HomeMy WebLinkAboutSubsoils Study for FoundationHuddleston-Berry
2789 Riverside Parkway
Grand Junction, Colorado 81501
Phone: 970-255-8005
Info@huddlestonberry. comßn gine t t tng, & T exing, LLC
June2l,2022
Project#02490-0002
Shining Light Services
PO Box 759
Fruita, Colorado 81521
Attention: Mr. Tyler Didonato
Subject:Geotechnical Investigation
2} Limberpine Circle
Parachute, Colorado
Dear Mr. Didonato,
This letter presents the results of a geotechnical investigation conducted by Huddleston-Berry
Engineering & Testing, LLC (HBET) for 224 Limberpine Circle in Parachute, Colorado. The
site location is shown on Figure I - Site Location Map. The proposed construction is anticipated
to consist of a single-family residence. The scope of our investigation included evaluating the
subsurface conditions at the site to aid in developing foundation recommendations for the
proposed construction.
Site Conditions
At the time of the investigation, the site was open and fairly flat. Vegetation consisted of grasses
and weeds. The site was bordered to the northwest and southeast by vacant lots, to the northeast
by Limberpine Circle, and to the southwest by open land.
Subsurface Investisation
The subsurface investigation included one test pit at the site as shown on Figure 2 - Site Plan.
The test pit was excavated to a depth of 8.0 feet below the existing ground surface. A typed test
pit log is included in Appendix A.
The test pit encountered 1.0 foot of topsoil above tan, dry to moist, soft to medium stiff silty clay
with sand soils to a depth of 6.0 feet. The clay soils were underlain by tan, dry to moist, medium
stiff to stiff silty clay with sand, gravel, cobble, and boulder soils to the bottom of the excavation.
Groundwater was not encountered in the subsurface at the time of the investigation.
Laboratorv Testing
Laboratory testing was conducted on samples of the native soils collected from the test pit. The
testing included grain-size analysis, Atterberg limits determinationo natural moisture content
determination, and maximum dry density and optimum moisture content (Proctor) determination.
The laboratory testing results are included in Appendix B.
224Limberpine Circle
#02490-0002
06/21122
The laboratory testing results indicate that the native clay soils are slightly plastic. In general,
based on the Atterberg limits and our experience with similar soils in the vicinity of the subject
site, the native clay soils are anticipated to be slightly collapsible.
Foundation Recommendations
Based upon the results of the subsurface investigation and nature of the proposed construction,
shallow foundations are generally recommended. Spread footings and monolithic (turndown)
structural slab foundations are both appropriate alternatives. However, in order to provide a
uniform bearing stratum and reduce the risk of excessive differential movements, it is
recommended that the foundations be constructed above a minimum of 24-inches of structural
ltvldtffl:ü.Bf,ry
hgtudÃp&1aíh\â, LLC
fill.
€
The native clay soils, exclusive of topsoil, are suitable for reuse as structural fill; provided
particles in excess of 3-inches in diameter are removed. Imported structural fill should consist of
a granular, non-expansive, nonfug Jgi4lggmaterial approved by HBET.
For spread footing foundations, the footing areas may be trenched. However, for monolithic slab
foundations, the structural fill should extend across the entire building pad area to a depth of 24-
inches below the turndown edges. Structural fill should extend laterally beyond the edges of the
foundations a distance equal to the thickness ofstructural fill for both foundation types.
Prior to placement of structural fill, it is recommended that the bottom of the foundation
excavation be scarified to a depth of 6 to I inches, moisture conditioned, and compacted to a
minimum of 95Yo of the standard Proctor maximum dry density, within +2%o of the optimum
moisture content as determined in accordance with ASTM D698. Structural frll should be
moisture conditioned, placed in maximum 8-inch loose lifts, and compacted to a minimum of
95Yo of the standard Proctor maximum dry density for fine grained soils and 90Yo of the modified
Proctor maximum dry density for coarse grained soils, within +2o/o of the optimum moisture
content as determined in accordance with ASTM D698 and D1557, respectively.
Structural fill should be extended to within O.l-feet of the bottom of the foundation. No more
than 0.l-feet of gravel should be placed below the footings or turndown edge as a leveling
course.
F fill the native soils or imported granular materials, and foundation
lding pad as recommended. a maximum allowable bearins caoacitv of 1.5!Q¡g!-
may be used. In addition, a modulus of subgrade reaction of 150 pci may be used for structural
fîll consisting of the native soils and a modulus of 200 pci may be used for suitable imported
structural fill. Foundations subject to frost should be at lq&glllqiryþS below the finished grade.
Water soluble sulfates are common to the soils in Wcstcrn Colorado. Thcrcforc, at a minimum,
Type I-II sulfate resistant cement is recommended for construction at this site.
2Z \2008 A¡,T. PRO.IECTS\02490 - Shininc Light Sçryices\02490-0002 224 Liûberpine CircleU00 - Geo\02490-0002 LR062l22.doc
224 Limberpine Circle
#02490-0002
06/21/22
Any stemwalls or retaining walls should be designed to resist laterul earth pressures. For backfill
consisting of the native soils or imported granular, non-free draining, non-expansive material, we
recommend that the walls be designed for an equivalent active fluid unit weight of 45 pcf in
areas where no surcharge loads are present. An at-rest equivalent fluid unit weight of 65 pcf is
recommended for braced walls. Lateral earth pressures should be increased as necessary to
reflect any surcharge loading behind the walls.
Non-structural Floor Slab and Exterior Flatwork Recommendations
In order to limit the potential for excessive differential movements of slabs-on-grade it is
recommended that non-structural floating floor slabs be constructed above a minimum of 18-
inches of structural fill with subgrade preparation and fill placement in accordance with the
Foundation Recommendations section of this report. It is recommended that exterior flatwork be
constructed above a minimum of 12-inches of structural fill.
Drainage Recommendations
Gradins and drainøse øre critical to the lons-term performønce of the structure. Grading
around the structure should be designed to carry precipitation and runoff away from the
structure. It is recommended that the finished ground surface drop at least twelve inches within
the first ten feet away from the structure. It is also recommended that landscaping within five
feet of the structure include primarily desert plants with low water requirements. In addition, it
is recommended that automatic irrigation, including drip lines, within ten feet of foundations be
minimized.
HBET recommends that surface downspout extensions be used which discharge a minimum of
15 feet from the structure or beyond the backfill zone, whichever is greater. However, if
subsurface downspout drains are utilized, they should be carefully constructed of solid-wall PVC
and should daylight a minimum of 15 feet from the structure. In addition, an impermeable
membrane is recommended below subsurface downspout drains. Dry wells should not be used.
General Notes
The recommendations included above are based upon the results of the subsurface investigation
and on our local experience. These conclusions and recommendations are valid only for the
proposed construction.
As discussed previously, only one test pit was conducted at the site. Therefore, the precise nature
and extent of subsurface variability may not become evident until construction. As a result, it is
recommended that HBET provide construction materials testing and engineering oversight
during the entire construction process. In addition, the homeowner and any subcontractors
working on the project should be provided a copy of this report and informed of the issues
associated with the presence of moisture sensitive subgrade materials at this site.
ÃW ltrudd¡estæ-Beüy
t^ttuàaÍ & 1.,\ts.1,1,t
JZ:\2008 ALL PROJÊCTS\02490 - Shining Light Seruices\02490-0002 224 Limberpine Circleu0o - Geo\02490-0002LR062122.doc
224Limberpíne Circle
#02490-0002
06/21/22
It is ímøortønt to note that the recommendøtíons herein øre intended to reduce the risk of
structurøl movement and/or damøgq to vørvíng degrees, øssocíøted wìth volume change of the
native soíIs.HBET cannot nredict lonp-term chanses s u.hsu.rfaae m.oìsture
condítíons ønd/or the nrccise magnítude or extent of volume chanee. Where sísníficønt
increases in subsurface moísture occur due to poor grading, ímÛroÛer stotmwater
manøgement, utílitv líne føílure. excess írrigøtíon. or other cøuse, eíther during constructíon
or the result of øctíons of the prooertv owner, several ínches of movement sre possíble. I!
addìtíon, anv føílure to complv wíth the recommendatíons ín thís reoort releøses Huddleston-
Benv Eneíneeríng & Testíng, LLC of ønv liabílítv wíth reeard to the structure oerformance.
We are pleased to be of service to your project. Please contact us if you have any questions or
comments regarding the contents of this report.
Respectfully Submitted :
Huddleston-Berry Engineering and Testing' LLC
Michael A. Berry, P.E.
Vice President of Engineering
@t******
4Z:UOoS AI-L PROJECTS\02490 - Shiliug Liglrt ser viueñ2490-0002 224 Li[Lcrpile Circlú\200 . Cw\0!490-0001 LR062l 22.doc
FIGURES
*,Ðq7jrblli¡r.'nrgf G a rf i e I d Cou nty, CO
Date created:5/6/2022
Last Data Uploaded:5/6/2Q22 3:52:30 AM
FIGURE 1
Site Location Map
Deveroped or{;T*årHdg
ç.,Ð ry?|äblr,ç-nú" G a rf i e I d Cou nty, Co
Dale created:5/6/2022
Last Data Uploaded:5/6/2022 3:52:30 AM
FIGURE 2
Site Plan
D eve r o pe d r, W çU*frff, "
APPENDIX A
Typed Test Pit Log
LAB.GDT 6120122!no(-mç)-{otrtTtz-{U,='5'otrEI:'zc=trmv(tNs(o()oooN{oN00oooæòÀoÈ*{ÞÈÞ.o@.¿Lrl0aoo:].0aR"Ëo0aFoxohC){5oÞ-{91'B¡ıo5c!7orflo{z=mN)|9sf3ctoo.5oaa-o{mCN{!{zc=Emn{!!!omo.TIzo-{mv,5oomo@--1omxoÞız=m{o0mxoIızooz-{1o-{o7E'+mU,{Þn{mI(,lN(oN)N-lil:)FtEÐo-5ooc)¿moxmoE(DãØq.0)CLoo=!t-mmo(¡N(f)NNono+tl=iä#Ëäeq$EËËË9DÉhi 99oÐoczomrmIo2o¿U¿{m(t,-{!Ig.NmPODEPTH(ft)GRAPHICLOG{m7t-oma,o2.tl--tozSAMPLE ryPENUMBERRECOVERY %(ROD)BLOWCOUNTS(N VALUE)POCKET PEN.(tsf)DRY UNITWT(pc0MOISTUREcoNTENT (%)-l=+-l t!(DmÐGJFINES CONTENTLIQUIDLIMITPLASTICLIMITPLASTICITYINDEX!ì' . l/-. r\.' I,rf-'. .1.: i.:.'.rsìr\ t/_. ,\ ,t/lq.aÂ)É.Joð!t=.ôø-loll(tof-o@.:r-q'oa0¡ø@3oo-aØ(D=cL(<crlø2=.<+É.=U)q¡:ctoI-rvo)oo5o.zo3o6'f+(îo*o(é-G)EOoN)ol\)N-{o(,+Ø.<=o^Jd9.<9á.f=aCncL q,=ol-øG)4-r+Oıioøln=o-ôctctôIofCL@ocCLoøc-3=o)-ftpoo3ooØEÂ)9oo(Do
APPENDIX B
Laboratory Testing Results
NNò
@
Fo
úi
5
Øf
Fzı
Uz
I
É.U
@
=
NN
Huddleston-Berry Engineering & Testing, LLC
2789 Riverside Parkway
Grand Junction, CO 81501
970-25s-8005
GRAIN SIZE DISTRIBUTION
cLIENT Shinino Lioht PROJECT NAME 224 I imbernine Circle
PROJECT NUMBER 02490-0002 PROJECT LOCATION Parachute, CO
U,S. SIEVE OPENING IN INCHES I U.S. SIEVE NUMBERS I
10 1416 20 30 40 50 60 100140200
HYDROMETER
b 21.5 1 1t2318 3 4
F-to
r]t
=co
É.t!ztr
t--z
uJo
É.
UJfL
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
l0
5
0
10 1
GRAIN SIZE IN MILLIMETERS
0.1 0.001
I I II II-+
L ---
COBBLES GRAVEL SAND SILT OR CLAY
coarse fine coarse medium fine
Specimen ldentification Classification LL PL PI Cc Cu
o TP-1, GB-1 5129 SILTY CLAY with SAND(CL-ML)29 22 7
Specimen ldentification D100 D60 D30 D10 %Gravel %Sand %S¡It o/oClay
o TP-t, GB-1 5129 l9 3.6 t3.3 83.1
Huddleston-Berry Engineering & Testing, LLC
2789 Riverside Parkway
Grand Junction, CO 81501
970-255-8005
ATTERBERG LIMITS' RESULTS
CLIENT Shinino Lioht Services PROJECT NAME 224 Limberoine Circle
PROJECT NUMBER PROJECT LOCATION Parachute, CO
@
50
P
L
A
s
T
I
c
I
T
I
N
D
E
X
40
30
20
10
CL-ML @ @
0
0 40 6
LIOUID LIMIT
Specimen ldentification LL PL PI #200 Classification
O TP.I, GB.I 5129 29 22 7 83 SILTY GLAY with SAND(CL-ML)
NaôN
@
NN
N
o
?o
N
Huddleston-Berry Engineering & Testing, LLC
2789 Riverside Parkway
Grand Junction, CO 81501
970-255-8005
PROJECT LOCATION Parachute, CO
MOISTU RE.DENSITY RELATIONSHI P
PROJECT NAME 224 I imhernine Circle
PROJECT NUMBER 02490-0002
CLIENT Shininq Lioht
)ul
\
\
\
\
\
\
\
\
\
I \
\
\
\
7
/\
/
¿
Sample Date:
Sample No.:
Source of Material:
Description of Material:
5t2912022
22-0509
145
SILTY CLAYwith SANDíCL-MLI
Test Method (manual)ASTM D6984
140
135 TEST RESULTS
Maximum Dry DensitY 108'0 PCF
Optimum Water Content 15'0 %
130
GRADAT|ON RESULTS (% PASSING)
125
#200
83
#4
96
314"
100
0o.tt-6z
IJJâ
É.o
ATTERBERG LIMITS
1 20
LL PL
22
PI
29 7
115 Curves of 100% Saturation
for Specific Gravity Equalto
110
2.80
2.70
2.60
105
100
95
90
5 15
WATER CONTENT, 7o
0 10 20 25 30