HomeMy WebLinkAboutPermit Field Test & Inspection Report 2004-9-20
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SIP-20-20D4 a2:Slpm From-K & A Enilneerlnl, Inc
+541-884-9350
T-735 P 002/001 F-952
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K I A Engineering, IIIC.
P.O. Bar 28624, Elgen&. OR 87a
621 MarIc8f St., Suite II. !up... OR 17402
(&41) ...... Voice
(141) .... FAX
8eptember 21, 2804
Hayden Homes
2464 5W Glacier PlaCe. SUIte 110
Redmond, OR gn56
Subject Quality assurance - house foundation pad construotion
Jasper M6adows SubdMsion - ~ AddlUon
Springfl8ll1, Oregon
Pmject: ?4-IM
PURPOSE AND SCOPE
As reqU88t8d. K & A Engineering, Inc, has completed monrtortng the construction of Indlvlduaf foundation pads
at the SUbject new residentlal,1JI)(t1Vl81on, 39 indMdual foundation pads w.... canstrucl8d at 1tle site and
prepared ready tor fanning new foundaUon6,
Poor to con&truotion, a Geotechnlcallnvmlgation1 was made of the subdivision to develop specific
nroommsndatlons for developlng 1118 slt810r IIIIdent1a1 fou~ations,~. and utBJtIas.
The purpose of our services was to provide monItOr construction of foundation paas to asstJR that conatruotion
criteria outlined In tha ge0f8chn1ca1lnvestlgation was addressed. .
11118 report documents foundation pad construction and makes recommendatiOns for suitability for residential
foundation constructIOn.
FOUNDAl1ON PAD EXCAVAnoN
GIIIII'II
The foundltion pads developed for this project are to support conventlonaUy framed ruidllntial aInlctu1'88
supported by conventional cast-ln-place concrote $prBad footings. Due to the slope !If lt18 Sb most of tile
foundation pads were con&tructed In two or more benches, separated In grade by approximately 1 to 2-f8et.
FoundIdoD SOill
11Ie aeotectmlcallnve8tlgaUon (Bofre) had predicted that high plasticity silts or clays would underlie the site.
Excava~on for 1f18 pad8 conflnned that in most of Ihe foundation pads, there was 1 to 3-feet of a gray, highly
plude, modl!ral8Iy stiff. and moist silt. In some locations the gray 8I~ contained a slgnlftcant amount of sub-
rounded Ign8ou8 cobbles. 111Is si~ was oftan covered by 0.6--10 to-feet of damp, very low.-denslty peaty siltS.
Weathered )'IlBow-tan tuffaceous siltstone or sandstone was encountered underneath the plastic sills.
1 BOIre ~ Ine,. G8OleChnlcallnvesllgallon for lie Jasper Meadows Second Addition. Springfield, 0I10OI1,
fIbnwy 16. 2003.
8 'd Z8L9'oN
S3~OH N30AVH ~dH:Z 900Z 'g 'uBf
$ep-20-2004 02:31pm From-K & A En,lneerlni, Inc.
+S41-SB4-835e
T-735 P 00S/007 F-952
K & A Engineering, Inc.
The gray plaslic aftls and gray plastic tlllW with oobbles were deepest through the westllm portion 011h8
subdivision. Isolated zones of gray plastic sltt or plastic silt with cobbles WBI8 also encountered throughout f1e
central and eastern portions at the eubdMslon.
Faundallall Pad Gonalrlcllon
Because 1he depth and _nt of solis varied significantly across the subdlv"lQn, .,aah pad was evaluated
IndlYldually to detlrmlns the proper depth of excavation and the amount 01 select fin to be placed in the
r:xcavatIon.
For rnam' of ~ foundatiOn pacl8. the depth to weathered slRstoll9 or sandstone was less than 2..feat and, In
It1eso casas. the foundatiOn pads were excavated to bedrOCk, and graded smooth, level, and free from loose
materials, 111 ~ casas the base or the excavation was in two benches separated in grade from 1 to 2.feet
SeleCt granular fill was placed In the prepared mccavatfon and brougtlt to footing grade.
In those mas of deeper 0I1Y plastic sUI, the sifts were removed to a minimum depth at 1 &-inch88 below footing
grade. The battom$ of the excavatlons were grBdad smoolt1, levsl, and free from loose matB~als. In most
cases the base of the excavation W88 In two benc~BS separated In grade from 1 to 2-f8el Select granular nn
was placed in tho pt(IpAt'9d axcavatIon and broogt}t to footing arade. .
In aU cases whell peaty slits were encountered, the peaty-slits were compl8tely remcvad frOm the fDundatlon
aru.
..
SGIeIt CIrInUIar FilII
SeleCt granular fills consisted of a 8ub-base materfaJ and a baSe material. The sulJ..base I j ~rial was placed on
1h8 prepared subgrade in the foundation pads and COl19/at8d or a S-Inch mInUs weU-araded quany .lg(Iragata.
1be base material was placed over the sub-J)ase rock anti consl8tBd of a 1 *""npt! minus dense1lraded quany
aggl1lg8te. Both aggreoates ware produced at the Marse Bros. Quany In SprlngtIeld.
1l1O 8IJb..bas8 thIokI18Bs generaflY ranged from 6 to 12-;ncheB. Base rock ranged from 4 to 12..fnches In
1hIcknees. In a fvw Goes (Iot8 33 through 39) the sub-base rock was elimInated and base rock was used
excluslv8ly forthe ssIect granular flU.
The select granular fills were w811 compacted in 12-inch maximum lifts (loose) using a steel-wheeled vlbratory
roller. Wattr was applied 18 necessary to maintain opflmUm water contsnt during compaction.
DenIIty of 8e1ecl BrIDu. filii
SUb-base
The denstty of 1118 sub-base was evalUated by In$psctJon of plKcment methods and tteld evaluation of water
COntent. The density was considered adequate If passes by the large vibratory 8tael-drum roller did not IBM
VisIble marks In the stlb-base agg~ at the edges of the drum III1d if the soH water content appeared to be
near optJmum as d8t8rmIned In the field.'
2 Squeezing a small amount of lie ftner aalJJ8lJate in the hand did not produce si~f.y(D.l free water and would mmaln In a
relllively uniform ~ wttHJUt immediately failing apart.
Project 74.04 Jasper Meadows Subdivision Pha88I1, Sprtngfield, OR Page 2 of S
Client Hayden Homes september 20, 2004
V 'd lELS'oN
S3~OH N30AVH ~dgv:l 900l 'g 'uef