HomeMy WebLinkAboutMULBERRY & GREENFIELDS - PUD MASTER PLAN - ODP210002 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT (3)400 North Link Lane | Fort Collins, Colorado 80524
Telephone: 970-206-9455 Fax: 970-206-9441
PRELIMINARY
GEOTECHNICAL INVESTIGATION
SPRINGER-FISCHER PROPERTY
FORT COLLINS, COLORADO
Prepared For:
HARTFORD HOMES
4801 Goodman Street
Timnath, Colorado 80542
Attention: Mr. Patrick McMeekin
Project No. FC07733-115
May 11, 2017
TABLE OF CONTENTS
SCOPE ....................................................................................................................... 1
SUMMARY OF CONCLUSIONS ............................................................................... 1
SITE DESCRIPTION AND PROPOSED CONSTRUCTION .................................... 2
GEOLOGIC HAZARDS .............................................................................................. 2
SUBSURFACE CONDITIONS ................................................................................... 4
DEVELOPMENT RECOMMENDATIONS ................................................................. 5
Site Grading ............................................................................................................ 5
Utility Construction .................................................................................................. 6
Preliminary Pavement Thicknesses ....................................................................... 7
CONSIDERATIONS FOR STRUCTURES ................................................................ 7
Foundations ............................................................................................................ 7
Floor Systems and Slab-on-Grade Construction ................................................... 8
Surface Drainage ................................................................................................... 8
General Design Considerations ............................................................................. 9
RECOMMENDED FUTURE INVESTIGATIONS AND TESTING ............................. 9
LIMITATIONS ........................................................................................................... 10
FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS
FIGURES 2 AND 3 – SUMMARY LOGS OF EXPLORATORY BORINGS
FIGURE 4 – DEPTH-TO-GROUNDWATER CONTOUR MAP
APPENDIX A – LABORATORY TEST RESULTS
TABLE A-1 – SUMMARY OF LABORATORY TEST RESULTS
APPENDIX B – GUIDELINE SITE GRADING SPECIFICATIONS
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
SCOPE
This report presents the results of our Preliminary Geotechnical Investigation
for the Springer-Fischer Property in Fort Collins, Colorado. The purpose of our
investigation was to identify geologic hazards that may exist at the site and to
evaluate the subsurface conditions to assist in planning and budgeting for the
proposed development. The report includes description of subsoil, bedrock, and
groundwater conditions found in our exploratory borings, and discussions of site
development as influenced by geotechnical considerations.
This report was prepared based upon our understanding of the development
plans. The recommendations are considered preliminary and can be used as
guidelines for further planning of development and design of grading. We should
review final development and grading plans to determine if additional investigation is
merited, or if we need to revise our recommendations. Additional investigations will
be required to design building foundations and pavements. A summary of our
findings and recommendations is presented below. More detailed discussions of
the data, analysis and recommendations are presented in the report.
SUMMARY OF CONCLUSIONS
1. No geologic or geotechnical conditions were identified which would
preclude development of this site. The primary geotechnical hazard at
this site is the presence of shallow groundwater, which may limit
basement depths over portions of the site.
2. Soils encountered in our borings consisted of 4 to 12 feet of interlayered
sand and clay over clean to clayey sand to the depths explored. No
bedrock was encountered in our investigation. Groundwater was
encountered in all eight borings during drilling at depths of 5½ to 11 feet.
We recommend a minimum 3-foot separation from floor slabs and footing
foundations to groundwater; this may limit basement excavation depths.
A groundwater contour map is provided as Figure 4 to assist in planning
site grading with consideration for the recommended 3-foot separation.
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
3. Spread footing foundations are likely appropriate for structures at this
site.
4. The risk of poor slab-on-grade performance is likely to be low across the
site.
5. Pavement subgrade at this site will likely consist of A-4 and A-6 material
according to AASHTO criteria, with expected subgrade support of poor to
good. Mitigation for swell is likely not necessary. Preliminary pavement
thickness recommendations are provided in this report.
6. Overall surface drainage should be designed to provide rapid run-off of
surface water away from the proposed residences. Water should not be
allowed to pond near the crest of slopes, on or adjacent to pavements, or
adjacent to structures. All permanent slopes should be re-vegetated to
reduce erosion.
7. Further investigations are required to make design recommendations for
foundations, floors, and pavements.
SITE DESCRIPTION AND PROPOSED CONSTRUCTION
The project area lies on the north side of Mulberry Street east of Timberline
Road / County Road 9E in Fort Collins, Colorado. At the time of our investigation,
the property was in use for agriculture. The ground surface had been plowed and
was relatively flat; ground cover consisted of crops. A ditch runs through the
southwest corner of the property and the Cache la Poudre river is located
approximately one mile to the southwest. The site is planned for residential
development.
GEOLOGIC HAZARDS
Colorado is a challenging location to practice geotechnical engineering. The
climate is relatively dry and the near-surface soils are typically dry and relatively
stiff. These soils and related sedimentary bedrock formations tend to react to
changes in moisture conditions. Some of the soils swell as they increase in moisture
and are called expansive soils. Other soils can settle significantly upon wetting and
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
are referred to as collapsing soils. Most of the land available for development east
of the Front Range is underlain by expansive clay or claystone bedrock near the
surface. Laboratory tests on samples from this site indicate generally low swell
potential. Areas of more expansive soil may be present.
It is normal in the Front Range of Colorado and nearby eastern plains to
measure radon gas in poorly ventilated spaces in contact with soil or bedrock.
Radon 222 gas is considered a health hazard and is one of several radioactive
products in the chain of the natural decay of uranium into stable lead. Radioactive
nuclides are common in the soils and sedimentary rocks underlying the subject site.
Because these sources exist, there is potential for radon gas accumulation in
poorly ventilated spaces. The amount of soil gas that can accumulate is a function
of many factors, including the radio-nuclide activity of the soil and bedrock,
construction methods and materials, pathways for soil gas, and existence of poorly-
ventilated accumulation areas. Typical mitigation methods consist of sealing soil
gas entry areas and ventilation of below-grade spaces and perimeter drain systems
(if any). Radon rarely accumulates to significant levels in above-grade spaces. The
only reliable method to determine the concentration of radon is to perform testing
after construction.
Shallow groundwater is present at this site. We recommend a minimum 3-
foot, preferably 5-foot separation from floor slabs and footing foundations to
groundwater. A depth-to-groundwater contour map is provided as Figure 4 to assist
in planning site grading with consideration for this separation. Groundwater levels
fluctuate seasonally and respond to irrigation as well as the water level in nearby
ditches, canals and other water sources. Groundwater levels may also lower
following utility installation.
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
FIELD AND LABORATORY INVESTIGATIONS
Subsurface conditions were investigated by drilling eight exploratory borings
at the approximate locations shown on Figure 1. The borings were drilled using a
truck-mounted drill rig with 4-inch diameter, continuous-flight augers. Our field
representative observed drilling, logged the soils found in the borings and obtained
samples. Summary logs of the subsurface conditions found in the borings and field
penetration resistance values are presented on Figures 2 and 3.
Samples recovered from the borings were returned to our laboratory and
visually classified by the geotechnical engineer for this project. Laboratory testing
included moisture content, dry unit weight, swell-consolidation, Atterberg Limits,
particle-size analyses, and water-soluble sulfate analyses. Swell consolidation tests
were wetted at a pressure that approximated the weight of the overlying soils
(overburden pressure). Laboratory test results are presented in Appendix A.
SUBSURFACE CONDITIONS
Soils encountered in our borings consisted of 4 to 12 feet of sandy clay and
clayey sand overlying clean to clayey sand to the depths explored. Bedrock was not
encountered in our borings. The soils generally classified as medium stiff to stiff and
very loose to very dense based on field penetration test results. Fines contents
(percent clay and silt-sized particles) measured in laboratory varied from 4 to 58
percent. Swell-consolidation tests were performed on seven soil samples; results
indicated 0.0 to 1.2 percent swell with all but one sample swelling less than 1
percent.
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
Groundwater was encountered in all eight borings during drilling at depths of
5½ to 11 feet. The borings were destroyed before secondary measurements could
be made. Further description of the subsurface conditions is provided on our boring
logs and in our laboratory test results.
DEVELOPMENT RECOMMENDATIONS
Site Grading
The properties of fill will affect the performance of foundations, slabs-on-
grade, utilities, and pavements. The ground surface in areas to be filled should be
stripped of vegetation, scarified, moisture-conditioned, and densely compacted.
The on-site soils can be used as site grading fill provided they are substantially free
of organics and other deleterious materials. Permanent cut and fill slopes should be
no steeper than 3:1 (horizontal to vertical) and be seeded or mulched to reduce
erosion. Use of flatter (4:1) slopes is preferable.
Our experience has shown clay fill moisture treated to optimum moisture
content or above will exhibit lower swell than drier material. Clay fill should be
moisture-conditioned to between optimum and 3 percent above optimum moisture
content and compacted to at least 95 percent of standard Proctor maximum dry
density (ASTM D 698). Sand fill should be moisture-conditioned to within 2 percent
of optimum moisture content. The placement and compaction of site grading fill
should be observed and density tested by our representative during construction.
Guideline grading specifications are presented in Appendix B. Permanent slopes
should be terraced and re-vegetated to reduce erosion.
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
Utility Construction
We believe excavations for utility installation can be performed with heavy-
duty trenchers, excavators, or large backhoes. Groundwater is shallow at this site
and will likely be encountered during utility construction. Bracing and/or temporary
dewatering may be required during utility construction. Dewatering may be
accomplished by sloping excavations to occasional sumps where water can be
removed by pumping. The sumps should be several feet below the bottom of the
excavations so that water is pumped down through the soils rather than up through
the bottom of the excavations to reduce potential that the support capacity of the
subsoils will be compromised.
Utility trenches should be sloped or shored to meet local, state, and federal
safety regulations. Excavation slopes specified by OSHA are dependent upon soil
types and groundwater conditions encountered. Seepage and groundwater
conditions in trenches may downgrade the soil type. Initial trench excavations may
be unstable and require flatter slopes than required by OSHA. Contractors should
identify the soils encountered in the excavations and refer to OSHA standards to
determine appropriate slopes. Excavations deeper than 20 feet should be designed
by a professional engineer.
Water and sewer lines are usually constructed beneath paved roads.
Compaction of trench backfill can have a significant effect on the life and
serviceability of pavements. Our experience indicates compacted trench backfill
may settle 1 to 2 percent. More settlement may occur if wetting of the fill occurs.
Trench backfill should be placed in thin loose lifts, moisture-conditioned and
compacted as recommended in the Site Grading section of this report. The
placement and compaction of backfill should be observed and tested by our firm
during construction.
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
Preliminary Pavement Thicknesses
Pavement subgrade will likely consist of A-4 and A-6 material according to
AASHTO criteria. Any fill material used is assumed to have equal or better
properties than the on-site soil. We judge the risk of pavement distress due to
expansive soils is most likely low at this site. Preliminary pavement thickness
alternatives are presented in Table A below. These thicknesses should be used for
planning purposes only. We recommend a subgrade investigation and final
pavement design after site grading is complete.
TABLE A
PRELIMINARY PAVEMENT THICKNESS ALTERNATIVES
Classification HMA* + ABC* PCC*
Local Standard
Residential (EDLA = 10)
4"-5.5” HMA +
6”-8” ABC
6”- 7” PCC
Residential Collector
(EDLA = 50)
5.5”- 6.5" HMA +
6"-10” ABC
6”- 7" PCC
*HMA = Hot Mix Asphalt; ABC = Aggregate Base Course; PCC = Portland Cement Concrete
CONSIDERATIONS FOR STRUCTURES
The following discussion is preliminary and not intended for design or
construction. After grading is completed, a design level geotechnical investigation
should be conducted which provides recommendations and design criteria for the
planned construction.
Foundations
Subsurface conditions encountered in our borings were relatively consistent.
We judge that spread footing foundations are likely appropriate for structures at this
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
site. A design-level geotechnical investigation is necessary to provide more detailed
foundation recommendations.
Floor Systems and Slab-on-Grade Construction
Soils encountered in our borings were generally low-swelling or non-
expansive. The risk of poor slab-on-grade performance due to soil conditions at this
site is most likely low. Slab-on-grade floors may still experience some movements.
Structurally supported floors can be considered in order to minimize movements
and associated distress to floor systems.
Surface Drainage
The performance of improvements will be influenced by surface drainage.
The ground surface around proposed structures should be shaped to provide runoff
of surface water away from the structure and off of pavements. We generally
recommend slopes of at least 12 inches in the first 10 feet where practical in the
landscaping areas surrounding structures. There are practical limitations on
achieving these slopes. Irrigation should be minimized to control wetting. Roof
downspouts should discharge beyond the limits of backfill. Water should not be
allowed to pond on or adjacent to pavements. Proper control of surface runoff is
also important to limit the erosion of surface soils. Sheet flow should not be
directed over unprotected slopes. Water should not be allowed to pond at the crest
of slopes. Permanent slopes should be re-vegetated to reduce erosion.
Water can follow poorly compacted fill behind curb and gutter and in utility
trenches. This water can soften fill and undermine the performance of the
roadways, flatwork, and foundations. We recommend compactive effort be used in
placement of all fill.
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
General Design Considerations
Exterior sidewalks and pavements supported above the on-site soils are
subject to post construction movement. Flat grades should be avoided to prevent
possible ponding, particularly next to the building due to soil movement. Positive
grades away from the buildings should be used for sidewalks and flatwork around
the perimeter of the buildings in order to reduce the possibility of lifting of this
flatwork, resulting in ponding next to the structures.
Joints next to buildings should be thoroughly sealed to prevent the infiltration
of surface water. Where concrete pavement is used, joints should also be sealed to
reduce the infiltration of water. Since some post construction movement of
pavement and flatwork may occur, joints around the buildings should be periodically
observed and resealed where necessary.
Roof drains should be discharged well away from the structures, preferably
by closed pipe systems. Where roof drains are allowed to discharge on concrete
flatwork or pavement areas next to the structures, care should be taken to insure
the area is as water tight as practical to eliminate the infiltration of this water next to
structures.
RECOMMENDED FUTURE INVESTIGATIONS AND TESTING
Based on the results of this investigation and the proposed development, we
recommend our firm perform the following investigations:
1. Review of site grading plans once the plans are available;
2. Subgrade Investigation and Pavement Design after grading;
3. Design-level Soils and Foundation Investigation after grading; and
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HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
4. Construction testing and observation during site development, and building
construction, including compaction testing of grading fill, utility trench backfill
and pavements, and foundation installation observations.
LIMITATIONS
This report has been prepared for the exclusive use of Hartford Homes for
the purpose of providing geotechnical design and construction criteria for the
proposed project. The information and conclusions presented herein are based
upon consideration of many factors including, but not limited to, the type of
development proposed, the geologic setting, and the subsurface conditions
encountered. The information contained in the report are not valid for use by others.
Standards of practice evolve in the area of geotechnical engineering. The
information provided is appropriate for about five years. If the development of the
site does not occur within five years, we should be contacted to determine if we
should update this report.
Eight borings were drilled during this investigation to obtain a reasonably
accurate picture of the subsurface conditions. Variations in the subsurface
conditions not indicated by our borings are possible. We believe this investigation
was conducted with that level of skill and care ordinarily used by geotechnical
engineers practicing in this area at this time. No warranty, express or implied, is
made.
TH-1 TH-2
TH-4
TH-7 TH-8
TH-6
TH-5
TH-3
Mulberry Street
MULBERRY ST.
VINE DR.I - 25CR 9ESITE
LEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
TH-1
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL I T PROJECT NO. FC07733-115 FIGURE 1
Locations of
Exploratory Borings
VICINITY MAP
(FORT COLLINS, COLORADO)
NOT TO SCALE
500'
APPROXIMATE
SCALE: 1" = 500'
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
11/12
8/12
10/12
10/12
WC=15.5DD=110LL=33 PI=17-200=58
WC=22.0DD=105SW=0.0SS=0.170
WC=18.6DD=105-200=8
WC=15.5DD=110LL=33 PI=17-200=58
WC=22.0DD=105SW=0.0SS=0.170
WC=18.6DD=105-200=8
TH-1
10/12
24/12
9/12
6/12
6/12
WC=16.3DD=108SW=1.2
WC=5.2-200=4
WC=16.3DD=108SW=1.2
WC=5.2-200=4
TH-2
5/12
25/12
10/12
5/12
8/12
WC=13.2DD=119SW=0.0
WC=15.7-200=42
WC=22.5DD=105-200=37
WC=13.2DD=119SW=0.0
WC=15.7-200=42
WC=22.5DD=105-200=37
TH-3
3/12
50/7
WC=11.4-200=20WC=11.4-200=20
TH-4
Summary Logs of
Exploratory Borings
FIGURE 2 DEPTH - FEETDEPTH - FEETHARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
8/12
15/12
9/12
8/12
WC=20.8DD=103SW=0.5SS=0.030
SW=0.5
WC=20.8DD=103SW=0.5SS=0.030
SW=0.5
TH-5
3/12
32/12
33/12
28/12
WC=15.1LL=23 PI=10-200=37
WC=7.3-200=4
WC=15.1LL=23 PI=10-200=37
WC=7.3-200=4
TH-6
5/12
23/12
WC=15.0DD=111SW=0.1
WC=15.0DD=111SW=0.1
TH-7
6/12
8/12
8/12
16/12
5/12
WC=8.8-200=30
WC=23.0DD=104SW=0.0
WC=17.8DD=110-200=19
WC=8.8-200=30
WC=23.0DD=104SW=0.0
WC=17.8DD=110-200=19
TH-8
DEPTH - FEETDRIVE SAMPLE. THE SYMBOL 8/12 INDICATES 8 BLOWS OF A 140-POUND HAMMER
FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES.
CLAY, SANDY AND SAND, CLAYEY, MOIST, BROWN, MEDIUM STIFF TO STIFF / LOOSE TO
MEDIUM DENSE, BROWN (SC, CL)
1.
NOTES:
THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN
THIS REPORT.
SAND, RELATIVELY CLEAN TO CLAYEY WITH OCCASIONAL GRAVEL, MOIST TO WET, VERY
LOOSE TO VERY DENSE, BROWN (SP, SC, SP-SC)
3.
LEGEND:DEPTH - FEETWATER LEVEL MEASURED AT TIME OF DRILLING.
Summary Logs of
Exploratory Borings
THE BORINGS WERE DRILLED ON APRIL 19, 2017, USING 4-INCH DIAMETER
CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG.
FIGURE 3
WC
DD
SW
-200
LL
PI
SS
-
-
-
-
-
-
-
INDICATES MOISTURE CONTENT (%).
INDICATES DRY DENSITY (PCF).
INDICATES SWELL WHEN WETTED UNDER OVERBURDEN PRESSURE (%).
INDICATES PASSING NO. 200 SIEVE (%).
INDICATES LIQUID LIMIT.
INDICATES PLASTICITY INDEX.
INDICATES SOLUBLE SULFATE CONTENT (%).
2.
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
TH-1 TH-2
TH-4
TH-7
TH-8
TH-6
TH-5
TH-3
Mulberry Road
11
10
9
8
6
7
MULBERRY RD.
VINE DR.I - 25CR 9ESITE
LEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
INDICATES
DEPTH-TO-GROUNDWATER
(FEET)
TH-1
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HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL I T PROJECT NO. FC07733-115 FIGURE 4
Depth-to-Groundwater
Countour Map
VICINITY MAP
(FORT COLLINS, COLORADO)
NOT TO SCALE
500'
APPROXIMATE
SCALE: 1" = 500'
APPENDIX A
RESULTS OF LABORATORY TESTING
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=105 PCF
From TH - 1 AT 9 FEET MOISTURE CONTENT=22.0 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=108 PCF
From TH - 2 AT 4 FEET MOISTURE CONTENT=16.3 %
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-1COMPRESSION % EXPANSION-6
-5
-4
-3
-2
-1
0
NO MOVEMENT DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=119 PCF
From TH - 3 AT 2 FEET MOISTURE CONTENT=13.2 %
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results
FIGURE A-1
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
NO MOVEMENT DUE TO WETTING
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=103 PCF
From TH - 5 AT 2 FEET MOISTURE CONTENT=20.8 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=PCF
From TH - 5 AT 14 FEET MOISTURE CONTENT=%
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-2COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=111 PCF
From TH - 7 AT 2 FEET MOISTURE CONTENT=15.0 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=104 PCF
From TH - 8 AT 9 FEET MOISTURE CONTENT=23.0 %
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-3COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
NO MOVEMENT DUE TO WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of SAND, GRAVELLY (SP)GRAVEL 30 %SAND 66 %
From TH - 2 AT 9 FEET SILT & CLAY 4 %LIQUID LIMIT %
PLASTICITY INDEX %
Sample of SAND, CLAYEY, GRAVELLY (SC)GRAVEL 17 %SAND 63 %
From TH - 4 AT 4 FEET SILT & CLAY 20 %LIQUID LIMIT %
PLASTICITY INDEX %
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
FIGURE A-4
Gradation
Test Results
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR.7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING0
10
20
30
50
60
70
80
90
100 PERCENT RETAINED40
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR.7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSINGPERCENT RETAINED0
10
20
30
40
50
60
70
80
90
100
Sample of SAND, GRAVELLY (SP)GRAVEL 34 %SAND 62 %
From TH - 6 AT 9 FEET SILT & CLAY 4 %LIQUID LIMIT %
PLASTICITY INDEX %
Sample of GRAVEL %SAND %
From SILT & CLAY %LIQUID LIMIT %
PLASTICITY INDEX %
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL | T PROJECT NO. FC07733-115
FIGURE A-5
Gradation
Test Results
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR.7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING0
10
20
30
50
60
70
80
90
100 PERCENT RETAINED40
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR.7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSINGPERCENT RETAINED0
10
20
30
40
50
60
70
80
90
100
PASSING WATER-
MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 SOLUBLE
DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE SIEVE SULFATES
BORING (FEET)(%)(PCF)(%)(PSF)(%)(%)DESCRIPTION
TH-1 2 15.5 110 33 17 58 CLAY, SANDY (CL)
TH-1 9 22.0 105 0.0 1,100 0.17 SAND, CLAYEY (SC)
TH-1 14 18.6 105 8 SAND, SLIGHTLY CLAYEY (SP-SC)
TH-2 4 16.3 108 1.2 500 CLAY, SANDY (CL)
TH-2 9 5.2 4 SAND, GRAVELLY (SP)
TH-3 2 13.2 119 0.0 200 CLAY, SANDY (CL)
TH-3 9 15.7 42 SAND, CLAYEY (SC)
TH-3 19 22.5 105 37 SAND, CLAYEY (SC)
TH-4 4 11.4 20 SAND, CLAYEY, GRAVELLY (SC)
TH-5 2 20.8 103 0.5 200 0.03 CLAY, SANDY (CL)
TH-5 14 0.5 1,800 CLAY, SANDY (CL)
TH-6 4 15.1 23 10 37 SAND, CLAYEY (SC)
TH-6 9 7.3 4 SAND, GRAVELLY (SP)
TH-7 2 15.0 111 0.1 200 SAND, CLAYEY (SC)
TH-8 4 8.8 30 SAND, CLAYEY (SC)
TH-8 9 23.0 104 0.0 1,100 SAND, CLAYEY (SC)
TH-8 14 17.8 110 19 SAND, CLAYEY (SC)
SWELL TEST RESULTS*
TABLE A-I
SUMMARY OF LABORATORY TESTING
ATTERBERG LIMITS
Page 1 of 1
HARTFORD HOMES
SPRINGER-FISCHER PROPERTY
CTL|T PROJECT NO. FC07733-115
APPENDIX B
GUIDELINE SITE GRADING SPECIFICATIONS
HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
B-1
GUIDELINE SITE GRADING SPECIFICATIONS
1. DESCRIPTION
This item shall consist of the excavation, transportation, placement, and
compaction of materials from locations indicated on the plans, or staked by
the Engineer, as necessary to achieve preliminary street and overlot
elevations. These specifications shall also apply to compaction of excess cut
materials that may be placed outside of the development boundaries.
2. GENERAL
The Soils Engineer shall be the Owner's representative. The Soils Engineer
shall approve fill materials, method of placement, moisture contents and
percent compaction, and shall give written approval of the completed fill.
3. CLEARING JOB SITE
The Contractor shall remove all vegetation and debris before excavation or fill
placement is begun. The Contractor shall dispose of the cleared material to
provide the Owner with a clean, neat appearing job site. Cleared material
shall not be placed in areas to receive fill or where the material will support
structures of any kind.
4. SCARIFYING AREA TO BE FILLED
All topsoil and vegetable matter shall be removed from the ground surface
upon which fill is to be placed. The surface shall then be plowed or scarified
until the surface is free from ruts, hummocks or other uneven features, which
would prevent uniform compaction.
5. COMPACTING AREA TO BE FILLED
After the foundation for the fill has been cleared and scarified, it shall be
disked or bladed until it is free from large clods, brought to the proper moisture
content (0 to 3 percent above optimum moisture content for clays and within 2
percent of optimum moisture content for sands) and compacted to not less
than 95 percent of maximum dry density as determined in accordance with
ASTM D 698.
6. FILL MATERIALS
Fill soils shall be free from organics, debris or other deleterious substances,
and shall not contain rocks or lumps having a diameter greater than six (6)
HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
B-2
inches. Fill materials shall be obtained from cut areas shown on the plans or
staked in the field by the Engineer.
On-site materials classifying as CL, CH, SC, SM, SW, SP, GP, GC, and GM
are acceptable. Concrete, asphalt, organic matter and other deleterious
materials or debris shall not be used as fill.
7. MOISTURE CONTENT AND DENSITY
Fill material shall be moisture conditioned and compacted to the criteria in the
table, below. Maximum density and optimum moisture content shall be
determined from the appropriate Proctor compaction tests. Sufficient
laboratory compaction tests shall be made to determine the optimum moisture
content for the various soils encountered in borrow areas.
FILL COMPACTION AND MOISTURE REQUIREMENTS
Soil
Type
Depth from
Final Grade
(feet)
Moisture Requirement
(% from optimum)
Density Requirement
Clay
0 to 15 feet
0 to +3 95% of ASTM D 698
Sand -2 to +2 95% of ASTM D 698
Clay Greater than
15 feet
-2 to +1 98% of ASTM D 698
Sand -2 to +1 95% of ASTM D 1557
The Contractor may be required to add moisture to the excavation materials in
the borrow area if, in the opinion of the Soils Engineer, it is not possible to
obtain uniform moisture content by adding water on the fill surface. The
Contractor may be required to rake or disk the fill soils to provide uniform
moisture content through the soils.
The application of water to embankment materials shall be made with any
type of watering equipment approved by the Soils Engineer, which will give the
desired results. Water jets from the spreader shall not be directed at the
embankment with such force that fill materials are washed out.
Should too much water be added to any part of the fill, such that the material
is too wet to permit the desired compaction from being obtained, rolling and all
work on that section of the fill shall be delayed until the material has been
HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
B-3
allowed to dry to the required moisture content. The Contractor will be
permitted to rework wet material in an approved manner to hasten its drying.
8. COMPACTION OF FILL AREAS
Selected fill material shall be placed and mixed in evenly spread layers. After
each fill layer has been placed, it shall be uniformly compacted to not less
than the specified percentage of maximum density. Fill shall be compacted to
the criteria above. At the option of the Soils Engineer, soils classifying as SW,
GP, GC, or GM may be compacted to 95 percent of maximum density as
determined in accordance with ASTM D 1557 or 70 percent relative density for
cohesionless sand soils. Fill materials shall be placed such that the thickness
of loose materials does not exceed 12 inches and the compacted lift thickness
does not exceed 6 inches.
Compaction as specified above shall be obtained by the use of sheepsfoot
rollers, multiple-wheel pneumatic-tired rollers, or other equipment approved by
the Engineer for soils classifying as CL, CH, or SC. Granular fill shall be
compacted using vibratory equipment or other equipment approved by the
Soils Engineer. Compaction shall be accomplished while the fill material is at
the specified moisture content. Compaction of each layer shall be continuous
over the entire area. Compaction equipment shall make sufficient trips to
ensure that the required density is obtained.
9. COMPACTION OF SLOPES
Fill slopes shall be compacted by means of sheepsfoot rollers or other
suitable equipment. Compaction operations shall be continued until slopes
are stable, but not too dense for planting, and there is not appreciable amount
of loose soils on the slopes. Compaction of slopes may be done
progressively in increments of three to five feet (3' to 5') in height or after the
fill is brought to its total height. Permanent fill slopes shall not exceed 3:1
(horizontal to vertical).
10. PLACEMENT OF FILL ON NATURAL SLOPES
Where natural slopes are steeper than 20 percent in grade and the placement
of fill is required, benches shall be cut at the rate of one bench for each 5 feet
in height (minimum of two benches). Benches shall be at least 10 feet in
width. Larger bench widths may be required by the Engineer. Fill shall be
placed on completed benches as outlined within this specification.
11. DENSITY TESTS
Field density tests shall be made by the Soils Engineer at locations and
depths of his choosing. Where sheepsfoot rollers are used, the soil may be
HARTFORD HOMES
SPRINGER-FISHER PROPERTY
CTL | T PROJECT NO. FC07733-115
B-4
disturbed to a depth of several inches. Density tests shall be taken in
compacted material below the disturbed surface. When density tests indicate
that the density or moisture content of any layer of fill or portion thereof is not
within specification, the particular layer or portion shall be reworked until the
required density or moisture content has been achieved.
12. SEASONAL LIMITS
No fill material shall be placed, spread or rolled while it is frozen, thawing, or
during unfavorable weather conditions. When work is interrupted by heavy
precipitation, fill operations shall not be resumed until the Soils Engineer
indicates that the moisture content and density of previously placed materials
are as specified.
13. NOTICE REGARDING START OF GRADING
The Contractor shall submit notification to the Soils Engineer and Owner
advising them of the start of grading operations at least three (3) days in
advance of the starting date. Notification shall also be submitted at least 3
days in advance of any resumption dates when grading operations have been
stopped for any reason other than adverse weather conditions.
14. REPORTING OF FIELD DENSITY TESTS
Density tests made by the Soils Engineer, as specified under "Density Tests"
above, shall be submitted progressively to the Owner. Dry density, moisture
content, and percentage compaction shall be reported for each test taken.
15. DECLARATION REGARDING COMPLETED FILL
The Soils Engineer shall provide a written declaration stating that the site was
filled with acceptable materials, and was placed in general accordance with
the specifications.