PZ - Geotech ReportJuly 13, 2018
ALC Architecture
Attention: Richard Wilmot
Subject: Razberry Crossing Update
E Star Drive and Bright Angel Ave
Meridian, Idaho
Cartwright Project No. 318012
97,11ETOTOTIF141 rn
Page I of' 2
This letter presents the results of our geotechnical evaluation to assess the 3 adjacent properties
at the northwest corner of E Star Drive and N Bright Angel Avenue in Meridian, Idaho. The
proposed project includes assessing the current conditions at the site and reviewing the Initial
Geotechnical Report prepared for the development referenced as follows:
® Report — Geotechnical Engineering Services Razberry Crossing Subdivision prepared by
GeoEngineers and dated July 15, 2004.
As part of our study, we performed a field evaluation of the site on July 12, 2018. Observations
were made of the existing conditions at the site, including the exposed subgrade soils.
Exposed subgrade soils were observed across the site and a hand auger excavation was
performed to assess the current subsurface conditions. Photographs of the site are presented
below.
Photo 1: Looking southeast across site
Photograph 2: Looking west across site
Observations noted during our field evaluation included:
® The exposed subgrade soils observed across the site consist of fine silty sand with varying
amounts of gravel.
GEC I ECI-INICAI_ FENGIN PING
BOISE, ID (208) 454-.1090
Page 2 of 2
® The subgrade soils observed in the hand auger boring consist of predominantly silty soils
with varying amounts of sand and some gravel.
® No groundwater was observed in the hand auger hole.
The results of our field evaluation and review indicate that the surface and subsurface conditions
are consistent with those presented in the above reference report. In our opinion, the
conclusions and recommendations from the referenced report are still valid for the proposed
development.
Our professional services have been performed, our findings obtained, and our letter prepared
in accordance with generally accepted geotechnical engineering principles and practices. This
warranty is in lieu of all other warranties, either expressed or implied.
Sincerely,
Cartwright Northwest
Seth P. Olsen, P.E.
Senior Geotechnical Engineer
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BOISI D ('208)-184-1090
Report
Geotechnical Engineering Services
Razberry Crossing Subdivision
Meridian, Idaho
July 15, 2004
For
Consacre
Consacre
3090 Gentry Way, Suite 150
Meridian, Idaho 83642
Attention: Amanda Alvaro
Ll
July 15, 2004
Report
Geotechnical Engineering Services
Razberry Crossing Subdivision
Meridian, Idaho
GEI File No. 10283-001-03
This report presents the results of our geotechnical engineering services at the proposed Razberry
Crossing subdivision to be located at the intersection of Locust Grove Road and East Star Lane in
Meridian, Idaho as shown in the Vicinity Map, Figure 1. Our services have been completed in general
accordance with our proposal dated May 20, 2004, which you authorized on June 8, 2004.
We understand that the site is to be developed with a mixture of commercial and residential
properties. The project will include building residential streets (that will be dedicated to ACHD) and a
storm water infiltration system. We completed a preliminary geotechnical engineering study for this site
dated November 22, 2002. The purpose of this study was to provide design level geotechnical
engineering services for the project. Specifically, we completed the following services:
1. Excavated a series of 10 test pits at representative locations within the site using a backhoe
subcontracted to GeoEngineers.
2. Evaluated the pertinent physical properties of the soil in our laboratory. Laboratory testing included
moisture content determinations. No R -value tests were completed because of the silt and clay
encountered at the subgrade elevations.
3. Provided earthwork recommendations including site preparation, structural fill criteria, and the use of
on-site soils as structural fill.
4. Evaluated the groundwater conditions encountered at the site and estimated the seasonal high
groundwater elevation.
5. Estimated the infiltration rate for design of the proposed storm water disposal system.
6. Provided a design pavement section for local residential streets.
7. Summarized our recommendations and conclusions in this report.
Consacre
July 15, 2004
Page 2
SITE CONDITIONS
SURFACE CONDITIONS
The property is nearly flat. The site has been historically farmed, and the ground surface drains
toward the west. The ground appears to have lain fallow for several years.
SUBSURFACE CONDITIONS
Subsurface conditions at the site were explored to depths ranging from approximately 4 to 14 feet by
excavating ten test pits on July 2, 2004. The test pits were excavated with a Case 580L rubber -tired
backhoe subcontracted to GeoEngineers. The test pits were excavated at the approximate locations
shown in the Site Plan, Figure 2. Details of the field exploration, laboratory testing programs and the
exploration logs are presented in Appendix A.
We excavated three test pits, TP -1 through TP -3, within the proposed infiltration pond. We
- encountered stiff silt in the upper 31/2 to 41/2 feet. Below the silt, we encountered cemented soil (caliche)
to depths of 41/2 to 51/2 feet. We encountered gravel with sand and varying silt content below the caliche
to the bottom of the explorations at 101/2 to 14 feet.
Test pits TP4 through TP -10 were excavated along the alignment of the proposed roadways. The
locations for these test pits were staked in the field by the surveyors from Claiborn-Waite Consulting. We
- excavated within 20 feet of the stakes that they placed. The sod and root zone that we encountered in
TP4 through TP -10 was less than 1/2 -foot thick. Below the root zone, we encountered several feet of
stiff silt and/or clay. We often encountered a layer of caliche on the order of 3 to 5 feet below the existing
ground surface, and we occasionally encountered silty sand or silty gravel underlying the silt and clay.
No groundwater seepage was observed during our explorations. A piezometer was installed to a
depth of 14 feet in test pit TP -2, and we returned to the site on July 8, 2004 to measure the groundwater
within this piezometer as well as the piezometers installed previously at this site. Our groundwater
measurements are shown below. Groundwater depths are expected to vary as a function of season,
precipitation, irrigation, and other factors.
Test Pit Depth to Groundwater
(07-08-04)
TP -1 >14.1 feet (dry)
TP -1-02 16.5 feet
TP -2-02 16.6 feet
CONCLUSIONS AND RECOMMENDATIONS
SITE PREPARATION
We recommend that the proposed roadway areas be stripped of all sod and vegetation. This material
should be wasted off-site or used for landscaping purposes. The prevailing surficial site soils consist of
silt and clay and are moisture -sensitive, difficult to operate on and very difficult to compact during wet
- weather. Rubber -tired vehicles will disturb this type of soil when it is above the optimum moisture
content. It readily absorbs moisture and is difficult to dry out. It has a moderate erosion potential in -
IG e o E n g i n e e r s File No. 10283-001-03
Consacre
S my 15, 2004
Page 3
place and is easily transported by running water when disturbed. Therefore, silt fences and other
measures may be necessary to control erosion and sediment transport during construction. The vegetation
and topsoil act as protective layers to the surficial soil and should be removed only where and when
necessary.
The areas that are stripped or excavated to design subgrade elevations should be proofrolled with
heavy rubber -tired construction equipment. Any soft, loose or otherwise unsuitable areas identified
during proofrolling should be recompacted if practical or removed and replaced with structural fill. We
recommend the proofrolling of the subgrade be observed by a representative from our firm to assess the
adequacy of the subgrade conditions and to identify areas needing remedial work. We recommend that
this procedure not be performed during wet weather. If construction needs to continue during wet
weather, it may be necessary to overexcavate disturbed material and place a layer of sand and gravel with
less than 5 percent fines to provide a working surface over moisture -sensitive soils.
STRUCTURAL ILL
General
All new fill placed in roadway areas should be placed and compacted as structural fill subsequent to
site preparation work as appropriate. The fill should be placed in horizontal lifts not exceeding 10 inches
in loose thickness or that necessary to obtain adequate compaction. Each lift must be thoroughly and
uniformly compacted. We recommend that all structural fill placed within 2 feet of the bottom of
pavement elevation be compacted to at least 95 percent of the maximum dry density (MDD) as
determined by the ASTM D 1557 test procedure. Below this depth in roadway areas, we recommend that
structural fill be compacted tout least 90 percent of the MDD.
All structural fill material should be free of organics, debris and other deleterious material, with no
individual particles larger than 5 inches in diameter or one-half the lift thickness, whichever is smaller.
As the amount of fines increases, the soil becomes increasingly sensitive to small changes in moisture
content and adequate compaction becomes more difficult to achieve, particularly during wet weather.
Generally, soils containing more than about 5 percent fines by weight cannot be properly compacted
when the moisture content is more than a few percent from optimum.
Sufficient earthwork monitoring and a sufficient number of in-place density tests should be performed
to evaluate fill placement and compaction operations and to confirm that the required compaction is being
achieved.
Suitability of On -Site Soil
The surficial soils we encountered within the upper 4 to 5 feet consist of silt and clay. The clay
material is not suitable for structural fill. The gravel with sand soil typically encountered below the silt
and clay are well suited for use as structural fill; however, it is buried beneath several feet of overburden
and it will not likely comprise a significant amount of the soil excavated for utility installation. The silt
soils can be used as structural fill, but they are moisture sensitive and will be difficult to compact if the
moisture content is more than a few percent either wet or dry of optimum. From previous experience
with similar soils, we would expect the optimum moisture content to be in the range of 14 to 19 percent
for the silt and clay soils. The in-situ moisture contents observed during our investigation suggest that
G e o E n g i u e e r s File No. 10283-001-03
Consacre
'July 15, 2004
Page 4
moisture will need to be added to the soils to obtain adequate compaction. The moisture content of the
soils which we excavated was typically well below optimum for soils excavated above the water table.
These samples were obtained during the month of July. We would expect moisture conditions in the soil
to be somewhat higher during the winter months. It will likely be necessary to stop placing on-site soil as
structural fill during rains.
The silt encountered in our explorations has a low swell potential based on the Atterberg limits tests
which we completed for our preliminary evaluation of this project, however, the clay (not encountered in
our preliminary evaluation) has a moderate swell potential based on Soil Conservation Service soil survey
data. We recommend that the clay not be used for structural fill. It should also be removed from below
structural improvements that are sensitive to expansion, including, but not limited to, roadways and
sidewalks. While we did not complete expansion tests on the clay, it is'a low plasticity clay which
typically corresponds to a moderate risk of expansion damage to sidewalks and roads. In our experience,
covering this type of clay with at least 2 feet of non -plastic soil before constructing sidewalks and
pavements will usually protect the flatwork.
Imported Soil
Imported soil should conform to the recommendations provided in the "General" sectionabove. We
suggest that the fines content be limited to about 30 percent and that the Plasticity Index of such fines be
less than 10 for imported fill that will be placed during dry weather and on dry subgrades, provided that
the moisture content is near optimum to obtain adequate compaction. If structural fill is placed during
wet weather or will be reworked during wet weather, we recommend that select imported fill be used
consisting of well -graded sand and gravel with a fines content limited to 5 percent based on that portion
passing the 3/4 -inch sieve.
PERMANENTSLOPES
We recommend a maximum permanent slope inclination of 2H: 1V (horizontal to vertical) in the
native soil or in structural fill placed in accordance with our recommendations. Fill should be carefully
compacted on the slope face, or the fill embankment can be overbuilt and cut back to a 2H:1V
configuration. Permanent slopes must be hydroseeded or otherwise protected from erosion. Temporary
erosion control measures may be necessary until permanent vegetation is established.
INFILTRATION CONSIDERATIONS
Groundwater
We have completed several measurements of the groundwater levels at this site We have also
reviewed measurements by the Idaho Department of Water Resources (IDWR) that were obtained from
nearby water wells and other sources. These measurements indicate that groundwater in this vicinity
typically fluctuates about four to six feet with the seasonal high groundwater typically occurring in late
September. Based on our review of the limited IDWR and other data and our readings, we estimate the
seasonal high groundwater levels at the location of our piezometers on site (see attached Site Plan,
Figure 1) will be as shown in the table below. Fluctuations between the seasonal high groundwater
measurements and the November measurements in nearby wells ranged from one to two feet of change.
G e o E n g i n e e r s File No. 10283-001-03
Consacre
July 15, 2004
Page 5
,l
,;
We estimate that the water levels measured in the month of July are within about 2 feet of the seasonal
high groundwater level.
The estimates of seasonal high groundwater as shown above are estimates that should be refined by
additional measurements that extend through the late summer and early fall months.
Infiltration Rates
Test pits TP -1 through TP -3 were located in the proposed infiltration pond area of this site (Figure 2).
The table below describes the soil conditions and the allowable infiltration rate for each layer. We
recommend that the stormwater be discharged into the gravel with sand which we encountered below a
depth of about 51/2 feet in these three test pits.
Test Pit
Groundwater Measurements (feet)
Estimated Depth
To Seasonal
High
Groundwater
(feet)
Piezometer
Location
November 7,
2002
February 24
2004
March 31,
2004
July
TP -1-02
15.0
16.6 + (dry)
16.6 + (dry)
16,5
14
TP -2-02
16.1
17.8 + (dry)
17.8 + (dry)
16.6
14
I'P-2
n/a
n/a
n/a
>14.1 (dr)
>12
The estimates of seasonal high groundwater as shown above are estimates that should be refined by
additional measurements that extend through the late summer and early fall months.
Infiltration Rates
Test pits TP -1 through TP -3 were located in the proposed infiltration pond area of this site (Figure 2).
The table below describes the soil conditions and the allowable infiltration rate for each layer. We
recommend that the stormwater be discharged into the gravel with sand which we encountered below a
depth of about 51/2 feet in these three test pits.
Test Pit
Depth
Soil Tye
Allowable Infiltration Rate
TP -1 to
TP -3
0 to 4 feet
Silt
Not suitable for infiltration
4 to 51/2 feet
Caliche
Not suitable for infiltration
5 1/2 to 14 feet
Gravel with
Sand
8 inches per hour
The allowable infiltration rates listed above are based on the soil types encountered. They also
assume that the infiltration system will be designed and constructed in general accordance with Ada
County Highway District Development Policy Manual recommendations. If another methodology will be
" used, please consult with us to be sure that the infiltration rates above are applicable.
PAVEMENT SECTIONS
The pavement subgrade should be prepared in accordance with the recommendations in the "Site
Preparation" section of this report. No R -value tests were performed at the site, so we have used the
default pavement sections as described below which correspond to an approximate R -value of 10.
Residential Street Collector Street
Asphalt concrete 21/z inches 3 inches
3/4 -inch minus crushed base 4 inches 6 inches
6 -inch minus aggregate sub -base 14 inches 18 inches
a
1
G e o E n g i n e e r s File No. 10283-001-03
Consacre
July 15, 2004
Page 6
The thicknesses above are minimum thicknesses for each layer. The materials should meet the
requirements specified below.
We recommend that the roadway construction be completed in accordance with the current edition of
the Idaho Standards for Public Works Construction (ISPWC).
We recommend that the subbase material conform to all specifications for "6 -inch uncrushed
aggregate" as described in Section 801 of the ISPWC. The base course should conform to all of the
specifications for "3/4 -inch (Type I) crushed aggregate for base" as described in Section 802 of the
ISPWC. The plantmix pavement should conform to all of the specifications for Class II mix as described
in Section 810 of the ISPWC.
LIMITATION
We have prepared this report for use by the Consacre and the rest of the design team for the proposed
Razberry Crossing Subdivision to be constructed in Meridian, Idaho.
Within the limitations of scope, schedule and budget, our services have been executed in accordance
with generally accepted practices in the field of geotechnical engineering in this area at the time this
report was prepared. No warranty or other conditions, express or implied, should be understood.
Any electronic form or hard copy of this document (email, text, table, and/or figure), if provided, and
any attachments are only a copy of a master document. The master hard copy is stored by GeoEngineers,
Inc. and will serve as the official document of record.
Please refer to Appendix B titled "Report Limitations and Guidelines for Use" for additional
information pertaining to use of this report.
G e o E n g i n e e r s
File No. 10283-001-03
Consacre
July 15, 2004
Page 7
We appreciate this opportunity to be of service to Consacre. Please call if you have any questions
regarding this report, or if you need additional information.
DOD:DEA:mlh
DocId: BOIS\1028300104R.doe
Attachments
Figure I
Figure 2
Appendix A
Figure A-1
Figures A-2 to A-11
Figure A-12
Appendix B
Yours very truly,
GeoEngineers, Inc.
Doug Z. Argo, P.E.
Senior Enginep-)
�L'avid A. O'Day, P.E.
Principal
Vicinity Map
Site Plan
Field Exploration and Laboratory Testing
Soil Classification System
Logs of Test Pits
Moisture Content Results
Report Limitations and Guidelines for Use
One copy submitted
Cc: Brent Claiborn (Two copies)
Claibom Waite Consulting
Copyright® 2004 by GooEngineers, Inc. All rights reserved.
G e o E n g i n e e r s
File No. 10283-001-03
N
O
OD
Q
I—
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d
G e o B n g i n e e r s File No. 10283-001
APPENDIX
FIELD PL ATI N AND LABORATORY TESTING
EXPLORATION PROGRAM
The subsurface conditions of the site were explored using a rubber -tired backhoe on July 2, 2004.
Ten test pits were completed at the site to depths ranging from 51/2 to 14 feet deep. The approximate
locations of the explorations are shown in Figure 2. The explorations were located in the field by the
surveyors from Claibom Waite Consulting. Our test pits were located within approximately 20 feet of the
stakes placed by the surveyors within the proposed roadways and within the limits of the proposed
infiltration pond as defined by the stakes which the surveyors placed at the corners.
The test pits were observed by a geotechnical engineer from our firm who maintained detailed logs
and obtained representative samples of the soils encountered for further examination in our laboratory.
The soils encountered were visually classified in accordance with the system shown in Figure A-1. The
logs of the explorations are presented in Figures A-2 through A-11. The elevations indicated on the logs
are based on interpolation of the topography on the preliminary plat map provided to us relative to the
exploration locations. The densities noted on the logs are based on probing the exposed soils with a 1/2 -
inch -diameter steel rod, the difficulty of digging and our experience and judgment.
All soil samples were brought to our laboratory for further examination and laboratory testing.
Representative samples obtained from the explorations were tested to determine field moisture content.
The results of the moisture contents are presented in Figure A-12.
G e o E n g i n e e e s A-1 File No. 10283-001-031071504
SOIL CLASSIFICATION SYSTEM)
GROUP
MAJOR DIVISIONS
GROUP NAME
SYMBOL
GW
WELL -GRADED GRAVEL, FINE TO COARSE GRAVEL
GRAVEL
CLEAN GRAVEL
COARSE
GP
POORLY -GRADED GRAVEL
GRAINED More Than 50%
SOILS of Coarse Fraction
GRAVEL
GM
SILTY GRAVEL
Retained
WITH FINES
on No. 4 Sieve
GC
CLAYEY GRAVEL
SW
WELL -GRADED SAND, FINE TO COARSE SAND
SAND
CLEAN SAND
More Than 50%
SP
POORLY -GRADED SAND
Retained on
No. 200 Sieve More Than 50%.
SM
SILTY SAND
of Coarse Fraction
SAND
Passes
WITH FINES
Sc
CLAYEY SAND
No. 4 Sieve
ML
SILT
FINE SILT AND CLAY
INORGANIC
GRAINED
CL
CLAY
SOILS
Liquid Limit
ORGANIC
OL
ORGANIC SILT, ORGANIC CLAY
Less Than 50
MH
SILT OF HIGH PLASTICITY, ELASTIC SILT
More Than 50% SILT AND CLAY
INORGANIC
Passes
CH
CLAY OF HIGH PLASTICITY, FAT CLAY
No. 200 Slave
Liquid Limit
ORGANIC
OH
ORGANIC CLAY, ORGANIC SILT
50 or More
HIGHLY ORGANIC SOILS
PT
PEAT
NOTES:
SOIL MOISTURE
MODIFIERS:
t. Field classification Is based on visual examination
of soil in
Dry -
Absence of moisture, dusty, dry to the touch
general accordance with ASTM D2488-90.
Moist •
Damp, but no visible water
2. Soil classification using laboratory tests
is in general
accordance with ASTM D2487.90.
Wet -
Visible free water or saturated, usually soil is obtained from below
3. Descriptions of soil density or consistency are based on
water table
Interpretation of blow count data, visual appearance of soils,
and/or test data.
GWENGINEER��r
SOIL CLA551FICATtON SYSTEM
E
FIGURE A-1
fAsoila-l.doc
Date Excavated: 07/02/04 Logged by: DEA
Equipment: Case 580L Surface Elevation (ft), 2599.5
I
Date Excavated: 07/02/04
Equipment: Case 580L
Logged by: DEA
Surface Elevation (ft), 2599.5
Date Excavated: 07/02/04 Logged by: DEA
Equipment: Case 580L Surface Elevation (ft)• 2599.5
Date Excavated: by: DEA
Equipment: Case 580L Surface Elevation
I1 4
Date Excavated: 07/02/04
Equipment: Case580L
I
Logged by: DEA
Surface Elevation (ftp 2600
M
Date Excavated: 07/02/04
Equipment: Case 580L
C
Logged by: DEA
Surface Elevation (ft)• 2601.5
Date Excavated: 07/02/04
Equipment- Case 580L
Logged by: DEA
Surface Elevation (ft), 2602
Date Excavated: 07/02/04 Logged by: DEA
Equipment: Case 580L Surface Elevation (ft)• 2602
Date Excavated: 07/02/04 Logged by: DEA
Equipment: Case 580L Surface Elevation (ft)• 2603
Date Excavated: 07/02/04
Equipment: Case 580L
Logged by: DEA
Surface Elevation (ft)- 2604
�
J L® OF TEST PIT TP -10
Project: Razberry Crossing
Project Location: Boise, Idaho
Proiect Number: 10283-001-03
Figure: A-11
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0
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N+GINEE 5
APPENDIX
G e o 13 n g i n e e r File No. 10283-001
® '0
REPORT LIMITATIONS AN UI LIN USE'
This appendix provides information to help you manage your risks with respect to the use of this
report.
GEOTECHNICAL VI M FOR SPECIFICPURPOSES,
PERSONS AND PROJECTS
This report has been prepared for use by Consacre and the rest of the design team for Razberry
Crossing to be located northwest of the intersection of Locust Grove and East Star Lane as shown in
Figure 1. This report may be made available to local regulators for review. This report is not intended for
use by others, and the information contained herein is not applicable to other sites.
GeoEngineers structures our services to meet the specific needs of our clients. For example, a
geotechnical or geologic study conducted for a civil engineer or architect may not fulfill the needs of a
construction contractor or even another civil engineer or architect that are involved in the same project.
Because each geotechnical or geologic study is unique, each geotechnical engineering or geologic report
is unique, prepared solely for the specific client and project site. No one except Consacre and the design
team should rely on this report without first conferring with GeoEngineers. This report should not be
applied for any purpose or project except the one originally contemplated.
GEOTECHNICAL N IN IN L I T IS BASED ON A UNIQUE
T OF PROJECT-SPECIFICCT
This report has been prepared for the Razberry Crossing Subdivision in Meridian, Idaho.
GeoEngineers considered a number of unique, project -specific factors when establishing the scope of
services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on
this report if it was:
0 not prepared for you,
• not prepared for your project,
• not prepared for the specific site explored, or
• completed before important project changes were made.
For example, changes that can affect the applicability of this report include those that affect:
• the function of the proposed structure;
® elevation, configuration, location, orientation or weight of the proposed structure;
® composition of the design team; or
® project ownership.
If important changes are made after the date of this report, GeoEngineers should be given the
opportunity to review our interpretations and recommendations and provide written modifications or
confirmation, as appropriate.
1 Developed based on material provided by ASFE, Professional )~firms Practicing in the Geosciences; www.asfe.org .
G e o E n g i n e e r s B-1 File No. 10283-001-03\071504
® 1,
SUBSURFACE CONDITIONS CAN CHANGE
This geotechnical or geologic report is based on conditions that existed at the time the study was
performed. The findings and conclusions of this report may be affected by the passage of time, by
manmade events such as construction on or adjacent to the site, or by natural events such as floods,
earthquakes, slope instability or groundwater fluctuations. Always contact GeoEngineers before applying
a report to determine if it remains applicable.
MOST GEOTECHNICAL AND GEOLOGIC FINDINGS ARE PROFESSIONAL OPINION
Our interpretations of subsurface conditions are based on field observations from widely spaced
sampling locations at the site. Site exploration identifies subsurface conditions only at those points where
subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data
and then applied our professional judgment to render an opinion about subsurface conditions throughout
the site. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this
report. Our report, conclusions and interpretations should not be construed as a warranty of the
subsurface conditions.
GEOTECHNICAL ENGINEERING REPORT RECOMMENDATIONS ARE NOT FINAL
Do not over -rely on the preliminary construction recommendations included in this report. These
recommendations are not final, because they were developed principally from GeoEngineers' professional
judgment and opinion. GeoEngineers' recommendations can be finalized only by observing actual
subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or
liability for this report's recommendations if we do not perform construction observation.
Sufficient monitoring, testing and consultation by GeoEngineers should be provided during
construction to confirm that the conditions encountered are consistent with those indicated by the
explorations, to provide recommendations for design changes should the conditions revealed during the
work differ from those anticipated, and to evaluate whether or not earthwork activities are completed in
accordance with our recommendations. Retaining GeoEngineers for construction observation for this
project is the most effective method of managing the risks associated with unanticipated conditions.
A GEOTECHNICAL ENGINEERING OR GEOLOGIC REPORT COULD BE SUBJECT TO
MISINTERPRETATION
Misinterpretation of this report by other design team members can result in costly problems- You
could lower that risk by having GeoEngineers confer with appropriate members of the design team after
submitting the report. Also retain GeoEngineers to review pertinent elements of the design team's plans
and specifications. Contractors can also misinterpret a geotechnical engineering or geologic report.
Reduce that risk by having GeoEngineers participate in pre-bid and preconstruction conferences, and by
providing construction observation.
DO NOT REDRAW THE EXPLORATION LOGS
Geotechnical engineers and geologists prepare final boring and testing logs based upon their
interpretation of field logs and laboratory data. To prevent errors or omissions, the logs included in a
G e o E n g i n e e r s B-2 File No. 10283-001-03\071504
geotechnical engineering or geologic report should never be redrawn for inclusion in architectural or other
design drawings. Only photographic or electronic reproduction is acceptable, but recognize that
separating logs from the report can elevate risk.
GIVE CONTRACTORSMLT T AND GUIDANCE
Some owners and design professionals believe they can make contractors liable for unanticipated
subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems,
give contractors the complete geotechnical engineering or geologic report, but preface it with a clearly
written letter of transmittal. In that letter, advise contractors that isle report was not prepared for purposes
of bid development and that the report's accuracy is limited; encourage them to confer with GeoEngineers
and/or to conduct additional study to obtain the specific types of information they need or prefer. A pre-
bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study.
Only then might an owner be in a position to give contractors the best information available, while
requiring them to at least share the financial responsibilities stemming from unanticipated conditions.
Further, a contingency for unanticipated conditions should be included in your project budget and
schedule.
CONTRACTORS N I LE FOR SITE SAFETY ON THEIR N
CONSTRUCTION J T
Our geotechnical recommendations are not intended to direct the contractor's procedures, methods,
schedule or management of the work site. The contractor is solely responsible for job site safety and for
managing construction operations to minimize risks to on-site personnel and to adjacent properties.
READ THESE VI I N L LY
Some clients, design professionals and contractors may not recognize that the geoscience practices
(geotechnical engineering or geology) are far less exact than other engineering and natural science
disciplines. This lack of understanding can create unrealistic expectations that could lead to
disappointments, claims and disputes. GeoEngineers includes these explanatory "limitations" provisions
in our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these
"Report Limitations and Guidelines for Use" apply to your project or site.
GEOTECHNICAL, L I NVI ONM NTL REPORTS SHOULDNOT
BE
INTERCHANGED
The equipment, techniques and personnel used to perform an environmental study differ significantly
from those used to perform a geotechnical or geologic study and vice versa. For that reason, a
geotechnical engineering or geologic report does not usually relate any environmental findings,
conclusions or recommendations; e.g., about the likelihood of encountering underground storage tanks or
regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic
concerns regarding a specific project.
G e o E n g i n e e r s B-3 Pile No. 10283-001-03\071504