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20050682 (2).pdfDATE RECEIVED CITY OF EDMONDS CONSTRUCTION PERMIT APPLICATION OWNER NAME/NAME OF BUSINESS MAILING ADDRESS CITY ZIP TELEPHONE E���� NAME J o11lv Ia .&/Flcl-✓�•✓�i�r�S, . T -✓C, ADDRESS Opel`�`k e/V4/ �Ir TEL 2`, 9�1r�? CBL.# 716 %,beau, 411V Ade, 41-/61 t WDRESS yt PERMIT EXPIRES PERMIT NUMBER �� (`� �\ l C. c� JOB SUITEIAPT# ADDRESS PLAT NAME/SUBDIVISION NO. LOT NO. LID NO. LID FEE S PUBLIC RIGHT OF WAY PER OFFICIAL STREET MAP TESCPApproved RW Permit Required - 0 EXISTING PROPOSED Street use Permit Required 0 Inspection Required 0 SWewalk Required 0 REQUIRED DEDICATION FT underground 0 wiring required 0 METER SIZE LINE SIZE NO. OF FIXTURES PRV REQUIRED YES13 NO I3 x LU REMARKS W OWNEWCONTRACTOR RESPONSIBLE FOR EROSION CONTROUDRAINAGE t7 A _ _ _ �. _ ,. w ENGINEERING REVIEWED BY DATE CITY FIRE REVIEWED BY DATE Lu ZIP Ti cc 000 ZS/ 0570 LL STATE ^/LICENSE �NUMBER � EXPIRATION DATE CHECKED BY VARIANCE OR CU SHORELINE OR ADB# i INSPECTION SEPA •"MVV/ y �`�� /( `-'lJ +- 0 YESOO NO COMPLETED EXEMPT 'i 7ze.PROPERTY TAX ACCOUNT PARCEL NO, CA# ZONE SIGN AREA HEIGHT ❑ NEW ❑ ADDITION ❑ REMODEL REPAIR ❑ DEMOLISH ❑GARAGE CARPORT %'�/ y �r /�C��a WAIVER ALloweo PROPOSED ALLOWED PROPOSED r �JSTIIly rl RESIDENTIAL ❑ LOT COVERAGE REQUIRED SETBACKS (FT. PROPOSED SETBACKS FT.) PLUMBING / MECH ) ALLOWED PROPOSED FRONT SIDE REAR FRONT UR SIDE REAR i ❑ COMMERCIAL [3z CCOMPLIANCE OR 1:1MIXED USE CHANGE OF USE z PARKING LOTAREA PLANNING REVIEWED BY DATE g ❑ MULTIFAMILY' ❑ SIGN REQ'D PROVIDED 7 d ❑ GRADING CYDS ❑ l FENCE ! ( X FT.) REMARKS ❑ TANK ❑ OTHER C# f1± ❑ ROCKERY e7 0 RETAINING WALL ❑ MFIRE KLER FIREALA TYPE OF CONSTRUCTION CODE GROUP iu NUMBER NUMBER OF m /) n SPECIAL IN)PECTION CONSULTANT OCCUPANT OF ��// DWELLING C/''{✓D STORIES F1410 UIJITS LOAD DESCRIBE WORK TO BE DONEREQUIREDYES /f A REMARKS .G /�G/ ` L�z 9 OTE�I BY7/6.1:;-w��(iI STRUCTURAL DESIGN �p BY: iiii/ )64a VALUATION. $ -' Description FEE Description FEE (� -75iiIt Plan Check State Surcharge HEAT SOUR LOTSLOPE% VESTE Building Permit City Surcharge PLAN CHECK NO: Plumbing Base Fee THIS PERMIT AUTHORIZES ONLY THE WORK NOTED, THIS PERMIT COVERS WORK TO Mechanical C BE DONE ON PRIVATE PROPERTY ONLY. ANY CONSTRUCTION ON THE PUBIC K DONMAIN (CURBS, SIDEWALKS, DRIVEWAYS, MARQUEES, ETC.) WILL REQUIRE Grading J SEPARATE PERMISSION, PERMIT APPLICATION; SEE ECDC 1H.00.005(A)(5) Engr. Review PERMIT LIMIT: SEE ECDC 19,00,005(A)(6) Engr. Inspection SEE BACK OF PINK PERMIT FOR MORE INFORMATION *APPLICANT, ON BEHALF OF HIS OR HER SPOUSE, HEIRSi ASSIGNS AND SUCCESSORS Fire Review Plan Chk. Deposit IN INTEREST, AGREES TO INDEMNIFY, DEFEND AND HOLD HARMLESS THE CITY OF B EDMONDS, WASHINGTON, ITS OFFICIALS, EMPLOYEES, AND AGENTS FROM ANY AND Fire Inspection Receipt # ALL CLAIMS FOR DAMAGES OF WHATEVER NATURE, ARISING DIRECTLY OR INDIRECTLY p = FROM THE ISSUANCE OF THIS PERMIT, ISSUANCE OF THIS PERMIT SHALL NOT BE DEEMED TO MODIFY, WAIVE OR REDUCE ANY REQUIREMENT OF ANY CITY ORDINANCE Landscape InSp. Total Amt. Due = NOR LIMIT IN ANY WAY THE CITY'S ABILITY TO ENFORCE ANY ORDINANCE PROVISION.' Recording Fee Receipt # I HEREBY ACKNOWLEDGE THAT I HAVE READ THIS APPLICATION; THAT THE INFORMATION APPLICATION APPROVAL GIVEN IS CORRECT; AND THAT I AM THE OWNER, OR THE DULY AUTHORIZED AGENT OF THE OWNER, I AGREE TO COMPLY WITH CITY AND STATE LAWS REGULATING CONSTRUC• CALL This application is not a permit until signed by the TION; AND IN DOING THE WORK AUTHORIZED THEREBY, NO PERSON WILL BE EMPLOYED Building Official or his/her Deputy: and Fees are paid, and IN VIOLATION OF THE LABOR CODE OF THE STATE OF WASHINGTON RELATING TO FOR INSPECTION receipt is acknowledged in space provided. WORKMEN'S COMPENSATION INSURANCE AND RCW 16:27. OFF w IGN E DA - SIGNATURE60W�JNER1.OR AGENT): DATE SIGNED (425)4,61 /�/O 61 0G tom-` �' y y e 771 =OLIO RELEASED BY ( ATE ATTENTIO Ai0000 ITIS UNLAWFU TO USE OR OCCUPY A BUILDING OR STRUCTURE UNTIL LM EXT. 1333 1,110 � _ (J j I ' A FINAL INSPECTION HAS BEEN MADE AND APPROVAL OR A CERTI- FICATE OF OCCUPANCY HAS BEEN GRANTED. UBC109 / IBC110 / IRC110. ORIGINAL • FIL4jsYLOWIN PECTOR PINK •OWNLD -ASSESSOR Iola PRESS HARD in YOU ARE MAKING 4 COPIES 0 m 9 C M �O O n _ M m Z -'I D Z r_= an mn MM vN O r- M f r z i X. D Z r ==I 2 Z O n M FanGE8 MICROFILM Geotechnical &Earthquake Engineering Consultants September 15, 2005 File No. 05424 RECEIVED OCT 0 6 2005 , BUILDING. DEPARTMENT O Carl and Molly Forssen CITY OF EDMONDs .� 730 Elm Street n rn Edmonds, Washington WA 98020 CO Subject: Geotechnical Engineering Assessment = M C Sinkhole Remediation at 730 Elm St, Edmonds, WA v v mO n C. . Dear. Mr. and Mrs. Forssen, m . As requested, PanGEO provided an assessment of a sinkhole that had developed at your A { residence. An initial site visit was made on August 8, 2005 after we received a call from you the same day. Our observations were summarized in a memorandum dated August 9, 2005. In r=_ v summary, a sinkhole had formed and had undermined an existing footing at the entrance to. your O TI I garage. Based on our recommendations, as an emergency repair measure, two 2 -inch diameter rn t' steel pin piles were installed to underpin the subject footing. Details of the pin pile installation M rn are summarized in a field report dated August 10, 2005. Both the August 9 memorandum and v the August 10 field repoare attached for reference. rt N Cn, n SUBSURFACE EXPLORATIONS r rTI ,. In an attempt to determine the site subsurface conditions for evaluating the potential causes for is the sinkhole; two exploratory borings were drilled z > lit, on your property. Boring BH -1 was drilled within _ the sinkhole, and boring BH -2 was drilled through t .<T •, _,. ` ` the existing driveway pavement at a location. 0 `approximately 5 feet west and 10 feet north of BHOr. � �;w 1, where a slight surface depression was observed. , r,: The borings were drilled to depths of 24 to 34 feet, Plate 1. Drilling BH -2 using a portable drill rig owned and operated by CN Drilling of Seattle, WA. The drill rig was equipped with 4 -inch outside diameter hollow 3414 NE55th Street Seattle, W Sea A 98105 Tel: (20 6) 262-0370 F ax: (206) 262-0374 i Carl and Molly Forssen September 15, 2005 stern augers. Soil samples were obtained from the borings at 2'/z -foot intervals using Standard Penetration Test (SPT) sampling methods. SPT samples are obtained using a 24nch outside diameter split -spoon sampler, driven into the soil a distance of 18 inches using a 140 -pound weight falling a distance of 30 inches. The number of blows required for each 64nch increment of sampler penetration was recorded. The number of blows required to achieve the last 12 inches of sample penetration. is defined as the SPT N -value. The N -value provides an empirical measure of the relative density of cohesionless soil, or the relative consistency of fine-grained - soils. Z O An engineering geologist from PanGEO was present during the field exploration to observe the 0 drilling; assist in sampling, and to describe and document the soil samples obtained from the borings. The soil samples were described using the system outlined on Figure 1, and summary logs are included as Figures 2 and 3. C4_ vM co M SUBSURFACE CONDITIONS 040 Based on the area geology map reviewed (Booth, D.B, Cox, B.F., Troost, K.G. and Shimel, S.A., January 5, 2004, Draft Composite Map of the Sno-King Area, Central Puget Lowland, M Z Washington), the site is underlain by very dense glacial till and outwash. However, the mapped c Z.Z geologic units were not encountered in our borings. In summary, the. soil conditions encountered — in the two borings were quite erratic, but generally consistedof loose disturbed soils to the. ' � N I Om maximum depths explored. Boring BH - 1, which was drilled within the perimeter of the sinkhole, encountered very loose to m M loose,gravelly and silty sand to a depth of about 22 feet: Between 22 and 24 feet, the maximum v0 Cn depth of the borehole, the blow counts indicated that the soils became medium dense to dense.c N This is consistent with the driving conditions observed during the installation of pin piles. The. drilling action also indicated the potential presence of voids and/or very loose material at depts zrM of 12 to 16 feet. The standing water in the sinkhole at the location of BH -1 was 4'/z feet below the garage floor slab at the time of our drilling. Based on our discussion with you, we understand that the water in the sinkhole was pumped out at one time, and that the water level returned to the original level within about an hour. i z BH -2 was located in the driveway pavement, outside of the sinkhole perimeter.. The driveway at in this location had a slight depression. The subsurface conditions encountered in BH -2 consisted p of about 5 feet of fill underlain by about 12 feet of interbedded layers of very dense glacial till - like silty sand with gravel and loose silty fine sand. The drilling action indicated the presence of m a very soft soil layer or void between 14 and 16 feet. Loose silty sand with gravel was encountered at a depth of 19 feet and extended to the bottom of the hole at 34 feet. No groundwater level was measured in the test hole, but the wetness of the soil samples suggested the presence of groundwater at a depth of about 5 feet below grade at this location at the time of F. drilling. 05-124 Letter Report.doc 2 PanGEO, Inc. 1 Carl and Molly Forssen September 15, 2005 SUMMARY • A review of area topographic map and site reconnaissance suggests that the property may be situated in an old ravine that was filled either by natural mass wasting of soils or by past grading activities. • Results from our current study do, not provide conclusive evidence as to the cause of the sinkhole. Subsurface conditions encountered in the borings also do not present clear evidence to the cause of apparent voids encountered at 12 to 16 feet during the drilling our test borings. However, the depth of these voids and the absence of underlying highly z compressible soils indicate that the sinkhole is most likely caused by piping of soil particles into subsurface natural -or man-made voids or conduits near this depth. M m However, the nature and locations of these voids cannot be accurately determined at this time. m • Similar subsurface conditions may be present in other locations on your property and in m the neighborhood.. n C • Because the potential voids or very soft zones are quite deep (12 to 16 feet in B114 and = m ;. BH -2), we recommend that the apparent voids and very soft soil layers be backfilled with m � injection grouting. In general, this method consists of pumping a fluid clay/cement grout D z through a small diameter steel pipe that is driven into the ground to target a specific zone. r_ Soft zones or voids likely can be detected based on the driving resistance of the steel 0 Co PIP e The objective of this operation is to treat the existmi voids or very soft soils as . z,. PP J P g �' R, well as potentially plugging conduits that may had caused the loss soil particles. Mm • We further recommend that the existing sinkhole be backfilled with Control Density Fill o (CDF). When cured, CDF forms a weakly cemented block of material that will be less , C N susceptible to erosion and movements and therefore, in our opinion, a better backfill m CO material than sand and gravel. Z n • Because of the very loose soils underlying the site, the potential for future settlement of the CDF backfill cannot be precluded. Settlement of the CDF backfill could result in .JL additional loads on the recently installed pin piles and beam support for the garage ► Z footing. As a result, the beam and pin piles should be isolated from the CDF backfill. One possible alternative for isolating the pin piles is to encase each pin pile with a plastic co pipe (or two half pipes) before placing the CDF. The pipes should extend at least afoot O below the base of CDF. This is to allow slippage between the CDF and the pin piles in the event of differential_ settlement. rn • Because of the high groundwater. level on the property, you may also consider installing perimeter trench drain around your house. The trench drain should consist of gravel filled trench that is at least 12 -inch wide and 44bot deep. A 4 -inch perforated drain pipe should be placed at the bottom of the trench, and direct collected water to the storm drain system. . PanGEO, Inca 05=124 Letter Report.doc 3 Carl and Molly Forssen September 15, 2005 LIMITATIONS We have prepared this report for use by Mr. and Mrs. Carl and Molly Forssen. Recommendations contained in this report are based on a site reconnaissance, the information obtained from our subsurface exploration program, and our understanding of the project. The study was performed using a mutually agreed-upon scope of work in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. The, inference of subsurface conditions at the site was based on our interpretation of conditions encountered in the site subsurface explorations, supplemented with our knowledge of subsurface =� conditions from published literatures. Variations in soil conditions may exist between the rn locations of the site subsurface explorations and the actual conditions underlying the site. The �Mn nature and extent of soil variations may not be evident until construction occurs. If any soilCn conditions are encountered at the site that are different from those described in this report or if c m there are any changes in the project scope, path or utility locations, we should be notified rn O 0n immediately to review the applicability of our recommendations, e mZ The scope of our work does not include services related to construction safety precautions and D our recommendations are not intended to direct the contractor's methods, techniques, sequences > z or procedures, except as specifically described in our report for consideration in design. r �_ Additionally, the scope of our work specifically excludes the assessment of environmental 0 Oon ,on characteristics, particularly those involving hazardous substances or wetlands. This report may be used only by the client and for the purposes stated, within a reasonable time o CO) from its issuance, Land use, site conditions (both off and on-site), or other factors including n Fn advances in our understanding of applied science, may'change over time and could materially CO. r. affect our findings. Therefore, this report should not be relied upon after 24 months from its n issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the j time lapse. z It is the client's responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety, The use of CO information contained in this report for bidding purposes should be done at the contractor's option and risk, Any party other than the client who wishes to use this report shall notify m PanGEO such intended use and for permission to copy this report, Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. f 05-124 Letter Report.doe 4 PanGEO, Inc. RELATIVE DENSITY / CONSISTENCY' TEST SYMBOLS for In Situ and Laboratory Tests listed in "Other Tests" column. CBR California Bearing Ratio Comp Compaction Tests Con Consolidation DD Dry Density DS Direct Shear %F Fines Content GS Grain Size Perm Permeability PP Pocket Penetrometer UNIFIED SOIL CLASSIFICATION SYSTEM R R -value SG Specific Gravity ZO TV Torvane TXC Triaxial Compression m UCC Unconfined Compression • ' SYMBOLS mn Sampletin Situ test types and intervals _ ®2 -inch OD Split Spoon, SPT C M (1404b. hammer, 30' drop) m n 8 3.25 -inch OD Spilt Spoon C (3004b hammer, 30' drop) = M Z. Non-standard penetration A test (see boring log for details) Z. Thin wall (Shelby) tube (� . Own Grab Mm Notes: 1. Soil exploration logs contain material descriptions based on visual observation and field tests using a system O r modified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have been Rock core 0 f11 conducted (as noted in the '0ther Tests' column), unit descriptions may include a classification. Please refer to the C 0) discussions in the report text for a more complete description of the subsurface conditions. C CO) r Mn 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole logs. Vane Shear Z r Other symbols maybe used where field observations indicated mixed soil constituents or dual constituent materials. -1 DESCRIPTIONS OF SOIL STRUCTURES MONITORING WELL. 2 SZ Groundwater Level at D I time of drilling (ATD) Z T. Static Groundwater Level Cement / Concrete Seal N Bentonite grout / seal Z O' Silica sand backfill 0 W� COMPONENT DEFINITIONS Slotted tip M a 0. COMPONENT SIZE / SIEVE RANGE COMPONENT SIZE / SIEVE RANGE Boulder: > 12 inches Sand Cobbles: 3 to 12 inches Coarse Sand: I #4 to #10 sieve (4.5 to 2.0 mm) Gravel Medium Sand: 1 #10 to #40 sieve (2.0 to 0.42 mm) Coarse Gravel:: 3 to 314 inches Fine Sand: #40 to #200 sieve (0.42 to 0.074 mm) Fine Gravel: 3/4 inches to #4 sieve Silt 0.074 to 0.002 mm i j <0,002 mm RELATIVE DENSITY / CONSISTENCY' TEST SYMBOLS for In Situ and Laboratory Tests listed in "Other Tests" column. CBR California Bearing Ratio Comp Compaction Tests Con Consolidation DD Dry Density DS Direct Shear %F Fines Content GS Grain Size Perm Permeability PP Pocket Penetrometer UNIFIED SOIL CLASSIFICATION SYSTEM R R -value SG Specific Gravity ZO TV Torvane TXC Triaxial Compression m UCC Unconfined Compression • ' SYMBOLS mn Sampletin Situ test types and intervals _ ®2 -inch OD Split Spoon, SPT C M (1404b. hammer, 30' drop) m n 8 3.25 -inch OD Spilt Spoon C (3004b hammer, 30' drop) = M Z. Non-standard penetration A test (see boring log for details) Z. Thin wall (Shelby) tube (� . Own Grab Mm Notes: 1. Soil exploration logs contain material descriptions based on visual observation and field tests using a system O r modified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have been Rock core 0 f11 conducted (as noted in the '0ther Tests' column), unit descriptions may include a classification. Please refer to the C 0) discussions in the report text for a more complete description of the subsurface conditions. C CO) r Mn 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole logs. Vane Shear Z r Other symbols maybe used where field observations indicated mixed soil constituents or dual constituent materials. -1 DESCRIPTIONS OF SOIL STRUCTURES MONITORING WELL. 2 SZ Groundwater Level at D I time of drilling (ATD) Z T. Static Groundwater Level Cement / Concrete Seal N Bentonite grout / seal Z O' Silica sand backfill 0 W� COMPONENT DEFINITIONS Slotted tip M a 0. COMPONENT SIZE / SIEVE RANGE COMPONENT SIZE / SIEVE RANGE Boulder: > 12 inches Sand Cobbles: 3 to 12 inches Coarse Sand: #4 to #10 sieve (4.5 to 2.0 mm) Gravel Medium Sand: 1 #10 to #40 sieve (2.0 to 0.42 mm) Coarse Gravel:: 3 to 314 inches Fine Sand: #40 to #200 sieve (0.42 to 0.074 mm) Fine Gravel: 3/4 inches to #4 sieve Silt 0.074 to 0.002 mm Clay <0,002 mm Slough Bottom of Boring I MOISTURE CONTENT 1 ' � • ,.b.. ... .. 6666 _ Project: Forssen Residence Surface Elevation: Job Number: 05-124 Top of Casing Elev: Location: 730 Elm Street, Edmonds, WA Drilling Method: Hollow Stem Auger Coordinates: . Northing: , Easting: Sampling Method: Std. Pen. Test N -Value oa) c .� Z F co p PL Moisture LL s °' C ~ E MATERIAL DESCRIPTION CL Q a W m O ® RQD Recovery 0 0 50 100 Void - open hole, Z 0, m s5 IJWEEP qage seat an N ...t 2 Very loose to loose, brown, Gravelly SAND: wet (saturated), trace to C r=11 S-1 ; i *t; some silt, sand fine to coarse, gravel fine to coarse, rounded, tabular. - 1: .•.� (Caved Outwash). .m� n 10 2 6ef0•' Stratified with finer/coarser beds, 3" to 6", bedding sub -horizontal, O C S-2 1'©• abundent fine rootlets. I .. „ .. Driller reports void at 12.5 to 14.0 feet. O � (` ,Z,•,• C Z ... 15 •.Q.WNEW Sample rods sink 1 foot below tip of auger. Lifting rods allows heave into auger: Rods bind on sand, sampling impossible. Advance to 17:5 NEWS E. µ .0.06: feet. O an 4' d. • . Pulling auger and sampling in open hole. } .. S-3 3 '•Q• Gravelly fine to coarse sand with silt. 2 ... mm 20 2 Continuous drive to end of hole. Driller says sample comes from S-4 co 2 .6 dense material : 2 Brown, Gravelly SAND: wet (not saturated), some silt, gravel and. sand C'N t, 4 •: fine, gravel rounded, blocky, massive texture (13 inches), Underlain 7 :• by yellow gray SILT and fine SAND with Gravel, wet, non -plastic, s .• layered (7 inches). t Z ;Id . 25 2� Last 3 inches of sample, fine to medium SAND: wet (saturated), "t D laminated. Bottom of Boring, W 30 fS ;00,06 0 0 Goalw z n a Im Ui 35 0 ccZ Cnw o Completion Depth: 24•0tt Remarks: Standard Penetration Test (SPT) sampler driven with a 140 Ib, safety hammer. LL Date Borehole Started: 8/16/05 Hammer operated with a rope and cat -head mechanism. Groundwater measured in r Date Borehole Completed: 8/16/05 open hole. Logged By: SHE o Drilling Company: CN Drilling - x PmGE@) LL]LOG OF TEST BORING BH -1 I N C O R P O R A T E Dr Figure 2 t. 0. Phone: 206.262.0370 The stratification lines represent approximate boundaries. The transition may be gradual. Sheet 1. Of • Project: Forssen Residence Surface Elevation: Job Number: 05-124 Top of Casing Elev.: Location: 730 Elm Street, Edmonds, WA Drilling Method: Hollow Stem Auger Coordinates: Northing: , Easting: Sampling Method: Std, Pen, Test N -Value .. p M C to ZCL in co aa) o PL Moisture LL sa) M I- E n MATERIAL DESCRIPTION �. a w pW m 0CO ® RQD Recovery U) . U) 00 O 0 50 100 0 s halt. S-1 3 2 Loose, brown, Gravelly SAND: moist, trace to some silt, sand fine to Z coarse, gravel rounded and tabular, some debris like romex casing, O {'' 2 0 etc. Fill. S-2 ° •> Very loose, brown, Silty SAND with Gravel: wet (saturated), sand and rn gravel fine, gravel rounded, muddy material. (Disturbed Outwash). 5 S-3 5 i1 ,s Medium dense to very dense, brown gray, Silty SAND with Gravel: wet in (not saturated), trace to some clay in some layers, sand and gravel 12 fine to coarse. Bedded with till -like beds and laminated beds. Rusty O m S-4 30 laminae at top. (Stratified Drift). M O Silty fine to medium sand and fine gravel, laminated to till -like (photo), ..� O 10 20 occasional yellow laminae. O C S-5 33 Softer below first 12 inches of sample. dense, brown gray silty fine to —1Ed S medium sand, wet to saturated, till -like fabric., m Z s Loose at bottom gray silty fine sand, clean sand bed at top. p —I +' S -s ,2 D Z 4 ;. 4 15 Driller says very soft 14 to 16 feet. rods sink - skip 15 foot sample. i 0 Mn S-7 is Dense to medium dense, brown gray, very silty fine sand with gravel, i s non -plastic but slightly stick massive till -like. _ Loose, brown, silty SAND with Gravel: wet (saturated), sand fine to m m 20 coarse, gravel fine, rounded, tabular to blocky; massive to layered. O fA (Disturbed Outwash). O r �m s vi S-8 ; Z 0 2 Continuous drive on sampler, 22.5 feet to 34 feet. very loose to -1 R1 25 2 •: ' medium dense zones, sampler extracts easily despite continuous D drive. 2 s D sZ. Ln a „ 30 12 9 s 5 Z s 0. W 3 w 4 .• Z 0 ¢ 2 CL 2 m CL 35 2 Bottom of Boring. . . . ui 5 Z 4 0 W z : W w z Completion Depth: 34.Oft Remarks: Standard Penetration Test (SPT) sampler driven with a 140 Ib, safety hammer. o Date Borehole Started: 8/16/05 Hammer operated with a rope and cat -head mechanism. Groundwater not measured. i N Date Borehole Completed: 8/16/05 I w Logged By: SHE o Drilling Company: CN Drilling x PanGE® LOG OF TEST BORING BH-2LL � ° I M C O R P O R A T k D Figure 3 J Phone: 206.262.0370 .: The stratification lines represent approximate boundaries. The transition may be gradual. Sil@@t Of 2: Damage: A -PRO will not be responsible for any damage caused by this grouting work, including but not limited to damage to utilities, structures or ground surfaces, unless caused by A- PRO's negligence. 3. Building Permits and Engineering: Customer will apply for permits from the governments, as required. Permit=related costs, including engineering time, are not included in this proposal. The involvement of a registered professional engineer maybe required by the local government in order to obtain permits. The involvement of a registered professional z engineer may also be desirable for other reasons, including: L An engineer may provide expert advice. rn 2. The involvement of an engineer may help convince a prospective buyer of a property that a structural problem was dealt with appropriately. (Note that Washington state law requires property sellers to disclose to prospective buyers, by way of Form 17, significant or material issues related to the property.) o M o For these reasons, customer may want to consider engaging an engineer for the design of G the repair: For its part, A -PRO will use its best judgment and experience, consistent with _ m the level of care and skill ordinarily exercised by other members of its trade currently m practicing under similar conditions in this area. No warranty with respect to the design of z the repair, expressed or implied, is made. i CO 4. Dispute resolution: T M r In case of a dispute between the parties in this contract, a first attempt to resolve the _ dispute will be made by open, honest, and cooperative discussions between the parties, m M and, if resolution is not reached, a second attempt to resolve the dispute will be made with v the assistance of a mediator, and, if resolution is not reached, a resolution will be reached c N by binding arbitration in accordance with the Construction Industry Arbitration Rules of v, the American Arbitration Association. In the event that legal action is commenced by �' either party to enforce this Agreement or. to determine the rights of any party, including �. any appeal proceeding, thesubstantially prevailing party, in addition to any other remedy, shall be entitled to receive its reasonable attorneys fees and costs. `. z S. Choice of Law: _ This Agreement shall be governed by and construed under the laws of the State of z Washington. Jurisdiction and venue shall be in King County, Washington. o n 6. Entire Agreement: M This document is the full and complete agreement.between the parties with respect to its subject matter. Any prior representations, promises, contracts or agreements are fully superseded by this Agreement. :i. i i_ 730 Elm Street, Edmonds, WA August 9, 2005 Page 2 of 3 bottom of the hole. The water appeared to be stagnant and no odor was identified coming from the hole. No cracks were observed in the concrete floor slab of the garage, and we did not observe any visible signs of settlement of the garage footing. d During our site, an attempt was made to determine whether this sink hole was utility S _{ related. A representative from the City of Edmonds sewer department was on site during our visit and he indicated that the sewer lateral Z .' O for this residence is located near the west n property line, away from the sinkhole. In ' M addition, we spoke with a representative from the Cit}of Edmonds water department who m s ' , CO stated that the instrumentation on the water meter indicated that there was no leak in the Plate 2. Approximate extent of sinkhole rn �` water lateral: marked in blue. n" =m RECOMMENDATIONS p CZ Project Approach - In our opinion, it is imperative to provide support to the unden-nmed a column footing as soon as feasible, to alleviate undue increase in stress in the structureCO — and to minimize.the risk of damaging the house. Because of the need to restore the omn Wn foundation support for. the house, we recommend atwo-phase approach. Phase I will be installation of driven steelm piles to underpin the footing. The use of pin piles is MM Vi P P rP recommended because its installation can be accomplished from the ground level and o without major site preparation work. After the footing is underpinned, the pavement around the sink hole will. be partially removed and a backhoe test pit will be excavated. to r, m CO explore the. subsurface soil conditions and to assess the cause of the sinkhole. Based on Z the results of the exploration, PanGEO will provide additional recommendations for �n backfilling the sinkhole to restore the support for the concrete slab and pavement. Pin Piles - All 2 -inch piles shall be galvanized extra strong (schedule 80) steel pipes. 2- ► inch diameter pin piles are typically installed with a 90 -pound jackhammer, and can i safely support. 24ons per pile with an approximate factor of safety of 2 when driven to Cn practical refusal (less than 1 inch of penetration for 1 minute of continuous driving). The p number of piles required should be determined by the project structural engineer. n Installation of 2 - inch pin piles shall be monitored by PanGEO to verify that the driving nn criteria are met for each pile. {; PanGEO, Inc. ns-�Za reon Memo No l.aoo PmGE@. 1• C O 11 P.0 a A T f P Geotechnical and Earthquake Engineering Consuftants 3414 NE 55`h Street Project No. L� Page No. Seattle, WA 98105 05-124 1 of 2 Tel: (206) 262-0370 Fax: (206) 262-0374 Report No. Date / Day of Week _ . 1 August 10, 2005 / Wednesday Project Name Location or Address Forssen Residence — Sinkhole Remediation 730.E1m St, Edmonds, WA Owner's Representative ` Weather Carl and Molly Forssen Permit No. cloudy, mid 70s 0 Client Contractor PanGEO Field Rep. McDowell NW Pile KingTitian E. Adams, P.E.n samem mn PanGEO was on site as requested from 10:20 am to 1:50 pm to monitor the installation of pin piles for Cl) =J underpirmng.the garage footing that was undermined by the sinkhole. Recommendations for pin pile OM installation were outlined in our memorandum dated August 9, 2005. The following observations were made: a C Pin Pile Installation: McDowellNW Pile King installed two 2 -inch , A diameter pin piles at the site. The piles consisted of schedule 80 I y z galvanized pipe and were driven using a 904b jackhammer. The piles were located as shown on the attached Figure 1. The final location for pile P2 was moved approximately 12 inches east of the planned location. because an obstruction was encountered at a depth -- M m of about 13 feet below the top of the floor slab at the .planned v Cn :. location. Piles P 1 and P2 were driven to final depths of 30 feet and ,.. ' d_ n m s .,.-= 29 feet, respectively, below the top of the garage floor slab, rnCh The piles encountered very easy driving conditions to a depth of 84, ' z ` about 20 feet below the floor slab. ' The pile driving behavior suggests v: ` ~ 4` _ `}tj M the possible presence of 4-6 inch voids to depths of about 10-15' Pin Pile Installation below the floor slab, as the piles appeared to drop under their own Z weight intermittently in this depth range. Below 20 feet, the piles drove progressively slower until they _ reached the refusal criteria of 1 inch in 60 seconds. Actual final driving resistance observed for P1 and P2 was V4" and '�2" per 60 seconds, respectively. Based on the final driving resistance, these piles are adequate Z for supporting 2 tons of axial compression with a factor of safety of at least 2. m Sinkhole Configuration: The size and configuration of the sinkhole did not appear to have changed since our field visit on August 8, 2004. Dimensions of the hole just above the water line (maximum observed lateral extent) are included on Figure 1: The water surface was approximately 55 inches below the top of the garage floor slab (no noticeable change from Monday's measurement, as noted in our August 9, 2005 memorandum). The depth appears to vary somewhat across the base, but is difficult to delineate due to the water in the bottom of the. hole. Directly below the undermined garage footing, the bottom of the hole was f! about 6'%2 feet below the top of the garage floor slab. 1 Utility Line Location: Based on conversations with Molly Forssen and Dave Enright from Applied Professional Services (APS), we understand that APS was on site on August 9 to inspect the sewer lateral with a video camera and confirm its location relative to the sinkhole. Based on the results of the inspection, t t { s s i i i ! D�fILDI�� n � Geotechnical and Earthquake Engineering Consultants MO F-11 RA 3414 NE 55th Street Project No. Page No. Seattle, WA 98105 05-124 1 of 2 Tel: (206) 262=0370 Fax: (206) 262-0374 Report No. Date / Day of Week . 2 October 12, 2005 / Wednesday Project Name (Location or Address Forssen Residence - Sinkhole Remediation 730 Elm St, Edmonds, WA Owner's Representative Weather Carl and Molly Forssen Permit No.. Cloudy, light showers, mid 60s Z Client Contractor PanG)EO Field Rep: same McDowell NW Pile King Tiffany E. Adams, P.E. n PanGEO was on site as requested from 5:30 am to 1:20 pm to monitor the injection grouting, beneath the r" sinkhole. General recommendations for injection grouting were outlined in our report dated September 15, .�mn 2005. The following observations were made: i am Sinkhole Configuration: The size and configuration of the sinkhole did not appear to have changed since m v our last visit on August 16, 2004. The water surface was approximately 54 inches below the top of the n garage floor slab (no noticeable change from our previous measurements). The depth of the sinkhole varies = m somewhat across the base, but is difficult to delineate due to the presence of the garage floor slab over the m Z southern portion. However, the base of the southern portion of the sinkhole appeared to be slightly above c Z the water level within the hole, while the northern portion appeared to vary between 64 and 70 inches _ below, the driveway pavement. Cft Injection Grouting Under the Drivewtay: A -Pro drove a 2 -inch mn diameter galvanized steel pipe to a depth of about 20 feet at a location mm approximately 6 feet west and 8 feet north of the spread footing in the o center of the sinkhole, where a slight surface depression was N observed on the driveway pavement (within 1 ft of our test boring, �,, K CO BH -2). The pipe was driven using a 1404b pneumatic hammer and the pipes encountered difficult driving condition in the upper 10 ft of driving and very easy driving conditions from 12 ft to the final depth _ of 20 feet (behavior indicating void was not observed during driving). Injection Grouting at Hole in z Threaded couplers were used to connect the 4 ft long pipe segments Driveway Pavement > .� and end of the pipe was plugged during driving using a slip4n coupler. The pipe was then pulled up approximately 1 foot, to a tip depth of about 19 feet below the Z driveway pavement, in order to un -plug the end of the pipe. Approximately 1 cubic yard of a fluid clay- 0_ cement grout was pumped into the pipe. During pumping of the grout, bubbles were noted in the, northwest m m corner of the sinkhole. Towards the end of pumping at this location, the bubbles at the northwest corner had subsided somewhat and bubbles. The pressure gage on the grout pump indicated about 50 psi of pressure (with about 75 psi during each stroke) at the end of grouting. A -Pro attempted to pull up the pipe in order to pump grout again at a shallower depth. A -Pro was unable to pull out the pipe. The pipe was cutoff at the ground suuface, and then driven using the pneumatic hammer until the top of the pipe was approximately 12 inchs below the top of the driveway pavement. i Injection Grouting Under the Sinkhole: A -Pro drove a 2minch diameter galvanized steel pipe to a depth ' of about 18 feet within the northern portion of the sinkhole. The pipe was driven using a 140-1b pneumatic hammer and the pipes encountered very easy driving condition to the final depth of 18 feet (behavior indicating void was not observed during driving). Threaded cou lers were used to connect the 4 ft long E0/Z0 39dd 'ONI `039NVd t7LEOZ9Z90Z . ES :0Z S00Z/Et/0 C �.. i .. � i 10 C O•• O g A T• O �O - Geotechnlcal and Earthquake Engineering Consultants 3414 NE 55i° Street Project No. Page No. Seattle, WA 98105 05424 1 of 1 Tel: (206) 262-0370 Fax: (206) 262=0374.. Report No. Date /.Day of Week 3 October 19, 2005 / Tuesday. Project Name Location or Address Forssen Residence ..Sinkhole Remediation 730 Elm St, Edmonds, WA Owner's Representative Weather - Carl and Molly Forssen Permit No, Cloudy, mid 60s Z r Client Contractor PanG)EO Field Rep. O same A -Pro Tiffany E. Adams, P.E. PanG EO was onsite as requested from 2:30 pm to 3:30 pm to observe the backfilling of the sinkhole: The m folloAving observations were made: Pin Pile and Grade Beam Isolation: When I arrived on site, Randy Jeffries from A -Pro had already in encased the portion of the pin piles that extended through the sinkhole in corrugated plastic pipe: In C o10, addition, the open flanges of the grade beam had been filled with foam -board to prevent the CDF backfill 0 from adhering to the beam. In order to resort support to the concrete floor slab and asphalt pavement on top o of the beam, it was decided that the, sinkhole would be backfilled with CDF and foam board would be m z the CDF on inserted along the sides of the beam and concrete footing to provide a bond breaker between c z ' top of the beam and the rest of the GDF backfill in the sinkhole. CDF Backfill: Approximately 7 cubic yards of CDF was placed in0 Mn ;'!{ the sinkhole by free -fall method. The CDF was sluiced into the soft and loose soils at the base of the sinkhole and vibrated to improve the _ flow of the CDF underneath the concrete slab. Foam board was m. m o� inserted into the CDF along the sides of the grade beam and garage O footing once backfilling was complete. m French Drains VVe understand that the Forssens are planning to z0 install a French drain along the west side of the house foundation, as gond breakers installed around X recommended in our October 12 field report. Itis our opinion that _ the installation of the drain can be completed at a later date, provided pin piles and grade beam z I that water inflow into the garage remains minimal. _ z O. This completes our involvement at the site. QUILbING m O C T 2 0 2005 i PanGE& TECHNICAL MEMORANDUM 01 • • • • • , d • Geotechnical 6 Earthquake Engineering Consultants TO: Carl and Molly Forssen CC: Jeannine Graf (City 'of Edmonds) John Griffin (John D. Griffin Engineers) John McDowell (McDowell N.W. Pile King) PREPARED BY: Tiffany E. Adams, P.E. Z MICROFILM �A � 0_ , REVIEWED BY: Siew L. Tan, P.E. S�c� MICROFILM � Z � m ` SUBJECT: Geotechnical Assessment Sink Hole Remediation N c m 730 Elm Street, Edmonds, Washington ma -1 O PROJECT NO.: 05-124 mz DATE: August 92 2005 Q D Z r_. _ As requested, PanGEO, Inc. (PanGEO) visited the site on August. 8, 2005 to evaluate the Cn condition of a sink that developed on the property. Summarized below are our field on O �t observations, our recommendations for providing support to the house, and I' recommendations for additional geotechnical evaluation _ ' rn rn. O r- 5 0 mC CD. SINK HOLE DESCPIIP'TION , r m 0. We understand that the that you first noticed a � small depression in the asphalt pavement in front of your garage about 10 days ago, and. that you wMi broke through the asphalt pavement to expose the underlying void on August 7, after. significant 1 Z _ cracking of the pavement had developed. t CD z Based on observations made during our August O 8, 2005 site visit, the sinkhole measures about 9 ci. feet in diameter with a depth of about 6 feet. The ' m column footing in the middle of the garage is completely undermined by the sinkhole. ' Plate i. Sink Hole Location The sidewalls of the hole appear to be standing ; near -vertical and the exposed material consists of silty sand with gravel and fine roots. About 12 to 18 inches of standing water was in the R E:1 V. E x3414 N.E. SS" Street Seattle, WA 98105 AUG Q S ZUUn (206) 262=0370 FAX (206) 262-0374 DEVELC TY N E SERVICES S CTR- OF �nH� 1NT `rl�nNi7�l VLE0Z9Z90Z GT:8T S00Z/60/86 i i 730 Elm Street, Edmonds, WA August 9, 2005 Page 2 of 3 bottom of the hole. The water appeared to be stagnant and. ria odor was identified coming from the hole. No cracks were observed in the concrete floor slab of the garage, and we do did not observe any visible signs of settlement of the garage footingdo. During our site, an attempt was made to determine whether this sink hole was utility related. A representative from the City of Edmonds sewer department was on site during our visit and he indicated that the sewer lateral p for this residence is located near the west � n do I property line, away ftom the sinkhole. In M addition, we spoke with a representative from the City of Edmonds water department who ION stated that the instrumentation on the water v do I meter indicated that there was no leak in the Platen. Approximate extent of sinkhole al, marked in blue. 0 water later��, O C E ddd MENDATIONS m Z RECOM � inion it is imperative to provide support to the undermined a Z Project Approach - In our op Pe rI add = column footing as soon as feasible, to alleviate undue increase in stress in the structure and to minimize the risk of damaging the house. Because of the need to restore thefood foundation support for the house, we recommend atwo-phase approach. Phase I will be k installation of driven steesmall l pin piles to underpin the footing. The use of pin piles is recommended because its installation can be accomplished from the ground level and mm, a CA without major site preparation work. After the footing is underpinned, the pavement n m around the sink hole will be partially removed and a backhoe test pit will be excavated to Cn do expdo lore the subsurface soil conditions and to assess the cause of the sinkhole. Based. on do �... f Zr the results of the exploration, PanGEO will provide additional recommendations for backfilling the sinkhole.to restore the support for the concrete slab and pavement. y X . Pin Piles add All piles shall be galvanized extra strong (schedule 80) steel pipes. 2- ; inch diameter pin piles are typically installed with a 90 -pound tackhamtner, and can ado safely support 2 -tons per pile with an approximate factor of safety of 2 when driven to X practical refusal (less than l inch of penetration for I minute of continuous driving)• The Z do number of piles required should be determined by the project structural engineers Installation of 2 -inch pin piles shall be monitored by PanGEO to verify that the driving m criteria are met for each pile. do _dov' RECEIVE®do , do AU or do DEVELOPMENT SERVICES OTR. rPanG£O, Inca rr OS -12a Toch Memo No l.doo CITY OF EDMONDS 0 nanNH.4 b/_E0Z9Z90Z 6Z :81 S00Z/60/80 ; . JOHN GRIFFIN ENGNRS 4Y5 liY 1 S410tf r . iuvJc p Lam, i, JOHN D IFFIN ENGINEERS, INC. JOB_ _^� J`�� h�eop M0�5 r Consulting Engineer / , , r ire Avenue NE si'ieET �Jo. rJ — - OF Iyv L N GTON 98034 �, �— �� �r 0%,x(425) 821-9408 cni.ru�aTEDeY DATE CHECKED OY__. DATEWALE ' 3 CONAL �K' �1ao(L I i WAILL DLI I� .} lob 1210 ^ 420 z _ o piP_IRES Ott'w PL 0 4' g 14 -_ y. ID (pts -, co � gat . c_ am I��%�C�(? �� I m p_ t� �I? I n 2�I0 a �� 2, ✓ I I I m z -CZ D aNlI ` REGEwED J. � 4. po 0 rh� 14 mm r ` • / DEVELOPMENT SERVICES CTR, p yV i�'' �J �' CITY OF EDMONDS Cmi �W . , _� � I cl hIN•K � � o I' I ro`''( I it l' (vKGK� s� ll�i C X ° . 'i i 1. r i ....F� �I• I•�w I � , ' rpp Ido '(m6 IF-IS"ALdWL •:I" ! �- /r -` P, ew TeGf4 prooc MOIL , , MTo l 730 Elm Street, Edmonds, WA August 9, 2005 Page 2 of 3 bottom of the hole. The water appeared to be stagnant and no odor was identified coming from the hole. No cracks were observed in the concrete floor slab of the garage, and we did not observe any visible signs of settlement of the garage footing. ' During our site, an attempt was made to determine whether this sunk hole was utility related. A representative from the City of Edmonds sewer department was on site during ZO our visit and he indicated that the sewer lateral -� n for this residence is located near the west *; M property line, away from the sinkhole. In 5 addition, we spoke with a representative from t the City of Edmonds water department who N =. stated that the; instrumentation on the water crn meter indicated that there was no leak in the Plate 2. Approximate extent of sinkhole O water lateral. marked in blue. O c rnM RECOMMENDATIONS C Z D. Project Approach - In our opinion, it is imperative to provide support to the undermined _ column footing as soon as feasible, to alleviate undue increase in stress in the structure and to minimize the risk of damaging the house. Because of the need to restore the I foundation support for the house, we recommend a two-phase approach. Phase I will be installation of driven steel pm.piles to underpin the footing. The use of in piles is m rn pp• rp g P� P• recommended because its installation can.be accomplished from the ground level and 10 r without major site preparation work. After the footing is underpinned, the pavement N around the sink hole will be partially removed and a backhoe test pit will be excavated to r m n explore the subsurface soil conditions and to assess the cause of the sinkhole. Based on -Zi the results of the exploration, PanGEO will provide additional recommendations for' backfilling the sinkhole to restore the support for the concrete slab and pavement. f _ m Pin Piles All 24nch piles shall be galvanized extra strong (schedule 80) steel pipes. 2- ! _ - inch diameter pin piles are typically installed with a 90 -pound jackhammer, and can N safely support 2 -tons per pile with an approximate factor of safety of 2 when driven to ZO practical refusal (less than l inch of penetration for l minute of continuous driving). The -� number of piles required should be determined by the project structural engineer. rn Installation of 24nch pin piles shall be monitored by PanGEO to verify that the driving criteria are met for each pile. i 05-124 Tech Mcmo No I.doc PanGEO, Inc.. i - ■ c o■• o w w r a o Geotechnical and Earthquake Engineering Consultants 3414 NE 55`x' Street Project No. Page No. Seattle, WA 98105 05-124. 1 of 2 Tel: (206) 262-0370 Fax: (206) 262-0374 Report No. Date / Day of Week 1 August 10, 2005 / Wednesday Project Name Location or Address Forssen Residence — Sinkhole Remediation 730 Elm St, Edmonds, WA Owner's Representative Weather Carl and Molly Forssen Permit No. Cloudy, mid 70s Client Contractor PanGEO Field Rep. ! Z. same McDowell NW Pile King Tiffany E. Adams, P.E. O n rn PanGEO was on site as requested from 10:20 am to 1:50 pm to monitor the installation of pin piles for Mn underpinning the garage footing that was undermined by the sinkhole. Recommendations for pin pile =t installation were outlined in our memorandum dated August 9, 2005. The following observations were to OM made: Ma n in Pile Installation* McDowell NW Pile King installed two 24nch -t ` Pnsaaion� ;f ' :XM diameter pin piles at the. site. The piles consisted of schedule 80 _ _ m z galvanized pipe and were driven using a 904b jackC hammer. The A z piles were located as shown on the attached Figure 1. The final location for pile P2 was moved approximately 12 inches east of the <n i OM . planned location because an obstruction was encounteredat a depth --i -n r . of about 13 feet below the top of the floor slab at the planned Mm location. Piles P 1 and P2 were driven to final depths of 30 feet and — O to 29 feet respectively, below the top of the garage floor slab. t b� F c The piles encountered very easy driving conditions to a depth of _ c CO about 20 feet below the floor slab. The pile driving behavior suggests L "'_ r z n. the possible presence of 4-6 inch voids to depths of about 10-15' Pin Pile Installation below the floor slab, as the piles appeared to drop under their own 70 weight intermittently in this depth range. Below 20 feet, the piles drove progressively slower until they X. reached the refusal criteria of 1 inch in 60 seconds. Actual final driving resistance observed for P 1 and P2 z was 1/4" and `/z" per 60 seconds, respectively. Based on the final driving resistance, these piles are adequate Co for supporting 2 tons of axial compression with a factor of safety of at least 2. z 0 Sinkhole Configuration: The size and configuration of the sinkhole did not appear to have changed since m our field visit on August 8, 2004. Dimensions of the hole just above the water line (maximum observed lateral extent) are included on Figure 1. The water surface was approximately 55 inches below the top of i the garage floor. slab (no noticeable change from Monday's measurement, as noted in our August 9, 2005 memorandum). The depth appears to vary somewhat across the base, but is difficult to delineate due to the water in the bottom of the hole. Directly below the undermined garage footing, the bottom of the hole was about 6'/2 feet below the top of the garage floor slab. I Utility Line LocatioBased on conversations with Molly Forssen and Dave Enright from App n:lied Professional Services (APS), we understand that APS was on site on August 9 to inspect the sewer lateral with a video camera and confirm its location relative to the sinkhole. Based on the results of the inspection, i i i i I i i Project Name Location or Address Forssen Residence — Sinkhole Remediation 730 Elm St, Edmonds, WA Owner's Representative Weather Carl and Molly Forssen Permit No. Cloudy, tight showers, mid 60s Z PanGEO Field Re Client Contractor p• O same McDowell NW Pile Kin Tiffany E. Adams, P.E. PanGEO was on site as requested from 8:30 am to 1:20 pm to monitor the injection grouting beneath the M sinkhole. General recommendations for injection grouting were outlined in our report dated September 15, =M 2005. The following observations were made: N Sinkhole Configuration: The size and configuration of the sinkhole did not appear to have changed since c o our last visit on August 16, 2004. The water surface was approximately 54 inches below the top of the n garage floor slab (no noticeable change from our previous measurements). The depth of the sinkhole varies ` O C somewhat across the base, but is difficult to delineate due to the presence. of the garage floor slab over the m z southern portion. However, the base of the southern portion of the sinkhole appeared to be slightly above . A -i the water level within the hole, while the northern portion appeared to vary between 64 and 70 inches � � below the driveway pavement. N O� injection Grouting Under the Driveway: A -Pro drove a 2 -inch diameter galvanized steel pipe to a depth of about 20 feet at a location m rn approximately 6 feet west and 8 feet north of the spread footing in the o v, center of the sinkhole, where a slight surface depression was �I c N observed on the driveway pavement (within 1 ft of our test boring) ; BH -2). The pipe was driven using a 140-1b pneumatic hammer and t z � the pipes encountered difficult driving condition in the upper 10 ft of driving and very easy driving conditions from 12 ft to the final depth of 20 feet (behavior indicating void was not observed during driving). Injection Grouting at Hole in Threaded couplers were used to connect the 4 ft long pipe segments Driveway Pavement t z and end of the pipe was plugged during driving using a slip -in _ coupler. The pipe was then pulled up approximately 1 foot, to a tip depth of about 19 feet below the i driveway pavement, in order to un plug the end of the pipe. Approximately I cubic yard of a fluid clay- o cement grout was pumped into the pipe. During pumping of the grout, bubbles were noted in the northwest m corner of the sinkhole. Towards the. end of pumping at this location, the bubbles at. the northwest corner had subsided somewhat and bubbles. The pressure gage on the grout pump indicated about 50 psi of pressure (with about 75 psi during each stroke) at the end of grouting. A. Pro attempted to pull up the pipe in order to pump grout again at a shallower depth. A -Pro was unable to pull out the pipe. The pipe was cutoff at the ground surface, and then driven using the pneumatic hammer until the. top of the pipe was approximately 12 inchs below the top of the driveway pavement. Injection Grouting Under the Sinkhole: A -Pro drove a 24nch diameter galvanized steel pipe to a depth of about 18 feet within the northern portion of the sinkhole. The pipe was driven using a 1404b pneumatic hammer and the pipes encountered very easy driving condition to the final depth of 18 feet (behavior indicating void was not observed during driving). Threaded cou lers were used to connect the 4 ft long �, -,rte stir n�aNHa I?LE0Z9ZgAZ ESOOT S00Z/ET/0T \0 r. 8 w c o w r a 0 A r• O �� Geotechnical and Earthquake En Ineerin Consultants 3414 NE 55* Street Project No, Page No: Seattle, WA 98105 05424 1 of 1 Tel: (206) 262-0370 Fax: (206) 262-0374 Report No. Date ! Day of Week 3 October 19, 2005 / Tuesday Project Name Location or Address Forssen Residence Sinkhole Remediation 730 Elm St, Edmonds, WA is Owner's Representative Weather Carl and Molly Forssen Permit No. Cloudy, mid 60s zOr I Client Contractor PagG1EO Field Rep. sante A-Pro Tiff E. Adams, P.E Orr n PanGEO was on site as requested from 2:30 pm to 3:30 pin to observe the backfilling of the sinkhole. The M following. observations were made: -n Pin Pile and Grade Beam Isolation: When I arrived on site, Randy Jeffries from A-Pro had already o encased the ortion..of the pin piles. that extended through the sinkhole in corrugated plastic pipe. In rn P v addition, the open flanges of the grade beam had been filled with foam-board to prevent the CDF backfill -� n from adhering to the beam. In order to resort support to the concrete floor slab and asphalt pavement on top of the beam, it was decided that the sinkhole would be backfilled with CDF and foam board would be m M inserted along the sides of the beam and concrete footing to provide a bond breaker between the CDF on. c — �. z top of the beam and the rest of the CDF backfill in the sinkhole. CDF Backfill Approximately 7 cubic yards, of CDF was placed in rn PP Y Y �tlr : , o e4all method. The CDF was sluiced into the soft the sinkhole b fre and loose soils at the base of the sinkhole and vibrated to improve the Mm flow of the CDF underneath the concrete slab. Foani board was inserted into the CDF along the sides of the grade beam and garage c M footing once backfilling was complete. m to L: O French Drain: We understand that the Forssens are planning to -zt install a French drain along the west side of the house foundation, as X' g Bond breakers installed around recommended in our October 12 field report. It is our opinion that completed at a later date provided pin piles and grade beam f Z the installation of the drain can be , p that water inflow into the garage remains minimal,Cn y This completes our involvement at the site. 0 BUIOLDING M OCT 2 0 2005 i � f aVV V Signed: /R7./AT Ira/Ira 7[1HroJ ",WT 'fl��1NH,J ti/FL1747gC117 7.A :FT gGiA7. 730 Elm Street, Edmonds, WA August 9, 2005 Page 2 of 3 bottom of the hole. The water appeared to be stagnant and no odor was identified coming from the hole. No cracks were. observed in the concrete floor slab of the garage, and we did not observe any visible signs of settlement of the garage fooling: . During our site, an attempt was made .to determine whether this sink hole was utility related. A representative from the City of Edmonds sewer department was on site during - z our visit and he indicated that the sewer lateral for this residence is located near the west m property line, away from the sinkhole. In addition, we spoke with a representative from �_ n the City of Edmonds waxer department who N v m. stated that the instrumentation on the water C v meter indicated that there was no leak in the Plate 2. Approximate extent of sinkhole p water lateral. marked in blue. O C rn mz RECOMMENDATIONS C 2 Pro'ecE A roach` - Tu our opinion, it is imperative to provide support to the undermined _ J PP column footing as soon as feasible, to alleviate undue increase to stress in the structure to and to minimize the risk of damaging the house. Because of the need to restore the r j foundation support for the house, we recommend a two approach. Phase I will be _ rn m installation of driven steel pm piles to underpin the footing. The use of pin piles is recommended because its installation can be accomplished from the ground level and O N. r the footing is underpinned, the pavement rn C� without major site preparation work. Afte around the sink hole will be partially removed and a backhoe test pit will be excavated to } z r d to assess the cause of the sinkhole. Based on explore the subsurface soil conditions an the results of the exploration, PanGEO will provide additional recommendations for backfilling the sinkhole to restore the support for the concrete slab and pavement. D. Z , Pin Piles - All 2 -inch piles shall be galvanized extra strong (schedule 80) steel pipes. 2- 4 i inch diameter pin piles are typically installed with a 90 -pound jackhammer, and can CO -. safely support 2 -tons per pile with an approximate factor of safety of 2 when driven to z practical refusal (less than I inch of penetration for l minute of continuous driving). The O number of piles required should be determined by the project structural engineer. .rn Installation of 2 -inch pin piles shall be monitored by PanGEO to verify that the driving criteria are met for each pile. PanGEO, Inc, 05424 Tech Memo No' Ldoc , W C o ft r o w wino Geotechnical and Earth uake Engineering Consultants 3414 NE 55h Street Project No. t�a� Page No. Seattle, .WA 98.105 05-124 I of 2 Tel: (206) 262-0370 Fax: (206) 262-0374 Report No. po Date / Day of Week. 1 August 10, 2005 / Wednesday Project Name Location or Address Forsscn Residence — Sinkhole Remediation 730 Elm St, Edmonds, WA (Owner's Representative Weather Carl and Molly Forssen Permit No. Cloudy, mid 70s 2 Client . Contractor PanGEO Field Rep. O0 same McDowell NW Pile Kin Tiffany E. Adams, P.E. n M PanGEO was on site as requested from 10:20 am to 1:50 pm to monitor the installation of pin piles for underpinning the garage footing that was undermined by the sinkhole. Recommendations for pin pileCn installation were outlined in our memorandum dated August 9, 2005. The following observations were m o made: M O On Pin Pile Installation: McDowell NW Pile King installed two 2 -inch ` —� ` diameter pin piles at the site. The piles consisted. of schedule 80 Q -Zi galvanized pipe and were driven using a 90-1b jackhammer. The _ Z piles were located as shown on the attached Figure 1. The final location for pile p P2 was moved approximately 12 inches east of the --; 0M mn planned location because an obstruction was encountered at a depth I of about'l 3 feet below the top of the floor slab at the planned , _ M P 71 mo ai location. Piles PI and P2 were driven to final depths of 30 feet and 29 feet, respectively, below the top of the garage floor slab. T O.m i r it mZ.C CA The piles encountered very easy driving conditions to a depth of K co MO about 20 feet below the floor slab. The pile driving Z P g behavior suggests � �-.. � the possible presence of 4-6 inch voids to depths of about 10-15' P Pin Pile Installation below the floor slab, as the piles appeared to drop under their own ' weight intermittently in this depth range. Below 20 feet, the piles drove progressively slower until they l Z reached the refusal criteria of 1 inch in 60 seconds. Actual final driving resistance observed for PI and P2 _ was %4" and %2" per 60 seconds, respectively. Based on the final driving resistance, these piles are adequate co for supporting 2 tons of axial compression with a factor of safety of at least 2. O 0 Sinkhole Configuration: The size and configuration of the sinkhole did not appear to have changed since m our field visit on August 8, 2004. Dimensions of the hole just above the water line (maximum observed lateral extent) are included on Figure 1. The water surface was approximately 55 inches below the top of the garage floor slab (no noticeable change from Monday's measurement, as noted in our August 9, 2005 memorandum). The depth appears to vary somewhat across the base, but is difficult to delineate due to the water in the bottom of the hole. Directly below the undermined garage footing, the bottom of the hole was about 6'/s feet below the top of the garage floor slab. i Utility Line Location: Based on conversations with Molly Forssen and Dave Enright from Applied Professional Services (APS we understand that S )� t AP,. was on site on August 9 to inspect the sewer lateral with a video camera and confirm its location relative to the sinkhole. Based on the results of the inspection, 4 S: 1 i r t r GE@) L�bnl L . 1 R C o w i P R A• 7 b Gootechnical and Earth ueke EnginserIng Consultants 3414 NE 55`h Street Project No. Page No. Seattle, WA 98105 05.424 1 of 2 Tel: (206) 2624370 Fax: (206) 262=0374 Report No. Date / Day of Week 2 October 12, 2005 / Wednesday Project Name Location or Address Forssen Residence — Sinkhole Remediation 730 Elm St, Edmonds, WA Owner's Representative Weather Carl and Molly Forssen Permit No. Cloudy, light showers, mid 60s Client Contractor PanGEO Field Rep. same McDowell NW Pile King Tiffany E. Adams, P.E. PanGEO was on site as requested from 8:30 am to 1:20 pm to monitor the injection grouting beneath the sinkhole. General recommendations for injection grouting were outlined in our reportdated September 15, 2005. The following observations were made: Sinkhole Configuration: The size and configuration of the sinkhole did not appear to have changed since our last visit on August 16, 2004. The water surface was approximately 54 inches below the top of the f somewhat across the base, but is difficult to delineate due to the presence of the garage floor slab over the southern portion. However, the base of the southern portion of the sinkhole appeared to be slightly above the water level within the hole, while the northern portion appeared to vary between 64 and 70 inches below the driveway pavement. Injection Grouting Under the Driveway: A -Pro drove a 2 -inch diameter galvanized steel pipe to a depth of about 20 feet at a location approximately 6 feet west and 8 feet north of the spread footing in the center of the sinkhole, where a slight surface depression was observed on the driveway pavement (within I ft of our test boring, BH -2). The pipe was driven using a 1404b pneumatic hammer and GE@) L�bnl L . 1 R C o w i P R A• 7 b Gootechnical and Earth ueke EnginserIng Consultants 3414 NE 55`h Street Project No. Page No. Seattle, WA 98105 05.424 1 of 2 Tel: (206) 2624370 Fax: (206) 262=0374 Report No. Date / Day of Week 2 October 12, 2005 / Wednesday Project Name Location or Address Forssen Residence — Sinkhole Remediation 730 Elm St, Edmonds, WA Owner's Representative Weather Carl and Molly Forssen Permit No. Cloudy, light showers, mid 60s Client Contractor PanGEO Field Rep. same McDowell NW Pile King Tiffany E. Adams, P.E. PanGEO was on site as requested from 8:30 am to 1:20 pm to monitor the injection grouting beneath the sinkhole. General recommendations for injection grouting were outlined in our reportdated September 15, 2005. The following observations were made: Sinkhole Configuration: The size and configuration of the sinkhole did not appear to have changed since our last visit on August 16, 2004. The water surface was approximately 54 inches below the top of the garage floor slab (no noticeable change from our previous measurements). The depth of the sinkhole varies somewhat across the base, but is difficult to delineate due to the presence of the garage floor slab over the southern portion. However, the base of the southern portion of the sinkhole appeared to be slightly above the water level within the hole, while the northern portion appeared to vary between 64 and 70 inches below the driveway pavement. Injection Grouting Under the Driveway: A -Pro drove a 2 -inch diameter galvanized steel pipe to a depth of about 20 feet at a location approximately 6 feet west and 8 feet north of the spread footing in the center of the sinkhole, where a slight surface depression was observed on the driveway pavement (within I ft of our test boring, BH -2). The pipe was driven using a 1404b pneumatic hammer and the pipes encountered difficult driving condition in the upper 10 ft of driving and very easy driving conditions from 12 ft to the final depth of 20 feet (behavior indicating void was not observed during driving). Injection Grouting at Hole in Threaded couplers were used to connect the 4 ft long pipe segments Driveway Pavement and end of the pipe was plugged during driving using a slip -in coupler. The pipe was then pulled up approximately 1 foot, to a tip depth of about 19 feet below the driveway Ipavement, in order to un -plug the end of the pipe. Approximately l cubic yard of a fluid clay - cement grout was pumped into the pipe. During. pumping of the grout, bubbles were noted in the northwest corner of the sinkhole. Towards the end of pumping at this location, the bubbles at the northwest corner had subsided somewhat and bubbles. The pressure gage on the grout pump indicated about 50 psi of pressure (with about 75 psi during each stroke) at the end of grouting. A -Pro attempted to pull up the pipe in order to pump grout again at a shallower depth. A -Pro was unable to pull out the pipe. The pipe, was cutoff at the ground surface, and then driven using the pneumatic hammer until the. top of the pipe was approximately 12inchs below the top of the driveway pavement. ,Injection Grouting Under the Sinkhole: A -Pro drove a 2 -inch diameter galvanized steel pipe to a depth of about 18 feet within the northern portion of the sinkhole. The pipe was driven using a 1404b pneumatic hammer and the pipes encountered very easy driving condition to the final depth of 18 feet (behavior indicating void was not observed during driving). Threaded couplers were used to connect the 4 ft long, ' - I' �� I ;; y' . i 1 l l i. i ,� r