Loading...
S-61-18.pdfH C �M `P. H tL L CONSULTING ENGINEERS 28 August.1981 Project,No. 5870 W D. o JAMES SMITH cD 22919 100th Avenue W'. o Edmonds, Washington 98020 ? W - m`> Reference:, Proposed house :located. at Lot 2 Block 2, Plat of a W z Seahurst, Edmonds, Washington. m 0 Q' JW 0 Subject: Soil and foundation investigation m a o On 18 August,at the request of James Smith, Dale Hemphill • + • .1981, of r HEMPHILL ASSOCIATES investigated the site: of the propo.s.ed' house to be located at Lot 2,: Block 2, Plat of S.eahurst in W Edmonds, Washington. `, The purpose of the investigation was to `❑ determine the stability of the slopes adjacentto the proposed LU (n house and the adequacy of the existing foundations. © z ❑. W E a Geologic research and a soil investigation at the: site revealed that the the soils are composed of silts, sands, and gravels that o c� have been. glacially compacted.. The slopes to the west above the z z W railroad tracks are approximatelyto.40'.degrees, are tree and o < F .30 shrub covered, and appear to be fairly : stable. There' is no c�,❑ m evidence of any instability. The steepest. slopes at the site are . to the north and northwe t. in a. gully that had. been formed -.by concentrated stormwater runoff. Some sl.opes..in the gully. CA z0 .w " vertical and: expose glacially compacted' silts, sands, . and gravels.' U Control of the stormwater, runoff --will nearly eliminate any future W a N heavy erosion in the: gully. Minor: erosion will continue to occur z z due to freezing and thawing and wetting and drying. The minor z w - erosion will be a slow" process. The eroded... soils and any minor Z. Z Ui slides resulting from undercutting of the slopes. ` will eventually. Q 10 ; build up a pile.of protecting -slough. The protecting slough will 0 Q protect- the slopes against the weathering processes. F o W < HEMPHILL estimates that under the worse conditions the eroding slopes `will 'never reach the proposed house unless the protesting slough is allowed to be washed away by uncontrolled` stormwater runoff., Z. o"W The natural type of erosion processes of the slopes in the gu11y LU will be show, and any undesireable loss of the adjacent yards z ❑ can be prevented in the future by several methods of protecting. Q a the slopes.: Z Z 0 ' " Q Z .. :: . LLIDJ ORT 1 1 . • 4812 170th PLACE N. E. 0 REDMONO, WA.. 2B052.8 [2O6] ,BB3 3924 Sa Hong Consulting Engineers • Geotechnical Engineering • Material Testing 9 Construction Quality Contras Inspection • INSPECTION REPORT 1-0 -X' - -' PROJECT: Mr. Jim Smith's Property LOCATION: Lot 2(Portion), 81k 2, Plat of Seahurst, Edmonds, Wash. JOB NUMBER: 80012 DATE: December 1, 1980 GENERAL CONTRACTOR: CONTRACTOR'S REPRESENTATIVE: OUR REPRESENTATIVE: SH On December 1, 1980, Sa Hong inspected the foundation of the subject house. At the time of the visit, the foundation piers had been installed and a -ll the spread footings poured. Sa Hong found that foundation piers were not installed along the vicinity of the bluff where the slide scars were noted. At -the time of the—field inspection with you, we were concerned _ about the piers_ not being -installed as shown on the drawing attached herewith... You reasoned that the drill rig could not be assessed to the.pile locations properly. In our ..s0-1 s. report,.. We recommended .to you .that the pi le installation should -be inspected at the--time.�f --pi_ r construction_ by a soils engineer. The reason behind the aforementioned recommendation was to solve any. construction problems..In this case, you had the machine accessibility _.di_fficuli_t.e When the machine could not accessed, we could have ---.--....Anstall-ed.. more. -piles along the edge. of the bluff or modily the footing Sys -tem...... To ensu.re..the ~building safety against erosion. and slide we recommend-,.-.. i s be installed aloe the bluff before the occu an dd t��xgR lr...p� ice_.:.. ...., .._ 9 ..:._.-� _. P__.._c.Y The depth should be Bauch deeper than the existing pile you installed _In addition, the soil report called for a minimum 40' set back „from , the -Al 1de area.__Now your building footings were placed approximately 3,0.'..-.i nstead of 40'. This is a deviation from our soil report. PAGE. I.. OF 2 17809 55th Pl. W., Lynnwood, WA 98036 (206) 743-4774 Sa Hong Consulting Engineers • Geotechnical Engineering • Material Testing • Construction Quality Control Inspection • INSPECTION REPORT PROJECT: _Mr. Jim Smith's.Property DATE: December 1, 1980 LOCATION: Lot 2 (Portion), Bl k 2, Plat otE:NERAL CONTRACTOR: Seahurs.t,. Edmonds, Wash. CONTRACTOR'S REPRESENTATIVE: JOB NUMBER: 80012 OUR REPRESENTATIVE: SH. V We also redommend the toe of the s1Ope_ SliolJl.d bo.. reg nfnrr�a� i.",.F� either binwa11 or reinforced ear#h,,;,,The detailed design should.be requested by you to this office. We would not warrant any part of your structures that are not built .in accordance with our recommendations. This letter should be reported .to the Building Department, City. of Edmonds by the owner, and also should be reported to the future ..buyer of the property. Should any--question--anise., please contact this office at your -. convenience....., 17809 65th Pl. W., Lynnwood, WA 98036 • (206) 743-4774 BUILDING DEPARTMENT Sheet INSPECTION REPORT CITY OF EDMONDS PERMIT NUMBER PROJECT INSPECTOR ADDRESS ry-) ri( VA tr' i. t • 5�. DATE E INSPECTION (�zj;1oo - M': iSP DESCRIPTION j\AST W IT)4 AAP- 7A iAc)lJ C �� � �jc�LS ►2 t'��2� i7�, tj GYTu��l2 QPI { 98,o . }a� Act AT T1.4l-7-- f P-'R►2�D `ice TZZ%, R: - V\k5 i2�lPo2T CoQc- -Tb OF D� c XXQ,0 To bE-: voce V1 GD W iTHw T r --h m rc n vi- 1 V3 -,:, vC tm' ':5Aaorta1E kA\6N 4:- T1a V1 !! 0 F ►J W v5va—CAtI�,s ' 'SLT1c�fi.L� CJ —% 1 V -S &L-Ck AL- o(L- � aUtNv GAucu(-t: Tio �jS� owEVG12 ��k0f2� 1O V:k k;AU 9)P{ -c -V P4-) AU- CSU -oma �c V? kP p- A-V t u C, KrT �5S iN tuvy ►-)S6,- KV-�-C> TVc-- C_!Ty , 1 Sa Hong Consulting Engineers • Geotechnical Engineering • Material Testing • Construction Quality Control Inspection • J 3, 198C - Olympc Properties, Inc. 2291.9. 10Oth ,. W-; Edmonds, Wash. 98020 Attention: Mr. James Smith Subject jingle Family Development at a Portion. of Lot 2 ..81k.. 2. ,Plat of Seahursr Edmonds, Snohomish County Dear Sir. In May, 1980, we frequently visited your aroperty at the suo.ect site_..whici^_1.s situated on the Puget Souna duffs, The purpos-s of this study a -e to investigate slope stab,lity conditions ayly 16 recommend foundation design parameters I. SITE CONDITIONS The topographic features noted on site are as follows: aj Rolling upland terrain b) Steep bank slope with an approximate angle of 50 degrees from the horizontal towards the railroad track at the toe of the slope �} Steep landslide scarps Although, the landslides are mainly confined ir, the adjacent property located north of the subject property, the slides are heading towards 17809 65th PI, W., Lynnwood, WA 98036 • (206) 743-4774 the subject property. Some parts of the slides have already encroached into your lot. The vertical bluffs in some locations are as high as 30 feet. The total height of the bank is approximately 90 feet. Lovell Sauerland and Associates have conducted topographic surveying on the site as shown in Figure 1. A slope profile was developed based on the topographic measurements, as shown in Figure 2. As is evident from Figure 2, the slide debris composed of loose sand still exists on the -slope, indicating that the debris movement could occur at anytime. A storm drainage line constructed with corrugated metal pipes is located along the north side of the property. The outfall of the pipe is directly discharging at the toe of the slope, causing slope washing and undercutting the bank. We have advised Mr. J. Smith that this condition should be stopped by placing riprap and chute, since another slide could occur when the erosional condition persists in the area. We believe that the erosional undercutting was the major cause of the landslide in this area. You should contact adjacent property owner and discuss the problem as soon as possible. So far the main slide occured in your adjacent property located north of the subject site. II. SUBSURFACE SOIL CONDITIONS • The soils examined on the basis of soil exposures on steep slide scarp indicated that the on-site subsoils were mainly composed of compact to dense fine to medium sand(Esparance sand unit). Some groundwater seepage was noted from the sand layers. It should be realized that the sand layer exposed on the weathering can erode very fast. - 2 - III. RECOMMENDATIONS 3.1. CAUSE OF SLIDE The major slide in the area occured from the surface water erosion. Urbanizations along the steep slope in the vicinity of the subject property would have increased the storm water runoffs to the slope. The concentrated runoffs were dischargdd on a relatively steep slope. Consequently, the slope erosion would have inevitably occured, to cause gullying, undercutting, and sliding. Presently a tight -line carries water from the top of the bank to the toe of the slope where Burlington Railroad track exists. It is our opinion that, before the construction of the line, the slope was scoured.. and slided at very fast rates from the uncontrolled runoffs for a long time. After the construction of the tight -line, the rate of slide would have been decreased at a very slow rate. But the undercutting still occurs at the outfall of the tightline. In the future, if uncontrolled runoffs occur from any erosion such as storm drainage failure, or water main failure, there will. be another big loss of the ground. 3.2. FUTURE SLOPE CONDITIONS The slope angle will eventually recede to a 45 degree angle from the horizontal in the future, if the slopes are adequately protected from the surface water runoff. erosion. To control the runoffs, the surface water should be collected, and flow through a tight line to the toe of the slope. The existing storm drain outfall from the existing pipe. tend to cut the slope in the toe area of the bank. Therefore,-riprap should be constructed to prevent the future erosion as soon as possible. - 3 - The slope absenting vegetation cover due to the slide should be seeded or planted with vegetation so that no soil particles are consistently washed away by the rain. The owner should consult with landscape consultants to obtain a vegetation type and a method of planting. If, after the building construction completion, another major erosion occurs due to uncontrolled runoffs, then the damaged slopes should be restored by properly engineered structures such as gunite walls or bulkheads to prevent further erosion. To prevent the excessively expensive restoration work as described above, all the storm drainage systems in the area have to be inspected periodically. Any siltation in the drainage system. should be cleaned out so that the storm drainage systems are not clogged up. No existing vegetation cover on the slopes should be disturbed. In the slide area, the vegetation should be restored to alleviate future erosion. All the roof drain and surface water should be collected into catch basins and tight -line down to the slope. In our..opinion,_gunite... walls or bulkhead are not required at this time, if the slide preventive measures described above are applied. 3.3. FOUNDATION DESIGN PARAMETERS If the slide preventive measures discussed in the previous section are performed in a satisfactory manner, a building can be constructed with the following recommendations: a) The foundation should be set back at least 40 feet from the bluffs, providing that the bluffs side of the building be built on drilled piers as shown in Figure 2. - 4 - b) The back side of the building can be supported on spread footings with shear keys at 5 foot minimum depths. c) The shear keys and piers should be.structurally connected at the floor slab level so that should any potential lateral movements of the piers occur, the movements can be restrained by the structural connections between shear keys and piers. d) Spread footings can be designed on the basis of a bearing pressure of 2000 psf. e) The drilled pier. with 18 inch•in diameter can support 20 tons. The piers should be reinforced. IV. ADDITIONAL RECOMMENDATIONS The analyses and recommendations are formulated based on the site conditions as they presently exist. If, during construction, the site conditions are different from those encountered in this investigation, we should be notified so that we can review these conditions, and reconsider our recommendations wherever necessary. The owner should accept that any building built near the bluffs or steep slope involves some risk, during the service lifetime of the building. These unexpected conditions frequently require an additional expenditure to attain a properly constructed project. Therefore, some contingency fund should be made available to cover potential extra costs. This report is prepared for the exclusive use of the engineer, architect, and contractor, for specific application on this project in accordance with generally accepted soil and foundation engineering practice. No warranty, expressed, or implied, is made.. - 5 - In addition, geotechnical supervision is recommended, during the design and construction phase to insure that a safe, high quality construction is attained. Respectfully submitted, -9-a—H Hong, P.E. Geotechnical Engineer 9 � ass�arMrvo� • �h :� 9i %tiQAIAL 6 r � m m 70 r r l a" s r C7 O 3 a N LM �...{ M ko C)CDm-v ;a m �' m v rteC- > C - Al o -�-I cna-i a= s --A o m C-) rl C>CZ) mcn-nV) c ;a m mAr� �C-0QCC:) --q n a � Nt.0 nw 0 O � Co _0 (A s� Arm toe) ww C7 C7 7C �7 c ./ i J C)rrr"oory m All -- n 70 e Ca C� (D v a z ayo �� N m r cn ' C> 2 N m o CD � f mm � o C) m m z m Ca Q C7 C) C) N C7 ELEVATION IN FEET i _ , FOR JAMES A, SMITH EDMONDS, WASHINGTON DATUM: CIT`/OFEDMONDS (M.Lk..W.) L Lovell-Sauerland & Associates, Inc. S SURVEYORS • DEVELOPMENT CONSULTANTS • PLANNERS 23106 100TH AVE: W. • EDMONDS WA. 98020 • PHONE 775-1591 '\\ DRAWN CHECKEDDATE B. SCALE - FILE NO. ' o_oc_nn yen >Qn REZONING .. = SUBDIVISION- NA11,1E O 4 %] .,aa- AD3]RES o REQUEST FEE- s"}©, G RECEIPT NO DATE PROPERTY DESCRIPTION SKETCH: (Sketch of property to be rezoned. or. subd.ivid.ed showing streets, Property lines, etc.) 2�7z- RE kc) E � v E D 0 CT 6 1961 CITY. OF EDMONDS H,(••••'�.=••�-� GITY CLERK �M PLANNING COMMISSION November 6, 1961' Robert S. Bonney 18430 Olympic View Drive Edmonds, Washington Dear Mr. BonneyY I have been instructed to write you on behalf of the Edmonds Planning Commission to advise you that the sub -division of property for which you requested approval on October 6, 1961 -File #s.,18-61, has been approved by the Planning Commission) based on the sketch and legal descriptions which you submitted. Very truly yours, Nola Dougherty Secretary VDt�h sY ti' j� I 0 0 � h y . 2g•$G `� �v �os�.� c,. 00 REZONING. SUBDIVISION - NAME ADDRES 3 REQUEST -PLANNING C014DESSION APPLICATION 522 t2 el, �/ PHONE ee RECEIPT 140 DATE PROPERTY DESCRIPTION 4:5e —"I" —A. � �- SKETCH: (Sketch of property to be rezoned. or subdivided showing streets, Property lines., etc.) REHHED kL9 q (',T ii CITY OF EJ)MONDS BY., \ J TO: pity of Edmonds FRQ t Robext S. Bonney 4430 Olympic VI SW Drive Edmonds, ashingion R.;: Division following !Ott A Sec;, Zoe; thn -Blk Rge Road School 2 2 2/At 15 ED 1 IE: 3S 2= ON S LN SD 10T 2 491 � Z PROM Ski COR OD LUQ l YH W49 : TO U SW YOR TU 1� '�',.� Y CM V _ `: T viii` L0,T 3j0 TF sSEIZ DO PJB 1AS8 B14k O . Yr:LY div 30' NEly r'auW SKY UOR `iH&F TH C0511INFUE B1:11 1.5 2H SEIT TO IT ON KLM 95' E GP 'SISLY CUR, 11. jIY AT --G &A IV 461 '.Lr NWA 400 V/L . ID k, YT ILY IN 3b i West hot ALL flak, Pt)RTIOV UP LU1 2 Blk 2 D-2 P702 OF S�,ST, S1`TC- `f i 7?TC� 17 :�`3CT�i1 :F;D 1✓C1�t` ILiitTS: :3J';Cz_ l�T ; :tiG > it TEF, aw US CY SDAT 2 ";1 1 030191 L 454 TH >:i&Y 11 A P%` 6N S I (,1151 SD LOT 2 4 H1C 1 S �ti l.Y � ,�: ���.5 S IN OF SD ICT A i a 61 ' 95, FROM ` HE S4� C0R TH S 89042 & W A DIS OF 151 00 l�'( lJV-l.J .. X11.' 3l .tlV G '.t.il J.'i 9042. � 1 2460231 1.. O ":. 1 N800121 30 E%021 € 21 TH s' S01.? ° t 153,.0 R r1G. A PT OR WlY 1, a1W 01MIC RE Y ;-aL�111 '. .x�_z I_C, Ti IL;t .DRIVE 69.2' TH S 811421 W 147,731 � TO IPOB - tai IA W V}� -SKI Crr�r©n�Q�v�s L^ . BY:. ._3.1.., CfP O1. 2 .V]-X G L—G. OF �%t,.tia%4t1-- HO-PaIS� C0Ua `, WAS.",GTCN ��ri ? a'i. � a: c:C �2'. Gr .�D iC'�' 2H I"3 89°Q 2 ?3.246o 5°23 e L'U 1Ii , C'ti Fi hs i < X32 , j0" E^ ,i t 321 { IJ r3� r.i.. .FJ 153.0'-3.tL' .ba 1�iryi! '4ry:��i 1. rV ,YT _E.rEUir . il.[l. li .PJ . '�.J..L , IJ : .L. 4 1 ' Y7 Z"S 'jYrl I a., V .L.�J ii Lll i V ii 6 ' a . S 89042' W 147,731 :��_! "ITO"' - OCT G 196 .. CITY ©F' COMQN.DS i ,. October 5, 1961 T0: City of Edmonds FROM: Robert S. Bonney 18430 Olympic View Drive Edmonds, Washington RE: Division of following lot: Sec Lot Twp-Blk Rge Road School 2 2 2/Met 15 ED 1 D-2 PLAT OF SEAHURST LESS GAAP ON S IN SD LOT 2 491 E FROM SW COR SD LOT TH W 491 TO SD SW COR TH NELY ON W IN OF LOT 30t TSI SELY TO POB LESS BAAP ON WLY IN 30' NELY FROM SWLY COR THROF TH CONTINUE NELY 15'TH SELY TO A PT ON S.IN 95' E OF THE SWLY COR TH N1Y ALG THE S. LN 461 TH NWLY 404 M/L TO A, PT ON WLY IN 30t NELY OF THE SW COR OF SD LOT .& THE TPOB West Lot ALL THAT PORTION OF LOT 2 BLK 2 D-2 PLAT OF SEAHURST, SNO-. HOMISH CQUNW-, WASHINGTON LESS THE FOLLOWING DESCRIBED PORTIONS; BEGINNING AT THE.S_W__.... COR OF SD LOT 2 TH N 340191 E 45' TH SELY TO A PT -ON S IN OF' SD LOT 2 -WHICH IS NELY AIG THE S IN OF SD LOT A DIS OF 951 FROM THE SW COR TH S 89°421 W A DIS OF 95t TO TPOB -AM.-BEGIN AT THE SW COR OF SD LOT 2TH N 890421 E 2460231 TO THE TPOB TH N 800321 30'1 E 78.821 TH S 860171 E 153.01 TO A PT ON WLY MARGIN OLYMPIC VIEW DRIVE AS 1& 51'1 WLY `MARGIN .OIYFPIC VIE,fI DRIVE 69.2t TH S 89042t W 147-73T . TO TPOB D VCNW'E OCT 6 1961 CITY- Oy�FfJ EDMONDS BY........[ M..CITY R. S. Bonney 10/5/61 Page 2 East Lot THAT PORTION OF LOT 2 BLR 2 D-2 PLAT OF SEAHURST, SNO-- HOMISH COUNTY, WASHINGTON BEGIN AT THE SW COR OF SD LOT 2 TH N 89°421 E 2460231 TO THE TPOB .TH N 80032t3O" +' 78.821 TH S 86°17` E 153.01 TO A PT ON'WZY MARGIN OLYMPIC VIEW DRIVE TH S 15°511 W ALG WLY MARGIN OLYMPIC VIEW DRIVE 69.21 TH S 89°421 W 147.731 TO .TPOB RECEHED OCT 6 1961 CITYOFEDMONDS B..i<.:... r._._.......�........ CITY F K