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20020619.pdfDATE RECEIVED r" 2-- PERMIT EXPIRES USE PERM T CITY OF EDMONDS ZONE N EIERr�W -110q— CONSTRUCTION PERMIT APPLICATION JOB UITEJAPT# CONS ADDRESS FOWNER NAMEINAME OF BUSINESS D:;?o 0 —rffi4 PLAT NAMEISUBDIVISION NE LOT NO, LID NO. MM NG ADDRESS UD FEE S PUS IC P!G -� OF WAY PER OFFICIAL STREET MAP e st- us. —It R�d CITY EXISTING — PROPOSED — ZIP jTEL111ON1 1.7 REQUIRED .01C.I.11— FT NAME NO. OF FIXTURES PAV REQUIRED 14-0 L COkotft C44AMO [Q ADDRESS REMARK' -P�b.VA�k ?93-) OWNERICONTRACTOR RESPONSIBLE 10� �ROSK)14 C.Nle.U. AINAGE If -n CITY HOME Vz"' RE&-6d1- (-31�5 EZALWA el NAME *F ENGINEERING EDIDATE I C ADDRESS FIRE REVIEWED By CITY ZIP TELEPHONE I VARIANCE OR CU SHORELINE OR ADS# INSPECTION BOND R EXPIRATION Dv Pas—TED ES I 2-115W --FEPA —REVIEW SIGN AREA HEIGHT 4 PROPERTY TAX ACCOUNT PARCEL NO. COMPLETE EXEMPT ALLOWED PROPOSED ALLOWED IROP-ED q 2.6t�o 700 EXP , LOT C ERASE REQUIRED SETBACKS (Fr.) PROPOSED SETBACKS (FT) NEW In RESIDENTIAL JA PUU..IN. I ME.. AL WED O"PROPOSED FRONT SIDE+REAR FRO LIN SIDE BEAR COMMERCIAL o C MPLIANCE OR ADDITION CHANGE OF USE 0 0 P LOT AREA PLANNING RFVIEIA ED BY GAT E REMODEL APARTMENT SIGN REOZ PROVIDE 7 7 5-1 ti;' _3 F NCE REMARK' E] REPAIR ( REMARKS _X_FQ /a DEMOLISH 0 OTHER 10 A.A.. A 11 .PORT [3 OCKEIING 0 RENEWAL N CHECKED BY TYPE OWUCTION C27 CCU N C. (ME OF USE, BUSINESS OR A�r'IIM P GROUP U I I NUMBER NUMBWOF A a Or L CTOR JAREArAN OCCUPANT I DWELL NO R`"C L� 8P OF CA.EA- ? SPECIAL IN�PE LOAD as a OU REQUIRED N .. ER ZZO� YES 4/0 STORIES UNIT- n DESCRIBE WORK TO BE DONE REMARKS GRESS INSPECTIONS PER USC 1108/FINAL INSPECTION RE90 9 FEE G- LOT SLOPE Is PRUTILI—.1g. 1 4- (, Q 1 TED DATE Plumbing hill Mechanical t THIS PERMIT AUTHORIZES ONLY THE WORK NOTED. THIS PERMIT COVERS WORK TO HE DOME ON PRIVATE PROPERTY MIN. ANY CONSTRUCTION ON THE PUDUC '01 Grading LGo Recording Fee 2 MC ILLSEOUBRE - MAIN (CURDS, SIDEWALKS. DRIVEWAYS. MARQUEES, j W 00 SEPARATE PERMISSION. Engr. Review City Surcharge P ERMITAPPUCATION: INDAYS PERMIT ... 11. � PROVIDE- VICIFIX 115 --- WITHIN 180 DAYS :R Engr. Inspection State Surcharge SEE BACK OF PINK PERMIT FOR MORE INFORMATION Plan Chk Deposit 'APPLICANT, ON BEHAL F HIS OR HER SPOUSE, HEIRS, ASSIGNS AND SUCCESORS Traffic Mill IN INNTEREST. AGREES INDEMNIFY. DEFEND AND HOLD HARMLESS THE CITY OF Receipt # EDMONDS, WASHINGTON. ITS OFFICIALS, EMPLOYEES, AND AGENTS FROM ANY AND ALL CLAIMS FOR DAMAGES OF WHATINER NATURE, ARISING DIRECTLY OR INDMECTLY Fire Review it FROM THE ISSUANCE OF THIS PERMIT. ISSUANCE OF THIS PERMIT SMALL NOT BE Fire Inspection Total Amount DI a DEEMED TO MODIFY, WAIVE OR REDUCE ANY REQUIREMENT OF ANY CITY ORDINANCE NOR LIMIT IN ANY WAY THE CITYS ABILITY TO ENFORCE ANY ORDINANCE PROVISION,' Landscapainsp. Receipt # HEREBY ACKNOWLEDGE THAT I HAVE READ THIS APPLICA71ON: THAT THE INFORMATION APPLICATION APPROVAL GIVEN IS CORRECT. AND THAT AM THE OWNER, OR THE DULY AUTHORIZED ENT 01 THE OWNER. I AGREE To COMPLY WITH CITY AND STATE LAWS REGULATING CONSmUC- CALL Thisipplicaflorls, net a permit until signed by the TION. AND IN DOING THE WORK AUTHORIZED THEREBY. NO PERSON WILL BE EMPLOYED V'OL to L" ' CODE OF THE STATE OF WASHINGTON RELATING TO FOR INSPECTION Building /I ns�ffloi.l .1 his he, Deputy: ,it Foos am paid. and .ipli�..kn.wt.dg�di.�pacop�wided. W.a�VTN Q1oI..URAN.EAN.RCWmZ1, - 1 (425) OF ICIALS I.NATU7 DATE SIGN (a BAT qNED 2 "A� EXT 1333 BE OR OCCUPY A BUILDING OR STRUCTURE UNTIL 771-0221 A FINAL INSPECTION HAS BEEN MADE AND APPROVAL OR A CERTIFI- ORIGINAL - FILE - YELLOW INSPECTOR CATE OF OCCUPANCY HAS BEEN GRANTED. UBC SECTION 109 FAX PINK - OWNER - GOLD - ASSESSOR WAH FROM DOUGJOHNSONN FAX NO. 4257452813 Maj. 08 2002 07:06AM P2 10:17 62S74,Yb.1 1,256 N.rtbl-t 2")%h S---l- 5ui"'6 98005 (425)747-5618 FAX(425)747-8561 CONSULTANTS, INC- April 29, 2002 JN 02061 Doug Johnson P'0' Box I mulditeo, Washington 98275 z Subject Review of Plans praposed Residence 78XX — 175th Street Southwest 74 ffi Edmonds, Washington Dear Mr, Johnson! aspects of th� a plans for the propose d m C re 113 0 We have comploted a general review of the gootaChrilcal maidemea ile be eanstmoted at 78XX 176th stroot Southwer-t in Ed mondi. ThQ plans vim Sherstad prepared these Plans, which are dated C K . M hrough 12. Leonard reviewed included Sheets I t -d January J0, 2002 by North5here Land Surveying and date Im Z 2002. A site Plan Prepared April 1, 0 technical study of this site an March 21. 2002. also wc impanied the plans, We ccmpleted a geo > After re view of the aforementioned plans, we offer the following comments: 65 As discussed in our geotechnical study, the footings near the northern slope should be least 18-inches below the ground surface 0 n In � , l�� C excavated to beer on the dense, native wift At m m elevation of the adjacent sewer easemerd. C) No fill wits should be placed to the north of the residence on or near the Sleep s lope. 0 0 Fn, No drains should be outlet on or near the t op of the sleep slope. 7hey should be directed K CA M 0, to a suitable outfaill away from the sleep slopes. Foundation drains should be constructed as described and shown in our gearlechnical -d along the southern interior drain be constructis report. We recommend that an additional Z: side of the northern perimeter footing, in out judg I ement, considering the above clOrftallOrls, the plans appear to conform to the if the recommendations and conditions ca z chnical engineering report. recommendations in our ge*te th of the i gootachnical onginecerig report are satisfied during construction and use of the, Project, 0 please note: the m proposed project will not increase the potential for coil movement. presented in this report are directed toward the protecOcn of only the proposed recommendations reoldence from damage do to slope movement predicting the future behavior of steep slopes their stability is an inexact and imperfect science thart And the potential effects of development on is currently based mostly on the past behavio! r of slopes with similar characteristics. Landslides re, during, or after the development of property. and soil movement can occur on steep slopes befO emeni could occur, resulting slope mOv The owner must ultimately accept the possibility that some in possible loss of ground or damage to the facilities around the proposed residenc& R E C 'E' I V E' D 2002 ';�TVI� f�S GTR. FROM DOUGJOHNSONN FAX NO. 4257452813 May, 09 2002 07:06AM P3 'j5'0112Ua2 10:17 42'� i4 Nh-1 Doug Johnsw JN 02081 Page 2 April 22. 2002 We trust this letter fulfills your needs at this time. Please call with any questionS or if we can be of further assIstance. Respectfully submkted, GEOTECH CONSULTANTS. INC. S" "Nc"TON vA M NA A M; M -4, � , : �q 0- 0 c M "In 1 James H, Strange, Jr,, P.E. 10 c Proj" Manager ?'z JHS: jhs -w n rn M 0 0 fn z Z 0. L RECEIVED 13256 No heast 20th Street, Suite 16 IGEOTECH Washington 98005 CONSULTANTS, INC. APR 0 2 2002 (425) 747-5618 FAX (425) 747-8561 DEVELOPMENT SEPVICES CTR CITY OF EDMONDS March 21, 2002 JN 02061 Doug Johnson Construction P.O. Box 1508 Edmond;, Washington 98275 Subject: Transmittal Letter— Geotechnical Engineering Study Z' Proposed Residence 0: 78XX — 175th Street Southwest rq: Edmonds, Washington Dear Mr. Johnson: via facsimile: (425) 745-2813 rn We are pleased to present this geotechnical engineering report for the residence to be constructed M 0 in Edmonds, Washington. The scope of our work consisted of exploring site surface and subsurface conditions, and then developing this report to provide recommendations for general rh M earthwork and design criteria for foundations and retaining walls. This work was authorized by your to acceptance of our proposal, dated March 20, 2002. C: > Development of the property is in the planning stage, and detailed plans were not made available to us. We were provided with a lot survey showing the boundaries of the site and the easements. 0, -1, Some topographic information was sketched on a plan that we received from you. The proposed location of the house was also indicated on the site plan provided. Based on discussions with you, m T we understand that a residence will be constructed near the top of the steep adjacent slope. 0 0 C SITE CONDITIONS :m SURFACE ;a The Vicini ty Map, Plate 1, illustrates the general location of the site. The undeveloped, rectangular Z site features approximately 89 feet of frontage along 175th Street Southwest to the south and a depth on the order of 307 feet. The southern portion of the �site is consumed by a drainage channel and a driveway access easement for the adjacent house to the west. The proposed building pad is Z located on a flat portion of the site to the north of the driveway and to the south of a sewer easement that cuts across the lot from east to west. From the building pad to the north, the lot m descends approximately 4 feet to a 10-foot-wide private sewer easement. The area of the easement is relatively flat, and a steep slope begins at the northern edge of the easement. The northern portion of the site is a steep slope that descends approximately 30 feet to the north into a creek channel. The steep slope is inclined on the order of 50 percent (visually) and is well vegetated with blackberry vines and scattered medium-sized trees. No evidence of recent slope movement on this northern slope was observed during our visit to the site. GEOTECH CONSULTANTS, INC. Doug Johnson Construction JN 02061 March 21, 2002 Page 2 SUBSURFACE The subsurface conditions were explored by excavating four test pits 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 pits were excavated on February 11, 2002 with a tracked backhoe. A geotechnical z engineer from our staff observed the excavation process, logged the test pits, and obtained representative samples of the soil encountered. "Grab" samples of selected subsurface soil were collected from the backhoe bucket. The Test Pit Logs are attached to this report as Plate 3, SoH Conditions a m C The test pits revealed approximately 2 to 4 feet of loose, silty sand fill soils overlying 0 0 0 C: medium -dense to dense, native, gravelly, silty sand to sandy silt soils. The native soils were generally dense directly beneath the fill soils. The exception to this was in Test Pit 1, on the M m northwestern portion of the building site, which revealed approximately 2 to 3 feet of C: medium -dense, weathered soils overlying the dense, native soils. The soils encountered z were observed to become dense within 5 feet of the ground surface (in all of the test pits). On the Preliminary Surficial Geologic Map of The Edmonds East and Edmonds West 0 -n Quadrangles (Smith, c. 1975) the subject site is mapped as Vashon Till (Qvt), which is described as an extremely compact mixture of clay, silt, sand, and gravel. The test pits generally confirm this designation. M M 0 Groundwater Conditions 0 M C: (A No groundwater seepage was observed in the test pits. The test pits were left open for only a short time Therefore, the lack C period. of seepage levels on the logs does not preclude the presence of groundwater seepage in future excavations. X It should be noted that groundwater levels vary seasonally with rainfall and other factors. Z, We anticipate that groundwater could be found in more permeable pockets Within the till and between the loose, near -surface soil and the underlying dense glacial till. The final logs represent our interpretations of the field logs. The stratification lines on the logs z 9 represent the approximate boundaries between soil types at the exploration locations. The actual 0 m 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. The relative densities and moisture descriptions indicated on the test pit logs are interpretive descriptions based on the conditions observed during excavation. The compaction of backfill was not in the scope of our services. Loose soil Will therefore be found in the area of the test pits. If this presents a problem, the backfill will need to be removed and replaced with structural fill during construction. GEOTECH CONSULTANTS, INC. Doug Johnson March 21, 2002 CONCLUSIONS AND RECOMMENDATIONS GENERAL JN 02061 Page 3 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 test pits conducted for this study encountered dense glacial till soils underlying a relatively thin layer of loose fill and weathered soils. The foundations for the proposed residence should be excavated to bear directly on these dense, native soils. This is particularly important for the footings along the northern edge of the residence. In addition to bearing on the dense till soils, these northern footings should be excavated down to at least 18 inches below the ground surface elevation of the sewer easement, so that the upper, 4-foot slope above the easement does not affect the footing bearing. Additionally, the foundation for the house should be located at least 10 feet from the top of the steep slope beginning to the north of the sewer easement. It appears that slope movements have not occurred recently on the site. The near -surface loose, weathered soils will be subject to downslope creep and potentially sloughing over time. However, we anticipate that any future soil movement on the slope would be confined to the near -surface, loose, weathered soil, without significantly affecting the dense, glacially consolid3ted soil. No fill soils should be placed on or near the top of the steep slope. This restriction will require that the soils from the excavation be removed from the site. Water from storm and footing drains, and roof downspouts should not be discharged onto the slope. If discharging drain water into a sewer is not possible, we recommend tightlining the drains to the base of the slope. A significant geotechnical consideration for development of this site is the overly moist to wet condition of the silty soils. Based on our observations, the moisture contents of the on -site soils are above the optimum moisture content necessary for the required structural fill compaction. These fine-grained, silty soils are sensitive to moisture, which makes them impossible to adequately compact when they have moisture contents even 2 to 3 percent above their optimum moisture content. The reuse of these soils as structural fill to level the site will only be successful during hot, dry weather. Aeration of each loose lift of soil may be required to dry it before the lift is compacted. Imported granular fill will be needed wherever it is not possible to dry the on -site soils sufficiently before compaction. The erosion control measures needed during the site development will depend heavily on the weather conditions that are encountered. We anticipate that a silt fence will be needed around the clownslope sides of any cleared areas. Rocked construction access roads should be extended into the site to reduce the amount of mud carried off the property by trucks and equipment. Wherever possible, these roads should follow the alignment of planned pavements. Cut slopes and soil stockpiles should be covered with plastic during wet weather. Following rough grading, it may be necessary to mulch or hydroseed bare areas that will not be immediately covered with landscaping or an impervious surface. 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. GEOTECH CONSULTANTS, INC. z C M 0 80 C MT 0 "n m M 0 0 o Fn C (a F. U) I M 0 z z 0 m Doug Johnson JN 02061 March 21, 2002 Page 4 SEISMIC CONSIDERATIONS The site is located within Seismic Zone 3, as illustrated on Figure No. 16-2 of the 1997 Unifo 'rm Building Code (UBC). In accordance with Table 16-J of the 1997 LIBC, the site soil profile within 100 feet of the ground surface is best represented by Soil Profile Type Sc (Very Dense Soil), The site soils are not susceptible to seismic liquefaction because of their dense nature. z 0 -4 CONVENTIONAL FOUNDATIONS 0� The proposed structure can be supported on conventional continuous and spread footings bearing on undisturbed, dense, native soil. The northern footings should bear directly on the dense, native ra soils, but footings on other portions of the house may be overexcavated and restored to the footing 0 M C grade with lean -mix concrete. We recommend that continuous and individual spread footings have m 0 minimum widths of 12 and 16 inches, respectively. Footings should also be bottomed at least 18 0 C inches below the lowest adjacent finish ground surface. The local building codes should be -4 C reviewed to determine if different footing widths or embedment depths are required. Footing = m M z subgrades must be cleaned of loose or disturbed soil prior to pouring concrete. Depending upon ID -4 C site and equipment constraints, this may require removing the disturbed soil by hand. > Depending on the final site grades, some overexcavation may be required below the footings to =i 0 expose competent, native soil. Lean concrete (1.5 sack minimum) should be used to fill any n 23 overexcavated hole beneath the footings. If lean concrete is used, the overexcavation need only extend 6 inches beyond the edges of the footing. M M a5 0, An allowable bearing pressure of 2,000 pounds per square foot (psf]i is appropriate for footings 0 M C (a supported on dense, native soil. A one-third increase in this design bearing pressure may be used K Cn when considering short-term wind or seismic loads. For the above design criteria, it is anticipated m that the total post -construction settlement of footings founded on competent, native soil, or on structural fill up to 5 feet in thickness, will be about one-half inch, with differential settlements on the order of one-half inch in a distance of 50 feet along a continuous footing with a uniform load. 3: z Lateral loads due to wind or seismic forces may be resisted by friction between the foundation and the bearing soil, or by passive earth pressure acting on the vertical, embedded portions of the co foundation. For the letter condition, the foundation must be either poured directly against relatively z level, undisturbed soil or be surrounded by level structural fill. We recommend using the following ultimate values for the foundation's resistance to lateral loading: liiiIiiiIIIIM mull 0 M Co-ffici Coeffi icient of Friction 0.45 IPasSive ,u Earth Pressure 350 pcf P r Where: (1) pef Is pounds per cubic foot, and (11) passive earth pressure Is computed using the equivalent fluid density. GEOT5CH CONSULTANTS, INC. Doug Johnson JN 02061 March 21, 2002 Page 5 If the ground in front of a foundation is loose or sloping, the passive earth pressure given above will not be appropriate. We recommend maintaining a safety factor of at least 1.5 for the foundation's resistance to lateral loading, when using the above ultimate values. PERMANENT FOUNDATION AND RETAINING WALLS 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: Active Earth Pressure 35 pcf Passive Earth Pressure 350 pof Coefficient of Friction 0.45 Soil Linit Weight 135 pcf Where: (1) pef Is pounds per cubic foot, and (it) 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 par times the height of the wall should be added to the above active equivalent fluid pressure. The values given above are to be used to design permanent foundation and retaining walls only, The values for friction and passive resistance are ultimate values and do not include a safety factor. We recommend a safety factor of at least 1.5 for overturning and sliding, when using the above values to design the walls. Restrained wall soil parameters should be utilized for a distance of 1.5 times the wall height from corners in the walls. 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. Retainfincr WaH Backfill and Watmiroorlinct 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. If the native silty sand is used as backfill, a minimum 12-inch width of free -draining washed sand and gravel should be placed against the backfilled retaining walls. Free -draining backfill or gravel should be used for the entire width of the backfill where seepage is encountered. For GEOTECH CONSULTANTS, INC. ZL c) m 0 m M 0 0 M m 0 "n m M .0 0 rn C ce m 0 Z M Z Z 0 M Doug Johnson JN 02061 March 21, 2002 Page 6 increased protection, drain�age composites could be placed along cut slope faces, and the walls 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. 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 to reduce the potential for surface water to percolate into the backfili. The section entitled GENERAL EARTHINORK AND STRUCTURAL FILL contains recommendations regarding the placement and compaction of structural fill behind retaining and foundation walls. The above recommendations are not intended to waterproof the below -grade walls. The performance of subsurface drainage systems will degrade over time. Therefore, waterproofing should be provided where moist conditions or some seepage through the walls are not acceptable in the future. This typically includes limiting coid-joints and wall penetrations, and using bentonite panels or membranes on the outside of the walls. Applying a thin coat of asphalt emulsion is not considered waterproofing, but will only help to prevent moisture, generated from water vapor or capillary action, from seeping through the concrete. With any project, adequate ventilation of basement and crawl space areas is important to prevent a build up of moisture that may be transmitted through concrete walls from the surrounding soil. SLABS -ON -GRADE The building floors may be constructed as slabs -on -grade atop competent native soils, or o I n structural fill placed above competent native soils. We recommend removing the existing fill soils from beneath the slabs. The subgrade soil must be in a firm, non -yielding condition at the time of slab construction or underslab fill placement. Any soft areas encountered should be excavated and replaced with select, imported structural fill. All slabs -on -grade should be underlain by a capillary break or drainage layer consisting of a minimum 4-Inch thickness of coarse, free -draining structural fill with a gradation similar to that discussed in PERMANENT FOUNDATION AND RETAINING WALLS. As noted by the American Concrete Institute (ACI) in Section 3.2.3 of the Guides for Concrete Floor and Slab Structu , proper moisture protection is desirable immediately below any on -grade slab that will be covered by tile, wood, carpet, impermeable floor coverings, or any moisture -sensitive equipment or products. ACI also notes that vapor retarders, such as 6-mil visqueen, are typically used. A vapor retarder is defined as a material with a permeance of less than 0.3 US perms per square foot (psf) per hour, as determined by ASTM E 96. It is possible that concrete admixtures may meet this specification, although the manufacturers of the admixtures should be consulted. However, if no potential for vapor passage through the slab is desired, a vapor barrier should be used, A vapor barrier, as defined by ACI, is a product with a water transmission rate of 0.00 permis per square foot per hour when tested in accordance with ASTM E 96. Reinforced membranes having sealed overlaps can meet this requirement. Additionally, ACI (Section 4.1.5) recommends that a minimum of 4 inches of compactable granular fill, such as crushed rock, should be placed over the vapor retarder or barrier for protection. Sand is not recommended by ACI for use as the protection layer. GEOTECH CONSULTANTS, INC. z 0 0 M .n m M 0 80 m M m M 0 0 C: M 0 X z z 0 m Doug Johnson JN 02061 March 21, 2002 Page 7 EXCAVATIONS AND SLOPES Excavation slopes should not exceed the limits specified in local, state, and national government safety regulations. Temporary cuts to a 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, or existing utilities and structures. Based upon Washington Administrative Code (WAC) 296, Part N, the soil at the subject site would generally be classified as Type A. Therefore, temporary cut slopes greater than 4 feet in height cannot be excavated at an Z' inclination steeper than 0.75:1 (Horizontal:Vetcal), extending continuously between the top and the bottom of a cut. The loose fill soils should be trimmed back to a 1:1 (H:V) inclination. The above -recommended temporary slope inclinations are based on what has been successful at 4 T, other sitesvifith similar soil conditions. Temporary cuts are those that will remain unsupported for a ra relatively short duration to allow for the construction of foundations, retaining walls, or utilities. a M Temporary cut slopes should be protected with plastic sheeting during wet weather. The cut slopes (= C, M 01 should also be backfilled or retained as soon as possible to reduce the potential for instability. 0 Please note that loose soil can cave suddenly and without warning. Excavation, foundation, and C utility contractors should be made especially aware of this potential danger. m M Z All permanent cuts into native soil should be inclined no steeper than 2:1 (H:V). Water should not C: be allowed to flow uncontrolled over the top of any temporary or permanent slope. Also, all F- permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce MR erosion and improve the stability of the surficial layer of soil. 013 Any disturbance to the existing slope outside of the building limits may reduce the stability of the m M slope. Damage to the existing vegetation and ground should be minimized, and any disturbed C3 5 0 areas should be revegetated as soon as possible. Soil from the excavation should not be placed 9 on the slope, and this may require the off -site disposal of any surplus soil. C: DRAINAGE CONSIDERATIONS Foundation drains should be used where around the perimeter of the structure and behind the Z basement walls. Drains should also be placed at the base of all earth -retaining walls. These drains should be surrounded by at least 6 inches of 1-inch-minus, washed rock and then wrapped 0 in non -woven, geotextile filter fabric (Mirafi 140N, Supac 4NP, or similar material). At its highest Z point, a perforated pipe invert should be at least 6 inches below the bottom of a slab floor or the 9 " level of a crawl space, and it should be sloped for drainage. All roof and surface water drains must 0 be kept separate from the foundation drain system. A typical drain detail is attached to this report m as Plate 4. For the best long-term performance, perforated PVC pipe is recommended for all subsurface drains. No groundwater was observed during our field work. If seepage is encountered in an excavation, it should be drained from the site by directing it through drainage ditches, perforated pipe, or French drains, or by pumping it from sumps interconnected by shallow connector trenches at the bottom of the excavation. The excavation and site should be graded so that surface water is directed off the site and away from the tops of slopes. Water should not be allowed to stand in any area where foundations, slabs, or pavements are to be constructed. Final site grading in areas adjacent to the building GEOTECH CONSULTANTS, INC. Doug Johnson JN 02061 March 21, 2002 Page 8 should slope away at least 2 percent, except where the area is paved. Surface drains should be provided where necessary to prevent ponding of water behind foundation or retaining walls. GENERAL EARTHINORK AND STRUCTURAL FILL All building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and other deleterious material. The stripped or I -ernoved materials should not be mixed with any Z� 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, behind permanent retaining or foundation walls, or in other areas where the underlying soil needs Vj to support loads. All structural fill should be placed in horizontal lifts with a moisture content at, or a m near, the optimum moisture content, The optimum moisture content is that moisture content that C: m 0 results in the greatest compacted dry density. The moisture content of fill is very important and 8 0, C must be closely controlled during the filling and compaction process. -4 C X m m 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 10 > should not exceed 12 inches. We recommend testing the fill as it is placed, If the fill is not E: sufficiently compacted, it can be recompacted before another lift is placed. This eliminates the need to remove the fill to achieve the required compaction. The following table presents 0 -n ;0, recommended relative compactions for structural fill: -4- 0 Beneath footings, slabs 95% M Cn M or walkwa s Filled behind 90% Z slopes and retaining walls ;D 95% for upper 12 inches of Beneath paveme nts sub grade; 90% below that Z level Where: Minimum Relative Compaction Is the ratio, expressed In percentages, of the compacted dry density to the maximum dry Z density, as determined in accordance with ASTM Test 9 Designation D 1557-91 (Modifled Proctor). 0 In Use of On -Site So If grading activities take place during wet weather, or when the silty, on -site soil is wet, site preparation costs may be higher because of delays due to rain and the potential need to import granular fill, The on -site soil is generally silty and therefore moisture-sens itive. Grading operations will be difficult during wet weather, or when the moisture content Of this soil exceeds the optimum moisture content. The moisture content of the silty, on -site soil must be at, or near, the optimum moisture content, as the soil cannot be consistently compacted to the required density when the moisture content is significantly greater than optimum, The moisture content of the on -site soil was generally above the estimated optimum moisture content at the time of our GEOTECH CONSULTANTS, INC. Doug Johnson N 02061 - March 21, 2002 J Page 9 explorations. The on -site sands and silty sands underlying the existing fill could be used as structural fill, if grading operations are conducted during hot, dry weather, when drying the wetter soil by aeration is possible. During excessively dry weather, however, it may be necessary to add water to achieve the optimum moisture content. Moisture -sensitive soil may also be susceptible to excessive softening and "pumping" from construction equipment, or even foot traffic, when the moisture content is greater than the optimum moisture content. It may be beneficial to protect subgrades with a layer of imported sand or crushed rock to limit disturbance from traffic. The GENERAL section should be reviewed for considerations related to the reuse of on -site soils. 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 analyses, 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 pits 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 soil conditions are commonly encountered on construction sites and cannot be fully anticipated by merely taking soil samples in test pits. 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 residence 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. At additional cost, we can provide recommendations for reducing the risk of future movement on the steep slopes, which could involve regrading the slopes or installing subsurface drains or costly retaining structures. However, the owner 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 residence. This report has been prepared for the exclusive use of Doug Johnson Construction, and its representatives, for specific application to this project and site. Our recommendations and conclusions are based on observed site materials. Our conclusions and recommendations are professional opinions derived in accordance with current standards of practice within the scope of our services and within budget and time constraints. No warranty is expressed 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. GEOTECH CONSULTANTS, INC, z C m M 0 0 80 C m m C 0 _n ,n m m 0 0 0 a C M 0, Z z z 0 4 F) m Doug Johnson JN 02061 March 21, 2002 Page 10 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 Z' R 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, -4 -n The following plates are attached to complete this report: m m 0 Plate 1 Vicinity Map 0 c: Plate 2 Site Exploration Plan m M Z' Plates 3 Test Pit Logs 'C Plate 4 Typical Footing Drain We appreciate the opportunity to be of service on this Project. If you have any questions, or if we may be of further service, please do not hesitate to contact us. M m Respectfully submitted, C 1710 GEOTECH CONSULTANTS, INC. 0 WAS4 Z' 0 4., 3 z 0, 01 m EXPIRES 01-31- James H. Strange, Jr., P.E. Senior Geotechnical Engineer James R. Finley, P.E. Principal JHS/JRF: esm GEOTECH CONSULTANTS, INC� BROWNS BAY 2RD SW p p T� 17�TH ,EDERjCx PL 5 76TH SITE 71 END cob COUNTY PARK PARK z OVERLOOK pK '0 0 /7 S lg� -n p Z 0 M IOTTY T �-lw SW c 13- -2-T a .:: 18ST M 0 C EN p c 8 0 rn mz M 10 I. I ST SW a 19 �s IT 196TH ST SW PHU 97TM (F MELODY LS _STSW v NA 9� iE m T IV IM VIE IN ST 0 �T I. �T I. p �T ST S IPAL 0 c "2ND' isw M 0 TT 202NO PL SU L 20 '19 19 65T S� PINE .1 z �5 RIDGE PK MID -'ElF PLACE EW ST . . . . . . . . . . ST D ONI tl� ST z AYT e I MAPLEI-I ST MEMORIAL 0 YW E --I I ALDERI PAPX LNUT I H: N 111 -$ T 1 2 CEDAR '0 IA 213. _2 'j­ �T 215TH ST SW :�w VICINITY NIAP GEOTECH 78xx - 175th Street Southwest CONSULTANTS, INC. Edmonds, Washington 41 Ma ffin C 0) c co� Test Pit 1 Depth (feet) Observations 0.0-2.5 Gray -brown, gravelly, very silty sand with roots, wet, loose [Fill] 2.5-7.0 Brown, slightly silty SAND, medium -grained, moist, medium -dense. [SM] becomes dense at 4 feet. 7.0-9.0 Gray SILT, varved, moist to very moist, very sfiff to hard. [MLI Test Pit terminated at 9,0 feet on 02/11/2002. No groundwater was encountered, No caving was observed. Test Pit 2 Depth (feet) Observations 0.0-2.0 Gray, silty sand with quarry spalls, very moist, loose. [Fill] 2.0-4.0 Gray -brown, gravelly, very sandy SILT, non -plastic, moist, dense to very dense, [SMIMLI Test Pit terminated at 4.0 feet on 02111/2002. No groundwater was encountered. No caving was observed. Test Pit 3 Depth (feet) Observations 0.0-3.0 Gray, silty sand with gravel, wet, loose. [Fill] 3.0-6.0 Gray and brown, gravelly, very sandy SILT, non -plastic, moist, very dense, [SMIMLI 5.0-8.0 Brown, gravelly, slightly silty SAND, fine to medium -grained, moist, very dense. [SPISM] Test Pit terminated at 8.0 feet on 02/11/2002, No groundwater was encountered. No caving was observed. Test Pit 4 Depth (feet) Observations 0.0-2.0 Gray, silty sand with gravel, wet, loose. [Fill] 2.0-8.0 Gray -brown, gravelly, silty SAND, fine- to medium -grained, moist, dense. [SM] - becomes less gravelly, less silty, dense to very dense. ISPISMI Test Pit terminated at 8.0 feet on 02/11/2002. No groundwater was encountered. No caving was observed. TEST PIT LOGS 78xx - 175th Street Southwest GEOTECH CONSULXANTS� MC. Edmonds, Washington JJ-OA % pAde., z =4 :R m Im a t' 0 80, a M 0 z 0 m M V ra 0 0 r1i M 1z" z 0, m Slope backfill away from foundation. Provide surface drains where necessary. Backrill (See text for requirements) Nonwoven Geotextile Filter Fabric - Tightline Roof Drain (Do not connect to footing drain) Vapor Retarder or Barrier SLAB I Free -Draining Gravel 4" Perforated Hard PVC Pipe (if appropriate) (Invert at least 6 inches below slab or crawl space. Slope to drain to appropriate outfall. Place holes downward.) NOTES: (1) In crawl spaces, provide an outlet drain to prevent buildup of water that bypasses the perimeter footing drains. (2) Refer to report text for additional drainage and waterproofing considerations. FOOTING D %JN DETAIL GEOTECH 78xx - 175th Street Southwest CONSULTAMS� INC. Edmonds, Washington I —nde: I PM& 02061 1 March Not to Scale z =i "a INAGE DETENTION SYSTEM STANDARD DRA WORKsHEET r By- CALC ADDRM 50 .17 DATE: *****DESIGN DATA***** PIPE DIA PIPE LIS ORIFICE z IMPERVIOUS AREA rn M DETENTION PIPE LEMIN LOCKING LID (TYPICAL _40, ranswb opAts 0 C: MINIMUM -4 M or :C A z TIGHTL C014: Box OR RISCR .5% To rA SL YLrI 6' OUTLET CONTROF "I". 0.n APR1 2'2002 .ORIFICE UPPER CATCH BASIN CONTROL CATCH BASIN DEVELOPMENT SERVICES CTR- CITY OF EDMONDS In M RECEIVED 0 0 SYSTEM CROSS SECTION MO DEVELOPMENT SERVICES CT' 2,X2'X6'.I)EtP, 4-6- SPALLS OR EOUAL CITY OF EDMONO 3/4 XtSTING CRADC 2'X WX 3' DEEP: CRUSHED ROCK FROM CONTROL CD z VASMED ROCK FROM CUNT OL OUTLET OUTFL I TRENCI MIN 10' LdNG, PERF IPC TO B LEVEL z 1.5 PERF W1 END CAP$ 0 pLL 1449 —1 "Cjf,,MNq V 0 M RhPRAP OUTLEr -TRENCH RUNOFF SPREADER DETENTION SYSTEM NOT AE CONNECTED TO DRAINS SHALL FOOTING NOTES.- VAs AD PC "'. RIF PIPE I ".A, PIPE , M P% itk TV NO S. mo inspection 0)!.7. ' Sys' is V =� . ti DO, I. call Engineering Division (771-MO) for. tightline and detention system WSP-t— APPROVED BY [_ : - gan flod Cos. before backfilling and for final inspections - a hVIo IND imeCance of rg, tom's o"I" III hed b 0 ra -on and ys g.pi t� us edi. he sto- po b lity ftheproperly...5. Material. om a t mrol fifice I on. ra� systems on private property is the ain 21 2, R7esponsibility for operation and maintenance of dr age C. Atarjal accumulated in the.storage pipe must be flushed responsibility of the property owne f the Ca ma to allow I - To proper ope-tion. no outlet control orifice out and removed from the Catch basins to allow us', D ent.11 Ii.. must be ke t o en at all times. 6 Height Calculation Worksheet R" Address: Z29(s I? S A Date:. IC7 -OC Inspector(s): 1. Datum Point 2. Datum Point Elevation: 9 0�) 6-,3 01 :B 3. Average Grade: L d-) 4. Maximum Elevation Allowe (average grade) + 25 6-5 ;1 5. Reference Point Elevation Shot to House: C In (datum elevation)+ 0' (grade to'transit level fine shot to house) C '�= 6, Measurements from line shot onto house to roof ridge: Ck 0 'n S, m M 0 0 Fn' a o) :mo Total 0 Wi 7. Actual Elevation: o 0 (reference point elevation) (measurements 0 M from #6) 9,9s ZT— Conclusion: & (actual) is grez --s iter less thaLA 2�� (allowed); therefore the house isl rl is not over the height require2cuper ECDC 16.20.30 requirements 13256 NE 20th Street' Suite 16 Bellevue, WA 98005 425-747-5619 FAX 425-747-8561 j R LOCATION 1'5 GENERAL CONTRACTOR IONTRACTOWS SUISHINTENDENT 7p TRAVEUFNE joi, RUNS. T. -;p — z , ____ IIAII� _ TIME OFF SITE DAY OF WEEK '65;n HOURS CHARGED ele'e . / CLIENTIDWNER IIIES PER.IT NUMBER RACI� 'w "T iT.. -FACTOR GRADING SUPMINTENDEN, VISITORS PAGE / OF Ai glAd e 711"*­"Z�+'�_�'t,z '� 41 J�11 7K, 4ell, lle,�_441 Jlk_ Jlk '1211k"40. si A ell A eq*­ �;L wi, -RECEIVED ­V 7 o 2002 CITY OF EDMONDS e �N J:P�ap6e- AJJ. A t �AE o ro � R a M m 0 80 c m m 0 _n n 2D m m c—o) c: 0 m 0), i:� M 0 z 4 ;D z Z' 9 0 m