HomeMy WebLinkAboutK D PARK 132 WILLOX LANE - Filed GR-GEOTECHNICAL REPORT/SOILS REPORT -May, 10,, 2004
W,iljox Court UO
EastMonrue: Drive Fort
Collins, CpIIb#d0I0525 AW:
Mr. Dan E.41es R,
e:: Gemtcchnioal $jjbsurfaoe:.E41.pra 134:
West Will' Lang Reconstruction Fort
Collins, Colorado EEC
Project No. 10 I . .42036 Mr..
Ecklese Earth
Engineering : Q e 6bb 'feted tedth .0—c ical subsurface,
exploi4tion yourettuesteci For ;the 'recostrudion of theeast, half of oe! build at 1,
14 West Willox Laue, in Fort Collins, Results.4f lbp su surf lag WH Colult . b ape exploration are rowe#
p dwi . th.this ,.roport., Thepurpose of this
report. 4s; to describe : the subsurfAce conditions encountered. in:.Uletest borings compIpted within, the
Approxivatp rcmustrucjfipnlocation an providd,. geotdohnidal tocom " da _tlons -f
on: n bu Mions: and meg...OT construction and bAQUJIoffmrenovationof.the existing floor :
slab: CENTRE FGF;t ADVANCED TpCHt4pL -
r: 2,30.1. RESEARCH BOULEVARD,.:.
SUIt'F_ 104 FORT COLLINS, COLORADO. 80526• 970)
Z24- ( 5 "2 . 2 (
FAX) 224-4564,
Earth Ecghm ing Cups IMM. Inc.
EEC Project No. 1042036 .
May 10, 2004
Page 2
To develop information on existing subsurface conditions in the area of the proposed
reconstruction, two (2) soil borings were extended to depths of approximately 14 feet
adjacent to the approximate building envelope. The locations of the test borings were
established in the field by estimating locations relative to the existing structure. The
boring locations should be considered accurate only to the degree implied by the
methods used to make the field measurements. A diagram indicating the approximate
boring locations is included with this report.
The borings were performed using a truck -mounted, rotary -type drill rig equipped with a
hydraulic bead employed in drilling and sampling operations. The boreholes were
advanced using 4-inch nominal diameter continuous flight augers. Samples of the
subsurface materials encountered were obtained using split -barrel and California barrel
sampling procedures in general accordance with ASTM Specification D-1586. A
relatively undisturbed soil sample was obtained by pushing a thin -walled Shelby tube into
the subgrade soils in general accordance with ASTM Specification D-1587. All samples
obtained in the field were sealed and returned to the laboratory for further examination,
classification and testing.
Moisture content tests were performed on each of the recovered samples. Atterberg
limits, washed sieve analysis and swell/consolidation tests were performed on selected
samples. The unconfined compressive strengths of appropriate samples were estimated
with a calibrated hand penetrometer. Results of the outlined tests are presented on the
attached boring logs.
As a part of the testing program, all samples were examined in the laboratory by an
engineer and classified in accordance with the attached General Notes and the Unified
Soil Classification System (USCS) based on the texture and plasticity of each soil
sample. The estimated USCS group symbols are included on the boring logs. A brief
description of the USCS is included with this report.
a
Earth Engineering Consuimms, Inc.
EEC Project No. 1042036
May 10, 2004
Page 3
EEC field personnel were on site during drilling. to evaluate the subsurface conditions
encountered and direct the drilling activities. Field boring logs were prepared based on
observations of disturbed samples and auger cuttings. Based on results of the field
borings and laboratory testing, subsurface conditions can be generalized as follows:
Fill consisting of sand and gravel with clay and cobbles was encountered at the surface of
the test borings. Natural sandy lean clay was encountered below the fill at depths of
approximately 1 %z and 2 feet and graded to clayey sand with depth. The sandy Iean clay
and clayey sand were medium stiff to stir and loose, respectively, and exhibited
negligible swell potentials at current moisture and density conditions. A very dense sand
and gravel stratum was encountered at depths of approximately 7 and 7%2 feet and
extended to the depths explored, approximately 14 feet.
The stratification boundaries indicated on the boring logs represent the approximate
locations of changes in soil types. In -situ, the transition of materials may be gradual and
indistinct.
Observations were made at the time of drilling to evaluate the presence and depth to free
water at the test boring locations. Free water was observed in both test borings at depths
of approximately 9 feet during our field exploration. Longer term observations would be
required, in holes that are cased and sealed from the influence of surface water, to more
accurately evaluate groundwater levels and fluctuations in those levels over time.
Fluctuations in groundwater levels can occur based on hydrologic conditions and other
conditions not apparent at the time of this report. Zones of perched and/or trapped water
may also be encountered in more permeable zones within the subgrade soils at times
throughout the year.
EuM Engineering ConwBmts.. TM.
EEC Project No. 1042036
May 10; 2004
Page 4
ANALYSES AND RECOMMENDATIONS
Foundations
It is our understanding a new foundation is to be constructed along the north and east
sides of the building envelope and consideration is being given to reusing the existing
footings on the south (front) side of the building envelope. We recommend the existing
footings be evaluated for bearing capacity and structural integrity prior to incorporation
into the new foundation system.
Based on materials observed at the test boring locations, it is our opinion the proposed.
lightly loaded addition could be supported on conventional footing foundations bearing
on the natural sandy lean clays. For design of footing foundations bearing on the medium
stiff' to stiff natural clays, we recommend using a net allowable total load soil bearing
pressure not to exceed 1,500 psf. The net bearing pressure refers to the pressure at
foundation bearing level in excess of the minimum surrounding overburden pressure.
Total load should include full dead and live loads.
The addition foundation should bear at least 30 inches below final adjacent exterior
grades to provide frost protection. We recommend formed continuous footings have a
minimum width of 12 inches and isolated column foundations have a minimum width of
24 inches.
Care should be exercised during construction to protect the integrity of the foundation
bearing soils for the addition. Bearing soils which are loosened or disturbed by
construction activities or which become dry and desiccated or wet and softened should be
removed and replaced or reworked in place prior to constructing the foundation.
Eunh Eng1 =ing CounImm, Im
EEC Project No. 1042036
May 10, 2004
Page 5
Care should also be taken to avoid disturbing the foundation bearing materials for the
existing building. Excavating adjacent to the existing foundations and placing fill
adjacent to the stemwalls will require extra care.
We estimate the long-term settlement of footing foundations designed and constructed as
recommended above would be less than 1 inch. The settlement of the new footings can
result in differential settlement between the existing structure and the new portion of the
building The structural design for the addition should account for differential movement
between the addition and the existing building.
F1oor.Slab
It is our understanding a new concrete course will be added to the existing concrete floor
slab to raise the elevation of the floor by approximately 3 inches. We recommend the new
course be an unbonded topping to allow for movement between the existing and new
concrete, particularly as the new concrete cures. In this case, plastic sheeting, roofing felt
or a bond -breaking compound could be used to prevent a bond between the new topping
and the existing floor slab.
Reinforcement such as deformed bars, welded wire fabric or fibers may be placed in the
topping to reduce the degree of shrinkage cracking. The new topping should have a
minimum thickness of 3 inches. As a minimum, we recommend placing control joints in
the new topping directly above the control joints in the existing slab.
Backfill
Backfill placed adjacent to the grade beams should consist of approved, low volume -
change materials which are free from organic matter and debris. On -site soils less than 4
inches in size could be used as backfill adjacent to the grade beams. The backfill
materials should be placed in maximum 9-inch loose lifts, adjusted to within f2% of
optimum moisture content at the time of compaction and compacted to at least 95% of
standard Proctor maximum dry density. Care should be exercised when placing and
compacting the wall' backfill to avoid placing undue lateral stresses on the grade beams.
We recommend compacting the backfill with light mechanical or hand compaction
equipment.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data
obtained from the soil borings performed at the indicated locations and from any other
information discussed in this report. This report does not reflect any variations which
may occur across the site. The nature and extent of such variations may not become
evident until construction. If variations appear evident, it will be necessary to re-evaluate
the recommendations of this report.
It is recommended that the • geotechnical engineer be retained to review the plans and
specifications so comments can be made regarding the -interpretation and implementation
of our geotechnical recommendations in the design and specifications. It is further
recommended that* the geotechnical engineer be retained for testing and observations
during earthwork and foundation construction phases to help determine that the design
requirements are fulfilled.
This report has been prepared for the exclusive use of Willox Court LLC for specific
application to the project discussed and has been prepared in accordance with generally
accepted geotechnical engineering practices. No warranty, express or implied, is
made. In the event that any changes in the nature, design or location of the project as
outlined in this report are planned, the conclusions and recommendations contained in
this report shall not be considered. valid unless the changes. are reviewed and the
conclusions of this report are modified or verified in writing by the geotechnical
engineer.
V.ec 6. 1 042.006
bby . 10, 2004
Page .1
Via, -appreciatb`the Qpp.brft—mt .0y.to, be of service. to Y u on. ft.-&,project If y914 have any
questions concerning. this report,if w*- be of further -a'dVie, or 4%w you in any Other
way', pleast do tahetit'ate to contact us.
Very .truly yours,
R Iffi Enie -ic , nepdag I bi M6.,
L,I= z.. auuUtaumu, X-..Z.
Senior Project Engineer
Reviewed .by:
Principal: Engineer
cc: Mr. Bill' Warta — Natio"Inspection Services
DRILI,Eq,G & SAMPLING SYMBOLS.-
SS- Split Spoon - 13/8" I.D., 2" OD., unless otherwise noted, Pg.: Piston Sampie
ST: Thin -Walled Tube. - 2." O.D., uniess::Otilerwisezotad ws.Wash Sample.
R, Ring Barrel Sampler - 2AT'.ilp'., 3"
PAi. PbWor AUgor, FT-... Fisk Tail Bit
Hk: H AdgerA RR -,:kick Bit
DR:,- ori& 4!%-Ni B, Bulk Sample'
ASge , AuIrSample 7
PM::
Pregpz;e,.,M0tpr, Bs::
Hollow Stem Auger Stan "
N"Penetmtion: Blows perfoot dfa WATER
LEVEL ;MEASL1RFbMNT.'SYUB0L&' 200:
sieve; the, , are,.desc "bed bt . _ p! : yri ., ,4s: gray 9 dry
well sand: F= d6ei tlipy-
gedes ork.'ed-as- t1p y* ift.to _0y, MT0.
0 w0itonstitil"
mW be :,added U, 0i od ihkobr cons6tacib. 9ddW,
aG,c.btdi4,t6 ft,feMft'proportions- based I
01il0a. ,
s1z .
a. In addition $Mt6 (U,-. disoils are difiued
on the basis cif and fine. gcaued
sails .on tle, tlasis oI' their consistency: Ex=pjo- Low
silty:_ CONSISTENCY OFFUMGRAINEI) SOILS
U4coa6ed'Co1W iV
Strength, QU, pilf Consistency
Modftve SrnYxe decomposition- . : 'and
color chai 000but Hid. ff MN-
ESS:'—
DEGREE' :
OF. .CENW14T-AnON, with knife, MoOOAWt C
0-bc:
sowweaw WO-Wt StE Can he scrat0hod-wi
8hAlej.Sj1Ut6,Ae and Claystone-
1 Hard Co.bo,scrudbed easilyvithbffc.
as sttatched with fitgertfail. Moderat6ly Ap*
be s cr.
w: fingernai 14l- fih VOY Sbft c , 1* Soft
easAy dented but n500, - I ) .000., soft 11001-
2j000 Medium Sandstone zaa :
conglomerate 01- 4,000 Stiff. -pa
a ol e 0 s4M P "Ing,4: 4j0Q1 - 8,000 Very Stiff.
Mated mol - 16"bob, Very hard
Ctment6d Can dbescratched with knife: REZ,A.TIVE DENSITY, OP
Q0AR!§E-0' SOILS: Q-3 wry Loose 4!
79, 1049 WdiumiDense 30-
49 Dense
5040 Very .,
Dense 80+ Extremely
Densg r it - ,
rs. poy Can
bOrok,napa -Ee;p.0 with ge. Gemerifed
UNEFIGED S®III.. CLASSIRCATI®N SYSTEM
Criteria for Assigning Group Symbols and Group names using laboratory Tests
Group Group Nome
Symbol
Coarse —Grained Grovels more than Clean Gravels Less
Soils more than 50% of coarse than 5% fines Cu>4 and <Q;S3E GW Well—groded groveir
50% retained on fraction retained
No. 200 sieve on No. 4 sieve Cu<4 and/or 1>Cc>3` GP Poorly—groded gravel`
Gravels with Fines Fines classify as ML or MH GM Silty grovel, G,H
more than 12%
fines Fines classify as CL or CH GC Clayey Gravel'"
Sands 50% or Clean Sands Less Cu fi and l< C<_3" SW Well —graded sand'
more coarse
fraction posses
than 5% fines
Cu<6 and/or 1>Cc>3" SP Poorly —graded sand'
No. 4 sieve
Sands with Fines Fines classify as ML or MH Sm Silty sand*'
more than 12%
fines Fines classify as CL or CH SC Clayey sonde"
tine —Grained Mlts and Clays inorganic PI>7 and plots on or above A"Line CL Leon clay' -
Soils 50% or Liquid Limit less
more posses the than 50 PK4 or plots below 'A"Line' ML silt
No. 200 sieve
organic Liquid Limit — oven dried Organic clay
0.75 OL
Liquid Limit — not dried Organic silt"'"0
Silts and Clays inorganic PI plots on or above "A"Line CH Fat clay"`"
Liquid Limit 50 or
more PI plots below "A"Line MH Elastic Sit""°
organic Liquid Limit — oven dried Organic clay"`'"
0.75 OH
Liquid limit — not dried Organic silt1LL0
Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat
osed on the material passing the 3-in. (75-
min) sieve
en D _....tea ..... - - -
bar 1 0 "x D
Off sod contains 15 to 29Xpius No. 200. odd
with sand" or "with grovel", which_ever is
if flatC.sample contained cobbles or boulders, predominant.
or both, add "frith cobbles or boulders, or both'
to group home. if
Mf so9 contains 2 30" plus No. 200
minontly Bond, odd 'sandy to group
cGroveis with 5 to 122 fines required dual
sod contains 215X
name. frnes
sand addl`wlth •sdnd"to
n
symbols:
GW-GM wen graded gravel with silt
If classify as CL-ML use dual symbol
CiG-CM. Or SC-SM.
WI soil contains 2 30% plus No. 200
predominantly grovel. add "grtriely to grauo
GW-GC well-gro I gravel with espy
GP -GM peony -eroded grovel with sill
if fines ore organic, add'wRh organic Mee la name. Name. Pb24 and plots an or above 'A' line.
GP- grovel with el
e
P f11''"9r b 9ro clay
Sande with 5 to 12X Mes require dual
group name
it sal contains > add -with " owS4 or plots below 'A' tine.,
ppi plots an orabove 'A" line. syrnbels:
to oup name. jlfAtterber9Hittiteplots shaded area. soil is o o Wills below 'A" Ilne SW=
SM wee-groded send with silt SW -
SC well-grodeo nand with clay CL-
ML; silty clay. SP=
SM poorly graded sand with silt SP-
SC poorly graded sand with day 6C
rx
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EC±#£CTk6l0436
APR,IL04:
134 WEST WILLOX LANE
FORT COLLINS, COLORADO
PROJECT NO: 1os203s DATE: APRIL 2004
LOG OF BORING B4
RIG TYPE: CUE45 SHEET I OFY WATER OEM.
FOREMAN:.,JJB _ START DATE- 04=2004_ _ WHILE DRILLING 9.0
AUGER TYPE. 4' CFA - FINISH DATE 041221QM AFTER GRILLING W
SP.T-HAMMER: AUTOMATIC_ - - _ SURFACE ELEV NIA 24 HOUR NIA
SOIL DESCRIPTION 0 x uU me o0 A-LIMRB 100 WELL
LL _ PIPI . VRE481alE I a mo pspTYPEJM- L
FILL • SAND d GRAVEL WITH CLAY 8 COBBLES
redbvwn t
demo
2
4500 17.3 111.2 32 1 18 64.4 _ C 500 NoneSANDYLEANCLAY (CL) ST
brown 3
5 1000 13.6melon. AN to sOR SS
4
5
0 swsdcmdm whh deplh
8
7
8
SAND AND GRAVEL (SP•GP)
reditvm 9
verydww
SOB" 4.0. with cobbles CS. _ 10
11
Wet Cave al 11.6
12
13
14
BOTTOM OF BORING 14.0'
16
17
18
19
20 .
21
22
23
24
25
Earth Engineering Consultants
134 WEST WILLOX LANE
FORT COLLINS, COLORADO _
PROJECT NO. 1042036 DATE; APRIL 2W4
LOG OF BORING.B-2
RIG TYPE: CME45 SHEET 1 1 WATER DEPTHV.; FOREMAN:JJ8 START DATE 04t2=54 DRILLING if
AUGER TYPE r CFAFOASH DATE 04127I M DRILLING 9.W
SPTHAMMER AUTOMATIC SURFACE ELEV WA R WA.-
SOIL DESCRIPTION o w 0u No oo AWOTe.- ads awett
2E89UR!- f00 PSRTYPE
FILL -SAND & GRAVEL WITH CLAY 6 Comm
redlbrown 1
dense
2
SANDY LEAN CLAY (CL)
brown 3
modem sw to slur
4
5CLAYEYSAND (SC) CS a 19.5 117.2 c 500 PSI None
brown
loose 6
7
SAND AND GRAVEL (SP-GP)
redlbrown S
very dense
with cobbles 9
Wet Cave at &V
Som _ 73 - E 10
11
12
13
14
BOTTOM OF BORING 14.0
15.
18
17
t8
19
20
21
22
23
24
25
Earth Engineering Consultants
WELL,.=NSO.Lt,t)A,T.10N.TE-'ST RESUM
Project. :134 W-est.W.111ok-Lme.
Fdft..:CAI s. C61otado
Ptje,ctNG..-.lG42036
Date MaY20.04-
SWELL / CONSOLIDATION TEST;RESULTS
1
Load o.SF),