17804 VISTA DEL MAR-Geotech letter.pdfI . NELSON GEOTECHNICAL
N G A AssoCIATE'-S, INC.
GEOTECHNICAL. ENGINEERS & GEOL.OGISTS
Main MOO
17311 - � 1W'Avemia NE� A-500
'A 98672
woodinvimi W
. (425):48&1669 FAX(425)4BI-2510
9, 20.13
21800. Nootka Road
Woodway,'Washington 98020
Construction Monitoring SummarYLet-tcr
wiffiams Regidonct
EAmands, W.&shington
NGA File No. 832.3BI I
Dear.ms. Williams: -
437 !��Penqy Road SCANNED
Wet-.wtcheb, WA 98801
(609) $66-7696 FAX(.509) 665r76q2JUL 08 2%
STREET FILE
We were requested by yom contractorRabloKearsley of Kearsley-HpMes td:prepare this summary letter
for your resid i�e pr Washington.
en ojectlocated at 1704 Vista Del 1, at, Drive in Edmonds,
Introduction
We wero retained to provide part-time, morutofing.and consultation sevices duriWz tbe caithw. rkphascof
cbristructionperlhe speciil*ln�pections,�iiidT�gtiiig-Alireeinentrequir&dby the City oflidmop.& (Pen -nit
No,20.11-0243).. Our eartbwork m0ait oringactivities at. the project. took place on a part-time basIs from
July r2,2011 through September 15, 2010 and included observing4bundation subgrade spit bearu'lg*
U servati,6hs
verifIcatiofi pi Imstallation, footing drain installation. and crosion Ontrol.rneasuies. 00 ob
er
and o Ions: WCV e documented in Field Reports I tffirou�,h 3, and, In memor-Indurn utled"Williahis
onalus'
Residence — briprovenient4% Recommendations Edmon&,. Washlqgton-'! date6 October I,-
2 0 2i till of which have I beerisubmitted to you. We PreviOUMY Prepared 0 9-c0technical engineering report.
nc -8 Vif el Mar
e p.r.ol)eily:t'tted!�GeotecimicaI FAigincering, Evaluation — Williams oside 0 — Lot sta 1)
d- We also prepke& a plan ieview,letterf6r the project
atedFebruaryll,2011,
dated June 17? 2011.
Construction Mionitoring Su3nmary Leqer NGA File No. U 23 BI I
February
william" Residence
Edmonds, Washi3igt(M, Affed
Site Observations
We monitored drilled pier in.stallation ar�tjvitjes on July 27, 2011 as docuiriented M. Field Rcl)o-.t 42. We
ob�erved the drilling of 14, 18-inch diarrieterhol0s advancedto depths of 20 to 23.5 fiTt below the ground
Ing
surface along the western, downhill side. or the residence, The holes were drilled vviih a large <1 ifli
ogly coris
i%��d of �rjwn-gr�jv, f7jile to medium sandi We did
ali,ger and the'sloil "posed Ln the cattings ni
riot observe evidence of caviOg Or 91"awidwater in the holes, bnt we did observe moist to wet, soil at tile
botk.)m of a, f.��w off the holm Afterrebar cages were lowered into the drilled l-iolcs, the- holes were
backfilled with structural concrete to 'Ile saale el I evation in each hole.
For aJ1 Other areas of the f0und.tition, we evaluated the subgrade using a 1/7-11'ach diameter probe rod linder
tyjodcrat.t,�, pressure. The exposed lburidatiOrl Soils consisted of native, browii�gray.. f tile to Modiurn sand to
saild with �ilt, which. we interpreted as We. foulld tbat the native subgradecould be penetrated
I ble
approxii-nately One to t'No "Aches. 'The subgrado -was inierpreted as mediurn dense to dense. s-ulial for
support of the platiried fouridation loads.
We also observed the iiistallation of the f6oling draii-is and drainage cx)mposite. The drains consisted of 4-
inch I -h, filter fabric. 'Me dra iris
I � perforated pipe;. whichwas; surrounded \vith crushed: rock and covered wit
appeared to be installed correctly and were loc3teet at or ricar tile, bottom of the footing. Priltia-P
coinposite had been installed along the iallor poillons of the retaiining: walls, The coiltractor ulfbi-illed us
t1lat tile roof dowrilspouts would not be connected to the fo,,,xing dmins, as We MOD-imended, in our
f4cotechnical reporL
we visited the site oil January 17. 2613: to observe tile f-111,1111ndscaping preparation, We observed that a
patio area Was beingy, created behind tile residence in the southern portioll of the hackyal-d, and tile. patio
subgrade appeared to be sloping away from the slope, Below the patio area, the ground slopes (]own for
about t1wee or four feel. to a small drainage ditch tha� was backfilled with bentonite to direct Water to a
�ulxsurface drain that Is conmected to the stormwater systwTi. Along tile top of slope, a short beran was
created to grade tile propej.iy back aw-ay from tile slope and to help preveialt water from flowilig Onto the
steep, slope. The liorthem portion of the backyard was graded rehatively flat and will be partially
vegetated. On the noahem sideof the house, a 4-inch perforatedlPVC drain was installed in a trench that
,was lined with Mter 11'abric wid backfillod with wastied. rook, Any water collected in this , pipe will be
directed to thestorrn system. During Our most recent site visit on Janivary 218, 2013, we observed that the
NELSON GEOTECHNICAL ASSOCIATES, INC.
Consiructlotl I Nionitorifl.c, Sulatuary Letter
Williams Residence
Fdmmds, Washingibn
NGA File No. 8323B I I
Febmary 8, 2013
]��a.Re '�
--------------- -------- -- ................ ----- ------
atiol ed throughout the backyard and side
"Indscapirig wa's all -most completod, We observed veget, .1 pla-lit
Val-& It was our Opinion that the erosion Control methods incorporated intothe lmi&cape desicyn aTe
adequate and should li.elplarevent surfaoe water rrom reaching thesteep slope.
S 4
, INED,
Jul, Y016
conelluslion
Based on our part-tilre Obselvatioas,it is our opirtioll that the carthwork activities At this site, including
r i i -n control inethods were
ell;ldential foundation subgrade, pier installation, siksurt"aCe drainage., and cros o
-1c
completed in general accordance with our rmommendations, contract lalans, and specffieafious� T-he 1 -w
I andscaped areas, and the steep slope should be closely nionitored for Any sigils of d.. If any distress
is observed, we, should be contacted. immediat6ly to ewaluate:the miditions And provide recommendations
for SIOPC 3-ej?airs. Also, long-terin maimenalice oftlx- drait"S and landscaped Areas is iniportant to prevent
water firoin flowing oVer' the slope at3d creating instabilty concerns. All other re�,,OmmendaUOIAS and
Peel-autions preSeated in our M-port and rimpo regarding mainta; in slope stability should be strictly
Sri -g�
followed, We reom-nmend that Our report. and:memci along with this letter be passed on to ftaure, holne
if the 10
owners 1 -1 use is sold.
0-0-0
NELSON GEOTECHNICAL ASSOCIATES, INC.
�Construction Monitoring Summary Letter
Unwiid- Wa fttton
p, sh
ROA Pile NO.. 8323.Bl I
Fobtu SCA;
ary 8 2013 -D
Page 4
JUL 0 8 2016
We appreciate t lic opportwity to be of service to.you oil this- ect. We consider our services -for. this
Pro)
projmt to be witplete, Unles.s. you spe(4i*1y contact. us f6t additional work. If you have. any. qumtions-
irec, rding this Idter or rewire ffirther information, please�oall,.,
Sincerely,
NELS . ON GEOTECHNICAL Assocmms, INC.
Ad� Dodoye-Alati
Project Geologist
Khale ' d A ShAwish, PE
Principal
Two Copies Submitted
81).KM,S--bd
NELSON GEOTECHNiCAL ASSOCIATES, INC,