SW3240304_Soils/Geotechnical Report_20240820

U1tC'(tC'�C Intertek- PSI
5021-A W. WT Harris Blvd.
Charlotte, North Carolina 28269
Phone: [phone]
Fax: [phone]
August 18, 2023
Waffle House, Inc.
5986 Financial Drive
Norcross, Georgia 30071
Attn: Mr. Erik Haeffs
email: erikhaeffs(D-wafflehouse.com
Re: Report of Geotechnical Engineering Services
Proposed Waffle House Restaurant
7421 NC-73
Denver, North Carolina
PSI Report No.: 05111114
Dear Mr. Haeffs:
Professional Service Industries (PSI), an Intertek Company, is pleased to transmit our
Geotechnical Engineering Services Report for the proposed Waffle House Restaurant to be
located at 7421 NC-73 in Denver, North Carolina. This report includes the results of field and
laboratory testing, and recommendations for foundation and pavement design, as well as general
site development.
PSI appreciates the opportunity to perform this Geotechnical Study and looks forward to
continued participation during the design and construction phases of this project. If you have any
questions pertaining to this report, or if PSI may be of further service, please contact our office at
704-598-2234.
PSI also has great interest in providing materials testing and inspection services during the
construction of this project. If you will advise us of the appropriate time to discuss these
engineering services, we will be pleased to meet with you at your convenience.
Very truly yours,
PROFESSIONAL SERVICE INDUSTRIES, INC. THIS ITEM HAS BEEN DIGITALLY SIGNED AND
1 SEALED BY: ,.\ cnR ''%�
�r U Lloyd T Digitally signed by -�.� (N....._O(� .,�
�. ESSj
Lloyd T Lasher O.of 9
Lasher Date:2023.08.18 _ _�a SEAL
11:45:25-06'00' = 53158
Bryan L. Gordon, II Lloyd T. Lasher, Jr., P.E. : <'•.Froo,,,E�•',e;�
Technician II - Construction Senior Geotechnical Engineer
North Carolina License #53158
ON THE DATE ADJACENT TO THE SEAL
PRINTED COPIES OF THIS DOCUMENT ARE NOT
CONSIDERED SIGNED AND SEALED.
THE SIGNATURE MUST BE VERIFIED ON ANY
ELECTRONIC COPIES
www.intertek.com/building '^
V 1

Proposed Waffle House Restaurant, Denver, NC
PSI Report No.05111114
tonAugust 18, 2023
TABLE OF CONTENTS
1 PROJECT INFORMATION ..................................................................................... 1
1.1 PROPOSAL AND PROJECT AUTHORIZATION ............................................ 1
1.2 PROJECT DESCRIPTION .............................................................................. 1
1.3 PURPOSE AND SCOPE OF WORK .............................................................. 2
2 EXPLORATION PROCEDURES............................................................................2
2.1 FIELD SERVICES........................................................................................... 2
2.2 LABORATORY TESTING ............................................................................... 3
3 SITE AND SUBSURFACE CONDITIONS ..............................................................3
3.1 SITE DESCRIPTION....................................................................................... 3
3.2 SITE GEOLOGY ............................................................................................. 4
3.3 SUBSURFACE CONDITIONS ........................................................................ 4
4 GEOTECHNICAL EVALUATION AND RECOMMENDATIONS ............................6
4.1 GEOTECHNICAL ASSESSMENT .................................................................. 6
4.2 SITE PREPARATION AND EARTHWORK..................................................... 7
4.3 SEISMIC CONSIDERATIONS ...................................................................... 10
4.4 FOUNDATION RECOMMENDATIONS ........................................................ 11
4.5 FLOOR SLAB RECOMMENDATIONS ......................................................... 12
4.6 PAVEMENT DESIGN GUIDELINES AND PARAMETERS........................... 13
5 CONSTRUCTION CONSIDERATIONS................................................................ 15
5.1 GROUNDWATER ......................................................................................... 15
5.2 EXCAVATION AND SAFETY........................................................................ 15
6 REPORT LIMITATIONS ....................................................................................... 16
APPENDIX
Site Vicinity Map
Boring Location Plan
General Notes and Soil Classification Chart
Boring Logs

Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18,2023
1 PROJECT INFORMATION
1.1 PROPOSAL AND PROJECT AUTHORIZATION
This report presents the findings and recommendations of a geotechnical exploration and
assessment performed by Professional Service Industries (PSI) for the proposed Waffle House
Restaurant to be located at 7421 NC-73 in Denver, North Carolina. These services were
performed in general accordance with PSI Proposal No. 0511-395291 dated March 15, 2023.
Authorization to proceed was given to PSI on June 20, 2023.
1.2 PROJECT DESCRIPTION
Project information was provided through an emailed request for quote (RFQ) from Erik Haeffs of
Waffle House, Inc. on March 3, 2023. The RFQ included a boring location, presented as "Soil Tests
Locations."An ALTA/NSPS Land Title Survey by Professional Land Surveyors dated June 19, 2023
and a Site Plan by labelled Sheet CO2.1 by Contineo Group dated July 3, 2023 were also provided.
Based on the provided information, we understand that the development will include construction
of a single-story building with a concrete slab-on-grade floor to be located in the southwestern
corner of the site. The building will have a footprint of approximately 2,600 square feet (20' by
90'). Based on structural loads from the, "Soils Report Criteria and Site Evaluation Authorization"
document provided by Erik Haeffs; maximum anticipated column and wall loads will be on the
order of 9 kips and 1.8 kips per foot, respectively. Proposed pavement areas are also proposed
to the north and west of the proposed building. Traffic loading information was not provided at the
time of this report. However, we anticipate that traffic loads will be produced primarily by automobile
traffic, occasional delivery and trash removal trucks, and rare fully loaded semi-tractor trailers.
The provided "Soils Report Criteria and Site Evaluation Authorization" document indicates a
finished floor elevation (FFE) of 780 feet. No finished floor elevation or proposed grading
information was included with the provided site plan. The ground surface across most of the site
generally has a downward slope from north to south. Based on a review of Google Earth, the
provided ALTA Survey and our site reconnaissance, the ground surface elevations across the
site range from about 762 feet to 778 feet and about 767 to 771 feet in the proposed building
area. Therefore, fill depths of about 5 to 10 feet are estimated for the proposed building. Proposed
grades for the remainder of the site were not provided but fills on the order of 10 feet and cuts of
up to 2 feet are anticipated based on current site grades and the proposed FFE. The need or
location of any proposed retaining structures or slopes required to facilitate the proposed grade
changes were not provided.
The information presented in this section was used in the evaluation. Estimated loads and
corresponding foundation sizes have a direct effect on the recommendations, including the type
of foundation, the allowable soil bearing capacity, and the estimated potential settlement. In
addition, estimated subgrade elevations and cut/fill quantities can have a direct effect on the
provided recommendations. If any of the noted information is incorrect or has changed, please
inform PSI so that we may amend the recommendations presented in this report, if appropriate.
If PSI is not retained to perform this function, PSI cannot be responsible for the impact of the
changes on the performance of the project.
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Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18,2023
1.3 PURPOSE AND SCOPE OF WORK
The purpose of this study was to obtain information regarding the general subsurface conditions
within the proposed construction area, to assess the engineering characteristics of the subsurface
materials, and to provide general design recommendations regarding the geotechnical aspects of
the proposed construction. To accomplish this, PSI performed a site reconnaissance, drilled six
soil test borings within the areas of proposed site improvements, conducted laboratory
classification testing and prepared this report summarizing the findings, as well as our conclusions
and recommendations.
The scope of our geotechnical services did not include an environmental assessment for
determining the presence or absence of wetlands, or hazardous or toxic materials in the soil,
bedrock, groundwater, or air, on or below or around this site. Any statement in this report or on
the boring logs regarding odors, colors, unusual or suspicious items, or conditions are strictly for
the information of our client.
PSI did not provide nor was it requested to provide any service to investigate or detect the
presence of moisture, mold or other biological contaminants in or around any structure, or any
service that was designed or intended to prevent or lower the risk of the occurrence of the
amplification of the same. Client acknowledges that mold is ubiquitous to the environment with
mold amplification occurring when building materials are impacted by moisture. Client further
acknowledges that site conditions are outside of PSI's control, and that mold amplification will
likely occur, or continue to occur, in the presence of moisture. As such, PSI cannot and shall not
be held responsible for the occurrence or recurrence of mold amplification.
2 EXPLORATION PROCEDURES
2.1 FIELD SERVICES
PSI advanced eight soil test borings (Borings B-1 through B-8) within the proposed site. Not all
borings provided from the "Soil Test Locations" matched up with the "Soils Report Criteria and
Site Evaluation Authorization." Borings B-2 and B-4 were drilled to represent the proposed
building footprint, borings B-5 through B-8 represent the proposed pavement areas, B-1
represents the location for the sign and B-3 represents the location for the detention pond. The
approximate boring locations are shown on the "Boring Location Plan" (Figure 2) included in the
Appendix. Horizontal and vertical survey control was not performed for the test boring locations
prior to our field exploration program. The borings were located based upon estimated distances
and relationships to obvious landmarks, and the site plan provided by the client. The boring
locations are considered accurate to the degree implied by these methods.
The soil test boring was advanced at this site by HPC Drilling, a subcontractor hired by PSI,
utilizing a CME-55-X truck-mounted drilling rig using hollow-stem, continuous-flight augers. All
boring and sampling operations were conducted in general compliance with ASTM D 1586. At
regular intervals, soil samples were obtained with a standard 2-inch O.D. split-barrel sampler.
An automatic trip drop hammer was used for the standard penetration testing, which generally
has a higher efficiency than a manual cathead-and-rope hammer. Typically, the automatic
hammer yields lower standard penetration test resistances (N-values) than a manual cathead-
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Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18,2023
and-rope hammer. This reduction has been taken into account in our evaluation. However, the
N-values reported on the logs, and the consistency descriptions on the boring logs are based on
the field-recorded values and were not corrected for hammer efficiency.
The recovered soil samples were classified visually in the field by the drill crew and/or a PSI
representative, then transported to our laboratory for additional visual classification and laboratory
testing. A"Boring Log" was prepared for each boring and the "Logs" are included in the Appendix of
the report. The logs were prepared using the observations made in the field, as well as the
classifications in the laboratory and the laboratory test results. Strata descriptions, presented on the
logs, were based on visual-manual evaluations by our geologist and include the classifications in
general accordance with the Unified Soil Classification System(USCS). The"Soil Classification Chart",
included in the Appendix, illustrates the USCS legend depicted on the logs. The ground surface
elevations at each boring ground surface were interpolated from the provided topographic information
and should be considered approximate.
Groundwater levels were measured in the boreholes during drilling and upon completion. The
results of the measurements are presented in Section 3.3.3 and included on the soil test boring
logs when encountered. The borings were backfilled after removal of augers using the soil
cuttings or bentonite chips for safety considerations. Therefore, delayed groundwater level
readings are not available. Prior to backfilling the cave in depth was recorded.
2.2 LABORATORY TESTING
A geologist visually-manually classified the soil samples in the laboratory in general accordance
with the Unified Soil Classification System (USCS) (ASTM D2487 and D2488). Percent finer than
the No. 200 sieve (ASTM D1140), Atterberg limits tests (ASTM D4318), and natural water content
determinations (ASTM D2216) were conducted on representative samples recovered from the
test boring locations. The laboratory test results are presented in Section 3.3.4 and/or are shown
on the individual boring logs.
3 SITE AND SUBSURFACE CONDITIONS
3.1 SITE DESCRIPTION
The site encompasses an area of approximately 1 acre and is located southwest of the
intersection of NC-73 and Brentwood Road in Denver, North Carolina. The site location is
depicted on the "Site Vicinity Map" (Figure 1) included in the Appendix.
At the time of our site reconnaissance, majority of the site was forested. Rip rap site drainage was
observed in the southern end of the site (NC-73 side) along with sewer and utility lines parallel to
NC-73. Additional rip rap was discovered scattered around the perimeter of the forested areas on
site. The southern portion of the site was grass-covered with patches of overgrown vegetation.
The ground surface across most of the site generally has a downward slope to the south. Based on
site topographic information provided, relief across the site is approximately 20 feet with about half
of that relief occurring in the southernmost portion of the site along NC Highway-73.
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Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18,2023
PSI performed a review of historical aerial photographs of the site available on Google Earth.
Based on this, the site generally appears in its current condition from prior to 1993 until the
construction of Brentwood Rd which appeared to happen in 2017.
3.2 SITE GEOLOGY
The project site is located within Lincoln County, North Carolina, and lies within the Charlotte and
Milton Belts of the Piedmont Physiographic Province of the eastern United States. This province is
characterized by broad, gently rolling ridges formed on the stronger bedrock of the area. Between
these ridges, lowlands and drainage areas are formed on the less resistant bedrock. The Piedmont
is a complex assemblage of igneous (volcanic and plutonic) and sedimentary rocks that were
generally formed during the Late Proterozoic Era and the Early Cambrian Period (approximately 550
to 900 million years ago). During and subsequent to formation, these rocks were subjected to several
major tectonic events, including plate collisions,folding,faulting, and igneous intrusions,that resulted
in the uplift and metamorphism of the preexisting rocks. The tectonic activity generally stopped about
200 to 250 million years ago and erosional forces have formed the current ground surface. Review
of the Geologic Map of the Charlotte 1° by 2° Quadrangle, North Carolina and South Carolina
(USGS, by Goldsmith, Milton and Horton, 1988)indicates the site is underlain by meta quartz diorite
of late Proterozoic to early Cambrian age.
Residual soils are the result of in-place physical and chemical weathering of the parent bedrock. In
the Charlotte and Milton Belts residual soils generally consist of clays, silts and sands corresponding
to the composition of the parent bedrock. Separating the residual soil from the underlying parent
bedrock is typically a transition zone of high consistency material referred to as partially weathered
rock. Partially weathered rock is defined as residual material with standard penetration resistance
(ASTM D1586) in excess of 50 blows per 6-inches penetration.
The weathering processes that produced the residual soils and partially weathered rock were
extremely variable, due to such factors as rock type and mineralogy, past groundwater conditions,
and the tectonic history of the specific area (resulting in localized fractures, joints and faults within
the bedrock). Differential weathering of the parent bedrock has resulted in highly variable subsurface
conditions and can include abrupt changes in soil type and consistency over relatively short
horizontal and vertical distances. Furthermore, depths to rock can also be highly variable; and
suspended boulders, discontinuous rock layers/lenses, or rock pinnacles can be present within the
residual soils and transitional zones of soft weathered rock.
3.3 SUBSURFACE CONDITIONS
General subsurface conditions encountered during the subsurface exploration are described
below. For more detailed soil descriptions and stratifications at the boring locations, the "Boring
Logs" should be reviewed. The "Boring Logs" represent our interpretation of the subsurface
conditions based on a review of the field logs and an engineering examination of the samples.
The horizontal stratification lines designating the interface between various strata represent
approximate boundaries. Transition between different strata in the field may be gradual in both
the horizontal and vertical directions. Groundwater, or lack thereof, encountered in the borings
and noted on the "Boring Logs" represents conditions only at the time of the exploration.
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Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18, 2023
3.3.1 SURFACE
Topsoil ranged from approximately 5 to 8 inches thick across all the borings. However, deeper
pockets of topsoil may be present in other areas of the site. The term topsoil, as used in this report, is
a general designation given to the surface horizon of soil which appears to have an elevated organic
content. No laboratory testing was performed on the topsoil to determine its suitability for supporting
plant life, or ability to satisfy a particular specification.
3.3.2 RESIDUUM
Residual soils were encountered beneath the topsoil layer and extended to boring termination at
all of the boring locations. The residual soils consisted of medium stiff to very stiff Sandy SILT
(ML), Sandy Elastic SILT (MH) and Elastic SILT with Sand (MH).
3.3.3 GROUNDWATER INFORMATION
The borings were checked for groundwater during drilling and upon completion. Groundwater was
apparent in 3 out of the 8 borings, B-1, B-2 and B-4 at depths of 17 to 18 feet during drilling and at a
depth of 13 feet upon completion. The stabilized groundwater level in all other borings may have either
been below the terminated depths of the borings or static levels were obscured as the on-site soils
encountered were relatively impermeable. The borings were backfilled immediately upon completion,
using the soil cuttings, for safety considerations. Therefore, delayed groundwater levels are not
available.
Measured Groundwater
Boring Depth (feet) Boring Cave-in
During At Depth (feet) depth
drilling completion
B-1 NA 13 20 14
B-2 17 13 20 17
B-3 NA NA 15 9
B-4 18 NA 20 11 1/2
B-5 NA NA 15 7
B-6 NA NA 10 6 '/2
B-7 NA NA 10 6
B-8 NA NA 10 5
The groundwater information presented in this report is the information that was collected at the
time of our field activities. We recommend that the Contractor determine the actual groundwater
level at the site at the time of the construction activities.
Subsurface water levels within this region tend to fluctuate with seasonal and climatic changes,
as well as with some types of construction operations. Generally, the highest groundwater levels
occur in late winter and early spring; and the lowest levels in late summer and early fall.
Therefore, water may be encountered during construction at depths not indicated during this
study.
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Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18, 2023
Additionally, perched groundwater conditions can develop over low permeability soil or weathered
rock following periods of heavy or prolonged precipitation. We anticipate groundwater may perch
above the elastic SILTS encountered in the soil borings. Groundwater may be encountered
during construction at depths not indicated during this exploration.
3.3.4 LABORATORY TEST RESULTS
The results of the laboratory testing program are summarized in the following table.
Sample Sample Moisture Percent ATTERBERG LIMITS USCS
Location Depth Content /o)Fines LL PL PI Soil
(/o) ((feet) Classification
B-1 6—7 1/2 39 50.8 NP NP NP ML
B-1 18 '/2- 20 30 -- NP NP NP ML
B-2 13 '/2- 15 58 54.2 NP NP NP ML
B-3 1 —2 1/2 24 83.1 73 38 35 MH*
B-3 13 1/2- 15 70 -- -- -- -- MH*
B-4 13 '/2- 15 54 -- NP NP NP ML
B-5 8 '/2- 10 47 -- -- -- -- ML
B-8 6—7 '/2 16 -- -- -- -- ML
NP = Non-Plastic.
*Typically, not recommended for direct support of foundations, slabs or pavements.
4 GEOTECHNICAL EVALUATION AND RECOMMENDATIONS
4.1 GEOTECHNICAL ASSESSMENT
Highly plastic Elastic SILT (MH) was encountered at the site. These soils generally exhibit
moderately to highly plastic properties and are typically susceptible to changes in volume with
even slight changes in moisture content (i.e. shrink/swell behavior). As a result, MH soils are not
recommended for direct support of foundations, slabs or pavements. For this site we recommend
a minimum 2-foot thick buffer of low-plasticity structural fill material between these soils and slabs
or foundations. A minimum of a 1-foot buffer would be recommended for the pavement areas.
The extent of MH soils requiring undercutting during the proposed construction will be dependent
upon proposed grading plans. When MH soils are encountered at or within 2 feet of the foundation
or slab bearing elevation, they should be removed and replaced with low-plasticity structural fill
as described above. Therefore, the project budget should include a contingency for the removal
and replacement of residual MH soils to provide the buffers described above. The high plasticity
MH soils should be replaced with properly compacted fill. In addition, MH soils are not
recommended for reuse as structural fill and may consolidate if several feet of additional fill are
added on top of the MH soils.
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Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18,2023
Based on finished site grades being approximately 10 to 15 feet higher than current, we anticipate
the recommended buffers will be obtained by new fill placement and the majority of the highly
plastic soils will not require undercutting and removal to obtain the recommended buffers in
proposed fill areas. However, these MH soils will likely not pass a proofroll and will be difficult to
dry and compact, especially if exposed to the elements or weather. Therefore, some undercutting
and replacement or the placement of stone or aggregate may be required to achieve a stable
platform for additional fill placement. Once site grades are finalized, we strongly recommend this
information be provided so that potential consolidation or settlement due to the proposed fill
weight can be evaluated. It may be necessary to surcharge or preload the residual soils in order
to reduce potential settlement within tolerable levels..
High plasticity MH soils are moisture sensitive and will likely become unstable due to the presence
of excess moisture and normal construction equipment traffic operating over them. Accordingly,
construction traffic should be kept to a minimum on the exposed soils to reduce the potential for
creating an unstable subgrade. Elevated moisture contents were noted in some of the recovered
soil samples. Some drying and reworking of the on-site soils should be anticipated.
The following geotechnical design recommendations are based on the information available on
the proposed construction, the data obtained from our SPT soil borings, and our engineering
studies on the existing soils on this site. Because the borings represent a limited statistical
sampling of the subsurface materials, conditions encountered during construction may be
different from those encountered in our borings. In these instances, adjustments to the design
and construction may be necessary depending on the actual conditions encountered. If there is
any change in the project criteria, including structural loading, the location or orientation of
structures, or if the construction of earth retaining walls are required, PSI should be allowed to
review the plan to determine if additional fieldwork and/or any modifications to our
recommendations will be required.
Once final design plans and specifications are available, a general review by PSI is recommended
as a means to check that the evaluations made in preparation of this report are correct and that
earthwork and foundation recommendations are properly interpreted and implemented.
4.2 SITE PREPARATION AND EARTHWORK
Based on the results of our field exploration, we anticipate site preparation procedures to include the
steps listed below. All work should be carried out in accordance with current regulatory criteria. The
earthwork, testing, and foundation inspection required herein should be performed under the
supervision of PSI personnel. Site clearing, stripping and grubbing operations should only be
performed in dry weather conditions.
Initially, wet soils, topsoil, organics, debris and other unsuitable materials, should be stripped from an
area extending at least ten feet beyond the outline of the proposed construction. Removal of trees
should also include removal of their stumps and root balls, which can extend to several feet below
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Proposed Waffle House Restaurant, Denver, NC
tonPSI Report No.05111114
August 18,2023
grade. Removal of the near-surface, high plasticity MH soils as discussed in Section 4.1 will also
be required. Depressions or low areas resulting from stripping and grubbing or removal of utility lines,
septic systems, and other subsurface appurtenances should be backfilled with compacted structural
fill in accordance with the recommendations presented in this report. All unsuitable materials resulting
from the clearing and demolition operations should be wasted in non-structural areas or legally
disposed off-site.
Based on grading plans, the need for undercutting of near surface plastic residual MH soils is not
anticipated to provide adequate buffers for structural elements, however; may be required to provide a
firm and stable subgrade for placement of new fill. Actual extents and depths of required undercut will
be dependent upon final site grades and will be determined in the field by PSI personnel during grading
operations. We do not recommend that the on-site Sandy Elastic SILT (MH) soils be reused as
structural fill.
We caution that the subgrade soils exposed after stripping may contain sufficient silt to render them
both moisture sensitive and frost susceptible. Due to their moisture sensitivity, proper site drainage
should be maintained during earthwork operations to reduce accumulation of moisture and wet
weather delays.These soils may become unstable due to the presence of excess moisture and normal
construction equipment traffic operating over them. Accordingly, construction traffic should be kept to
a minimum on the exposed soils to reduce the potential for creating an unstable subgrade. If the surface
soils become softened/unstable during wet weather or frozen, these soils should be removed before
additional fill is placed.
Drying soils for re-use as structural fill is often considered a routine aspect of typical grading operations
and is not considered a pay item. However, the silt soils encountered at the site will be more difficult
to dry and compact than most area soils typically considered suitable for support of commercial
construction. If unit prices for earthwork operations are established, they should be examined closely
before the contract is executed. If undercutting is a pay item, then undercut volumes should be
determined by field measurement. Methods such as counting trucks should not be used for
determination of undercut volume, as they are less accurate. Due to the presence of elevated in-situ
moistures for the site soils, some drying should be expected.
Recommended criteria for soil fill characteristics(both on-site and imported materials)and compaction
procedures are listed below. The project design documents should include the following
recommendations to address proper placement and compaction of project fill materials. Earthwork
operations should not begin until representative samples are collected and tested. The maximum dry
density and optimum moisture content should be determined.
Site preparation procedures should include stripping, removal of unsuitable surface soils, and rough
excavation grading,we recommend that areas to provide support for the floor slabs, pavements,and/or
structural fill be evaluated for the presence of soft, surficial soils and/or plastic soils by proofrolling and
inspection by the Geotechnical Engineer. The proofroll should be performed using a loaded tandem
axle dump truck, or similar rubber-tired equipment, weighing between 15 and 25 tons. The vehicle
should make at least four passes over each location, with the last two passes perpendicular to the first
two. Areas that wave, rut, or deflect significantly and continue to do so after several passes of the
proofroller should be undercut to firmer soils as recommended by the Geotechnical Engineer. Based
on the borings, some over-excavation of high plastic soils should be expected. Undercut areas should
be backfilled in thin lifts with approved, compacted fill materials. Proofroll operations should be
monitored carefully by PSI's Project Geotechnical Engineer.
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