211 Belvedere St., GEO Report
REPORT OF A GEOTECHNICAL EXPLORATION Proposed Residence – 211 Belvedere
Atlantic Beach, Florida May 5, 2021 PROJECT NO. 0930.2100100.0000
REPORT NO. 1863732
Prepared For: Ford Builders
29 20th Avenue South
Jacksonville, Beach 32250
Prepared By: UNIVERSAL ENGINEERING SCIENCES
5561 Florida Mining Boulevard South
Jacksonville, Florida 32257-3648 (904) 296-0757
Consultants in: Geotechnical Engineering • Environmental Sciences • Construction Materials Testing • Threshold Inspection
UNIVERSAL
ENGINEERING SCIENCES
May 5, 2021
Ford Builders 29 20th Avenue South Jacksonville, Beach 32250
Attention: Mr. Robert Ford Reference: REPORT OF A GEOTECHNICAL EXPLORATION Proposed Residence – 211 Belvedere
Atlantic Beach, Florida
UES Project No. 0930.2100100.0000 and Report No. 1863838 Dear Mr. Ford:
Universal Engineering Sciences, LLC. has completed the subsurface exploration at the proposed
Residence located at 211 Belvedere Street in Atlantic Beach, Florida. These services were provided in general accordance with our Proposal No. 1854514, dated April 9, 2021. This report contains the results of our exploration, an engineering evaluation with respect to the project characteristics described to us, and recommendations for groundwater considerations, foundation
design, and site preparation. A summary of our findings is as follows:
• The borings generally encountered very loose to loose fine sand (SP) and fine sand with silt (SP-SM) extending to approximately 3 to 4.5 feet below the existing grade, underlain by medium dense to dense fine sand with silt (SP-SM) and fine sand (SP) extending to
approximately 12 to 17 feet and further underlain by loose to medium dense fine sand (SP) extending to the deepest termination depths of 30 feet below existing grade.
• We measured the stabilized groundwater level at the boring locations between depths of
3.3 to 3.6 feet below the existing grade. We estimate the seasonal high groundwater level will generally occur at approximately 1 foot above the measured level at the time of our exploration.
• Assuming the building area will be constructed in accordance with our Site Preparation
Recommendations, we have recommended the proposed structure be supported on conventional, shallow spread foundations with an allowable soil bearing pressure of 2,500 pounds per square foot.
TABLE OF CONTENTS
1.0 INTRODUCTION ........................................................................................................ 1 1.1 GENERAL .............................................................................................................. 1 2.0 SCOPE OF SERVICES ................................................................................................ 1
2.1 PROJECT DESCRIPTION ........................................................................................ 1
2.2 PURPOSE ............................................................................................................... 1
2.3 FIELD EXPLORATION ........................................................................................... 2 2.4 LABORATORY TESTING ....................................................................................... 2 3.0 FINDINGS .................................................................................................................. 3 3.1 SOIL SURVEY ........................................................................................................ 3 3.2 SURFACE CONDITIONS ........................................................................................ 3
3.3 SUBSURFACE CONDITIONS ................................................................................. 3
4.0 RECOMMENDATIONS .............................................................................................. 4
4.1 GENERAL .............................................................................................................. 4 4.2 GROUNDWATER CONSIDERATIONS ................................................................... 4 4.3 BUILDING FOUNDATIONS .................................................................................... 5 4.3.1 Bearing Pressure ................................................................................................. 5
4.3.2 Foundation Size .................................................................................................. 5
4.3.3 Bearing Depth .................................................................................................... 5
4.3.4 Bearing Material ................................................................................................. 5 4.3.5 Settlement Estimates ........................................................................................... 6 4.3.6 Floor Slabs ......................................................................................................... 6 4.4 SITE PREPARATION .............................................................................................. 6 4.5 CONSTRUCTION RELATED SERVICES ................................................................. 8
5.0 LIMITATIONS ............................................................................................................ 8
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
1
1.0 INTRODUCTION
1.1 GENERAL
In this report, we present the results of the subsurface exploration of the site for the proposed residence located at 211 Belvedere Street in Atlantic Beach, Florida. We have divided this report into the following sections:
• SCOPE OF SERVICES - Defines what we did
• FINDINGS - Describes what we encountered
• RECOMMENDATIONS - Describes what we encourage you to do
• LIMITATIONS - Describes the restrictions inherent in this report
• APPENDICES - Presents support materials referenced in this report
2.0 SCOPE OF SERVICES 2.1 PROJECT DESCRIPTION Project information was provided to us in a recent correspondence with you. We were provided
with a copy of an aerial of the project area. It is understood that the proposed construction will consist of a one to two story residence with an underground stormwater vault in Atlantic Beach, Florida. Detailed structural loads have not been provided, therefore we assume maximum column and wall loads will not exceed 100 kips
and 4 klf, respectively. Detailed grading information has not been provided; therefore, we assume a maximum of two feet of elevating fill will be required for site development. We note that since the applicability of geotechnical recommendations is very dependent upon project characteristics, most specifically: improvement locations, grade alterations, and actual
structural loads applied, UES must review the preliminary and final site and grading plans, and structural design loads to validate all recommendations rendered herein. Without such review our recommendations should not be relied upon for final design or construction of any site improvements.
2.2 PURPOSE The purposes of this exploration were:
• to explore the general subsurface conditions at the site;
• to interpret and evaluate the subsurface conditions with respect to the proposed construction; and
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
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• to provide geotechnical engineering recommendations for groundwater considerations,
foundation design, and site preparation.
This report presents an evaluation of site conditions on the basis of traditional geotechnical procedures for site characterization. The recovered samples were not examined, either visually or analytically, for chemical composition or environmental hazards. Universal Engineering Sciences would be pleased to perform these services, if you desire.
Our exploration was confined to the zone of soil likely to be stressed by the proposed construction. Our work did not address the potential for surface expression of deep geological conditions. This evaluation requires a more extensive range of field services than performed in this study. We will be pleased to conduct an investigation to evaluate the probable effect of the
regional geology upon the proposed construction, if you desire.
2.3 FIELD EXPLORATION
A field exploration was performed on April 22 and 23, 2021. The approximate boring locations
are shown on the attached Boring Location Plan in Appendix A. The approximate boring locations were determined in the field by our personnel using measurements from existing landmarks and should be considered accurate only to the degree implied by the method of measurement used. Samples of the soils encountered will be held in our laboratory for your
inspection for 60 days unless we are notified otherwise.
To explore the subsurface conditions within the proposed building area, we located and drilled three (3) Standard Penetration Test (SPT) borings to depths of approximately 30 feet below the existing ground surface in general accordance with the methodology outlined in ASTM D 1586.
A summary of this field procedure is included in Appendix A. Split-spoon soil samples
recovered during performance of the boring were visually classified in the field and representative portions of the samples were transported to our laboratory for further evaluation.
2.4 LABORATORY TESTING Representative soil samples obtained during our field exploration were returned to our office and classified by a geotechnical engineer. The samples were visually classified in general accordance with ASTM D 2488 (Unified Soil Classification System).
Five (5) fines content tests, and five (5) moisture content tests, were conducted in the laboratory on representative soil samples obtained from the borings. These tests were performed to aid in classifying the soils and to help quantify and correlate engineering properties. The results of these tests are presented on the Boring Logs in Appendix A. A brief description of the
laboratory procedures used is also provided in Appendix A.
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
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3.0 FINDINGS
3.1 SOIL SURVEY
Based on the Soil Survey for Duval County, Florida, as prepared by the US Department of Agriculture Soil Conservation Service, the predominant predevelopment soil type at the site is identified as Urban Land – Boulogne (71).
A summary of characteristics of this soil series was obtained from the Soil Survey and are included in Table 1.
TABLE 1 Summary of Soil Survey Information
Soil Type Constituents Hydrologic Group Natural Drainage
Soil Permeability (Inches/Hr)
Seasonal High Water Table
Urban Land- Boulogne (71)
0-80” Fine sand A/D Poorly Drained
0-6” 6-16” 16-31” 31-39” 39-80”
6.0 – 20 2.0 – 6.0 6.0 – 20 0.6 – 2.0 0.06 – 0.2
0.5 – 1.5
3.2 SURFACE CONDITIONS
The site of the proposed construction is located at 211 Belvedere Street in Atlantic Beach, Florida. The site is cleared and generally vegetated with grasses and weeds. The site is bordered by single-family residential properties. The site appeared to be generally level.
3.3 SUBSURFACE CONDITIONS The boring locations and detailed subsurface conditions are illustrated in Appendix A: Boring Location Plan and Boring Logs. It should be noted that soil conditions will vary away from and
between boring locations. The classifications and descriptions shown on the logs are generally
based upon visual characterizations of the recovered soil samples and a limited number of laboratory tests. Also, see Appendix A: Key to Boring Logs, for further explanation of the symbols and placement of data on the Boring Logs.
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
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TABLE 2
General Soil Profile
Typical depth (ft) Soil Descriptions From To
0 3 to 4.5 Very loose to loose fine sand (SP) and fine sand with silt (SP-SM)
3 to 4.5 12 to 17 Medium dense to dense fine sand with silt (SP-SM) and fine sand (SP)
12 to 17 30* Loose to medium dense fine sand (SP)
* Termination Depth of Deepest Boring ( ) Indicates Unified Soil Classification
The stabilized groundwater level was recorded at a depth of 3.3 to 3.6 feet below the existing ground surface. It should be anticipated the groundwater level will fluctuate due to topography,
seasonal climatic variations, surface water runoff patterns, construction operations, and other
interrelated factors. 4.0 RECOMMENDATIONS
4.1 GENERAL
In this section of the report, we present our detailed recommendations for groundwater control, building foundation design, site preparation, and construction related services. The following recommendations are made based upon a review of the attached soil test data, our understanding
of the proposed construction, and experience with similar projects and subsurface conditions. We
recommend that we be provided the opportunity to review the project plans and specifications to confirm that our recommendations have been properly interpreted and implemented. If the structural loadings or the building location change significantly from those discussed previously, we request the opportunity to review and possibly amend our recommendations with respect to
those changes. The discovery of any subsurface conditions during construction which deviate
from those encountered in the borings should be reported to us immediately for observation, evaluation and recommendations.
4.2 GROUNDWATER CONSIDERATIONS
The groundwater table will fluctuate seasonally depending upon local rainfall. The rainy season in Northeast Florida is normally between June and September. We estimate the seasonal high groundwater level will be encountered approximately 1 foot above the measured levels at the
time of drilling. Note, it is possible the estimated seasonal high groundwater levels will
temporarily exceed these estimated levels during any given year in the future. Should impediments to surface water drainage exist on the site, or should rainfall intensity and duration, or total rainfall quantities exceed the normally anticipated rainfall quantities, groundwater levels
may exceed our seasonal high estimates. We recommend positive drainage be established and
maintained on the site during construction. We further recommend permanent measures be
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
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constructed to maintain positive drainage from the site throughout the life of the project. We recommend all foundation grade designs be based on the seasonal high groundwater conditions.
4.3 BUILDING FOUNDATIONS Based on the results of our exploration, we consider the subsurface conditions at the site adaptable for support of the proposed structure when constructed on a properly designed
conventional shallow foundation system. Provided the site preparation and earthwork
construction recommendations outlined in Section 4.4 of this report are performed, the following parameters may be used for foundation design. 4.3.1 Bearing Pressure
The maximum allowable net soil bearing pressure for use in shallow foundation design should not exceed 2,500 psf. Net bearing pressure is defined as the soil bearing pressure at the foundation bearing level in excess of the natural overburden pressure at that level. The foundations should be designed based on the maximum load which could be imposed by all
loading conditions.
4.3.2 Foundation Size The minimum widths recommended for any isolated column footings and continuous wall
footings are 24 inches and 16 inches, respectively. Even though the maximum allowable soil
bearing pressure may not be achieved, these width recommendations should control the minimum size of the foundations. 4.3.3 Bearing Depth
The exterior foundations should bear at a depth of at least 18 inches below the finished exterior grades (12 inches for monolithic slabs) and the interior foundations should bear at a depth of at least 12 inches below the finish floor elevation to provide confinement to the bearing level soils. It is recommended that stormwater be diverted away from the building exteriors to reduce the
possibility of erosion beneath the exterior footings.
4.3.4 Bearing Material The foundations may bear in either the compacted suitable natural soils or compacted structural
fill. The bearing level soils, after compaction, should exhibit densities equivalent to at least 95
percent of the Modified Proctor maximum dry density (ASTM D 1557) to a depth of at least one foot below the foundation bearing level.
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
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4.3.5 Settlement Estimates
Post-construction settlements of the structure will be influenced by several interrelated factors,
such as (1) subsurface stratification and strength/compressibility characteristics; (2) footing size, bearing level, applied loads, and resulting bearing pressures beneath the foundations; and (3) site preparation and earthwork construction techniques used by the contractor. Our settlement estimates for the structure are based on the use of site preparation/earthwork construction
techniques as recommended in Section 4.4 of this report. Any deviation from these
recommendations could result in an increase in the estimated post-construction settlements of the structure. Due to the sandy nature of the near-surface soils, we expect the majority of settlement to occur in
an elastic manner and fairly rapidly during construction. Using the recommended maximum
bearing pressure, the assumed maximum structural loads and the field data which we have correlated to geotechnical strength and compressibility characteristics of the subsurface soils, we estimate that total settlements of the structure could be on the order of one inch or less.
Differential settlements result from differences in applied bearing pressures and variations in the
compressibility characteristics of the subsurface soils. Because of the general uniformity of the subsurface conditions and the recommended site preparation and earthwork construction techniques outlined in Section 4.4, we anticipate that differential settlements of the structure should be within tolerable magnitudes (½ inch or less).
4.3.6 Floor Slabs The floor slab can be constructed as a slab-on-grade member using a modulus of subgrade reaction (K) of 100 pci provided the subgrade materials are compacted as outlined in Section 4.4.
It is recommended the floor slab bearing soils be covered with an impervious membrane to
reduce moisture entry and floor dampness in accordance with the most recent version of the Florida Building Code requirements. A 10-mil thick plastic membrane is commonly used for this purpose. Care should be exercised not to tear the membrane during placement of reinforcing steel and concrete.
4.4 SITE PREPARATION We recommend only normal, good practice site preparation techniques to prepare the existing subgrade to support the proposed structure. These techniques include clearing the construction
areas of utilities, stripping topsoils and vegetation, compacting the subgrade and placing
engineered fill to the desired grades. A more detailed synopsis of this work is as follows: 1. Prior to construction, the location of any existing underground utility lines within the construction area should be established. Provisions should then be made to relocate
interfering utilities to appropriate locations. It should be noted that if underground pipes
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
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are not properly removed or plugged, they may serve as conduits for subsurface erosion which may subsequently lead to excessive settlement of the overlying structure
2. Strip the proposed construction limits of any topsoils, vegetation, and other deleterious materials within and 5 feet beyond the perimeter of the proposed building areas and within and 3 feet beyond the perimeter of the proposed pavement areas and remove the existing structures and foundations. Expect typical stripping at this site to depths of 6 to
12 inches.
3. The groundwater level should be maintained at least 2 feet below the surface of any vibratory compaction procedures. If required, temporary groundwater control can probably be achieved by pumping from sumps located in perimeter ditches. Each sump
should be located outside the bearing area to avoid loosening of the fine sandy bearing
soils. 4. Compact the subgrade from the surface with a vibratory roller until you obtain a minimum density of at least 95 percent of the Modified Proctor maximum dry density
(ASTM D-1557), to a depth of two feet below the compacted surface. Typically, the
soils should exhibit moisture contents within ± 2 percent of the Modified Proctor optimum moisture content during compaction. A minimum of eight (8) complete coverages (in perpendicular directions) should be made in the building construction area with the dozer or roller to improve the uniformity and increase the density of the
underlying sandy soils
5. Care should be exercised to avoid damaging any nearby structures while the compaction operation is underway. Prior to commencing compaction, occupants of adjacent structures should be notified and the existing conditions of the structures be documented
with photographs and survey (if deemed necessary). Compaction should cease if deemed
detrimental to adjacent structures. Universal Engineering Sciences can provide vibration monitoring services to help document and evaluate the effects of the surface compaction operation on existing structures. In the absence of vibration monitoring it is recommended the vibratory roller remain a minimum of 50 feet from existing structures.
Within this zone, use of a bulldozer or a vibratory roller operating in the static mode is
recommended. 6. Place fill material, as required. The fill should consist of "clean," fine sand with less than 5 percent soil fines. You may use fill materials with soil fines between 5 and 12 percent,
but strict moisture control may be required. Typically, the soils should exhibit moisture
contents within ± 2 percent of the Modified Proctor optimum moisture content during compaction. Place fill in uniform 10 to 12-inch loose lifts and compact each lift to a minimum density of 95 percent of the Modified Proctor maximum dry density.
7. Perform compliance tests within the fill/backfill at every 5,000 square feet or a minimum
of two tests in the building area, whichever is greater.
UES Project No. 0930.2100100.0000 UES Report No. 1863838 May 5, 2021
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8. Test all footing cuts for compaction to a depth of 1 foot. We recommend you conduct
density testing in every column footing, and every 100 linear feet in wall footings.
Recompaction of the foundation excavation bearing level soils, if loosened by the excavation process, can probably be achieved by making several coverages with a light weight walk-behind vibratory sled or roller.
4.5 CONSTRUCTION RELATED SERVICES
We recommend the owner retain Universal Engineering Sciences to perform construction materials tests and observations on this project. Field tests and observations include verification of foundation and hardscape subgrades by performing quality assurance tests on the placement of
compacted structural fill. We can also provide concrete testing, and general construction
observation services. The geotechnical engineering design does not end with the advertisement of the construction documents. The design is an on-going process throughout construction. Because of our
familiarity with the site conditions and the intent of the engineering design, we are most qualified
to address problems that might arise during construction in a timely and cost-effective manner.
5.0 LIMITATIONS
During the early stages of most construction projects, geotechnical issues not addressed in this
report may arise. Because of the natural limitations inherent in working with the subsurface, it is not possible for a geotechnical engineer to predict and address all possible problems. A Geotechnical Business Council (GBC) publication, "Important Information About This Geotechnical Engineering Report" appears in Appendix B, and will help explain the nature of
geotechnical issues.
APPENDIX A BORING LOCATION PLAN BORING LOGS
KEY TO BORING LOGS FIELD EXPLORATION PROCEDURES LABORATORY TESTING PROCEDURES
2
5
10
18
16
39
30
17
8
12
6
WOH-1-1
2-2-3
2-4-6
8-10-8
2-4-12
8-16-23
7-14-16
3-6-11
2-3-5
3-5-7
2-2-4
7.3
26.8
1.5
8.1
Very loose to loose light gray fine SAND (SP)
Loose to medium dense dark brown fine SANDwith Silt with some pieces of cemented Hardpan(SP-SM)
Medium dense to dense brown fine SAND (SP)
Loose brown fine SAND (SP)
Loose to medium dense gray fine SAND (SP)
B-1
DATE STARTED:
DATE FINISHED:WATER TABLE (ft):
SHEET:
SECTION:
1 of 1
G.S. ELEVATION (ft):
3.6
4/26/21
4/23/21
4/23/21
BORING DESIGNATION:
TOWNSHIP:RANGE:
LL PI
DRILLED BY:
TYPE OF SAMPLING:
K(FT./
DAY)
ORG.CONT.
(%)
ATTERBERGLIMITS
EST. W.S.W.T. (ft):ASTM D 1586
UNIVERSAL ENGINEERING SCIENCES
CLIENT:
-200(%)MC(%)
DATE OF READING:
DEPTH(FT.)
BORING LOG
BLOWSPER 6"
INCREMENT
N(BLOWS/
FT.)
SAMPLE
SYMBOL
W.T.DESCRIPTION
DB/DH
PROJECT NO.:
REPORT NO.:
PAGE:
0930.2100100.0000
1863838
A-2
PROJECT:
LOCATION:
REMARKS:
GEOTECHNICAL EXPLORATION
211 BELVEDERE STREET
ATLANTIC BEACH, FLORIDA
Ford Builders
SEE BORING LOCATION PLAN
0
5
10
15
20
25
30
BORING_LOG 0930.2100100.0000-211 BELVEDERE STREET.GPJ UNIENGSC.GDT 5/4/21
1
2
3
14
36
26
21
10
7
16
9
WOH-1/12"
1-1-1
1-1-2
3-4-10
11-15-21
6-10-16
8-11-10
3-4-6
2-3-4
4-6-10
4-3-6
27.7
29.5
2.6
1.1
Very loose light gray fine SAND (SP)
Very loose to medium dense dark brown fineSAND with Silt and some some pieces ofcemented Hardpan (SP-SM)
Medium dense to dense brown fine SAND (SP)
Loose brown fine SAND (SP)
Loose to medium dense gray fine SAND (SP)
B-2
DATE STARTED:
DATE FINISHED:WATER TABLE (ft):
SHEET:
SECTION:
1 of 1
G.S. ELEVATION (ft):
3.6
4/26/21
4/22/21
4/23/21
BORING DESIGNATION:
TOWNSHIP:RANGE:
LL PI
DRILLED BY:
TYPE OF SAMPLING:
K(FT./
DAY)
ORG.CONT.
(%)
ATTERBERGLIMITS
EST. W.S.W.T. (ft):ASTM D 1586
UNIVERSAL ENGINEERING SCIENCES
CLIENT:
-200(%)MC(%)
DATE OF READING:
DEPTH(FT.)
BORING LOG
BLOWSPER 6"
INCREMENT
N(BLOWS/
FT.)
SAMPLE
SYMBOL
W.T.DESCRIPTION
DB/DH
PROJECT NO.:
REPORT NO.:
PAGE:
0930.2100100.0000
1863838
A-3
PROJECT:
LOCATION:
REMARKS:
GEOTECHNICAL EXPLORATION
211 BELVEDERE STREET
ATLANTIC BEACH, FLORIDA
Ford Builders
SEE BORING LOCATION PLAN
0
5
10
15
20
25
30
BORING_LOG 0930.2100100.0000-211 BELVEDERE STREET.GPJ UNIENGSC.GDT 5/4/21
2
4
13
20
26
36
33
13
4
15
5
WOH-1-1
2-2-2
1-5-8
8-10-10
6-10-16
8-16-20
8-17-16
3-5-8
2-1-3
4-7-8
2-2-3
24.87.0
Very loose to loose light gray fine SAND (SP)
Medium dense dark brown fine SAND with Siltand some pieces of cemented Hardpan (SP-SM)
Medium dense to dense brown fine SAND (SP)
Loose brown fine SAND (SP)
Loose to medium dense gray fine SAND (SP)
B-3
DATE STARTED:
DATE FINISHED:WATER TABLE (ft):
SHEET:
SECTION:
1 of 1
G.S. ELEVATION (ft):
3.3
4/26/21
4/22/21
4/22/21
BORING DESIGNATION:
TOWNSHIP:RANGE:
LL PI
DRILLED BY:
TYPE OF SAMPLING:
K(FT./
DAY)
ORG.CONT.
(%)
ATTERBERGLIMITS
EST. W.S.W.T. (ft):ASTM D 1586
UNIVERSAL ENGINEERING SCIENCES
CLIENT:
-200(%)MC(%)
DATE OF READING:
DEPTH(FT.)
BORING LOG
BLOWSPER 6"
INCREMENT
N(BLOWS/
FT.)
SAMPLE
SYMBOL
W.T.DESCRIPTION
DB/DH
PROJECT NO.:
REPORT NO.:
PAGE:
0930.2100100.0000
1863838
A-4
PROJECT:
LOCATION:
REMARKS:
GEOTECHNICAL EXPLORATION
211 BELVEDERE STREET
ATLANTIC BEACH, FLORIDA
Ford Builders
SEE BORING LOCATION PLAN
0
5
10
15
20
25
30
BORING_LOG 0930.2100100.0000-211 BELVEDERE STREET.GPJ UNIENGSC.GDT 5/4/21
ENGINEERING SCIENCES
UNIVERSAL KEY TO BORING LOGS
UNIFIED SOIL CLASSIFICATION SYSTEM SYMBOLS AND ABBREVIATIONS
MAJOR DIVISIONS GROUP
SYMBOLS TYPICAL NAMES SYMBOL DESCRIPTION
No. of Blows of a 140-lb. Weight Falling 30 Inches Required to Drive a Standard Spoon 1 Foot
Well-graded gravels and gravel-sand mixtures, little or no fines GW CLEAN GRAVELS GP Poorly graded gravels and gravel-sand mixtures, little or no fines
GM Silty gravels and gravel-sand-silt mixtures
GRAVELS50% or more of coarse fraction retained on No. 4 sieve GRAVELS WITH FINES GC Clayey gravels and gravel-sand-clay mixtures
SW** Well-graded sands and gravelly sands, little or no fines CLEAN SANDS 5% or less passing No. 200 sieve SP** Poorly graded sands and gravelly sands, little or no fines
SM** Silty sands, sand-silt mixtures COARSE GRAINED SOILS More than 50% retained on the No. 200 sieve* N-Value
WOR Weight of Drill Rods
WOH Weight of Drill Rods and Hammer
Sample from Auger Cuttings
Standard Penetration Test Sample
SANDS More than 50% of coarse fraction passes No. 4 sieve
Thin-wall Shelby Tube Sample (Undisturbed Sampler Used)
SANDS with 12% or more passing No. 200 sieve
% REC Percent Core Recovery from Rock Core Drilling
SC** Clayey sands, sand-clay mixtures RQD Rock Quality Designation
ML Inorganic silts, very fine sands, rock flour, silty or clayey fine sands
Stabilized Groundwater Level
CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, lean clays
SILTS AND CLAYS Liquid limit 50% or less
OL Organic silts and organic silty clays of low plasticity
MH Inorganic silts, micaceous or diamicaceous fine sands or silts, elastic silts
CH Inorganic clays or clays of high plasticity, fat clays
OH Organic clays of medium to high plasticity FINE-GRAINED SIOLS 50% or more passes the No. 200 sieve* Seasonal High Groundwater Level (also referred to as the W.S.W.T.)
NE Not Encountered
GNE Groundwater Not Encountered
BT Boring Terminated
-200 (%) Fines Content or % Passing No. 200 Sieve
SILTS AND CLAYS Liquid limit greater than 50%
MC (%) Moisture Content
LL Liquid Limit (Atterberg Limits Test)
PI Plasticity Index (Atterberg Limits Test) Peat, muck and other highly organic soils PT K Coefficient of Permeability *Based on the material passing the 3-inch (75 mm) sieve** Use dual symbol (such as SP-SM and SP-SC) for soils with more than 5% but less than 12% passing the No. 200 sieve Org. Cont. Organic Content
G.S. Elevation Ground Surface Elevation
MODIFIERS
These modifiers Provide Our Estimate of the Amount of Minor
Constituents (Silt or Clay Size Particles) in the Soil Sample Trace – 5% or less With Silt or With Clay – 6% to 11% Silty or Clayey – 12% to 30% Very Silty or Very Clayey – 31% to 50%
These Modifiers Provide Our Estimate of the Amount of Organic
Components in the Soil Sample Trace – Less than 3% Few – 3% to 4% Some – 5% to 8% Many – Greater than 8%
These Modifiers Provide Our Estimate of the Amount of Other Components (Shell, Gravel, Etc.) in the Soil Sample Trace – 5% or less Few – 6% to 12% Some – 13% to 30% Many – 31% to 50%
RELATIVE DENSITY (Sands and Gravels) Very loose – Less than 4 Blow/Foot Loose – 4 to 10 Blows/Foot Medium Dense – 11 to 30 Blows/Foot Dense – 31 to 50 Blows/Foot Very Dense – More than 50 Blows/Foot
CONSISTENCY (Silts and Clays) Very Soft – Less than 2 Blows/Foot Soft – 2 to 4 Blows/Foot Firm – 5 to 8 Blows/Foot Stiff – 9 to 15 Blows/Foot Very Stiff – 16 to 30 Blows/Foot Hard – More than 30 Blows/Foot
RELATIVE HARDNESS (Limestone) Soft – 100 Blows for more than 2 Inches Hard – 100 Blows for less than 2 Inches
FIELD EXPLORATION PROCEDURES Standard Penetration Test Boring The penetration boring was made in general accordance with the latest revision of ASTM D 1586, “Penetration Test and Split-Barrel Sampling of Soils”. The boring was advanced by rotary drilling techniques using a circulating bentonite fluid for borehole flushing and stability. At 2 ½
to 5 foot intervals, the drilling tools were removed from the borehole and a split-barrel sampler inserted to the borehole bottom and driven 18 inches into the soil using a 140 pound hammer falling on the average 30 inches per hammer blow. The number of blows for the final 12 inches of penetration is termed the “penetration resistance, blow count, or N-value”. This value is an index to several in-place geotechnical properties of the material tested, such as relative density
and Young’s Modulus. After driving the sampler 18 inches (or less if in hard rock-like material), the sampler was retrieved from the borehole and representative samples of the material within the split-barrel were placed in glass jars and sealed. After completing the drilling operations, the samples for
each boring were transported to our laboratory where they were examined by our engineer in order to verify the driller’s field classification.
LABORATORY TESTING PROCEDURES
Natural Moisture Content
The water content of the sample tested was determined in general accordance with the latest revision of ASTM D 2216. The water content is defined as the ratio of “pore” or “free” water in a given mass of material to the mass of solid material particles.
Percent Fines Content The percent fines or material passing the No. 200 mesh sieve of the sample tested was determined in general accordance with the latest revision of ASTM D 1140. The percent fines
are the soil particles in the silt and clay size range.
APPENDIX B
IMPORTANT INFORMATION ABOUT THIS GEOTECHNICAL ENGINEERING REPORT
Geotechnical-Engineering Report
Important Information about This
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.
While you cannot eliminate all such risks, you can manage them. The following information is provided to help.
The Geoprofessional Business Association (GBA)
has prepared this advisory to help you – assumedly
a client representative – interpret and apply this
geotechnical-engineering report as effectively as possible. In that way, you can benefit from a lowered
exposure to problems associated with subsurface
conditions at project sites and development of
them that, for decades, have been a principal cause
of construction delays, cost overruns, claims,
and disputes. If you have questions or want more
information about any of the issues discussed herein,
contact your GBA-member geotechnical engineer.
Active engagement in GBA exposes geotechnical
engineers to a wide array of risk-confrontation techniques that can be of genuine benefit for
everyone involved with a construction project.
Understand the Geotechnical-Engineering Services
Provided for this ReportGeotechnical-engineering services typically include the planning, collection, interpretation, and analysis of exploratory data from widely spaced borings and/or test pits. Field data are combined with results from laboratory tests of soil and rock samples obtained from field exploration (if applicable), observations made during site reconnaissance, and historical information to form one or more models of the expected subsurface conditions beneath the site. Local geology and alterations of the site surface and subsurface by previous and proposed construction are also important considerations. Geotechnical engineers apply their engineering training, experience, and judgment to adapt the requirements of the prospective project to the subsurface model(s). Estimates are made of the subsurface conditions that will likely be exposed during construction as well as the expected performance of foundations and other structures being planned and/or affected by construction activities.
The culmination of these geotechnical-engineering services is typically a geotechnical-engineering report providing the data obtained, a discussion of the subsurface model(s), the engineering and geologic engineering assessments and analyses made, and the recommendations developed to satisfy the given requirements of the project. These reports may be titled investigations, explorations, studies, assessments, or evaluations. Regardless of the title used, the geotechnical-engineering report is an engineering interpretation of the subsurface conditions within the context of the project and does not represent a close examination, systematic inquiry, or thorough investigation of all site and subsurface conditions.
Geotechnical-Engineering Services are Performed for Specific Purposes, Persons, and Projects, and At Specific TimesGeotechnical engineers structure their services to meet the specific needs, goals, and risk management preferences of their clients. A geotechnical-engineering study conducted for a given civil engineer
will not likely meet the needs of a civil-works constructor or even a
different civil engineer. Because each geotechnical-engineering study
is unique, each geotechnical-engineering report is unique, prepared solely for the client.
Likewise, geotechnical-engineering services are performed for a specific
project and purpose. For example, it is unlikely that a geotechnical-
engineering study for a refrigerated warehouse will be the same as
one prepared for a parking garage; and a few borings drilled during
a preliminary study to evaluate site feasibility will not be adequate to
develop geotechnical design recommendations for the project.
Do not rely on this report if your geotechnical engineer prepared it:
•for a different client;
•for a different project or purpose;
•for a different site (that may or may not include all or a portion of
the original site); or
•before important events occurred at the site or adjacent to it;
e.g., man-made events like construction or environmental
remediation, or natural events like floods, droughts, earthquakes,
or groundwater fluctuations.
Note, too, the reliability of a geotechnical-engineering report can
be affected by the passage of time, because of factors like changed
subsurface conditions; new or modified codes, standards, or
regulations; or new techniques or tools. If you are the least bit uncertain
about the continued reliability of this report, contact your geotechnical
engineer before applying the recommendations in it. A minor amount
of additional testing or analysis after the passage of time – if any is
required at all – could prevent major problems.
Read this Report in Full
Costly problems have occurred because those relying on a geotechnical-
engineering report did not read the report in its entirety. Do not rely on
an executive summary. Do not read selective elements only. Read and refer to the report in full.
You Need to Inform Your Geotechnical Engineer
About Change
Your geotechnical engineer considered unique, project-specific factors
when developing the scope of study behind this report and developing
the confirmation-dependent recommendations the report conveys.
Typical changes that could erode the reliability of this report include
those that affect:
•the site’s size or shape;
•the elevation, configuration, location, orientation,
function or weight of the proposed structure and
the desired performance criteria;
•the composition of the design team; or
•project ownership.
As a general rule, always inform your geotechnical engineer of project
or site changes – even minor ones – and request an assessment of their
impact. The geotechnical engineer who prepared this report cannot accept
responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered.
Most of the “Findings” Related in This Report
Are Professional Opinions
Before construction begins, geotechnical engineers explore a site’s
subsurface using various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing is performed. The data derived from
that sampling and testing were reviewed by your geotechnical engineer,
who then applied professional judgement to form opinions about
subsurface conditions throughout the site. Actual sitewide-subsurface
conditions may differ – maybe significantly – from those indicated in
this report. Confront that risk by retaining your geotechnical engineer
to serve on the design team through project completion to obtain
informed guidance quickly, whenever needed.
This Report’s Recommendations Are Confirmation-Dependent
The recommendations included in this report – including any options or
alternatives – are confirmation-dependent. In other words, they are not
final, because the geotechnical engineer who developed them relied heavily
on judgement and opinion to do so. Your geotechnical engineer can finalize
the recommendations only after observing actual subsurface conditions
exposed during construction. If through observation your geotechnical
engineer confirms that the conditions assumed to exist actually do exist,
the recommendations can be relied upon, assuming no other changes have
occurred. The geotechnical engineer who prepared this report cannot assume
responsibility or liability for confirmation-dependent recommendations if you
fail to retain that engineer to perform construction observation.
This Report Could Be Misinterpreted
Other design professionals’ misinterpretation of geotechnical-
engineering reports has resulted in costly problems. Confront that risk
by having your geotechnical engineer serve as a continuing member of
the design team, to:
•confer with other design-team members;
•help develop specifications;
•review pertinent elements of other design professionals’ plans and
specifications; and
• be available whenever geotechnical-engineering guidance is needed.
You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction-phase observations.
Give Constructors a Complete Report and GuidanceSome owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note
conspicuously that you’ve included the material for information purposes only. To avoid misunderstanding, you may also want to note that
“informational purposes” means constructors have no right to rely on
the interpretations, opinions, conclusions, or recommendations in the
report. Be certain that constructors know they may learn about specific
project requirements, including options selected from the report, only
from the design drawings and specifications. Remind constructors
that they may perform their own studies if they want to, and be sure to
allow enough time to permit them to do so. Only then might you be in
a position to give constructors the information available to you, while
requiring them to at least share some of the financial responsibilities
stemming from unanticipated conditions. Conducting prebid and
preconstruction conferences can also be valuable in this respect.
Read Responsibility Provisions Closely
Some client representatives, design professionals, and constructors do
not realize that geotechnical engineering is far less exact than other
engineering disciplines. This happens in part because soil and rock on
project sites are typically heterogeneous and not manufactured materials
with well-defined engineering properties like steel and concrete. That
lack of understanding has nurtured unrealistic expectations that have
resulted in disappointments, delays, cost overruns, claims, and disputes.
To confront that risk, geotechnical engineers commonly include
explanatory provisions in their reports. Sometimes labeled “limitations,”
many of these provisions indicate where geotechnical engineers’
responsibilities begin and end, to help others recognize their own
responsibilities and risks. Read these provisions closely. Ask questions.
Your geotechnical engineer should respond fully and frankly.
Geoenvironmental Concerns Are Not Covered
The personnel, equipment, and techniques used to perform an
environmental study – e.g., a “phase-one” or “phase-two” environmental
site assessment – differ significantly from those used to perform a
geotechnical-engineering study. For that reason, a geotechnical-engineering
report does not usually provide environmental findings, conclusions, or
recommendations; e.g., about the likelihood of encountering underground
storage tanks or regulated contaminants. Unanticipated subsurface
environmental problems have led to project failures. If you have not
obtained your own environmental information about the project site,
ask your geotechnical consultant for a recommendation on how to find
environmental risk-management guidance.
Obtain Professional Assistance to Deal with Moisture Infiltration and Mold
While your geotechnical engineer may have addressed groundwater,
water infiltration, or similar issues in this report, the engineer’s
services were not designed, conducted, or intended to prevent
migration of moisture – including water vapor – from the soil
through building slabs and walls and into the building interior, where
it can cause mold growth and material-performance deficiencies.
Accordingly, proper implementation of the geotechnical engineer’s recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by
including building-envelope or mold specialists on the design team. Geotechnical engineers are not building-envelope or mold specialists.
Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with GBA’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of
GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent or intentional (fraudulent) misrepresentation.
Telephone: 301/565-2733
e-mail: info@geoprofessional.org www.geoprofessional.org
WARRANTY Universal Engineering Sciences has prepared this report for our client for his exclusive use, in accordance with generally accepted soil and foundation engineering practices, and makes no other warranty either expressed or implied as to the professional advice provided in the report. UNANTICIPATED SOIL CONDITIONS The analysis and recommendations submitted in this report are based upon the data obtained from soil borings performed at the locations indicated on the Boring Location Plan. This report does not reflect any variations which may occur between these borings. The nature and extent of variations between borings may not become known until excavation begins. If variations appear, we may have to re-evaluate our recommendations after performing on-site observations and noting the characteristics of any variations. CHANGED CONDITIONS We recommend that the specifications for the project require that the contractor immediately notify Universal Engineering Sciences, as well as the owner, when subsurface conditions are encountered that are different from those present in this report. No claim by the contractor for any conditions differing from those anticipated in the plans, specifications, and those found in this report, should be allowed unless the contractor notifies the owner and Universal Engineering Sciences of such changed conditions. Further, we recommend that all foundation work and site improvements be observed by a representative of Universal Engineering Sciences to monitor field conditions and changes, to verify design assumptions and to evaluate and recommend any appropriate modifications to this report. MISINTERPRETATION OF SOIL ENGINEERING REPORT Universal Engineering Sciences is responsible for the conclusions and opinions contained within this report based upon the data relating only to the specific project and location discussed herein. If the conclusions or recommendations based upon the data presented are made by others, those conclusions or recommendations are not the responsibility of Universal Engineering Sciences. CHANGED STRUCTURE OR LOCATION This report was prepared in order to aid in the evaluation of this project and to assist the architect or engineer in the design of this project. If any changes in the design or location of the structure as outlined in this report are planned, or if any structures are included or added that are not discussed in the report, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the conclusions modified or approved by Universal Engineering Sciences. USE OF REPORT BY BIDDERS Bidders who are examining the report prior to submission of a bid are cautioned that this report was prepared as an aid to the designers of the project and it may affect actual construction operations.
Bidders are urged to make their own soil borings, test pits, test caissons or other investigations to determine those conditions that may affect construction operations. Universal Engineering Sciences cannot be responsible for any interpretations made from this report or the attached boring logs with regard to their adequacy in reflecting subsurface conditions which will affect construction operations. STRATA CHANGES Strata changes are indicated by a definite line on the boring logs which accompany this report. However, the actual change in the ground may be more gradual. Where changes occur between soil samples, the location of the change must necessarily be estimated using all available information and may not be shown at the exact depth. OBSERVATIONS DURING DRILLING Attempts are made to detect and/or identify occurrences during drilling and sampling, such as: water level, boulders, zones of lost circulation, relative ease or resistance to drilling progress, unusual sample recovery, variation of driving resistance, obstructions, etc.; however, lack of mention does not preclude their presence. WATER LEVELS Water level readings have been made in the drill holes during drilling and they indicate normally occurring conditions. Water levels may not have been stabilized at the last reading. This data has been reviewed and interpretations made in this report. However, it must be noted that fluctuations in the level of the groundwater may occur due to variations in rainfall, temperature, tides, and other factors not evident at the time measurements were made and reported. Since the probability of such variations is anticipated, design drawings and specifications should accommodate such possibilities and construction planning should be based upon such assumptions of variations. LOCATION OF BURIED OBJECTS All users of this report are cautioned that there was no requirement for Universal Engineering Sciences to attempt to locate any man-made buried objects during the course of this exploration and that no attempt was made by Universal Engineering Sciences to locate any such buried objects. Universal Engineering Sciences cannot be responsible for any buried man-made objects which are subsequently encountered during construction that are not discussed within the text of this report. TIME This report reflects the soil conditions at the time of exploration. If the report is not used in a reasonable amount of time, significant changes to the site may occur and additional reviews may be required.
CONSTRAINTS & RESTRICTIONS
The intent of this document is to bring to your attention the potential concerns and the basic limitations of a typical geotechnical report.