B08_40556700_Attachment_4_20181112_Jackson_Lake_Dam_Geotech.pdf

November 12, 2018

Mr. Dennis Brookie, RLA, PMP 12795 W. Alameda Parkway Lakewood, CO 80228

RE: GEOTECHNICAL INVESTIGATION REPORT FOR JACKSON LAKE DAM VISTOR FACILITIES

GRAND TETON NATIONAL PARK, TETON COUNTY, WYOMING

PROJECT NO: 14121.3645

Dear Mr. Brookie, We are pleased to present this report of our Geotechnical Investigation for the proposed upgrades to visitor facilities at Jackson Lake Dam. This report describes site conditions observed during the investigation and presents engineering analyses and recommendations for construction of the accessible fishing platform, installation of the articulated concrete mat boat ramp, and pavement design.

If you have any questions about this report, or if we may provide other services to you, please contact us. As the project progresses, we will be available to answer questions.

Respectfully submitted, JORGENSEN GEOTECHNICAL

Jack Fitzgerald, E.I. Colter H. Lane, P.E.

Geotechnical Investigation Report Jackson Lake Dam Visitor Facilities

Teton County, WY

Prepared for:

Mr. Dennis Brookie, RLA, PMP 12795 W. Alameda Parkway

Lakewood, CO 80228

Prepared by:

PO Box 9550 Jackson, WY 83002

November 12, 2018

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TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 PROPOSED CONSTRUCTION

3.0 INVESTIGATION PROCEDURE

FIELD INVESTIGATION .............................................................................................................. 1 3.1 LABORATORY ANALYSIS ............................................................................................................ 1 3.2 REPORT PREPARATION ............................................................................................................. 4 3.3

4.0 SITE CONDITIONS

DESCRIPTION ......................................................................................................................... 4 4.1 GEOLOGY .............................................................................................................................. 4 4.2 SOILS .................................................................................................................................... 4 4.3 GROUNDWATER ..................................................................................................................... 4 4.4 EARTHQUAKES AND GROUND SHAKING ....................................................................................... 5 4.5 GEOLOGIC HAZARDS AND LIQUEFACTION ..................................................................................... 5 4.6

5.0 ENGINEERING ANALYSIS

SETTLEMENT .......................................................................................................................... 6 5.1 BEARING CAPACITY ................................................................................................................. 6 5.2 LATERAL PRESSURES ................................................................................................................ 6 5.3

Active Pressures .......................................................................................................... 7 5.3.1 At-Rest Pressures ........................................................................................................ 7 5.3.2 Passive Pressures ........................................................................................................ 7 5.3.3

SOIL FRICTION ........................................................................................................................ 7 5.4 PARKING LOT AND ROAD DESIGN ............................................................................................... 7 5.5

6.0 RECOMMENDATIONS

FOUNDATIONS ....................................................................................................................... 9 6.1 SITE PREPARATION .................................................................................................................. 9 6.2 EXCAVATION AND CUT SLOPE STABILITY ...................................................................................... 9 6.3 FINAL BACKFILLING AND GRADING ........................................................................................... 10 6.4 SLABS-ON-GRADE ................................................................................................................. 10 6.5 BOAT RAMP – ARTICULATED CONCRETE MAT ............................................................................ 10 6.6 OBSERVATION DURING CONSTRUCTION ..................................................................................... 11 6.7

7.0 LIMITATIONS

8.0 REFERENCES

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LIST OF FIGURES

Figure 1: Site Location and Geologic Map Figure 2: Test Pit Location Map

LIST OF TABLES

Table 5-1: Lateral Pressure Parameters for Native Coarse-Grained Alluvium Site Soils Table 5-2: Structural Number Inputs Table 5-3: Moose Landing Boat Ramp Pavement Design Option 1 Table 5-4: Moose Landing Boat Ramp Pavement Design Option 2 Table 6-1: Compaction Parameters for Stony Fill

LIST OF APPENDICES

Appendix A: Test Pit Logs Appendix B: Laboratory Test Results Appendix C: USGS Seismic Design Maps Summary and Detailed Reports

Jorgensen Geotechnical, LLC November 12, 2018 Jackson Lake Dam – Geotechnical Investigation Report

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1.0 INTRODUCTION

At the request of the National Park Service, Jorgensen Geotechnical (JG) conducted a geotechnical site investigation for the proposed upgrades to the existing visitor facilities at the Jackson Lake Dam in Grand Teton National Park, Teton County, Wyoming. The purpose of the investigation was to observe soil conditions, evaluate soil-engineering properties, and to provide recommendations for the construction of the proposed upgrades. The scope of services included drilling and logging four exploratory boreholes, engineering analysis, laboratory analysis, and furnishing this report.

2.0 PROPOSED CONSTRUCTION

Preliminary plans indicate the improvements include expanding the existing parking lot north of the dam, and constructing a fishing platform and boat launch below the dam. Additionally, improvements to the south of the dam include replacing existing walkways and repairing existing retaining walls. It is our understanding that the new boat launch is proposed to be constructed using articulated concrete mats.

3.0 INVESTIGATION PROCEDURE

Field Investigation 3.1 Fieldwork conducted on September 28, 2018, consisted of drilling and logging four exploratory boreholes. These borehole depths varied from 6.0 to 11.0-feet below the ground surface (bgs).

Drilling was performed using a hollow-stem auger mounted on a Simco 2800HS drill rig.

Borehole JG-2 was terminated when the auger met a refusal condition in the soil (i.e., less than one foot of advance in one hour). Standard Penetration Tests (SPT) were performed at 2.5-ft intervals and samples were collected using a split spoon sampler driven in by a 140-lb. Rope and Cathead hammer. Blow counts (i.e., the number of blows to advance the sampler 6-inches) were recorded during each test, and adjusted to a hammer efficiency of 60% and overburden pressure of one atmosphere, as suggested by Youd and Idriss (1997) and Fang (1991), to obtain the standard adjusted (N1)60 values in blows per foot (bpf).

Soil type, thickness, consistency, and relative moisture content were observed and documented by a Jorgensen Geotechnical Engineer. Site conditions and actual soil conditions may differ from those represented in the borehole logs. The approximate borehole locations are shown in Figure 2 and detailed borehole logs are presented graphically in Appendix A.

Laboratory Analysis 3.2 Grain size distribution testing was performed on samples collected during the investigation and was conducted to ASTM standards. The purpose of this testing was primarily for classification purposes and to evaluate liquefaction potential. Test results are included in Appendix B and further discussed in Section 4.3 of this report.

Approximate

Site Location

Plotted by JFitzgerald on Oct 08, 2018 - 11:00am

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SHEET TITLE:

PROJECT NUMBER

REVIEWED BY:

DRAFTED BY:

PROJECT TITLE:

Geotechnical, LLC

307-733-5150 www.jorgeng.com

14121.3645

JWF

CHL

Figure 1

Site Location and

Geologic Map Teton County, Wyoming

Jackson Lake Dam

Geotechnical Site Investigation

From Love et al., 1992, Geologic Map of Grand Teton National Park

Map symbols:

Qa - Alluvium - stream and river deposits

Qs - Swamp deposits

Qg4j - Debris of Jackson Lake Moraine

Qf - Alluviual Fan Deposit

AutoCAD SHX Text

AutoCAD SHX Text

SCALE: 1 INCH = FEET

AutoCAD SHX Text

THIS SCALE VALID ONLY FOR PRINTS

AutoCAD SHX Text

AutoCAD SHX Text 8.5x11

AutoCAD SHX Text

AutoCAD SHX Text

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Report Preparation 3.3 This report describes the observed geologic site conditions and includes a site location and geologic map. Borehole logs are represented graphically as Appendix A. This report provides engineering analysis and recommendations for construction of the proposed additions, as well as asphalt pavement design associated with the proposed additions.

4.0 SITE CONDITIONS

Description 4.1 Jackson Lake Dam is located at the southwest outlet of Jackson Lake at an elevation of approximately 6,790-ft AMSL. The site was split into two areas: north and south of the dam.

Boreholes JG-1, JG-2, and JG-3 were drilled north of the dam and JG-4 was drilled to the south.

Geology 4.2 The site is found on the Geologic Map of Grand Teton National Park, Teton County, Wyoming (Love et al., 1992), which shows surficial deposits, bedrock units, and geologic structures (i.e., faults and folds) and is adapted as Figure 1. The map indicates the site is dominated by Quaternary Alluvium deposits (Qa), with other Quaternary aged glacial moraine debris (Qg4) and landslide deposits (Qls) nearby. Tertiary aged tuffaceous rock outcrops are mapped in the area but were not encountered during the investigation; depth to bedrock is unknown. The observed soil types are consistent with mapped geology. The Teton fault is located approximately 3.5 miles west of the project site.

Soils 4.3 Subsurface soils are dominated by stony gravel and cobble alluvium, referred to locally as “pit-run,” deposited by the Snake River. These alluvium deposits were logged in the field as dry, light brown to tan, medium dense to very dense, intact, and contained subangular to subrounded quartzite clasts up to 1.0-inch in diameter in a sandy matrix. Most samples contained shattered quartzite clasts, indicating the clast size was greater than the 2-inch diameter of the sampler. Adjusted blow counts in the pit run ranged from 14 bpf to 62 bpf indicating medium dense to very dense conditions. Blow counts observed in JG-2 were relatively low at 14 to 15 bpf. These lower blow counts were likely due to the sampler moving between larger clasts. The pit run was generally overlain by finer sandy alluvium. The sandy alluvium was logged in the field as slightly moist to very moist, light brown, medium dense, intact, and identified as silty sand and fine sand with gravel. Grain size distribution analysis identified the soil as silty sand (SM), with a moisture content of 2.6%. Groundwater was observed at approximately 6.0-ft bgs in JG-4.

Groundwater 4.4 Groundwater was not observed in any of the boreholes north of the dam during the investigation, but is likely to be relatively shallow due to the close vicinity to the Snake River.

The investigation was performed in late September, a time of year when groundwater levels are typically low. Groundwater was encountered at 6.0-ft bgs in JG-4, located south of the dam.

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Earthquakes and Ground Shaking 4.5 Jackson Hole is located within the Intermountain Seismic Belt, a zone of seismicity that extends from southern Utah through eastern Idaho, western Montana, and western Wyoming (Smith and Arabasz, 1991). The Teton Fault, located along the eastern margin of the Teton Range about 3.5 miles west of the project site, is considered an important structural element of the Intermountain Seismic Belt. Predicted recurrence intervals for maximum credible earthquakes have passed for most of the fault systems capable of generating magnitude 7.5 events in western Wyoming (Case, 1997), implying the risk of major earthquakes is relatively high.

A review of the USGS Fault Database (USGS, 2006) identifies the Teton Fault as the nearest Quaternary (i.e., relatively young and assumed active) fault to the project site. Slip rates of the Teton Fault are estimated to be between 0.2 and 1.0 mm/year.

Ground motion accelerations should be derived for the project site in accordance with the general procedure defined in the International Building Code (IBC). The IBC references ASCE 7- 10 to determine the ground motion accelerations. Based on subsurface soils, the site is classified as a Site Class D (“Stiff Soil”). For your convenience, USGS Seismic Design Maps Summary and Detailed Reports were produced assuming a risk category of I/II/III and are attached as Appendix C. These reports present design ground motion for structural design.

Seismic design values place the site in Seismic Design Category D.

The site is in an area of moderate seismic activity. The current horizontal peak ground acceleration (PGA) with 10% probability of exceedance in 50-years is approximately 0.19g, according to the USGS Unified Hazard Tool (USGS, 2014). This has been applied in this report for analysis of seismic lateral loading on retaining walls (Section 5.3).

The provisions of the IBC are intended to provide uniform levels of performance for structures, depending on their occupancy and use and the risk inherent to their failure. The approach adopted in the IBC is intended to provide a uniform margin of safety against collapse at the design ground motion. The design earthquake ground motion is selected at a ground shaking level that is 2/3 of the maximum considered earthquake (MCE) ground motion, which has a likelihood of exceedance of 2 percent in 50 years (a return period of about 2,500 years). The IBC is not intended to prevent damage or loss of function during a major earthquake; it is intended to reduce the risk of loss of life. Structural design should follow the level of risk tolerable to the owner.

Geologic Hazards and Liquefaction 4.6 The owner should be aware that in the event of a large magnitude earthquake (i.e., approximately 7.5), strong ground shaking and ground cracking could potentially cause damage to structures (Smith, et al, 1993). Several Quaternary-age faults exist in the vicinity of the site.

However, the distance of these faults from the specific project site indicates surface displacement at the project site due to faulting is unlikely.

Loose, saturated sands and silty sands, and in some cases, silts and gravels, may liquefy when exposed to seismic shaking. However, the stony alluvium encountered throughout the site

H:\2014\14121 - YNP IDIQ\3645 - GTNP Boat Launches\40-Geotech\Docs\Jackson Lake Dam\2018-11-12 Jackson Lake Dam Geotech.docx appears to be too stony to liquefy and adjusted blow count values indicate the soil does not present a potential liquefaction hazard. Liquefaction settlement and lateral spreading (i.e., slope instability associated with liquefaction) is not predicted to occur at this relatively flat site.

5.0 ENGINEERING ANALYSIS

Settlement 5.1 Any foundation elements should be placed on the stony alluvium. The depth to the alluvium varies throughout the site, but is generally very close to the ground surface. Significant consolidation (i.e., less than 1-inch total settlement or 0.5-inch differential settlement) of the stony alluvium is not anticipated. Any topsoil or silty sand encountered in any foundation excavation should be removed from below foundation elements.

Bearing Capacity 5.2 Bearing capacity of soil refers to its ability to resist shear failure under load. It is assumed any overlying topsoil will be removed and footings will be placed directly on native alluvium.

Compaction methods and specifications are discussed in Section 6.4. Soil parameters (i.e., inputs to the bearing capacity equation) were derived based on visual classification of the soil and rock. Allowable bearing capacity is estimated to be 5,000 psf, assuming moisture conditioning and re-compaction recommendations are followed.

Soil bearing capacity is dependent not only on the soil strength, but also the geometry of the foundation elements. The estimate above assumes 18-inch wide continuous footings buried 3 feet below final grade. If footing size and depth differs remarkably from these assumptions, this office should be notified to evaluate the foundation configuration.

Lateral Pressures 5.3 Lateral pressures were calculated using methods suggested by Bowles (1996). Lateral pressures were calculated for at-rest, active, and passive conditions and presented in Table 5-1. These values assume fine grained site material will be used as non-structural backfill. We have assumed an estimated internal friction angle of 35° and a unit weight of 135 pcf based on visual classification of the soils. Calculations assume level backfill against foundation walls or retaining walls.

Table 5-1: Lateral Pressure Parameters for Native Coarse-Grained Alluvium Site Soils

Condition Coefficient of Earth Pressures γK (equivalent fluid pressure)

Static Conditions Level Backfill

Ko = 0.43 Ka = 0.27 Kp = 3.69

58 pcf 37 pcf

498 pcf

Earthquake Conditions Level Backfill

Kae = 0.32 Kpe = 3.50

44 pcf

473 pcf

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Active Pressures 5.3.1 For lateral pressure design of retaining walls, which are allowed to deflect and develop an active soil wedge, the calculated equivalent fluid pressure (γKa) is 37 pcf (pounds per cubic foot). This pressure distribution would be equivalent to a force of approximately 18.5H2 pounds per horizontal foot of wall acting at one-third the wall height (H) above the base.

Lateral pressures on retaining walls from earthquakes were estimated using the Mononobe- Okabe equations (Bowles, 1996; Duncan et al, 1990). Because the maximum acceleration occurs only briefly during an earthquake, it is common practice when designing dams and other earth structures to reduce the design acceleration to ½ of the maximum design acceleration (Hynes- Griffin and Franklin, 1984). Thus, we have calculated seismic lateral pressures using a horizontal acceleration kh of 0.095g (1/2 of kh max) per the USGS (2014).

Research has indicated that lateral pressures due to earthquakes are non-hydrostatic in distribution, and the resultant acts above the lower third-point of the wall (Bakeer, et al, 1990).

Accordingly, active soil pressures must be divided into two components that act at different wall heights. The static force acts at the lower third-point, as discussed above. The resultant force from seismic lateral pressures is applied at 60% of the wall height above the base with a magnitude equal to the difference between seismic and static active pressures; i.e., ½ (γKae -γKa)H2 or 3.5H2 pounds per horizontal foot of wall applied.

At-Rest Pressures 5.3.2 For lateral pressure design of basement walls, which are restrained and not allowed to deflect, the calculated equivalent fluid pressure (γKo) is 58 pcf. Design control of such walls shall be whichever generates the higher resultant force: at-rest pressures or active seismic pressures.

Passive Pressures 5.3.3 For passive pressure design, the calculated equivalent fluid pressure (γKp) is 498 pcf, assuming a horizontal ground surface adjacent to the wall and reduced to 473 pcf for seismic conditions.

Passive pressure design should neglect loose fill and soil located within the frost zone.

Soil Friction 5.4 Terzaghi, et al (1996), suggest use of the internal strength of the soil for the friction angle along a concrete base in granular soils, with a maximum value of 30°. Accordingly, a friction value of 0.58, which is the tangent of 30°, is suggested if foundation elements are placed directly on the sandy gravel and cobble alluvium. The friction value may be combined with the passive pressure to resist horizontal loads.

Parking Lot and Road Design 5.5 Design parameters used in the pavement design are based on soil observations, empirical estimates, and estimated traffic loading. The design methods are consistent with those suggested in Chapter 4 of the AASHTO Guide of Pavement Structures (1993).

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Subgrade soils are predominately stony alluvium, extending to depths greater than 8.5-ft bgs.

Soil described as well-graded gravel with silt and sand corresponds to a classification of GW-GM (USCS) or A-1-b (AASHTO). AASHTO rates these soils as good for pavement subgrades. Strength of the soil was estimated to represent a CBR value of 47%. A structural number of 2.2 was estimated based on Table 4.7, AASHTO Guide for Pavement Design, 1993 using provided vehicle data, empirical inputs, and estimated values. Table 5-2 describes the inputs used

Table 5-2: Structural Number Inputs

Reliability Traffic Level Relative

Quality of Roadbed Soil

U.S. Climatic Region

75% Low to Medium Good to Very Good VI

Table 5-3 and Table 5-4 present pavement section options for roadway and parking areas using hot mixed asphalt (HMA), aggregate base course, and native pit-run subgrade as a pavement section. Option 1 presents a pavement section using 2-inches of HMA, 6-inches of aggregate base, and compacted native pit-run subbase. Option 2 presents a section with 4-inches of HMA and 6-inches of aggregate base above compacted subgrade soils. Unit prices for pit-run and crushed aggregate should be evaluated prior to construction to determine which section is more economical.

Table 5-3: Moose Landing Boat Ramp Pavement Design Option 1

Required SN=2.2

Material Thickness

Structural Coeff. Structural Number (inches) (feet) (mm)

HMA 2 0.17 50 0.44 0.88

Crushed Aggregate Base 6 0.50 150 0.12 0.72

Pit Run 6 0.50 150 0.10 0.60 Total Thickness 14.00 1.17 350 2.20

Table 5-4: Moose Landing Boat Ramp Pavement Design Option 2

Required SN=2.2

Material Thickness

Structural Coeff. Structural Number (inches) (feet) (mm)

HMA 4 0.33 100 0.44 1.76

Crushed Aggregate Base 6 0.50 150 0.12 0.72

Total Thickness 10.00 0.83 250 2.48

Silty, sandy soils were not encountered during the investigation at Moose Landing; however, due to the variable nature of alluvial deposits, it is possible they may be present. If Option 1 is selected and silty sand is encountered, it should be removed and replaced with compacted stony pit-run to a depth of at least 6-inches. If sandy deposits are thicker than 6-inches, then

H:\2014\14121 - YNP IDIQ\3645 - GTNP Boat Launches\40-Geotech\Docs\Jackson Lake Dam\2018-11-12 Jackson Lake Dam Geotech.docx the subbase should be separated from the compacted subgrade using a non-woven separation geotextile. If Option 2 is selected, the pavement section may be consistently applied across the project site. In the event silty sand is present as the road subgrade, a separation fabric shall be used. See Section 6.2 for recommendations for preparation of subgrade soils.

6.0 RECOMMENDATIONS

Foundations 6.1 At the time this report, it is unknown if the fishing platform would be constructed on a foundation. If a foundation is incorporated into the construction, the following is recommended:

1. The stony sandy gravel and cobble alluvium will likely provide adequate support for anticipated foundation loads of the proposed facility. We recommend that the foundation system for the fishing platform be placed entirely on the native stony material.

2. All footings should be placed below the frost line. We recommend placing the bottom of footing elevation at least 36-inches below the final ground surface. Depending on the final footing elevation, it may be necessary to place fill around the footings to maintain frost cover.

Site Preparation 6.2 Prior to the placement of structural fill, the site should be cleared and stripped of topsoil and organic debris. No brush, roots, frozen material, or other deleterious or unsuitable materials shall be incorporated in the subgrade. All exposed subgrade surfaces should be free of mounds and depressions which could prevent uniform compaction. If unexpected fills or obstructions are encountered during site clearing or excavation, such features should be removed and the excavation thoroughly cleared prior to placement and/or construction.

During excavation for the pavement subgrade, removal of large cobbles may disturb and loosen the surrounding material. In all areas where pavement will be placed, the subgrade should be compacted with a smooth-drum vibratory roller, in vibratory mode with a minimum of three passes, prior to placement of structural fill or footing construction. The actual number of passes should be determined by observing whether the surface is yielding after each pass. If the surface appears to be yielding, the number of passes should be increased until a non-yielding condition is observed and approved by a representative of this office.

Excavation and Cut Slope Stability 6.3 OSHA regulations (29CFR1926) appear to classify the alluvium as Type C soil. Simple cut slopes should be no steeper than 1.5H:1V (45°). The contractor shall be responsible for adherence to OSHA other safety regulations by observing soil and groundwater conditions at the time of construction.

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Final Backfilling and Grading 6.4 Properly compacted backfill is extremely important. Traditional density testing of stony material can yield variable results. Therefore, a method specification is developed in order to define the appropriate material type, lift thickness, compaction equipment, and number of passes required to provide consistent density results. Table 6-1 provides a method specification for compaction of stony material. The alluvium may be placed in lifts no greater than 12-inches loose thickness, as indicated by Table 6-1 and compacted. Large cobbles should not be used as structural backfill, except as specified in Table 6-1.

Table 6-1: Compaction Parameters for Stony Fill

Compactor Type Lift Thickness Maximum Particle Size Minimum Number of Passes

5-ton vibratory 12 inches 9-inch* 3 1.5-ton vibratory 9 inches 6-inch 5

Hand-held 4 inches 4-inch 5

* Occasional clasts to 12-inch are permitted, if encountered, but should not be nested.

If the number of passes and equipment used are verified by a qualified observer, density testing is not required. Stony material will compact into a dense, strong structural fill, and tight moisture control is usually not required. The actual number of passes should be determined by observing the compaction after each pass to determine the surface is non-yielding. If the fill surface appears to be yielding, the number of passes should be increased until a non-yielding condition is observed. Fill material should be placed in horizontal lifts.

The provisions described in the United States Department of Transportation FP-14 sections

208.09 and 208.10 are acceptable provisions to the recommendations made above for backfill and compaction, respectively. If any imported fill is used, it may be tested according to AASHTO T99 to determine optimum moisture content and maximum dry density. AASHTO T310 is recommended to verify compaction during construction. Due to the stony nature of native material, it is likely incapable of being tested by AASHTO T99. In this case, layers of the stony material should be compacted until further consolidation is no longer observed. According to FP-14 Section 208.09, structural backfill should be placed and compacted in horizontal lifts of thickness not to exceed 6-inches.

Slabs-on-Grade 6.5 Slabs should be at least 4 inches thick, and any slabs bearing vehicles should be at least 6 inches thick, or as approved by a Structural Engineer. Minor floor cracking of slab-on-grade construction is difficult, if not impossible, to prevent. Such cracking is normal and should be expected to occur with time.

Boat Ramp – Articulated Concrete Mat 6.6 It is our understanding that the proposed boat ramp will be constructed using articulated concrete mats. The surface of the bank may require smoothing prior to mat placement and

H:\2014\14121 - YNP IDIQ\3645 - GTNP Boat Launches\40-Geotech\Docs\Jackson Lake Dam\2018-11-12 Jackson Lake Dam Geotech.docx proper bank stabilization practices should be followed, but we do not anticipate any geotechnical issues with this construction.

Observation during Construction 6.7 Recommendations in this report are contingent upon our involvement. If any unexpected soils or conditions are revealed during construction, this office should be notified immediately to evaluate the conditions and make necessary modifications. All excavations, foundation subgrades, and roadway elements should be observed by a representative of JG prior to fill or concrete placement, especially if questionable materials are exposed. Site grading, leak-proof testing, and soil compaction should be observed by a representative of this office. Notice shall be provided a minimum of 24 hours before the requested observation

7.0 LIMITATIONS

This report has been prepared based on a limited amount of data. Actual site conditions may vary. The report is for single use and under no circumstances are the figures and test to be used separately. These services have been performed in a manner consistent with the level of care and skill ordinarily exercised by members of the profession currently practicing under similar conditions. No warranty is made or implied.

8.0 REFERENCES

American Association of State Highway and Transportation Officials (AASHTO), 1993, AASHTO Guide for Pavement Structures.

Bowles, J.E., 1996, Foundation Analysis and Design, 5th Ed.: McGraw Hill.

Case, J.C., 1997, Earthquakes and Active Faults in Wyoming; Wyoming State Geological Survey, Preliminary Hazards Report 97-2.

Fang, H.Y., 1991, Foundation Engineering Handbook, 2nd Ed.: Chapman & Hall, New York.

Gilbert, J.D., D. Ostenaa, and C. Wood, 1983, Seismotectonic Study Jackson Lake Dam and Reservoir, Minidoka Project, Idaho-Wyoming: Seismotectonic Report 83-8, US Bur. Reclam.

International Building Code, 2015.

Love, J.D., Reed, J.C., and Cristiansen, A.C., 1992, Geologic Map of Grand Teton National Park, Teton County, Wyoming: Geologic Investigation Series Map I-2031, Scale 1:62,500.

Machette, N.M., Pierce, K.L., McCalpin, J.P., Haller, K.M., and Dart, R.L., 2001, Map and Data for Quaternary faults and folds in Wyoming, United States Geological Survey, Open-File Report 01- 461.

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O’Connell, D.R.H., Wood, C.K., Ostenaa, D.A., Block, L.V., and LaForge, R.C., 2003, Final Report, Ground Motion Evaluation for Jackson Lake Dam, Minidoka Project, Wyoming: U.S. Bureau of Reclamation Report 2003-2.

Pit Slope Manual, 1982, Chapter 9, Waste Embankments: Mining Research Laboratories, CANMET Report 77-01.

Smith, R.B. and Arabasz, W.J., 1991, Seismicity of the Intermountain Seismic Belt, in Slemmons, D.B., Engdahl, E.R., Zoback, M.L., and Blackwell, D.D., editors, Neotectonics of North America:

Geological Society of America, Decade Map Volume 1, p. 185-228.

Smith, R.B., Byrd, J.O.D., and Susong, D.D., 1993, The Teton fault, Wyoming: Seismotectonics, Quaternary History, and Earthquake Hazards, in Snoke, Q.W., Steidtmann, J.R., and Roberts, S.M., editors, Geology of Wyoming; Geological Survey of Wyoming Memoir No. 5, p. 628-667.

Terzaghi, K., R.B. Peck, and G. Mesri, 1996, Soil Mechanics in Engineering Practice, 3rd Ed.: John Wiley & Sons.

Transportation Research Board, National Cooperative Highway Research Program (NCHRP), 2004, Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures:

Publication No: 1-37A

U.S. Department of Transportation, Federal Highway Administration (FHWA), 2006, Geotechnical Aspects of Pavement, NHI Course No. 132040: Publication No. FHWA-IF-99-015.

U.S. Geological Survey, 2006, Quaternary fault and fold database for the United States, accessed October 3, 2018, from USGS web site: http//earthquake.usgs.gov/hazards/qfaults/.

U.S. Geological Survey Earthquake Hazards Program, 2014, Unified Hazard Tool, accessed November 12, 2018, https://earthquake.usgs.gov/hazards/interactive/index.php

Whitman, R.V., 1990, Seismic Design and Behavior of Gravity Retaining Walls in Design and Performance of Earth Retaining Structures (P.C. Lambe and L.A. Hansen ed): ASCE Geotechnical Special Publication 25, p. 817-842.

Youd, T.L., and I.M. Idriss, 1997, Proceedings of the NCEER Workshop on Evaluation of Liquefaction Resistance of Soils: Tech. Report NCEER-97-0022.

Zhang, J.M., Y. Shamoto, and K. Tokimatsu, 1998, Earth Pressures on Rigid Walls during Earthquakes in Proceedings of the Specialty Conference on Geotechnical Earthquake Engineering and Soil Dynamics III (P. Dahoulas, M. Yegian, and R.D. Holtz ed), p. 1057-1069.

APPENDIX A

Borehole Logs

30-2-

11-11-

12-14-

63%

20%

47%

D1

0.0-0.3ft GRAVEL with sand: Dry, light brown, dense, intact [ROADBASE] 0.3-4.5ft GRAVEL/COBBLE with sand: Slightly moist, brown, dense, intact, subangular to subrounded quartzite clasts [NATIVE ALLUVIUM]

2.5ft Silty SAND with gravel: slightly moist, dark brown, medium dense, intact. Fine sand and gravels with some fines. [SANDY ALLUVIUM]

Smooth drilling to 4.0 ft.

4.5-6.5ft GRAVELS/COBBLES with sand: Dry, tan to light brown, medium dense, intact, shattered subangular to subrounded quartzite gravels and cobbles. [GRAVEL/COBBLE ALLUVIUM]

Stopped at request.

Backfilled with cuttings.

No groundwater encountered during drilling.

COMMENTS:

D R

Y D

E N

S

IT

Y

P C

F

DESCRIPTION

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

LI

M

IT

S

P

LA

S T

IC

IT

Y

IN

D E

X

D E

P T

H ft.

G R

A P

H

IC

A L

LO

G

S A

M P

LE

S .P

.T

N

B

LO

W S

/6

IN

R E

C O

V E

R Y

U N

C O

N F

IN

E

D S

T R

E N

G T

H

T S

F

C

LA

S S

IF

IC

A T

IO

N

(N 1)

B

LO

W

S /F

T

W E

LL

C

O M

P

LE

T

IO

N

TEST HOLE LOCATION: See Site Map

ELEVATION G.S. (ft.): ~6753 ft.

DRILL TYPE: Simco 2800HS HAMMER: 140# Rope and Cathead

TOTAL DEPTH (ft.): 6.5 GROUNDWATER LEVEL (ft.): N/A

DRILL CO: LK Drilling DRILLER: Steve

MEASURED FROM: G.S.

LOGGED BY: jwf

Jorgensen Geotechnical

Jackson, WY 83002

Telephone: 307-733-5150

Fax: 307-733-5187

DATE: 09/28/2018PROJECT NAME: Grand Teton National Park Boat Launches - Jackson Lake Dam

PROJECT LOCATION: Teton County, Moran, WY HOLE NO.: JG-1

TEST HOLE LOG

T E

S T

H O

LE

L

O G

J O

R G

E N

S E

N G

E O

.3

5_

JA

C

K S

O N

L A

K E

D A

M L

O G

S .G

P J

J O

R G

E N

S E

N G

E O

8-

5.

G

D T

/9 /1

8-7-5

6-9-7

7-7-13

27%

N.R.

N.R.

0.0-6.0ft GRAVELS/COBBLES with sand: Dry, tan to light brown, medium dense, intact, shattered subangular to subrounded quartzite gravels and cobbles. [GRAVEL/COBBLE ALLUVIUM]

Grinding and rough drilling at 0.5ft. Stone in shoe, shattered quartzite clasts.

2.5ft As above, slightly moist. [GRAVEL/COBBLE

ALLUVIUM]

4.5ft As above, stone in shoe. Sample at 4.5 due to refusal. [GRAVEL/COBBLE ALLUVIUM]

Stopped at refusal.

Backfilled with cuttings.

No groundwater encountered during drilling.

COMMENTS: ~30 ft. from edge of rip-rap. Observed standing water to the north

D R

Y D

E N

S

IT

Y

P C

F

DESCRIPTION

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

LI

M

IT

S

P

LA

S T

IC

IT

Y

IN

D E

X

D E

P T

H ft.

G R

A P

H

IC

A L

LO

G

S A

M P

LE

S .P

.T

N

B

LO

W S

/6

IN

R E

C O

V E

R Y

U N

C O

N F

IN

E

D S

T R

E N

G T

H

T S

F

C

LA

S S

IF

IC

A T

IO

N

(N 1)

B

LO

W

S /F

T

W E

LL

C

O M

P

LE

T

IO

N

TEST HOLE LOCATION: See Site Map

ELEVATION G.S. (ft.): ~6743 ft.

DRILL TYPE: Simco 2800HS HAMMER: 140# Rope and Cathead

TOTAL DEPTH (ft.): 6 GROUNDWATER LEVEL (ft.): N/A

DRILL CO: LK Drilling DRILLER: Steve

MEASURED FROM: G.S.

LOGGED BY: jwf

Jorgensen Geotechnical

Jackson, WY 83002

Telephone: 307-733-5150

Fax: 307-733-5187

DATE: 09/28/2018PROJECT NAME: Grand Teton National Park Boat Launches - Jackson Lake Dam

PROJECT LOCATION: Teton County, Moran, WY HOLE NO.: JG-2

TEST HOLE LOG

T E

S T

H O

LE

L

O G

J O

R G

E N

S E

N G

E O

.3

5_

JA

C

K S

O N

L A

K E

D A

M L

O G

S .G

P J

J O

R G

E N

S E

N G

E O

8-

5.

G

15-16-

6-22-

6-8-10

37%

37%

10%

D1

0.0-6.5ft GRAVELS/COBBLES with sand: Dry, tan to light brown, medium dense, intact, shattered subangular to subrounded quartzite gravels and cobbles. [ALLUVIUM]

Shattered quartzite clasts at 0.5ft.

2.5ft As above, larger clasts. [ALLUVIUM]

5.0ft As above, slightly moist to moist, brown, medium dense. Shattered clast in shoe. [ALLUVIUM]

Stopped at request.

Backfilled with cuttings.

No groundwater encountered during drilling.

COMMENTS: Observed standing water to the north

D R

Y D

E N

S

IT

Y

P C

F

DESCRIPTION

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

LI

M

IT

S

P

LA

S T

IC

IT

Y

IN

D E

X

D E

P T

H ft.

G R

A P

H

IC

A L

LO

G

S A

M P

LE

S .P

.T

N

B

LO

W S

/6

IN

R E

C O

V E

R Y

U N

C O

N F

IN

E

D S

T R

E N

G T

H

T S

F

C

LA

S S

IF

IC

A T

IO

N

(N 1)

B

LO

W

S /F

T

W E

LL

C

O M

P

LE

T

IO

N

TEST HOLE LOCATION: See Site Map

ELEVATION G.S. (ft.): ~6746 ft.

DRILL TYPE: Simco 2800HS HAMMER: 140# Rope and Cathead

TOTAL DEPTH (ft.): 6.5 GROUNDWATER LEVEL (ft.): N/A

DRILL CO: LK Drilling DRILLER: Steve

MEASURED FROM: G.S.

LOGGED BY: jwf

Jorgensen Geotechnical

Jackson, WY 83002

Telephone: 307-733-5150

Fax: 307-733-5187

DATE: 09/28/2018PROJECT NAME: Grand Teton National Park Boat Launches - Jackson Lake Dam

PROJECT LOCATION: Teton County, Moran, WY HOLE NO.: JG-3

TEST HOLE LOG

T E

S T

H O

LE

L

O G

J O

R G

E N

S E

N G

E O

.3

5_

JA

C

K S

O N

L A

K E

D A

M L

O G

S .G

P J

J O

R G

E N

S E

N G

E O

8-

5.

G

10-10-

6-8-7

5-6-7

13-19-

30-37-

7%

17%

47%

40%

100%

2.6

D1

D2

D3

D4

D5

SP-SM

0.0-2.5ft GRAVEL/COBBLE with silt: Dry, brown, medium dense, intact, subangular to subrounded quartzite clasts. [NATIVE ALLUVIUM]

2.5-7.5ft Silty SAND with gravel: slightly moist to moist, light brown, medium dense, intact, subangular to subrounded quartzite clasts [SANDY ALLUVIUM]

5.0ft Fine SAND with gravel: Moist to very moist, light brown, medium dense. Shattered clast from 6.2 to 6.5. [SANDY ALLUVIUM]

7.5-11.0ft GRAVEL/COBBLE with silt and sand: very moist, tan, dense to very dense, intact.

[GRAVEL/COBBLE ALLUVIUM]

9.5ft As above, large quartzite clasts. Sample at 9.5 ft due to auger refusal [GRAVEL/COBBLE

ALLUVIUM]

Stopped at request.

Backfilled with cuttings.

Groundwater encountered at approximately 6.0 ft.

COMMENTS:

D R

Y D

E N

S

IT

Y

P C

F

DESCRIPTION

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

LI

M

IT

S

P

LA

S T

IC

IT

Y

IN

D E

X

D E

P T

H ft.

G R

A P

H

IC

A L

LO

G

S A

M P

LE

S .P

.T

N

B

LO

W S

/6

IN

R E

C O

V E

R Y

U N

C O

N F

IN

E

D S

T R

E N

G T

H

T S

F

C

LA

S S

IF

IC

A T

IO

N

(N 1)

B

LO

W

S /F

T

W E

LL

C

O M

P

LE

T

IO

N

TEST HOLE LOCATION: See Site Map

ELEVATION G.S. (ft.): ~6810 ft.

DRILL TYPE: Simco 2800HS HAMMER: 140# Rope and Cathead

TOTAL DEPTH (ft.): 11 GROUNDWATER LEVEL (ft.): 6.0

DRILL CO: LK Drilling DRILLER: Steve

MEASURED FROM: G.S.

LOGGED BY: jwf

Jorgensen Geotechnical

Jackson, WY 83002

Telephone: 307-733-5150

Fax: 307-733-5187

DATE: 09/28/2018PROJECT NAME: Grand Teton National Park Boat Launches - Jackson Lake Dam

PROJECT LOCATION: Teton County, Moran, WY HOLE NO.: JG-4

TEST HOLE LOG

T E

S T

H O

LE

L

O G

J O

R G

E N

S E

N G

E O

.3

5_

JA

C

K S

O N

L A

K E

D A

M L

O G

S .G

P J

J O

R G

E N

S E

N G

E O

8-

5.

G

APPENDIX B

Laboratory Testing Results

0.0010.010.1110100

3.8319 0.37

D100 D60

6 810 14

Specimen Identification

Specimen Identification

Classification

12.0

D10

41 3/4 1/23/8

CuPI Cc

GRAIN SIZE DISTRIBUTION

GRAIN SIZE IN MILLIMETERS

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T coarse fine coarse medium

D30

16 20 30 40 501.5 3

%Gravel %Sand %Silt %Clay

JG-3

100 1403 2

HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS

0.72

52.0

COBBLES

GRAVEL SAND

SILT OR CLAY

JG-3

LL PL

76.94

36.0 fine

Jorgensen Geotechnical 1315 HWY 89 S. Suite 201 Jackson, WY 83002 Telephone: 307-733-5150 Fax: 307-733-5187

Project: GTNP Boat Launches - Jackson Lake Dam

Location: Teton County, Moran, WY

Number: 14121.3645

U S

_G R

A

IN

_S

IZ

E

.3

_J

A C

K S

O N

L A

K E

D A

M L

O G

S .G

P J

J O

R G

E N

S E

N G

E O

8-

5.

G

2/

APPENDIX C

USGS Seismic Design Maps Summary and Detailed Reports

10/10/2018 Design Maps Summary Report https://prod01-earthquake.cr.usgs.gov/designmaps/us/summary.php?template=minimal&latitude=43.857379&longitude=-110.589707&siteclass=3&risk… 1/1

Report Title

Building Code Reference Document

Site Coordinates

Site Soil Classification

Risk Category

Design Maps Summary Report User–Specified Input

Jackson Lake Dam Wed October 10, 2018 22:17:42 UTC

2012/2015 International Building Code (which utilizes USGS hazard data available in 2008)

43.85738°N, 110.58971°W

Site Class D – “Stiff Soil”

I/II/III

USGS–Provided Output

SS = 1.591 g SMS = 1.591 g SDS = 1.060 g

S1 = 0.472 g SM1 = 0.721 g SD1 = 0.481 g

For information on how the SS and S1 values above have been calculated from probabilistic (risk-targeted) and deterministic ground motions in the direction of maximum horizontal response, please return to the application and select the “2009 NEHRP” building code reference document.

Although this information is a product of the U.S. Geological Survey, we provide no warranty, expressed or implied, as to the accuracy of the data contained therein. This tool is not a substitute for technical subject-matter knowledge.

https://www.usgs.gov/

10/10/2018 Design Maps Detailed Report https://prod01-earthquake.cr.usgs.gov/designmaps/us/report.php?template=minimal&latitude=43.857379&longitude=-110.589707&siteclass=3&riskcat… 1/4

From Figure 1613.3.1(1) [1]

From Figure 1613.3.1(2) [2]

Design Maps Detailed Report 2012/2015 International Building Code (43.85738°N, 110.58971°W)

Site Class D – “Stiff Soil”, Risk Category I/II/III

Section 1613.3.1 — Mapped acceleration parameters

Note: Ground motion values provided below are for the direction of maximum horizontal spectral response acceleration. They have been converted from corresponding geometric mean ground motions computed by the USGS by applying factors of 1.1 (to obtain SS) and

1.3 (to obtain S1). Maps in the 2012/2015 International Building Code are provided for Site Class B. Adjustments for other Site Classes are made, as needed, in Section 1613.3.3.

SS = 1.591 g

S1 = 0.472 g

Section 1613.3.2 — Site class definitions

The authority having jurisdiction (not the USGS), site-specific geotechnical data, and/or the default has classified the site as Site Class D, based on the site soil properties in accordance with Section 1613.

2010 ASCE-7 Standard – Table 20.3-1

SITE CLASS DEFINITIONS

Site Class vS N or Nch su

A. Hard Rock >5,000 ft/s N/A N/A

B. Rock 2,500 to 5,000 ft/s N/A N/A

C. Very dense soil and soft rock 1,200 to 2,500 ft/s >50 >2,000 psf

D. Stiff Soil 600 to 1,200 ft/s 15 to 50 1,000 to 2,000 psf

E. Soft clay soil <600 ft/s <15 <1,000 psf

Any profile with more than 10 ft of soil having the characteristics:

Plasticity index PI > 20, Moisture content w ≥ 40%, and Undrained shear strength su < 500 psf

F. Soils requiring site response analysis in accordance with Section 21.1

See Section 20.3.1

For SI: 1ft/s = 0.3048 m/s 1lb/ft² = 0.0479 kN/m² https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/IBC-2012-Fig1613p3p1(1).pdf https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/IBC-2012-Fig1613p3p1(2).pdf https://www.usgs.gov/ https://prod01-earthquake.cr.usgs.gov/designmaps/us/report.php?template=minimal&latitude=43.857379&longitude=-110.589707&siteclass=3&riskcat… 2/4

Section 1613.3.3 — Site coefficients and adjusted maximum considered earthquake spectral response acceleration parameters

TABLE 1613.3.3(1)

VALUES OF SITE COEFFICIENT Fa

Site Class Mapped Spectral Response Acceleration at Short Period

SS ≤ 0.25 SS = 0.50 SS = 0.75 SS = 1.00 SS ≥ 1.25

A 0.8 0.8 0.8 0.8 0.8

B 1.0 1.0 1.0 1.0 1.0

C 1.2 1.2 1.1 1.0 1.0

D 1.6 1.4 1.2 1.1 1.0

E 2.5 1.7 1.2 0.9 0.9

F See Section 11.4.7 of ASCE 7

Note: Use straight–line interpolation for intermediate values of SS

For Site Class = D and SS = 1.591 g, Fa = 1.000

TABLE 1613.3.3(2)

VALUES OF SITE COEFFICIENT Fv

Site Class Mapped Spectral Response Acceleration at 1–s Period

S1 ≤ 0.10 S1 = 0.20 S1 = 0.30 S1 = 0.40 S1 ≥ 0.50

A 0.8 0.8 0.8 0.8 0.8

B 1.0 1.0 1.0 1.0 1.0

C 1.7 1.6 1.5 1.4 1.3

D 2.4 2.0 1.8 1.6 1.5

E 3.5 3.2 2.8 2.4 2.4

F See Section 11.4.7 of ASCE 7

Note: Use straight–line interpolation for intermediate values of S1

For Site Class = D and S1 = 0.472 g, Fv = 1.528 https://prod01-earthquake.cr.usgs.gov/designmaps/us/report.php?template=minimal&latitude=43.857379&longitude=-110.589707&siteclass=3&riskcat… 3/4

Equation (16-37):

Equation (16-38):

Equation (16-39):

Equation (16-40):

SMS = FaSS = 1.000 x 1.591 = 1.591 g

SM1 = FvS1 = 1.528 x 0.472 = 0.721 g

Section 1613.3.4 — Design spectral response acceleration parameters

SDS = ⅔ SMS = ⅔ x 1.591 = 1.060 g

SD1 = ⅔ SM1 = ⅔ x 0.721 = 0.481 g https://prod01-earthquake.cr.usgs.gov/designmaps/us/report.php?template=minimal&latitude=43.857379&longitude=-110.589707&siteclass=3&riskcat… 4/4

Section 1613.3.5 — Determination of seismic design category

TABLE 1613.3.5(1)

SEISMIC DESIGN CATEGORY BASED ON SHORT-PERIOD (0.2 second) RESPONSE ACCELERATION

VALUE OF SDS

RISK CATEGORY

I or II III IV

SDS < 0.167g A A A

0.167g ≤ SDS < 0.33g B B C

0.33g ≤ SDS < 0.50g C C D

0.50g ≤ SDS D D D

For Risk Category = I and SDS = 1.060 g, Seismic Design Category = D

TABLE 1613.3.5(2)

SEISMIC DESIGN CATEGORY BASED ON 1-SECOND PERIOD RESPONSE ACCELERATION

VALUE OF SD1

RISK CATEGORY

I or II III IV

SD1 < 0.067g A A A

0.067g ≤ SD1 < 0.133g B B C

0.133g ≤ SD1 < 0.20g C C D

0.20g ≤ SD1 D D D

For Risk Category = I and SD1 = 0.481 g, Seismic Design Category = D

Note: When S1 is greater than or equal to 0.75g, the Seismic Design Category is E for buildings in Risk Categories I, II, and III, and F for those in Risk Category IV, irrespective of the above.

Seismic Design Category ≡ “the more severe design category in accordance with Table 1613.3.5(1) or 1613.3.5(2)” = D

Note: See Section 1613.3.5.1 for alternative approaches to calculating Seismic Design Category.

References

1. Figure 1613.3.1(1): https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/IBC-2012-Fig1613p3p1(1).pdf

2. Figure 1613.3.1(2): https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/IBC-2012-Fig1613p3p1(2).pdf