assessment of previous geotechnical design...

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• Assessment of previous geotechnical design recommendations relative to foundation support and the conditions found at the location of the FTR.

• Assessment of the stability of the proposed berms founded on soft, weak soils during construction.

METHODS OF STUDY

Our field study was performed February 26, 2019 and consisted of advancing two cone penetrometer test (CPT) soundings (19-CPT-18 [“18A”] within the proposed footprint of the training building and 19-CPT-19 near the anticipated tallest berm). This testing equipment and associated operating services were provided by ConeTec of Salt Lake City, Utah, under subcontract to Gerhart Cole. The locations of the CPT soundings are shown in Figure 1 and were selected based on direction from the design team. Also shown in the figure is 15-CPT-03 which is a previous CPT sounding within the footprint of the FTR made by Epic Engineering during preliminary studies for the USCF. The 2019 CPT soundings were advanced using truck-mounted equipment with a 15-cm2 piezocone (tip net area ratio of 0.80), with depths of 30 and 50 feet. At the time the soundings were made, a working platform had not been constructed in the area of the proposed tanks. Pore pressure dissipation tests were performed at selected depths to help assess groundwater conditions. Additional information regarding these soundings is summarized in Table 1. It should be noted that any latitude, longitude, or elevation information shown in the Attachment is approximate, obtained in the field at the time of the field study without the benefit of a more traditional land survey. The location/position information shown in Table 1 and provided by the project team is considered to be more reliable. One benefit of cone penetration testing is that it provides a near continuous measurement of penetration resistance within a soil profile. This ability, coupled with other measurements made by the cone, helps delineate stratigraphy more precisely than with traditional test hole drilling. The CPT, however, does not provide a soil sample. When interpreting soil type from CPT results, it is important to recognize that the soil behavior type (SBT) index shown on the logs is determined by correlation, and actual soil types may vary; soil behavior type index is not the same as a Unified Soil Classification System (USCS) soil type which is typically shown on test hole logs. Specific subsurface conditions indicated by the CPT soundings are discussed in the next section. Complete CPT sounding logs together with supplemental data such as pore pressure dissipation testing data are included in Attachment A. The log for Epic’s previous 15-CPT-03 (“CPT-03”) sounding is also included in Attachment A. SITE CONDITIONS

For a comprehensive discussion of regional geologic setting and site-specific surface and subsurface conditions, the reader is referred to our Phase 2 report for the USCF site dated January 9, 2018.

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Based on the CPT soundings made, the native subsurface soil profile generally consists of soft to medium stiff silt (ML), silty clay (CL-ML), and clay (CL) along with loose to medium dense silty sand (SM) and poorly graded sand (SP), extending from the pre-construction ground surface to a depth of about 6 feet. These soils are underlain by soft to medium stiff lean clay (CL) and high plasticity clay (CH) that generally extends to a depth of at least 16 feet, where the sequence may be interrupted by a sand layer several feet thick; otherwise the clays appear to extend to depths on the order of 22 to 25 feet, where they become increasingly stiffer and interbedded with silt and sand layers to depths which exceed 30 feet. Table 1 as well as a similar table in Attachment A summarizes inferred groundwater levels from pore pressure dissipation (PPD) testing. In the case of CPT-based PPD testing data, depth to water table is based on the shallowest measurement. The groundwater data from the field study indicates the water table at the time of the field study was within about 3 to 5 feet of the ground surface, and this is generally consistent with previous observations in the general vicinity. While the water table depth can be inferred from CPT pore pressure dissipation testing results, they can be affected by groundwater gradients. It should be recognized that groundwater levels fluctuate in response to meteoric events and with seasonal changes. ANALYSIS AND DESIGN RECOMMENDATIONS

General

Based on information provided by DFCM, we understand that the FTR facility will consist of one single story building approximately 50 feet by 100 feet in plan. Structural loadings are not available at this time, but we anticipate that service-state loadings will be less than 3 kips/lineal-foot and 50 kips for wall and column loads, respectively, and that there are no special settlement considerations. Another feature of FTR facility is the use of earthen berms to delineate firing lanes and serve as backstops. As shown in preliminary drawings provided to us, the berms are to be on the order of 15 to 36 feet tall, having crest widths of approximately 7 feet together with steep side slopes, although we understand from subsequent conversations with team members that the maximum height of the berms will likely be much less than 36 feet. Recommendations Regarding Grading and Earthwork

We understand that grading plans for the site have not yet been developed. It should be recognized that an important consideration affecting future performance of foundations at this site will be site grading. It is the combined effect of any new fill together with the structural loads from the buildings that dictate the amount of settlement that will occur. From a geotechnical engineering standpoint, it is advantageous to minimize fill heights and footprints in order to provide larger allowable bearing capacities based on service state loads for building foundations. However, it is also recognized that some minimum amount of granular fill is advantageous in providing a surface to facilitate construction and site mobility. Also, grading should be planned such that ground will slope away from structures and provide overall drainage for the site.

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Although the reader should refer to our report “Geotechnical Study – Phase 2, Utah State Correctional Facility (USCF)” dated January 9, 2018 for more complete coverage of earthwork issues and recommendations, particular discussion of a few matter follow. To avoid pumping and overstressing of the subgrade, the Contractor may need to use lightweight equipment, and/or track-mounted (not wheeled) equipment in the performance of earthwork activities.

Given the relatively soft and loose soils found at shallow depths across the site, special consideration must be given to site preparation (stripping and subgrade compaction) activities to reduce the potential for creating unstable, pumping soil conditions. We recommend that only minimal site stripping occur within the planned building and pavement areas. The root mat of existing grasses and weeds should generally remain in place. The intent of this approach is to preserve, to the extent possible, the firmer surficial soil crust that exists in areas. Existing vegetation which is relatively sparse should be closely mowed (residual of about 1 inch or less and with cuttings removed) or preferably burned (if allowed) to reduce the amount of surficial vegetation. Larger roots of shrubs and/or trees should locally be removed to a depth of 12 inches. Following stripping, the exposed subgrade should be proof-rolled with the type of equipment anticipated to be used in construction of the building pad to identify any areas of significant instability. Where significant instability or pumping conditions are observed, these areas should be stabilized with the placement of clean, angular gravel and/or geotextile reinforcement fabric or geogrid. The Geotechnical Engineer should assess the severity of the conditions exposed, and assist the contractor in identifying an appropriate means to mitigate the unstable conditions. Fill materials supporting improvements where settlement or stability is of concern should not be placed in free water or on frozen ground. While frozen ground conditions may facilitate mobility on otherwise soft and/or loose subgrade, placing earthwork on a frozen subgrade is generally not recommended. Compaction and/or proof-rolling of the subgrade is ineffective if it is frozen. In no case should frozen materials be placed as fill. We recommend that select structural fill be used when excavations for either foundations or slabs extend below the native subgrade. If a thickness of structural fill is used to increase bearing capacity (shear resistance), the materials should be select structural fill. Once these requirements are satisfied, remaining fill used below either structure foundations or slabs may be grading fill as described below. Select structural fill material should meet criteria for A-1-a soil as designated by AASHTO M 145. The fill should extend a minimum of 1 foot below the foundation and extend laterally beyond the edge of the foundation a minimum distance equal to the thickness of the fill. The material should be placed in maximum 10-inch loose lifts, moisture conditioned to within 2 percent of optimum moisture content, and compacted to a minimum of 95 percent of the maximum dry density (MDD) as determined by ASTM D 1557 (modified Proctor). Apart from the select structural fill, we recommend that grading fill be placed beneath all building and pavement areas, and all other areas where settlement would be a potential

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concern. Grading fill should meet criteria for A-2-4 or A-2-5 or better (including A-1) as designated by AASHTO M145. The material should be placed in maximum 10-inch loose lifts, moisture conditioned to within 2 percent of optimum moisture content. Beneath structures and pavements, the material should be compacted to a minimum of 95 percent of MDD (modified Proctor, ASTM D 1557). Compaction in other areas may be reduced to 90 percent. It should be noted, however, that if fill placement activities occur during extended wet weather conditions, the contractor may elect to use an imported material with limited fines (15% or less passing the #200 mesh sieve) and a higher gravel content (maximum 50% passing the #4 mesh sieve). Such material will be less susceptible to instability under wet weather placement conditions. For other fill areas (excluding backfill areas and beneath berms), consideration may be given to using a landscape fill material. This material may consist of native sand, silt and clay soils having an organic content less than 5 percent, or imported material (subject to Engineer’s approval), as desired. Native soils excavated from depths below approximately 2 to 5 feet will likely be wet, and due to their generally cohesive nature, may have a blocky structure. If used as fill, such material will likely require disking and drying prior to placement. Landscape fill soils should be placed in uniform loose lifts of less than 12-inches and lightly compacted with track-mounted equipment. No minimum compaction criteria are necessary for this material. It must be recognized that if structures, pavement, or hardscaping are subsequently placed in landscape fill areas, all underlying fill and the native subgrade will likely need to be reworked (removed and replaced). The landscape fill as described above could present stability and/or limited mobility issues, particularly if the fill is not more densely compacted and/or the subgrade becomes wet (such as from surface water). To provide a higher degree of stability / mobility /traffickability, the contractor may elect to use a higher quality, imported granular material like grading fill or select structural fill.

To provide a relatively high degree of mobility for haul trucks and equipment across the site (which can be very challenging during wet periods), consideration should be given to constructing a working platform at the site that can be installed prior to placing other fill materials or foundations. After proof-rolling and subgrade compaction, it is recommended that the subgrade be overlain with a separation/reinforcement geotextile fabric, such as Mirafi 600X or approved substitute. Fabric rolls should be overlapped a minimum of 1 foot, with greater overlap (2 feet or more) in areas of extreme rutting/pumping. It is critically important that the fabric be pulled and held taut as backfill is placed over the fabric. Care should be taken to avoid direct contact between the fabric and equipment tires or tracks. The fill should be back-dumped on the fabric or subgrade soil and spread with low-pressure tracked equipment. For the working platform, an initial 12-inch thick layer of select structural fill material would then be placed over the fabric. This material should be compacted with a medium-weight, smooth drum, static roller under the observation of the Geotechnical Engineer, with the intent of producing as firm of lift as reasonably possible. The Geotechnical Engineer will assist the Contractor in establishing an optimal rolling pattern without over-stressing the subgrade. While the pattern would initially be evaluated at the beginning of the work, periodic re-evaluation as the work progresses

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across the site should be expected due to the inherent variability of the subgrade. Afterward, a 6-inch lift of select structural fill material is recommended to be placed over the separation geotextile. This material should meet criteria for A-1-a soil as designated by AASHTO M 145, with a maximum particle size of 1 inch. This material should be moisture conditioned to within 2 percent of optimum moisture content and compacted using typical compaction methods (likely including vibration) to a minimum of 95 percent of the maximum dry density (MDD) as determined by ASTM D 1557 (modified Proctor). Another lift would then be placed, moisture-conditioned as above, and the compacted to a minimum of 95 percent of MDD (modified Proctor), resulting in a total 24-inch compacted thickness, inclusive of three lifts. It is important to recognize that there may be difficulty in achieving compaction and the Geotechnical Engineer should be consulted as needed to assess the causes and recommend remedial measures and/or modify the acceptance requirements. Without such input and with indiscriminate attempts to achieve target compaction levels, there is potential for aggravating / destabilizing already challenging ground conditions. Analysis and Recommendations for Training Building Foundation

Results of the field study suggest that subsurface conditions at the FTR building are similar to those used in development of shallow foundation recommendations for the UCSF buildings. We note that some of the deeper soils differ somewhat, but this is not of practical concern for shallow foundations. As discussed in the Phase 2 Geotechnical Study for the USCF, there are several design considerations associated with this site. Two primary considerations – adverse consolidation (primary and secondary) settlement, and relatively low bearing capacity for foundations – stem from the soft clay soil present. As discussed above, an important consideration affecting the foundation performance will be site grading. It is the combined effect of any new fill together with the structural loads from the buildings that dictate the amount of settlement. Hence, from a geotechnical engineering standpoint, it is advantageous to minimize fill heights and footprints in order to provide larger allowable bearing capacities for building foundations. It is anticipated that the FTR building will be supported on shallow foundations. (If another type of foundation system is desired, please contact us for applicable design parameters). For the site, we assessed settlement and bearing capacity (resistance) for shallow foundations by considering three ranges of fill height: from 1.5 to 3 feet, from 3 to 4.5 feet, and from 4.5 to 6.0 feet. For the middle range, we estimate that the pressure caused by placement of these various depths of fill (which would consider any working platform as fill) will produce ground settlement ranging up to approximately 1/2-inch to 1-3/4 inches. This settlement should occur relatively quickly, with approximately 75% occurring within a few weeks. Additional settlement coming from the subsequent load of buildings will tend to occur more slowly as the clay soil begin to exceed their preconsolidation (i.e., yield) pressure. For the USCF project, a frost depth of 30 inches (consistent with local practice) has been adopted as a design criterion and is reflected in our recommendations the FTR building. Additionally, also consistent with USCF project design criteria, our

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recommendations reflect a 2-inch or less, long-term (75-year) settlement criterion for the FTR building (which is inclusive of immediate, primary consolidation, and secondary (creep) settlements), with up to 1 inch of allowable differential settlement over a distance of 25 feet. To reduce unnecessary conservatism, parametric design charts have been prepared (see Figures 2 through 7) indicating allowable bearing pressure for both square (column) and strip (continuous wall) foundations as a function of foundation (footing) width and allowable settlement for the three different ranges of grading fill thickness. The charts also indicate potential increases in allowable bearing capacity with the addition of some structural fill (via over excavation, “OX”) below the foundation. It can be seen in Figures 2 through 7 that each Figure consists of two charts, with the 2-inch settlement (“S=2-in”) curve in the lower chart representing total combined immediate, primary consolidation, and secondary (creep) settlement. Settlement in the upper chart is similar, but without including secondary settlement. We recommend that the lower chart be used for design, with the upper chart being presented as a means of expressing secondary settlement effects. Differential settlement between any two adjacent, similarly sized and loaded foundation elements in the same structure is expected to be about half the total estimated settlement.

When using allowable bearing capacities from these charts, pressures related to the settlement criteria are those associated with dead loads and any sustained live loads. Pressures relating to shear strength limit criteria are pressures reflecting combined total dead and live loads. For seismic cases, the allowable bearing pressure can be increased by one-third. The allowable bearing pressures shown in the charts are based on a factor of safety of 3 against general shear failure. For LRFD-based design, allowable bearing capacity can be multiplied by the factor of safety to obtain the ultimate (i.e., unfactored) soil resistance. Foundation widths smaller than the smallest widths shown on the charts are not recommended.

When evaluating the lateral sliding resistance for cast-in-place concrete foundations bearing on native near-surface clayey soils, the lesser of an adhesion of 450 psf or the product of the effective overburden pressure times a friction coefficient of 0.35 may be used. For such foundation elements bearing on the important granular fill, a friction coefficient of 0.50 may be used. Being ultimate values, these values should be considered as representing the maximum resistance to sliding just as sliding starts to occur and contain no inherent factor of safety.

Analysis and Recommendations for Berms

The soft soils at the site can affect the stability of the berms during construction, and we have performed stability analyses to evaluate the height that can be reached in a single phase of construction as well as expected settlement. Berm geometry used in our analyses is as described previously. Differing geometries may present different stability conditions and should be assessed; this is particularly true if the crest width is appreciably greater. It should be recognized that independent of soft soil foundation conditions, for berms constructed of coarser granular materials, side slopes steeper

8

than 1.5H:1V will likely present raveling issues within the berm material and require internal reinforcement (the design of which is beyond the scope of this document). For berms constructed of finer grained materials, flatter slopes would similarly be required. Absent a description of the materials preferred to be used for the berms, we have assumed in our analyses that the soils used will be permeable enough to preclude the development of excess internal pore pressures during placement and compaction (even if the compaction only consists of relatively uniform coverage from wheeled construction equipment). In terms of shear strength, we have modeled the berm materials has having a friction angle of 32 degrees and 50 psf compaction. Based on our analyses and factor of safety of 1.2 against short-term shear failure during construction (which would present the more adverse stability condition when compared to long term stability, and assuming seismic stability is not applicable), our recommended maximum berm height during a single stage of construction is shown in Table 2. As expected, the results show that berms with flatter slopes are inherently more stable, and hence can be constructed to greater heights in a single stage of construction. Once the maximum stage height is reached, the embankment should be allowed to settle and the foundation soils gain strength. After a period of time (from many months to perhaps a year or somewhat more), construction might resume to raise the embankment higher. The use of staged construction methods typically requires monitoring and instrumentation. Given that berm geometries and heights are not well established at this time, further analyses and instrumentation recommendations cannot be made/provided at this time. Once available, we recommend that final plans for berms be reviewed and reassessed as needed. Calculated amounts of settlement caused by construction of the berms are presented in Table 2. It is anticipated that the primary consolidation settlements induced by berm construction will occur during construction of the berm and continue over a period of many months (perhaps up to a year or somewhat more). Additional secondary settlements of smaller magnitude are expected to occur throughout the life of the project. OTHER ITEMS

It is important to recognize that this document does not constitute a specification, and should not be referred to as such in project design drawings or documents. The scope of this document is such that it does not address all geotechnical engineering aspects relating to the project features highlighted herein. For additional information and recommendations, the reader is referred to previous studies prepared for the USCF project, particularly the Phase 2 study report. ADDITIONAL SERVICES

At this stage of the project, we anticipate there will be a need for additional services. Such services would include, but are not necessarily limited to:

• Review of final design drawings and specifications, particularly with respect to berm construction

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• Observation of site stripping, proof-rolling, and excavation activities

• Observation and testing of earthwork

• Observation of footing excavations

• Consultation as may be required during construction.

It is our opinion that active involvement of the geotechnical design engineer throughout all phases of this project will help in making this project a success. LIMITATIONS

Assessments and recommendations in this document are based on our field test data as well as our understanding of the project’s design and manner of construction. If the project’s design or manner of construction changes, or if conditions are found later that are different from those described, we should be notified immediately so that we can make revisions as necessary. We recommend that all construction related submittals, foundation plans, and work plans be reviewed by Gerhart Cole for compatibility with our recommendations.

This document was prepared solely for the use of our Client for the referenced project, and may not contain sufficient information for other parties or uses. We represent that our services are performed within the limitations prescribed by our Client, in a manner consistent with the level of care and skill ordinarily exercised by other professional consultants under similar circumstances. No other representation, expressed or implied, and no warranty or guarantee is included or intended. We do not assume responsibility for the accuracy of information provided by others.

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Table 1 Study Location Summary Table

CPT Date

Advanced WGS 84 Latitude

WGS 84 Longitude

Project Northing 1

Project Easting 1

Elev.1 (ft) Total depth

(ft)

Water depth2

(ft)

15-CPT-03 (Epic) 04/30/15 40.808333 -112.084192 - - - - - - 4219.4 125.2 3.8

19-CPT-18a 02/26/19 40.808237 -112.083861 7463589 1478972 4219.8 30.0 5.0

19-CPT-19 02/26/19 40.808563 -112.086748 7463810 1477984 4218.4 50.0 2.9

Notes: 1. Project survey information provided by design team; may be estimated in some cases; world geodetic system (WGS) coordinates by GC

2. CPT-based water depths calculated from PPD data

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Table 2 Berm Stability and Settlement Analysis Results

Embankment Configuration

Maximum Height (ft) in Single

Stage of Construction

Estimated Elastic and Primary

Consolidation Settlement (in) at

Crest, Toe

1H:1V Side Slopes. 7-ft wide crest 10 3, 1

1.5H:1V Side Slopes. 7-ft wide crest 26 15, 1

2H:1V Side Slopes. 7-ft wide crest 33 21, 1

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

EE

E

E

E

E

E

#*

#*

APPROXIMATE LIMIT OF FIREARMS TRAINING RANGE

15-BH-08

15-CPT-03

15-TP-09

16-TH-06

16-CPT-07

17-TH-06

17-TH-08

17-TP-10

17-CPT-17

17-CPT-19

17-CPT-20

17-CPT-21

17-CPT-26

17-CPT-27

17-CPT-28

17-CPT-29

18-RMP-CPT-1218-RMP-CPT-13

18-RMP-CPT-14

18-CPT-11

18-CPT-12

18-CPT-13

18-CPT-14

19-CPT-18

19-CPT-19

LEGEND#* CPT - This Study

E Previous Study Point

USCF PROJECT - FIREARMS TRAINING RANGE

Figure 1

0 250 500125

Feet

PHASE 5 GEOTECHNICAL STUDY LOCATIONS ±B

RIG

HT

ON

CA

NA

L

150 SOUTH

NORTH POINT CONSOLIDATED CANAL

OLD

CO

NVEYO

RRO

UTE

Figure 2

Allowable Bearing Pressure Versus Foundation Sizeas Function of Settlement (inches) and Shear Strength Limit,

Continuous (Strip) Foundation, 1.5 to 3 feet of Site Fill

Firearms Training Range

0

0.5

1

1.5

2

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3

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Allo

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Bearing P

ressure

(ksf)

Foundation Width (ft)

a) 100% Primary Consolidation Settlement

0

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Allo

wable

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ressure

(ksf)


S=2in Strength Limit, no OX Strength Limit, OX=1ft Strength Limit, OX=2ft

b) 100% Primary Consolidation Settlement + 75 year Creep

Figure 3


Square Foundation, 1.5 to 3 feet of Site Fill


0

0.5

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Figure 4


Continuous (Strip) Foundation, 3 to 4.5 feet of Site Fill


0

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Figure 5


Square Foundation, 3 to 4.5 feet of Site Fill


0

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Figure 6


Continuous (Strip) Foundation, 4.5 to 6 feet of Site Fill


0

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0 1 2 3 4 5 6 7

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0

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Figure 7


Square Foundation, 4.5 to 6 feet of Site Fill


0

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4

0 3 6 9 12 15

Allo

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ressure

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0

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3

3.5

4

0 3 6 9 12 15

Allo

wable

Bearing P

ressure

(ksf)




12

ATTACHMENT A – CONE PENETRATION TEST (CPT) RESULTS

The reported coordinates were acquired from consumer grade GPS equipment and are only approximate locations. The coordinates should not be used for design purposes.

0 100 200 300 400

0

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qt (tsf)

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pth

(fe

et)

0.0 1.0 2.0 3.0 4.0

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0.0 2.0 4.0 6.0

Rf (%)

0 6 12

SBT

Gerhart ColeJob No: 19-52026

Date: 2019-02-26 12:46

Site: USCF

Sounding: 19-CPT-18A

Cone: 553:T1500F15U500

Max Depth: 9.150 m / 30.02 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: 0.150 m

File: 19-52026_CP18A.CORUnit Wt: SBT (R&C1986)

SBT: Robertson and Campanella, 1986Coords: Lat: 40.807991 Long: -112.083164

Clayey SiltSilty ClayClayey SiltSiltSandy SiltSilty Sand/SandSandy Silt

ClaySensitive FinesSilty Clay

Sensitive Fines

Silt

Sensitive Fines

Silt

Sandy SiltSilty Sand/Sand

Sand

Silty Sand/SandSiltSensitive Fines

Sandy SiltSilt

SiltSandy Silt

Silt

Sensitive Fines

11.7

Ueq(ft)

Target Depth Target Depth Target Depth Target Depth

Overplot Item: Assumed UeqUeq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic Line Phreatic Surface


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0 6 12

SBT


Date: 2019-02-26 14:11

Site: USCF

Sounding: 19-CPT-19

Cone: 553:T1500F15U500


File: 19-52026_CP19.CORUnit Wt: SBT (R&C1986)

SBT: Robertson and Campanella, 1986Coords: Lat: 40.808567 Long: -112.086719

Silt

Clayey SiltSiltSilt

Silty Sand/SandSandy SiltClayey Silt

Clay

Silty Clay

Silt

Sensitive Fines

Silty Sand/SandSandy Silt

Sensitive Fines

Sandy SiltSandy Silt

Sandy SiltSilt

SiltSandy SiltSandy SiltSandy SiltSiltSandy SiltSiltSilty Sand/Sand

Sand

Silt

Sand

SiltSiltSandy Silt

Silt

Sandy SiltSiltSandy SiltSilty Sand/SandSiltSilty Sand/Sand

25.8

36.3

47.8

Ueq(ft)



Normalized Cone Penetration Test Plots


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0 3 6 9

SBT Qtn


Date: 2019-02-26 12:46

Site: USCF


Cone: 553:T1500F15U500


File: 19-52026_CP18A.CORUnit Wt: SBTQtn (PKR2009)

SBT: Robertson, 2009 and 2010Coords: Lat: 40.807991 Long: -112.083164

Silt Mixtures

Silt Mixtures

Sand Mixtures

Sands

Sand Mixtures

Clays

Sand Mixtures

Sensitive, Fine Grained

Sand Mixtures

Sand MixturesSandsSand Mixtures

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Silt Mixtures

Sand Mixtures

11.7

Ueq(ft)




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0 100 200 3000

u (ft)

0.0 1.0 2.0 3.0 4.0

Ic (PKR 2009)

0 3 6 9

SBT Qtn


Date: 2019-02-26 14:11

Site: USCF

Sounding: 19-CPT-19

Cone: 553:T1500F15U500


File: 19-52026_CP19.CORUnit Wt: SBTQtn (PKR2009)

SBT: Robertson, 2009 and 2010Coords: Lat: 40.808567 Long: -112.086719

Sand MixturesSilt Mixtures

Sand Mixtures

SandsSand MixturesSilt Mixtures

Clays

Silt MixturesSand MixturesSilt Mixtures

Sand Mixtures


Silt MixturesSandsSand MixturesSand Mixtures

Silt Mixtures


SandsSand MixturesSandsSilt MixturesSilt MixturesSilt MixturesSands

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25.8

36.3

47.8

Ueq(ft)



Pore Pressure Dissipation Summary and

Pore Pressure Dissipation Plots

Job No: 19-52026

Client: Gerhart Cole

Project: USCF

Start Date: 26-Feb-2019

End Date: 26-Feb-2019

Sounding ID File NameCone Area

(cm2)

Duration

(s)

Test Depth

(ft.)

Estimated

Equilibrium Pore

Pressure Ueq

(ft.)

Calculated

Phreatic

Surface

(ft.)

Refer to

Notation

Number

19-CPT-15 19-52026_CP15 15 600 31.41 29.3 2.1

19-CPT-16 19-52026_CP16 15 600 33.79 31.1 2.7

19-CPT-18A 19-52026_CP18A 15 600 16.73 11.7 5.0

19-CPT-19 19-52026_CP19 15 600 28.71 25.8 2.9

19-CPT-19 19-52026_CP19 15 720 38.88 36.3 2.5

19-CPT-19 19-52026_CP19 15 600 49.29 47.8 1.5

1. Dissipation ended before equilibrium was reached.

CPTu PORE PRESSURE DISSIPATION SUMMARY

Sheet 1 of 1

0 200 400 600

0.0

10.0

20.0

0.0

-10.0

-20.0

Time (s)

Pore

Pre

ssure

(ft

)Gerhart Cole

Job No: 19-52026

Date: 26-Feb-2019 12:46:21

Site: USCF


Cone: 553 Area=15 cm²

Trace Summary: Filename: 19-52026_CP18A.PPD

Depth: 5.100 m / 16.732 ft

Duration: 600.0 s

u Min: -18.0 ft

u Max: 17.9 ft

u Final: 11.6 ft

WT: 1.528 m / 5.012 ft

Ueq: 11.7 ft

0 200 400 600

0.0

20.0

40.0

60.0

80.0

Time (s)

Pore

Pre

ssure

(ft

)Gerhart Cole

Job No: 19-52026

Date: 26-Feb-2019 14:11:18

Site: USCF

Sounding: 19-CPT-19


Trace Summary: Filename: 19-52026_CP19.PPD

Depth: 8.750 m / 28.707 ft

Duration: 600.0 s

u Min: -9.5 ft

u Max: 73.1 ft

u Final: 25.6 ft

WT: 0.881 m / 2.890 ft

Ueq: 25.8 ft

0 250 500 750

0.0

10.0

20.0

30.0

40.0

Time (s)

Pore

Pre

ssure

(ft

)Gerhart Cole

Job No: 19-52026

Date: 26-Feb-2019 14:11:18

Site: USCF

Sounding: 19-CPT-19



Depth: 11.850 m / 38.877 ft

Duration: 720.0 s

u Min: -3.4 ft

u Max: 36.5 ft

u Final: 36.4 ft

WT: 0.771 m / 2.530 ft

Ueq: 36.3 ft

0 200 400 600

0.0

20.0

40.0

60.0

Time (s)

Pore

Pre

ssure

(ft

)Gerhart Cole

Job No: 19-52026

Date: 26-Feb-2019 14:11:18

Site: USCF

Sounding: 19-CPT-19



Depth: 15.025 m / 49.294 ft

Duration: 600.0 s

u Min: -11.6 ft

u Max: 48.1 ft

u Final: 47.8 ft

WT: 0.445 m / 1.460 ft

Ueq: 47.8 ft

0 200 400 600

0

5

10

15

20

25

30

35

40

45

50

qt (tsf)

De

pth

(fe

et)

0.0 2.0 4.0 6.0

fs (tsf)

0 100 200 3000

u (ft)

0.0 2.0 4.0 6.0 8.0

Rf (%)

0 6 12

SBT

Epic EngineeringJob No: 15-52051

Date: 04:30:15 14:08

Site: I-80/7200 West Expanded

Sounding: CPT-03

Cone: 335:T1500F15U500


File: 15-52051_CP03.CORUnit Wt: SBT Chart Soil Zones

SBT: Lunne, Robertson and Powell, 1997Coords: Lat: 40.808330 Long: -112.084180

Clayey Silt

Silt

Silty Sand/Sand

Sandy Silt

SiltSilty Clay

Clay

Silt

Sensitive Fines

Sandy Silt

Silty Sand/SandSilt

Sandy Silt

Clayey Silt

Sensitive Fines

Sandy Silt

Sensitive Fines

Silt

Sandy SiltSand

Sandy Silt

Silt

Sensitive Fines

Sandy Silt

Sandy Silt

Silt

Sandy Silt

Silty Sand/Sand

Sand

Sandy Silt

Sandy SiltSilty Sand/SandSiltSandy SiltSiltSandy SiltSilty Sand/Sand

Silt

Sandy Silt

Ueq=33.6'

Ueq=83.7'

Equilibrium Pore Pressure from Dissipation

0 200 400 600

50

55

60

65

70

75

80

85

90

95

100

qt (tsf)

De

pth

(fe

et)

0.0 2.0 4.0 6.0

fs (tsf)

0 100 200 3000

u (ft)

0.0 2.0 4.0 6.0 8.0

Rf (%)

0 6 12

SBT


Date: 04:30:15 14:08


Sounding: CPT-03

Cone: 335:T1500F15U500




Sandy SiltSilt

Sandy Silt

Silty Sand/Sand

SiltSilty Sand/Sand

Sand

Silty Sand/SandSand

Gravelly Sand

Sand

Sand

Silty Sand/Sand

Sandy Silt

Silt

Sandy Silt

SiltSensitive Fines

Sandy Silt

Silt

Sandy Silt

Silt

Sandy Silt

Sandy Silt

Sandy Silt

Gravelly Sand

Silty Sand/Sand

Sandy Silt

SiltSandy Silt

SiltSandy Silt

Ueq=33.6'

Ueq=83.7'


0 200 400 600

100

105

110

115

120

125

130

135

140

145

150

qt (tsf)

De

pth

(fe

et)

0.0 2.0 4.0 6.0

fs (tsf)

0 100 200 3000

u (ft)

0.0 2.0 4.0 6.0 8.0

Rf (%)

0 6 12

SBT


Date: 04:30:15 14:08


Sounding: CPT-03

Cone: 335:T1500F15U500




Sandy Silt

Silt

Sandy Silt

Silty Sand/Sand

Sandy Silt

Silt

Sandy Silt

Clayey Silt

Silt

Sandy SiltSilt

Sandy SiltSilty Sand/SandSand

Silty Sand/Sand

Cemented SandSand

Gravelly Sand

Ueq=33.6'

Ueq=83.7'


assessment of previous geotechnical design...

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