HomeMy WebLinkAboutPermit Field Test & Inspection Report 2004-9-20
\1DlC\ ~\J\e cr
S,p-20-2004 D2:91pm Frgm-K & A Enllneerlnl. Ine
+541-B8H3SB
T-735 P 002/001 F-952
.'
a
.ngln.IHrng
K I A Engineering, '1tC.
P.O. Bar 28624, Elgen, OR ITa
521 MIrket IL, Suitt B. !up... OR 17402
(&41) I8U88I Voice
(141) 184-. FAX
September 21,.
Hayden Horrm
2464 9N GlaCIer Place, Sub 110
Redmond, OR 97758
Subject Quality assurance - house foundation pad construction
Jasper Meadows SubdMsion - ~ Addition
SprlngfI8ICI, Oregon
Pmject: 74.04
PURPOSE AND SCOPE
As 1'8t1uested. K & A Engineering, Inc, has complet8d mOnftortng tile construction of Individual foundation pads
at 1he SUbject new residentlalsUbdlVlalon. 39 inalVidual foundation pads W8f1 Constructad at 1he site and
prepared ready tor 10nnIng naw foundatlon$.
Poor to construotiollt a Geotechnlcallnvcmlgation 1 was made of the subdivision to develop specific
rucommsndattons for developing ttI8 sft8 for residential tounpatlons,~. and utDltJes.
The purpose Of our allVices was to provide monItOr construction of foundation paas to assure that conmmtion
crlt8rla outlined In the geotachnlcaJ Investigation was addressed. .
1l1l8 report documents foundation pad construction and makes recommendations tor suitability for residential
foundation Cv,rdu lICIiOn.
(
FOUNDA11ON PAD EXCAVAnoN
GlllnJ
The foundation pads doveloped for this proJect an: to support conventionally framed resid.,ntialBtnlctur88
supported by conventional cast-ln-place conCI'GtB sprBad footings. Due to the slope ar It18 Sb most of 1111
foundation pads were constructed In two or more benches, separated In grade by approximately 1 to 2-feet.
FoundIUoII SOill
1l1e GeoteChnlcaIlIMI8tIgaUon (Bolre) had predicted 1hat hIgh plasticity eJlts or clays would underUa the site.
Excavation for the pad8 conflnned that ill most of Ihe foundation pads, there was 1 to 3-feet of a gray, highly
plu1lc, modllral8ly atIff. and moist silt. In some locations the gray sI~ contained a slgnlftcant amount of sub-
rounded Igneou8 cobbJe$, ThIs silt was often covered by 0.&.10 1.().feet of damp, very 1ow--d8ns1ty peaty siltS,
Wea!hered ydow-tan tuffaceous siltStone or sandstone was encounternd underneath the plastic sills.
1 BoIre AssOcIatDs, Ine" G80IeChnIcaJ MslgdOl1 for lie Jasper Meadows keond AdditiCll, SprIngfteld, Oreaon,
Ftbruary 16, 2003.
E 'd lEL9'oN
S3~OH N30AVH ~dtt:l 900l '9 'uer
$1P-20-2004 02:31pm Frum-K & A En,lnBBrlnl, Ine
+S~1-GB4-m8
T-735 P OQ9/007 F-952
K & A Enafneerlng, loc.
The gray plastic slits and gray plastic Jllte with oobbles were deepest through rile westsm portion 011h8
subdivision. Isolated zones of gmy plastic silt Dr plastic silt with cobbles were also encountered throughout 1he
central and eastern portions 01 the subdlvlslon.
fallldlllall hd GORdrUcIIon
Because the depth and 8)(lent of solis varied significantly across the 8ub~lv~n, ~oh pad was evaluated
IndlYldually to d8tlrmlne the proper depth of excavation and tJle amount of &elect fin to be placed in the
mccavatIon.
For many of ~ foundatiOn pad8, the depth to weathered slRstone or sandstone was less than 2.feet and, In
these cases. the foundation pads were excavated to bedrOCk, and graded smooth, level, and free from loose
materfals. In ~ casH 1he baSe or the excavation was in two bellCheS sapamted in grade from 1 m 2.feet
StI8Ct aranular fiB \\lIS placed In the prepared excavation and brought to footing grade.
In those at!a of dMper 0l1Y plastic sil, the silts war! removed to a minimum depth of 1 &-inch08 belOw fooUna
grade. The batlDlTB of the excavaIfons were grBded smoo1tI, revel, and me from loose materials. In most
cases the base of tho eavatlon W89 In two benches separated In grade from 1 to 2-fael Select granular nn
was placed in the pt(Ipat'Qd axcawUon and brooght 10 footing grade.
In aU cases where peaty slits wtl1 encountered, the peaty-sJlts were completely remavad frOm the folllldatlon
area.
.... tIr8md8r FilII
Select granular fills CDl'lslsted or a sub-base mater1al and a D8S8 matet11l1. The ~bue material was placed on
1he prepared subgrade in the foundatton pads and con9lat8d 01' a a-lnch mInUs weU.gradad quany 199rogate.
The bQe material was placed over the stJb-l>ase rock anti consl8tBd of a 1 *-Inph minus clensellraded quarry
aggntgate. Bo1h aoor8Q8t88 ware produced at the Morse Bros. Quany In Sprlng1leId.
l110 8tJb..baSG tf1IeJcn8ss generallY ranged tram 6 to 12-jnche8. Base rock ranged from 4 to 12-inches In
1hIcknuaa. In a f1w Goes (Iot8 33 through 39) the sub-ba8e rock was eliminated and base rock was used
exclusl\lBly forthe n/Ict granufar flU.
l11e select granular fills were well compacted in 12-inch maximum lifts (loose) using a steel-Wheeled v1bt cWt I
roller. Water wu applied 88 necessary to maintain optlmum watDr content during compaction.
DInIIty or 8c11c1..... fila
SUb-base
The density of the Bub-base was evaluated by InSpection of placement methods and fleld evaluation of water
content. The denslly was considered adequate If passes by the large vibratory ateel-drum roRer did not I8ave
vIslbIe marIeS In the sub-base Qrqm at the edges of 1he dlUlT1 BJId if the 80~ wamr corrtBnt appeared 10 be
near optimum 88 d8termInecJ In the field. II
2 Squeezlna a small amount of 118 ftner aaoreaal8 in the hand did not produce silJRificant free water and would remain In a
rellliYely uniform ~ witKwt immediately falling apart.
Project 74.04 Jasper Meadows Subdivision Phase II, Springfield, OR Page 2 Of S
Client HaYden Homes september 20, 2004
t 'd l8L9'oN
S3~OH N30AVH ~d9t:l gOal 'g 'uBf