0 ft Design Summary Max fb/Fb Ratio = 0.308 : 1 fb : Actual : 229.90 psi at 2.540 ft in Span # 1 Fb: Allowable: 745.78 psi Load Comb: +D+L+H Max fv/FvRatio = 0.225 : 1 fv : Actual : 27.03 psi at 0.000 ft in Span # 1 Fv: Allowable: 120.00 psi Load Comb: +D+L+H Max Reactions (k) g Lr L s w E hi Left Support 0.12 0.99 Right Support 0.09 0.63 D 0.0240 L 0.240 L 0.150 4x12 6.0 ft Max Deflections Transient Downward 0.015 in Total Downward 0.017 in Ratio 4901 Ratio 4348 LC: L Only Transient Upward 0.000 in Ratio 9999 LC: LC:+D+L+H Total Upward 0.000 in Ratio 9999 LC: Multiple Simple Beam LIC# : KW-06016108. Build:20.24.03.04 Wood Beam Design: TYPICAL STAIRS Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Project File: TV Deck.ec6 Calculations per NDS 2018, IBC 2021, ASCE 7-16 BEAM Size: 2x12, Sawn, Braced @ 1/4 Points Using Allowable Stress Design with IBC 2021 Load Combinations, Major Axis Bending Wood Species: Hem -Fir Wood Grade: No.2 Fb - Tension 850.0 psi Fc - Prll 1,300.0 psi Fv 150.0 psi Ebend- xx 1,300.0 ksi Density 26.840 pcf Fb - Compr 850.0 psi Fc - Perp 405.0 psi Ft 525.0 psi Eminbend - xx 470.0 ksi Applied Loads Beam self weight calculated and added to loads Unif Load: D = 0.0060, L = 0.060 k/ft, Trib= 2.0 ft Design Summary D(0.0120) L(0.120) Max fb/Fb Ratio = 0.620. 1 fb : Actual : 410.04 psi at 4.000 ft in Span # 1 Fb: Allowable: 661.22 psi Load Comb: +D+L+H 2X12 Max fv/FvRatio = 0.316 : 1 8.0 rt fv : Actual : 36.84 psi at 0.000 ft in Span # 1 Fv : Allowable: 116.40 psi Load Comb: +D+L+H Max Deflections Max Reactions (k) D Lr L s W E H Transient Downward 0.048 in Total Downward 0.054 in Left Support 0.06 0.48 Ratio 1997 Ratio 1773 Right Support 0.06 0.48 LC: L Only LC: +D+L+H Transient Upward 0.000 in Total Upward 0.000 in Ratio 9999 Ratio 9999 LC: LC: Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Wood Ledger Project File: TV Deck.ec6 LIC# : KW-06016108, Build:20.24.03.04 I.L. GROSS STRUCTURAL ENGINEERS (c) ENERCALC INC 1983-2023 DESCRIPTION: Typical Deck Ledger Code Reference: Calculations per NDS 2018, IBC 2021, ASCE 7-16 Load Combinations Used : IBC 2021 General Information Ledger Width 3.0 in Design Method: ASD (using Service Load Combinations Ledger Depth 11.250 in Wood Stress Grade : Hem -Fir, No.2 Ledger Wood Specie Hem -Fir Fb Allow 850.0 psi G : Specific Gravity 0.43 Fv Allow 150.0 psi Bolt Diameter 3/8" in Fyb : Bolt Bending Yield 45,000 psi Bolt Spacing 8.0 in - Wood as Main Supporting Member - Cm - Wet Service Factoi 0.850 Width 3.0 in Ct - Temperature Factor 1.0 Wood Species Hem -Fir Cg - Group Action Facto 1.0 G : Specific Gravity 0.43 C A - Geometry Factor 1.0 Analytical model uses 100 spans to ensure that all possible combinations of belt luatlon nd load location are evaluated. Ina results are an enve ope solution. Load Data Dead Roof Live Floor Live Snow Wind Seismic Earth Uniform Load... 20.0 plf plf 195.0 plf plf plf plf plf Point Load... Ibs Ibs Ibs Ibs Ibs Ibs Ibs Spacing in Offset in Horizontal Shear Ibs Ibs Ibs Ibs Ibs Ibs Ibs Project Title: Engineer: Project ID: Project Descr: Wood Ledger LIC# : KW-06016108, Build:20.24.03.04 I.L. GROSS STRUCTURAL ENGINEERS DESCRIPTION: Typical Deck Ledger DESIGN SUMMARY Maximum Ledger Bending Load Combination ... +D+L Moment 7.963 ft-lb fb : Actual Stress 1.510 psi Fb : Allowable Stress 722.50 psi Stress Ratio 0.002090 :1 Maximum Ledger Shear Maximum Bolt Bearing Summary Load Combination .. . +D+L Max. Vertical Load 143.333 Ibs Bolt Allow Vertical Load 198.782 Ibs Max. Horizontal Load 0.0 Ibs Bolt Allow Horizontal Loac 316.955 Ibs Load Combination ... Angle of Resultant 90.0 deg +D+L Diagonal Component 143.333 Ibs Shear 71.667 Ibs Allow Diagonal Bolt Force 198.782 Ibs fv : Actual Stress 4.247 psi Stress Ratio, Wood @ Bolt 0.7211 :1 Fv : Allowable Stress 85.0 psi Stress Ratio 0.04996 :1 Allowable Bolt Capacity Governing Load CombinatibP+L Resutant Load Angle : Theta 90.0 deg Thomson Velguth Residence Deck VM New Deck Project File: TV Deck.ec6 (c) ENERCALC INC 1983-2023 I Design • Dowel Bearing Strengths (for specific gravity & bolt diameter) Ledger, Perp to Grain 2,950.0 psi Ledger, Parallel to Grain 4,800.0 psi Supporting Member, Perp to Grp 2,950.0 psi Supporting Member, Parallel to Gr 4,800.0 psi Note ! Refer to NDS Section 11.3 for Bolt Capacity calculation method. Ktheta = 1.250 Fe theta = 198.782 Bolt Capacity - Load Perpendicular to Grain Fern 2,950.0 Fes 2,950.0 Fyb 45,000.0 Re 1.0 Rt 1.0 k1 0.4142 k2 1.116 k3 1.116 Im : Eq 11.3-1 Rd = 5.0 Z = 663.75 Ibs Is : Eq 11.3-2 Rd = 5.0 Z = 663.75 Ibs II : Eq 11.3-3 Rd = 4.50 Z = 305.483 Ibs Illm : Eq 11.3-4 Rd = 4.0 Z = 308.594 Ibs Ills : Eq 11.3-5 Rd = 4.0 Z = 308.594 Ibs IV : Eq 11.3-6 Rd = 4.0 Z = 233.862 Ibs min : Basic Design Value = 233.862 Ibs Reference design value - Perpendicular to Grain Z * CM * CD* Ct * Cg * Cdelta = 198.782 Ibs Bolt Capacity - Load Parallel to Grain Fern 4,800.0 Fes 4,800.0 Fyb 45,000.0 Re 1.0 Rt 1.0 k1 0.4142 k2 1.072 k3 1.072 Im : Eq 11.3-1 Rd = 4.0 Z = 1,350.0 Ibs Is : Eq 11.3-2 Rd = 4.0 Z = 1,350.0 Ibs II : Eq 11.3-3 Rd = 3.60 Z = 621.32 Ibs Illm : Eq 11.3-4 Rd = 3.20 Z = 602.97 Ibs Ills : Eq 11.3-5 Rd = 3.20 Z = 602.97 Ibs IV : Eq 11.3-6 Rd = 3.20 Z = 372.888 Ibs Zmin : Basic Design Value = 372.888 Ibs Reference design value - Parallel to Grain : Z * CM * CD* Ct * Cg * Cdelta = 316.955 Ibs Wood Column DESCRIPTION: Typical 6x6 Posts Code References Calculations per NDS 2018, IBC 2021, ASCE 7-16 Load Combinations Used : IBC 2021 General Information Analysis Method Allowable Stress Design End Fixities Top Free, Bottom Fixed Overall Column Height 8 ft ( Used for non -slender calculations) Wood Species Hem -Fir Wood Grade No.2 Fb + 850.0 psi Fv 150.0 psi Fb - 850.0 psi Ft 525.0 psi Fc - Prll 1,300.0 psi Density 26.840 pcf Fc - Perp 405.0 psi E : Modulus of Elasticity ... x-x Bending y-y Bending Basic 1,300.0 1,300.0 Minimum 470.0 470.0 Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Wood Section Name Wood Grading/Manuf Wood Member Type Exact Width Exact Depth 6x6 Graded Lumber Sawn 5.50 in 5.50 in Area 30.250 in Ix 76.255 in ly 76.255 in Incising Factors for Bending 0.80 Axial for Elastic Modulus 0.95 Project File: TV Deck.ec6 Allow Stress Modification Factors 2 4 4 Cf or Cv for Bending 1.0 Cf or Cv for Compressioi 1.0 Cf or Cv for Tension 1.0 Cm : Wet Use Factor 1.0 Ct : Temperature Faci 1.0 Cfu : Flat Use Factor 1.0 Kf : Built-up columns 1.0 1,300.0 ksi Use Cr: Repetitive ? No Column Buckling Condition: ABOUT X-X Axis: Lux = 8 ft, Kx = 1.20 ABOUT Y-Y Axis: Luy = 8 ft, Ky = 1.20 Applied Loads Column self weight included : 45.106 Ibs Dead Load Factor AXIAL LOADS ... Axial Load at 8.0 ft, D = 0.390, L = 3.330 k BENDING LOADS ... Lat. Point Load at 8.0 ft creating Mx-x, E = 0.4310 k DESIGN SUMMARY Bending & Shear Check Results Service loads entered. Load Factors will be applied for calculations. PASS Max. Axial+Bending Stress Ratio = 0.9806 : 1 Maximum SERVICE Lateral Load Reactions. . Load Combination +D+0.70E Top along Y-1 0.4310 k Bottom along Y-Y 0.4310 k Governing NDS Forumla Comp + Mxx, NDS Eq. 3.9-3 Top along X-)� 0.0 k Bottom along X-X 0.0 k Location of max.above base 0.0 ft Maximum SERVICE Load Lateral Deflections ... At maximum location values are . Along Y-Y 1.343 in at 8.0 ft above base Applied Axial 0.4351 k for load combination : E Only Applied Mx -2.414 k-ft Applied My 0.0 k-ft Along X-X 0.0 in at 0.0 ft above base Fc: Allowable 628.28 psi for load combination : n/a Other Factors used to calculate allowable stresses ... PASS Maximum Shear Stress Ratio = 0.07792 : 1 Bendina Compression Tension Load Combination +D+0.70E Location of max.above base 8.0 ft Applied Design Shear 22.441 psi Allowable Shear 192.0 psi Load Combination Results Maximum Axial + Bending Stress Ratios Maximum Shear Ratios Load Combination CID C P Stress Ratio Status Location Stress Ratio Status Location D Only 0.900 0.586 0.02621 PASS 0.0 ft 0.0 PASS 8.0 ft +D+L 1.000 0.546 0.2192 PASS 0.0 ft 0.0 PASS 8.0 ft +D+0.750L 1.250 0.462 0.1613 PASS 0.0 ft 0.0 PASS 8.0 ft +D+0.70E 1.600 0.378 0.9806 PASS 0.0 ft 0.07792 PASS 8.0 ft +D+0.750L+0.5250E 1.600 0.378 0.8587 PASS 0.0 ft 0.05844 PASS 8.0 ft +0.60D 1.600 0.378 0.01374 PASS 0.0 ft 0.0 PASS 8.0 ft +0.60D+0.70E 1.600 0.378 0.9721 PASS 0.0ft 0.07792 PASS 8.0 ft Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Wood Column LIC# : KW-06016108, Build:20.24.03.04 I.L. GROSS STRUCTURAL ENGINEERS DESCRIPTION: Typical 6x6 Posts Maximum Reactions Note: Only non -zero reactions are listed. X-X Axis Reaction k Y-Y Axis Reaction Axial Reaction My - End Moments k-ft Mx - End Moments Load Combination @ Base @ Top @ Base @ Top @ Base @ Base @ Top @ Base @ Top Project File: TV Deck.ec6 (c) ENERCALC INC 1983-2023 D Only 0.431 0.435 +D+L 0.431 3.765 +D+0.750L 0.431 2.933 +D+0.70E 0.302 0.431 0.435 2.414 +D+0.750L+0.5250E 0.226 0.431 2.933 1.810 +0.60D 0.431 0.261 +0.60D+0.70E 0.302 0.431 0.261 2.414 L Only 0.431 3.330 E Only 0.431 0.431 3.448 Maximum Deflections for Load Combinations Load Combination Max. X-X Deflection Distance Max. Y-Y Deflection Distance D Only 0.0000 in 0.000ft 0.000 in 0.000ft +D+L 0.0000 in 0.000ft 0.000 in 0.000ft +D+0.750L 0.0000in 0.000ft 0.000 in 0.000ft +D+0.70E 0.0000in 0.000ft 0.940in 8.000ft +D+0.750L+0.5250E 0.0000in 0.000ft 0.705in 8.000ft +0.60D 0.0000in 0.000ft 0.000 in 0.000ft +0.60D+0.70E 0.0000in 0.000ft 0.940in 8.000ft L Only 0.0000in 0.000ft 0.000 in 0.000ft EOnly 0.0000in 0.000ft 1.329in 7.946ft Sketches 0 Ln 5.50 in Load 1 3 720k 3 720k 043k +X Wood Column DESCRIPTION: Typical 4x4 Posts Code References Calculations per NDS 2018, IBC 2021, ASCE 7-16 Load Combinations Used : IBC 2021 General Information Analysis Method Allowable Stress Design End Fixities Top Free, Bottom Fixed Overall Column Height 8 ft ( Used for non -slender calculations) Wood Species Hem -Fir Wood Grade No.2 Fb + 850.0 psi Fv 150.0 psi Fb - 850.0 psi Ft 525.0 psi Fc - Prll 1,300.0 psi Density 26.840 pcf Fc - Perp 405.0 psi E : Modulus of Elasticity ... x-x Bending y-y Bending Basic 1,300.0 1,300.0 Minimum 470.0 470.0 Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Wood Section Name Wood Grading/Manuf Wood Member Type Exact Width Exact Depth 4x4 Graded Lumber Sawn 3.50 in 3.50 in Area 12.250 in Ix 12.505 in ly 12.505 in Incising Factors for Bending 0.80 Axial for Elastic Modulus 0.95 Project File: TV Deck.ec6 Allow Stress Modification Factors 2 4 4 Cf or Cv for Bending 1.50 Cf or Cv for Compressioi 1.150 Cf or Cv for Tension 1.50 Cm : Wet Use Factor 1.0 Ct : Temperature Faci 1.0 Cfu : Flat Use Factor 1.0 Kf : Built-up columns 1.0 1,300.0 ksi Use Cr: Repetitive ? No Column Buckling Condition: ABOUT X-X Axis: Lux = 8 ft, Kx = 1.20 ABOUT Y-Y Axis: Luy = 8 ft, Ky = 1.20 Applied Loads Column self weight included : 18.266 Ibs Dead Load Factor AXIAL LOADS ... Axial Load at 8.0 ft, D = 0.3450, L = 0.420 k BENDING LOADS ... Lat. Point Load at 8.0 ft creating Mx-x, E = 0.0660 k DESIGN SUMMARY Bending & Shear Check Results Service loads entered. Load Factors will be applied for calculations. PASS Max. Axial+Bending Stress Ratio = 0.4360 : 1 Maximum SERVICE Lateral Load Reactions. . Load Combination +D+0.70E Top along Y-1 0.4310 k Bottom along Y-Y 0.0660 k Governing NDS Forumla Comp + Mxx, NDS Eq. 3.9-3 Top along X-)� 0.0 k Bottom along X-X 0.0 k Location of max.above base 0.0 ft Maximum SERVICE Load Lateral Deflections ... At maximum location values are . Along Y-Y 1.254 in at 8.0 ft above base Applied Axial 0.3633 k for load combination : E Only Applied Mx -0.3696 k-ft Applied My 0.0 k-ft Along X-X 0.0 in at 0.0 ft above base Fc: Allowable 275.990 psi for load combination : n/a Other Factors used to calculate allowable stresses ... PASS Maximum Shear Stress Ratio = 0.02946 : 1 Bendina Compression Tension Load Combination +D+0.70E Location of max.above base 8.0 ft Applied Design Shear 8.486 psi Allowable Shear 192.0 psi Load Combination Results Maximum Axial + Bending Stress Ratios Maximum Shear Ratios Load Combination CID C P Stress Ratio Status Location Stress Ratio Status Location D Only 0.900 0.249 0.1108 PASS 0.0 ft 0.0 PASS 8.0 ft +D+L 1.000 0.225 0.2372 PASS 0.0 ft 0.0 PASS 8.0 ft +D+0.750L 1.250 0.183 0.2028 PASS 0.0 ft 0.0 PASS 8.0 ft +D+0.70E 1.600 0.144 0.4360 PASS 0.0 ft 0.02946 PASS 8.0 ft +D+0.750L+0.5250E 1.600 0.144 0.3942 PASS 0.0 ft 0.02210 PASS 8.0 ft +0.60D 1.600 0.144 0.06447 PASS 0.0 ft 0.0 PASS 8.0 ft +0.60D+0.70E 1.600 0.144 0.4098 PASS 0.0ft 0.02946 PASS 8.0 ft Project Title: Thomson Velguth Residence Deck Engineer: VM Project ID: Project Descr: New Deck Wood Column LIC# : KW-06016108, Build:20.24.03.04 I.L. GROSS STRUCTURAL ENGINEERS DESCRIPTION: Typical 4x4 Posts Maximum Reactions Note: Only non -zero reactions are listed. X-X Axis Reaction k Y-Y Axis Reaction Axial Reaction My - End Moments k-ft Mx - End Moments Load Combination @ Base @ Top @ Base @ Top @ Base @ Base @ Top @ Base @ Top Project File: TV Deck.ec6 (c) ENERCALC INC 1983-2023 D Only 0.431 0.363 +D+L 0.431 0.783 +D+0.750L 0.431 0.678 +D+0.70E 0.046 0.431 0.363 0.370 +D+0.750L+0.5250E 0.035 0.431 0.678 0.277 +0.60D 0.431 0.218 +0.60D+0.70E 0.046 0.431 0.218 0.370 L Only 0.431 0.420 E Only 0.066 0.431 0.528 Maximum Deflections for Load Combinations Load Combination Max. X-X Deflection Distance Max. Y-Y Deflection Distance D Only 0.0000 in 0.000ft 0.000 in 0.000ft +D+L 0.0000 in 0.000ft 0.000 in 0.000ft +D+0.750L 0.0000in 0.000ft 0.000 in 0.000ft +D+0.70E 0.0000in 0.000ft 0.878in 8.000ft +D+0.750L+0.5250E 0.0000in 0.000ft 0.658in 8.000ft +0.60D 0.0000in 0.000ft 0.000 in 0.000ft +0.60D+0.70E 0.0000in 0.000ft 0.878in 8.000ft L Only 0.0000in 0.000ft 0.000 in 0.000ft E Only 0.0000in 0.000ft 1.241 in 7.946ft Sketches c 0 Iq co M-11l© 1 +X