HomeMy WebLinkAbout20022892.tiff AgPro Environmental Services,LLC
Percolation Test Data
r.
Preliminary and General Percolation Test
Site Name: Buxman Estates Site Description 8 Use: Residence
Number of Bedrooms: N/A Number of Bathrooms: N/A Number of Employees: N/A
Confining Layers: Refer to submitted soils report
Minutes between percolation readings: 10
Hole#1 Hole#2 Hole#3 Hole#4 Hole#5 Hole#6
Time Distance Amount of Distance Amount of Distance Amount of Distance Amount of Distance Amount of Distance Amount of
Time Elapsed from B.M. Fall from B.M. Fall from B.M. Fall from B.M.. Fall from B.M. Fall from B.M. Fall
8:40 14.125 18.875 17.875 17.250
8:50 0:10 14.375 0.250 19.000 0.125 17.875 - 17.500 0.250 - -
_
9:00 0:10 14.500 0.125 19.125 0.125 18.250 0.375 17.875 0.375 - -
9:10 0:10 14.750 0.250 19.375 0.250 18.500 0.250 18.250 0.375 - -
es" 9:20 0:10 15.000 0.250 19.500 0.125 18.750 0.250 18.625 0.375 - -
9:30 0:10 15.125 0.125 19.875 0.375 19.000 0.250 19.000 0.375 - -
9:40 0:10 15.500 0.375 20.000 0.125 19.250 0.250 19.125 0.125 - -
Drop last 3 readings 0.75 0.63 0.75 0.88
Pero Rate(irdmin) 0.025 0.02083 0.025 0.02917
Drop last 2 readings 0.50 0.50 0.50 0.50
Perc Rate(in/min) 0.025 0.025 0.025 0.025
Soil Profile Average Perc Rate(last 30 minutes)(in/min) 0.025
Refer to submitted Soils Report Average Perc Time(last 30 minutes)(min/ln) 40
Average Perc Rate(last 20 minutes)(in/min) 0.025
Average Pere Time(last 20 minutes)(minlin) 40
2002-2892
CDSEngineering Corporation
November 20, 2000
Project No. 00-0909
Mr. Don Buxman
C/o Thomas E. Hellerich, LLC
First Choice Bank Building
5801 W. 11`h St., Suite 101
Greeley, CO 80634
Dear Mr. Buxman,
Enclosed is the report you requested of the geotechnical investigation for the proposed minor
subdivision to be located on a portion of the W'h of the SW'/<, Section 21, T. 6 N., R. 66 W. of the
6th P.M., Weld County, Colorado.
The site is suitable for the construction of the proposed residences, provided the design
criteria and recommendations given in this report are met.
If you have any further questions concerning the information in this report,please contact this
office.
Respectfully,
CDS ENGINEERIN CORPORATION
Steven J. Calkum
Reviewed by:
,`l
ny J. Wernsman, P.E. _
nclosures
165 2nd Street S.W. • Loveland, CO 80537 • (970)667-8010 • Fax: (970) 667-8024
TABLE OF CONTENTS
Page
Letter of Transmittal
Table of Contents ii
Scope 1
Site Investigation 1
Site Location and Description 1
Subsurface Conditions 2
Foundation Recommendations 2,3
- Continuous Spread Footing and/or Grade Beam 3
Slab Construction 3
Concrete Reinforcement 4
Foundation Drain System 4
Conclusions 4
Location of Test Borings Drawing No. 1
Symbols and Soil Properties Diagram No. 1
Log of Borings Drawing No. 2
Swell-Consolidation Test Results Figure Nos. 1-1 to 1-3
Summary of Test Results Table No. 1
Post-Construction Site
Preparation and Maintenance Appendix 1
ii
�-. 1
SCOPE
This report presents the results of a geotechnical investigation for the proposed minor
subdivision to be located on a portion of the WYE of the SWY, Section 21, T. 6 N., R. 66 W. of 6t
P.M., Weld County, Colorado. The investigation was prepared by means of test borings and
laboratory testing of samples obtained from these borings.
This investigation was made to determine the type and depth of foundation, allowable soil
bearing pressures, groundwater conditions, and any problems that might be encountered during or
after construction due to subsurface conditions.
SITE INVESTIGATION
The field investigation performed on October 30, 2000, consisted of drilling, logging, and
sampling three(3)test holes. The Location of the Test Holes is shown on Drawing No. 1. A Log of
Borings is shown on Drawing No.2. A Summary of the Swell-Consolidation Test Results is shown
on Figure Nos. 1-1 to 1-3. A Summary of Test Results is shown on Table No. 1.
The test borings were advanced with a four-inch (4") diameter auger drill. Laboratory
samples were obtained by driving a two and one-half inch (2''/") California type sampler into
undisturbed soils with a 140-pound hammer falling thirty inches(30")and by taking bag samples of
auger cuttings.
Laboratory tests performed were - Swell-Consolidation, Natural Moisture, Natural Dry
Densities, Grain-Size Analysis, Unconfined Compressive Strengths, and Atterberg Limits.
SITE LOCATION AND DESCRIPTION
The site is located west of the City of Windsor, Weld County, Colorado, south of Colorado
Highway 392. The site slopes slightly to the northeast, and vegetation consists of various grasses
and small brush.
e•-• 2
SUBSURFACE CONDITIONS
Refer to Log of Borings, Drawing No. 2. The subsurface conditions appear uniform
throughout the site. A general description of the soils and/or rock encountered are as follows:
Topsoil - A layer of approximately six to twelve inches (6" to 12") of topsoil overlies the site.
The topsoil should not be used as foundation bearing material, structural fill, or backfill. It is
suggested that the topsoil which has been stripped be stockpiled and used for landscaped areas.
Sandy Silty Clay/Clayey Sand—Brown to tan,damp to moist,stiff to soft,sand silty clay/clayey
sand was encountered beneath the topsoil to a depth of approximately five to seven feet (5' to
7').
Bedrock— Olive tan, damp to moist, fine sandstone/siltstone/silty claystone was encountered
beneath the sandy silty clay/clayey sand to a depth of sixteen feet(16'),where drilling operations
ceased.
Groundwater was encountered in the test holes at 5'-9"to 7'-9" on November 1, 2000.
FOUNDATION RECOMMENDATIONS
The type of foundation best suited for a particular building site is dependant not only on the
characteristics of the soil and rock but also depends on the type of structure, depth to groundwater,
the proposed depth of excavation, and owner preference. The recommendations that follow are
primarily based on the type of soil encountered.
The upper soils at the site exhibit no swell pressures and a volume change as high as—0.3%
when wetted. The lower soils exhibit swell pressures as high as 900 pounds per square foot with a
volume change as high as +0.2%.
Due to the conditions mentioned above, we recommend the foundation be a continuous
spread footing and/or grade beam foundation.
,.. 3
Continuous Spread Footing and/or Grade Beam Foundations
The foundation should be a continuous spread footing and/or grade beam foundation designed
for a maximum allowable bearing capacity of 1250 to 2500 pounds per square foot(dead load
plus full live load) and a minimum dead load of 0 to 500 pounds per square foot to help
counteract the swelling should the subsoils become wetted. The foundation is to bear on
undisturbed native sands and clays,and not on uncompacted fill,topsoil,or frozen ground. The
bottom of all foundation components should be kept at least twenty-four inches(24")above the
highest seasonal groundwater depth and at least thirty inches(30")below finished grade for frost
protection. The open excavation should not be left open for an extended period of time or
exposed to adverse weather conditions. The completed open excavation should be inspected by a
representative of CDS Engineering Corporation in order to verify the subsurface conditions from
test hole data.
SLAB CONSTRUCTION
Changes in the moisture contents may result in consolidation or swelling of the subsoils,
resulting in vertical slab movement. Therefore, slabs constructed should be "free-floating" so that
the slabs can move unimpaired. Slabs placed on potentially expansive soils are expected to heave.
Slabs should be isolated from all structural members of the foundation, utility lines, and
partition walls. There should be a minimum two-inch (2") void placed above or below partition
walls located over slabs for slabs placed on the upper soils. The void should be increased to four
inches(4")for slabs placed on bedrock stratum. Failure to allow the slab to float independently will
most likely result in structural,architectural,and utility line damage. All slabs should be scored into
maximum 225 square foot areas or maximum dimensions of fifteen feet(15')with a minimum depth
of one inch(I")to localize and control any cracking due to heaving. Slabs less than thirty foot(30')
square should be scored at least once in each direction. The minimum slab thickness should be four
inches (4"), with four inches (4") of clean, washed gravel under the slab. A polyethylene moisture
barrier is recommended under slabs in habitable areas to prevent moisture migration through slabs.
4
CONCRETE REINFORCEMENT
The reinforcement listed below are recommended minimums. Caissons should be reinforced
with a minimum of two (2) No. 5 Grade 60 rebar for the full length and extending into the grade
beams with a minimum of twelve inches(12"). Grade beams should be reinforced with two(2)No.
5 Grade 60 rebar top and bottom with a middle row of two (2) rebar for basement heights. Spread
Footings should be reinforced with a minimum of two(2)No.4 Grade 60 rebar. Foundation walls on
footings should be reinforced the same as the grade beams for caissons with the exception that No.4
rebar may be used. Floating slabs should be reinforced with a minimum WWF 6 x 6 10/10.
FOUNDATION DRAIN SYSTEM
A peripheral or perimeter drain system is recommended where slabs are to be placed below
finished grade. The drain should flow by daylighting. If this is not possible, the drain should be
connected to the storm sewer, or provisions for a sump pump for future installation.
CONCLUSIONS
The soils and rock at the site show both a slight swell and consolidation potential;therefore,
future owners should be cautioned that there is a risk of future damage caused by introduction of
excess water to the soils.and/or rock. All future owners should be directed to those items under
"Post-Construction Site Preparation and Maintenance" in Appendix I, included in this report. Our
experience has shown that damage to foundations usually results from saturation of the foundation
soils caused by improper drainage,excessive irrigation,poorly compacted backfills,and leaky water
and sewer lines. The elimination of the potential sources of excessive water will greatly minimize
the risks of construction at this site.
The findings and recommendations of this report have been obtained in accordance with
accepted professional engineering practices in the field of Geotechnical Engineering. There is no
other warranty, either expressed or implied. This report applies only to the type of construction
anticipated in the area tested. The current technology is not at a stage where a guarantee of
"absolutely no damage" can be assured by design and construction practices.
r
W<5
9 Tµ3
r
4G' ® TH
9-nu
•
LOCATION OF TEST BORINGS
auwh 'r'4 Ju
e "TI=5T HoLE LUCATI 0 N ° No
r, SCALE:1lt;soot
pDATE: 1
10-30-OO
Cps ENC,INEEIQING 6aecr
r-`•� � �o. OQ-O909
S"f:BOLS AND SOIL PROPERTIES
DIAGRAM NO. 1
SOIL AND ROCK
SAMPLERS
CLAY (CL,OL,MH,CH.CH) , CALIFORNIA
U
'i�� SILT (ML,OL) THIN-WALLED
.iii.
SAND (SW,SP,SM,SC) II SPLIT BARREL
TTzt! -- GRAVEL (GW OP,GM,GC) BAG SAMPLE .
WEATHERED ROCK
PITCHER
SHALE & CLAYSTONE
® I JAR SAMPLE
. SANDSTONE
PENETRATION RESISTANCE FOR COHESIONLESS SOILS ON STRENGTH CLASSIFICATIONS FOR COHESIVE SOIL
BASIS OF THE STANDARD PENETRATION TEST
•
NUMBER OF BLOWS
PER FT. , N 't RELATIVE DENSITY CONSISTENCY COHESION. KSF*^
0 - 4 VERY LOOSE SOFT LESS THAN 0.5
4 - 10 LOOSE FIRM 0.5 - 1 .0
10 - 30 MEDIUM STIFF 1 .0 - 2.0
30 - 50 DENSE VERY STIFF 2.0 - 4.0
OVER 50 VERY DENSE HARD GREATER THAN 4 .0
it BLOWS PER FOOT - BLOW OF 140 LB. , ** EQUIVALENT TO PP/2 AND OU/2
HAMMER DROPPED 30 IN. TO DRIVE
2- INC, SPLIT-BARREL SAMPLER ONE
FOOT (ASTM DL586-67 ) .
. ,
eyy LOG OF BORINGS
/.� O W
711-1 1142. TU5
0
< ,•� r Top As;I -- C. ".4..
�/G .r �,, •-•:: . ScnNdy 5;(#7 Clay 1/Clar7 Send --
,�'•' &Mai 'IO +ONA� clamp 4D nto M.,
A/6" ; - 9A6" ,' f;' 54; 40 5nk+ 1
n 1
• ,�,� 1516 1 nR'UVOL� -- Olive -{ah a }h
• ..� t7��" '�- •1 •
�Is4-, 5 ow16+olhr' 5;ks4One/
30��'� 71•` r'" 540/6" ay Aire he.
10 -+ i _�`' 6013"
— _ - I
4
15 F-4.4.,, I
IJ
)0
Drily : lo- M - on
•
DRAWING
.••••-••1/4 ^ NO.
GYOU%)Waite D epriAl ON l 1 - 1 -O0
2
•
- 5lou. L Drl kk CIA ll- l - OO •
CDS ENGINEERING CORPORATION 1 PlIOJECT
p0 - O909
BORING NO. I
K I DEPTH z
J 3
J 0
W
3 S
N � d.
g Z
O 3
OJ '
O
a' '•° LOAD (KSF) '° io
SAMPLE OF AAN0Y 51Lrf CIA"( NAT. MOISTURE CONTENT ►�,
NAT DRY DENSITY 10 5E
‘SORINO NO. I '
I .DEPtH
J � _• J D
CO I
tZ
O
H
3
cn �
U
O1 ''° LOAD (KSF) '°
loo
SAMPLE OF „� o„p/c NAT. MOISTURE CONTENT 25flc"
NAT. DRY DENSITY 19' PCF
SWELL —CONSOLIDATION TEST RESULTS
LIAURE
NC.
/
on FN&N ERIN 0 CQRPORATIONt- LOVELAND PR°JECT 00-0`10
-• BORING NO. I
�' Ii 1 g , DEPTH 5 '
J O
if, _
r ,z
a
Qp03
J
Z u
O VI
V
a' 1.0 LOAD (KSF) '
ido
CLAYEY 5A.ND! NAT. MOISTURE CONTENT 1 "SAMPLE OF =BEDRocI�_ NAT. DRY DENSITY 98'.6
J ell I DEPTH 3 '
4
J Q
W
I» '
It
d 3
a) q
g
oi ''° LOAD (KSF) '° ioo
SAMPLE OF NAT. MOISTURE CONTENT ) l.ociw
SWELL —CONSOLIDATION�EST R SULIgY /Iy� N Pc�.
f RE
NO.IU
ii
- 0 CORPQ ATIO L0VEL AND'f{ROJECT00 �pp
GM ff��M JO�
BORING NO. 3
at I 3 DEPTH $"
J 4
p Q
, I TM...HE'D
O
Q
c 3
ill it
i.o LOAD (KSF) 'o
SAMPLE _.HE Lac NAT. MOISTURE CONTENT 7 J.
NAT DRY DEI�$ITY _1Q5-e "
* NGNOp_TH .
J
J
CO
41(
J_0
O
Z0)
C)
° 1.° LOAD (KSF) '° ioo
SAMPLE OF NAT. MOISTURE CONTENT no
SAMPLE OF--------- NAT. DRY DENSITY n
SWELL -CONSOLIDATI N U
FIGUNE
NO.
1-3
ie• i�+ i& EHRINa CORPORATIO Loveuuto PROJECT
BO 0509
TABLE I . SHEET 1 OF 2
SUMMARY OF TEST RESULTS
Date: November 20, 2000
TEST HOLE NO. TH 1 TH 1 TH 1 TH 2 TH 2
DEPTH (FT.) 2 7 8-12 5 6-8
SOIL OR ROCK • Sandy Sandy Silty Bedrock Clayey Bedrock
Silty Clay Clay / Sand /
Bedrock Bedrock
NATURAL MOISTURE (%)
18.8 25.8 24.3 23.1 24.0
20.7 20.0 26.3
DRY DENSITY (PCF) 108.0 98.0 98.6
101.9 105.0 93.9
PENETRATION 2/6 24/6 15/6
(BLOWS / IN.) 2/6 50/4 * 27/6
% SWELL @ 500 PSF -0.2 +0.2 -0.3
SWELL PRESSURE (PSF) 900
^ UNCONFINED
COMPRESSIVE 1240 6475 1970
STRENGTH (PSF)
% STRAIN
SO4 (PPM)
LIQUID LIMIT 31
PLASTICITY INDEX 13
% PASSING #200 58.7
USC CL
AASHTO GROUP INDEX
MAXIMUM DRY DENSITY
(PCF)
OPTIMUM MOISTURE * Sampler
CONTENT (%) Full
CBR
R-VALUE
^ CDS ENGINEERING CORPORATION Project No. 00-0909
Loveland, Colorado
TABLE I SHEET 2 OF 2
SUMMARY OF TEST RESULTS
Date: November 20, 2000
TEST HOLE NO. TH 2 TH 3 TH 3 TH 3 TH 3
DEPTH (FT.) 8-12 3 8 9-12 12-16
SOIL OR ROCK Bedrock . Sandy Bedrock Bedrock Bedrock
Silty Clay
NATURAL MOISTURE (%) 29.9 11.0 21.9 21.0 27.2
12.1 17.1
DRY DENSITY (PCF) 114.4 105.5
117.2 104.1
PENETRATION 9/6 40/6
(BLOWS / IN.) 9/6 50/3`
% SWELL @ 500 PSF ±0.0 -0.1
SWELL PRESSURE (PSF)
UNCONFINED
COMPRESSIVE 2145 5055
STRENGTH (PSF)
% STRAIN
SO4 (PPM)
LIQUID LIMIT
PLASTICITY INDEX Non Plastic
% PASSING #200 20.8
USC SC
AASHTO GROUP INDEX
MAXIMUM DRY DENSITY
(PCF)
OPTIMUM MOISTURE * Sampler
CONTENT (%) Full
CBR
R-VALUE
CDS ENGINEERING CORPORATION Project No. 00-0909
Loveland, Colorado
APPENDIX I
POST-CONSTRUCTION SITE PREPARATION AND MAINTENANCE
Backfill
When encountering potentially expansive or consolidating soils,measures should be taken to prevent
the soil from being wetted during and after construction. Generally, this can be accomplished by
ensuring that the backfill placed around the foundation walls will not settle after completion of
construction, and that this backfill material is relatively impervious. Water may need to be added to
backfill material to allow proper compaction -- do not puddle or saturate. Backfill should be
mechanically compacted to at least 95% of Standard Proctor around all structures, and 90% of
Standard Proctor elsewhere. Compaction requirements should be verified with field tests by the
Engineer.
Surface Drainage
The final grade should have a positive slope away from the foundation walls on all sides. A
minimum of twelve inches (12") in the first ten feet (10') is recommended. Downspouts and sill
cocks should discharge into splash blocks that extend beyond the limits of the backfill. Splash
�^ blocks should slope away from the foundation walls. The use of long downspout extensions in lieu
of splash blocks is advisable. Surface drainage away from the foundation should be maintained
throughout the lifetime of the structure.
Lawn Irrigation
Do not install sprinkler systems next to foundation walls, porches, or patio slabs. If sprinkler
systems are installed,the sprinkler heads should be placed so that the spray from the heads under full
pressure does not fall within five feet (5') of foundation walls, porches, or patio slabs. Lawn
irrigation must be carefully controlled.
If the future owners desire to plant next to foundation walls,porches,or patio slabs,and are willing
to assume the risk of structural damage,etc.,then it is advisable to plant only flowers and shrubbery
(no lawn) of varieties that require very little moisture. These flowers and shrubs should be hand
watered only. Landscaping with a plastic covering around the foundation area is not recommended.
Check with your local landscaper for fabrics which allow evaporation when inhibiting plant growth
when a plastic landscape covering is desired.
Experience shows that the majority of problems with foundations due to water conditions are
generally due to the owner's negligence of maintaining proper drainage of water from the foundation
area. The future owners should be directed to pertinent information in this report.
e
REV 06/17/85
Hello