HomeMy WebLinkAboutObservation of Excavation 10.07.19It t n r,,T,'*1#i"iffff;;1i';0"''"'-
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Octcber 7,ztlg
Joel & Cindy Fischer
30û1 South Grand Avenue
Glenrvcad Springs, Coiorado 816G1
iaeici::ri v.iis
Fioject l.lc. t9-7-56ó
Subject: ûbservaticn of Ðx*avatron, Froposecl F'esiclei:ce, TBI) {525Û) County Rcad 3 17
igea-¡er cre.ek Road)" sautli of Rifte. {iarfield ccunly, cc!*iad¡:
Dcai Joel & {--inrå-l'"
As requested, a representative ol,-Ku¡nar &, Asscciates, inc. c.¡bserved the exeavation at tire
subjoct site on Septernber Zij,2*19 i* çvalua3e lhe soils î,xpûs€d for farinCa¡i*tl supp<;fi" The
{Ìndi:igs *f ovr atiserva-tions and recominsü.rlati*ns for the fcundaiion rlesign ar€ prÐssr1ted in this
repcfi. The serviees r/et€ p*rfo';neð in aecordance with oilr agl?elneni fbr prclbssicnal
eilgilteering seryic*s to yütl, dateci Septemirer 19, 2Üi 9"
Tire proposed house v¡lil be a *ne-slory mcriuiar sTftlÇture ovç1" â baseinenî lev*i. The i:asement
flosr Ë,i11 be siab-o* g.ade'
At tir* f iri:e *r" oi:-r Visit t* the site, îlre fìrrindaticn çv.cavaiion had been cut in +ûe ievei up t*
g feet belcÌ/¿ the acijacett ground sîlrface, Th* soìls expcsed in tl:e bottom of lire exea:¡atisn
conslsted of scft, s?,ndy silty *iay. Results cf swsLX-eonsolidatic* testi:rg perfcnneci on sa;nples
taj<e* Êcm t}-re síte, slicrr¿n on Figure 1, iitdical* the soils are mcderaiely comprcssibie uiriler"
condifions cf io;Ldi*g anei wetiing with a 1os' collairse pcTential v¿l¡cn w*lt*d under a constatii
iight surc?rarg* and high ccnipressÌbiiity uirdei a¿lditianaÌ laaiirig. liio free v"ater w¡is
ensouütsr*d in îhe exc¡,v.-atåon and the soils rvere n.tois¡"
C*ns1clari*g ih* conditi*ns exposed i¡r the exca.¡aiioil and the nai¡-rre of the pii:poseii
eo*structi*rr, spr*a-ei fooiings placed a¡: the undisþ¿rbed nai:ural soil d*sigrred Ítx a:i aliolvabl*
saii Searìng .É'âsslåïÕ *f i,ZSil p:;f,ca,r: be usçri 'for siipp*rt cf the propos*d iesideíicr:. Thc
ex':.,serJ sojls t*lii; t* i:*rlpress-1,}ren wo|reð, at;d there co:;ld be p*st*coastructioir settlelneif of'
thc foi¡*dai-ion ma11ly if tlie bealìlig soiis bcccir:e wçt. Fcctings shculd be a tnii:im¡:¡n wicltir *í
Z$ inclres fcr co::tiriuaus walls and 2 f'eet 'ior eclum*s. Lcose aztç| dieiurhed si:iTs itr fcoiing areas
shouirj be ram*ved and the beaiing level extended clcwn Ío th* r"utdisturl:ed nair¡.rai soils. Thû
beartng soiis sho*l.C l-,:* protei:ied against ft'+st and *onci-ete sh*Eld nût be piaced Ûn li"oze¡r s*ils"
Èxtcric¡ f'*otings shosld b* provirltC wilir ai}:-qriate soíi toor*t ¿þûrrr) iheir bçarjriä el*vaiirxts far
h.osi ir"ofecîic,n. CçrrÍinr-¡ous fcrt:rclation ro¡ails sht,-rild -bc reini*rceil top ar:eibcttan io span iccal
i:|1i'il
Joel& Cindy Fischer'
ûcíober 7 ,2fr19
Page2
anoma\ies such as by ass*rrring an u1:lslrppcrterl length cf at least 14 feet' Foundaticn walls
acting asrctainiggstn¡ctures should ais* bc designed to resisi alalaral eafih pressure base¡i on a¡r
equivatrent fiçid unii weight cf at least 55 pcf for on*site soil as backfiii. A perimeîer fcunriation
drain should be pravided tc pi"ev.^nt te'rr,pæary build*p cf hyCr"osraiic prossure behind the
basement ,.valls aird piavent wetting of the lo.,vçr level. Structural fiil placeri within tfoor sla.b
eteas çan ccnsist of thc cn-site saiis compaet*d to aJ least 95% of slan¿lard Proct*r density aT a
moisture cûntent near cptimum. A.t \çast 4 inches c¡i %'inch sereened rock sirould be piaced
clirectly beio:r. fhs basement slab-on-gra.do tc aat as a ï:reak f+r cap1llary n:oisture dse a¡:d
faciiitate drai¡age. Backfîll plaeed arcund the struct*re shouid be compactcd ai'¡cl The surfac-e
graded tg prevelt pondicg -withi¡r at least 1û feet cf the buiiding. Landsca"pe tiaaÎ requires reg*lar
lreav-y inigaticn. sucl: as scd, and spr-inkier heads sllould nûf bs 1aç:atsd witirin 1t l.*et cf the
fornrdation.
'The recom:nci:daticns subinitted in t-iris letter zu'c based oil cu-l' oTrseryaiion +f the soils exposeei
rvitlrin tl-¡e .íorindatían ex*avation and do irr-¡t i¡rol*cie subsurface explorati*n ta eva,luate lhe
subsr:rface corrditicns r'¡ithin the loaderi riepth of ftrundatii-'r: infl.*ence. This sti;dy is bas*d on
tlie assurrption lÍrat soiis trcricath ihe tootrngs irave equai cr betier support th,an thcse e:xpcsed.
Tha ¡jsk of forincatioll rricveü1Ð11t iriay ì:e grf;ãir.r than indicated in this report becasse of pcssibie
-,,aîiaticns in tire sr-li:suriãce ccnditions. In crrier ic; reveal the natrsre an'i extenl of vaiatioüs in
the subsuilace co*ciiÉicns belo,,v the ez*eval:ir:n, ririlling rvsuld be required. it is possible tire
data *bgained by,'subsu-;:íace explar¿,tion couiii *hange the recomine*clations ccntained iil This
1*11s¡" ür,:r sei-vices rJo nai includc det*rmining the ¡:reseirce, preventicn or ¡:*ssibility 'lí:noid or
oti:er.bici*gica-l eontamii:anis (MûBC) *leveiopir:g in ihe fu.h;re. if tlie ciienT is çonc*¡"¡¡+rl abouT
If you. hr,v* arty questioits nr reeil frlrther assistatiee, pl*ase call cuu"oifice'
Sincereiy,
K¿rmar & .ÀsssaÈætes, årae.
Daniel E. Hardin,
Rev. by: SLP
DEHlkac
attachments Figure 1 - Swell-Consoiidation Test Results
cc : Jack Albrigtrt {.i ¡: l:" :,1 :ç}b¡':lgli !,::ê9s..'r rij .ij .iË.'J .2)
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Fig. 1Kumar & Associates
SÂMPLE OF: Sondy Silly CloY
FROM: Footing Orode - NorlhEasî Corner
WC = 20.5 %, ÐD = 89 pcf
ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
DUE TO WETTING
2
o
-2
JJl¡¡ã-+
I
z9-6F
ô
=o9-so(J
-10
-12
-14 t.0 _ KSF
SAMPLE OF: Sondy Sllty CloY
FROM: Footlng Grode - Norlhwesl Corner
WC = 19.7 %, DÐ = 94 pcf
2
X
0 ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
DUE TO WETTING
JJ
bJ
=uo -¿
I
z9-t
ô
=o(n -Azo(J
-B
-10
APPUED - KSF
1 9-7-566
t.0
SWELL_CONSOLIDATION TIST RTSULTS