GM35-15_East_Beach_Road_Geotechnical_Recomm._30Oct2015.pdf

Memorandum

Western Federal Lands Highway Division 610 E. Fifth Street

Vancouver, WA 98661-3801

In Reply Refer To: HFL-17

From: Diann Morehouse, Geotechnical Engineer

To: Kirk Loftsgaarden, Project Manager Gabriel Krumbein, Highway Designer

Date: October 30, 2015

Subject: Final Geotechnical Recommendations East Beach Road

WA CLALLAM 92210(1)

Geotechnical Memorandum GM 35-15

Introduction This memorandum provides geotechnical recommendations for the rehabilitation of East Beach Road and Joyce Piedmont Road, located within Olympic National Park, Clallam County, Washington. The project is located about 14 miles west of Port Angeles. Vicinity and Location Maps are provided in Figures A-1 and A-2 (Attachment A).

Scope of Project Project scope includes rehabilitation of 3.2 miles of the East Beach Road and 2000 feet of the Joyce Piedmont Road. The proposed project consists of milling and overlaying the existing pavement surface, replacing of a 7-foot diameter culvert with a 10-foot diameter culvert, and stabilizing limited areas along the road that exhibit pavement distress due to poor subgrade conditions and surficial fill slope instabilities.

General Project Information East Beach Road lies along the north shore of Lake Crescent in a forest environment. Single occupancy homes lie between the East Beach Road and the lake even though the project lies entirely within Olympic National Park boundaries. Olympic National Park Log Cabin Resort is accessed from East Beach Road and is located at Station 140+00. In addition to cabins, the resort supports a RV campground. The East Beach picnic area is accessed from East Beach Road at approximately Station 268+30. East Beach Road also provides access to the Spruce Railroad Trail.

Geotechnical Memorandum GM35-15 Page 2 October 2015

Joyce Piedmont Road runs in a northerly direction towards the town of Joyce and Highway 112 from its intersection with the East Beach Road at Station 134+72.

Climate The local climate is typical of the mountainous valleys in the Western Olympic Peninsula – long wet winters with mild summers. The project is located at an approximate elevation of 650 feet.

A Western Regional Climate Center (WRCC) monitoring station is located at the Elwha Ranger Station (COOP# 452548) about 7 miles east of the project at an elevation of 380 feet. A second WRCC monitoring station is Forks 1E (COOP# 452914), located about 30 miles west of the project at an elevation of 350 feet. The average maximum and minimum temperatures, precipitation, and snowfall recorded at each station are summarized in Tables 1 and 2.

Table 1: Period of Record Monthly Climate Summary for WRCC Elwha Ranger Station, Washington, COOP # 452548 between 07/1/1942 and 12/31/2014.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Max.Temp.(°F) 40.9 45.2 50.5 56.8 63.6 67.9 73.9 74.1 68.7 57 46.6 42.2 57 Min.Temp.(°F) 30.8 32.2 33.8 37.1 41.9 46.3 49.7 50.6 47.3 41 35.5 32.4 40 Precip. (in.) 8.91 6.72 6.11 3.33 1.79 1.22 0.75 1.1 1.73 5.25 9 9.73 56 Snowfall (in.) 6.5 1.8 1.1 0 0 0 0 0 0 0 1.2 3.4 14

Table 2: Period of Record Monthly Climate Summary for WRCC Forks 1E, Washington, COOP # 452914 between 11/1/1907 and 01/19/2015.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Max. Temp.(°F) 44.9 48.7 51.6 56.9 62.9 66.9 71.6 72.5 69.2 60.3 50.6 45.5 59 Min. Temp. (°F) 33.4 34.2 35.3 37.5 42 46.4 49.3 49.6 46.7 42.3 37.3 34.3 41 Precip. (in.) 17.8 13.6 13 8.58 5.25 3.51 2.29 2.46 4.79 11.7 16.4 18.6 118 Snowfall (in.) 5.6 2.1 2.1 0.2 0 0 0 0 0 0 0.7 2.3 13

Geology Geologic mapping shows bedrock along the first half of East Beach Road and all of Joyce Piedmont Road as the Aldwell Formation (middle Eocene-aged); thin to medium-bedded, well-indurated marine siltstone and sandy siltstone. Deposits of Pleistocene-aged Vashon glacial till overlie the formation.

The remainder of the project is shown to cross into the Lyre Formation. The Lyre Formation (middle Eocene-aged) consists of conglomerate and sandstone rocks. The conglomerate consists of pebble to boulder-sized clasts of argillite, quartzite, chert, metavolcanic rocks, gneiss, quartz, and minor basalt. Overlying the Lyre Formation is Holocene and possibility Pleistocene-aged landslide deposits. These landslide deposits consist of clay, silt, sand, and gravel with larger rocks un-stratified and chaotic in nature. Earth-slumps result from wave action undercutting embankments (Schasse, (2003)). A thrust fault is shown generally parallel to the northeast shore of Lake Crescent and East Beach Road (Figure A-3, Attachment A).

Geotechnical Memorandum GM35-15 Page 3 October 2015

The Washington Division of Geology and Earth Resources Liquefaction Susceptibility Map show East Beach Road and Joyce Piedmont Road are located in a “low to moderate” liquefaction susceptibility area (Figure A-4). Liquefaction occurs during a strong earthquake event with the shaking causing the soil to rapidly lose strength resulting in the soil behaving like quicksand.

Liquefaction of the soil can cause pipelines and underground utilities to rupture, foundations to move, and can pull roadways apart.

Geotechnical Investigation The geotechnical investigation for this project consists of a site reconnaissance in April 2014 and subsurface investigation consisting of seven borings. Western Federal Lands Highway Division (WFLHD) conducted the subsurface investigation in July 2014. Washington State Department of Transportation (WSDOT) performed the subsurface drilling operations using a track-mounted CME-55 drill. Figures C-1 through C7 shows the locations of the seven borings (Attachment C). The borings were advanced with an 8-inch hollow stem auger. Upon refusal an HQ3 coring system was used to advance the borings to termination depth. Boring depths ranged from 14.5 feet to 23.0 feet. Drive samples were obtained at select intervals using a 2-inch outside diameter (O.D.) Standard Penetration Test (SPT) split spoon sampler or a 2.5-inch O.D. split spoon sampler to acquire disturbed soil samples and determine relative density and consistency of the soils. The WSDOT field inspector classified and logged the soil strata and thicknesses for each boring, as shown in the boring logs (Attachment D). Rock core pictures are also contained in Attachment D.

Selected soil samples were tested in the WFLHD materials testing laboratory in Vancouver, Washington. Tests were conducted to determine soil classification and determination of mechanical and index properties of the soil. The following is a list of index tests that were completed and the protocols that were followed:

• Particle Size Analysis to 0.002 mm - AASHTO T 88,

• Liquid Limit, Plastic Limit, and Plasticity Index of Soils - AASHTO T 89/90

• Specific Gravity of Soils - AASHTO T 100,

• Natural Moisture Content - AASHTO T 265 (Sample dried at 140° F), and

• Organic Content by % Loss on Ignition – AASHTO T 267.

Table 3 shows a summary of the laboratory test results contained in Attachment E.

Asphalt thickness within the borings range from 5 inches to 13 inches thick. The soils that were tested classified as clayey sand, and clayey gravel.

Boring B14-01 encountered loose to medium dense well-graded gravel between 8-inches and

6.8 feet below ground surface. Underlying the well-graded gravel is dense silty gravel with sand between the depths of 6.8 feet and 21.5 feet below the ground surface. Cobbles were encountered between the depths of 6.75 feet and 11 feet, and 13 feet and 18 feet. Asphalt measured 8 inches thick.

Geotechnical Memorandum GM35-15 Page 4 October 2015

Boring B14-02 encountered loose silty sand with gravel between 7-inches and 3 feet below ground surface. Underlying the silty sand is dense to very dense silty gravel with sand between 3 feet and 21.5 feet. Organics were encountered between 3 feet and 5 feet. Asphalt measured 7 inches thick.

Boring B14-03 encountered medium dense silty sand between 9-inches and 1-foot-below the ground surface. Underlying the silty sand is medium dense to dense fine clayey sand between the depths of 1-foot and 9.5 feet. Silty gravel was encountered between the depths of 9.5 feet and 21.5 feet. Asphalt measured 9 inches thick.

Boring B14-04 encountered silty sand and silty gravel between 1.1 feet and 3 feet below ground surface. Underlying the silty gravel is 11.5 feet of silty gravel with cobbles. Water was encountered 8.7 feet below ground surface. It is interpreted that most, if not all of the material encountered in the boring is fill. Asphalt measured 13 inches thick.

Boring B14-05 encountered silty sand with gravel and silty gravel with sand between 8-inches and 4.9 feet below the ground surface. Cobbles and boulders up to 32 inches in diameter were encountered between the depths of 4.9 feet and 16.5 feet. Based on the core recoveries in this section of the boring, it is assumed a matrix of gravel, sand, and silt is located in the voids of the boulders and cobbles. Asphalt measured 8 inches thick.

Boring B14-06 encountered clayey sand between 5-inches and 9.5 feet below the ground surface. Underlying the clayey sand is clayey gravel with sand with chucks of weathered siltstone. Water was encountered at a depth of 13 feet. The interface of clayey gravel and siltstone is at 16.3 feet below the ground surface.

Boring B14-07 encountered clayey gravel and silty gravel between the depths of 7-inches and

13.5 feet. Wood was encountered between 13.5 feet and 15.5 feet below the ground surface.

Underlying the wood layer is dark gray, coarse-grained sandstone between 15.5 feet and 23 feet below the ground surface.

Geotechnical Memorandum GM35-15 Page 5

Table 1: Laboratory test results summary.

Existing Conditions and General Observations This section describes existing conditions and general observations for both East Beach Road and Joyce Piedmont Road.

Background A ferry transported wagons from a dock at the east side of Lake Crescent to Fairholm (west end of Lake Crescent) until 1920s when the Olympic Highway was completed along the south shoreline of Lake Crescent. East Beach Road was the access to the ferry dock. Historical topography maps from 1918 show East Beach Road and Joyce Piedmont Road relatively in the same location as their present locations.

The original type of road construction is interpreted to be partial to full bench and sidecast methods. In the areas where benching methods were used it is believed that the materials were sidecast onto the slope as fill, and that the materials were sidecast with little regard for proper benching, compaction, and thorough removal of organics. It is believed that the resulting sidecast mass remained in a loose unconsolidated state, and in a condition that promoted downhill creeping of the fill over time.

General Existing Site Conditions East Beach Road is generally 16 feet wide from the beginning of the project (BOP) at Lyre River Bridge (Station 100+00) to the intersection with Joyce Piedmont Road (approximately Station 134+50). This section of road has unpaved shoulders with widths that range from 1 foot to several feet. Through this section of road, there are areas where the ditch is in-filled and cannot carry water.

Geotechnical Memorandum GM35-15 Page 6 October 2015

The road width generally ranges between 16 feet and 21 feet from the intersection with Joyce Piedmont Road to the end of project (EOP), Station 134+50 to Station 270+00. This section also has unpaved shoulders with the left shoulder ranging between about 6 inches to 2 feet wide measured to the edge of ditch, where ditches are located or to the toe of a cut slope. The right shoulder varies from about 6 inches to several feet to the slope hinge point.

Joyce Piedmont Road is generally 18 feet wide from the intersection with East Beach Road to the EOP on Joyce Piedmont Road.

Creep Slope creep is the downward progression of a surficial layer of soil and rock on a slope. Slope creep can occur on the either the fill side of the road, or the cut side of the road, or both sides.

Evidence of fill slope creep is typically subsidence within the pavement profile or tension cracks in the pavement. Evidence of cut slope creep is infilling of ditch lines, tension cracks higher up on the cut slope, or leaning trees (utility pole). Many of the cut and fill slopes along East Beach Road and Joyce Piedmont Road exhibit varying degrees of active slope creep. Active slope creep will vary in respect to magnitude and rate of movement. Typically, slope creep is more active during wet months of the year and may intensify during years of higher than normal precipitation, preceding high precipitation events, or after removing the toe of a cut slope during ditch maintenance.

Ditches Along East Beach Road, the ditch system is not operating effectively due to 1) a creeping slope above the ditch narrowing or obstructing the ditch, 2) excess vegetation that inhibits efficient water flow, or 3) a profile that forms a sag curve without an apparent culvert to drain the water. The ineffective ditches allow water to bypass the ditch and flow across the pavement or migrate within the base rock. Flow within the base rock and subgrade may cause piping which can create voids and a reduction of subgrade strength that can result in pavement damage.

Along Joyce Piedmont Road, the ditches appear to have been cleaned sometime between February 2014 and August 2015. In some areas, the toe of the cut slope was cut into and stripped of vegetation (Picture B-34). This maintenance method increases sediment in the ditch and deposition farther down line and can result in increased slope creep.

In order to reduce the ongoing maintenance of cleaning and reestablishing ditches, a wall or buttress, or other mitigation would be required between the cut slope and ditch. However, this mitigation is outside the scope of this project.

Roadway Distress Pavement distress in the outboard lane typically takes the form of edge cracking, alligator cracking, and tension cracking. Edge cracking in the pavement can be the result of pavement being constructed on sidecast embankment fills. Alligator cracking is the result of weak pavement structure or subgrade conditions, poor drainage, excessive loading, or more likely a combination of these causes. Tension cracking is predominantly arcuate or sinuous

Geotechnical Memorandum GM35-15 Page 7 October 2015 longitudinally along the road and exhibits pavement subsidence, which is usually indicative of slope creep and/or settlement of embankment fill materials. The majority of the pavement distress and patching between Station 140+00 and EOP is located on the outboard side of the road.

The inboard lane typically exhibits alligator and block cracking. Block cracking is typically associated in areas of the pavement that tend to have lower stress over time.

Between station 179+00 and 199+00 the road drops down close to the lake surface elevation and a steep cut slope. Through this section, there is a higher frequency of patched potholes.

Based on the material encountered in borings B14-04 and B14-05, and site conditions it is interpreted that soil particles are piping through the cobbles and boulder within the subgrade due to either poorly performing ditches or wave action of the lake water.

Recommendations Subgrade stabilization mitigation is recommended in areas that exhibit subsidence and pavement distress that are indicative of poor subgrade soil conditions. The approximate locations and recommendations are shown in Table 4 for East Beach Road and Table 5 for Joyce Piedmont Road. The recommendations are divided into two priorities, whereas Priority 1 has the higher interpreted need for mitigation.

Deep Patch Design Two types of deep patches are proposed for this project. Both deep patch designs require subexcavating to a depth of 18 inches into subgrade and lining the bottom and sides of the excavation with a geotextile. Install stabilization geogrid on top of the geotextile, so the geogrid can be wrapped up along the embankment face and lapped back a minimum of 4 feet on top of the 9-inch layer. Install the second layer geogrid, so it can be wrapped up and lapped back extending the full width of the site excavation directly beneath the base course. Deep Patch, Type I will have a vertical face closest to the embankment slope under the right edge of the pavement. Deep Patch, Type II is constructed the same as Type I except that the face will daylight out the embankment slope.

Subexcavation Design The subexcavation design requires subexcavating to a depth of 12 inches into the subgrade and lining the bottom and sides of the excavation with a geotextile before backfilling.

Geotechnical Memorandum GM35-15 Page 8

Table 2: Recommendations for East Beach Road

Table 3: Recommendations for Joyce Piedmont Road

Construction Materials All the excavations will be backfilled with select borrow. Stabilization geogrid having an ultimate tensile strength of at least 1800 lb. /ft. is required. Refer to the final contract documents for the complete design and material requirements for the deep patch and subexcavation repairs.

Geotechnical Memorandum GM35-15 Page 9 October 2015

Construction Advisory for Subgrade Stabilization Locations The actual limits of many of the subgrade reinforcement locations have become obscured as a result of routine maintenance such as patching and overlays. The WFLHD geotechnical engineer can assist the project engineer and contractor in verifying the limits of all subgrade reinforcement locations, if necessary.

Most of the subexcavation repair zones have not been investigated with borings, but it is interpreted that the materials encountered in the excavations will be similar to those encountered in the investigation borings. Encountering scattered cobbles, decomposing organics and voids may be possible. Larger material may be encountered within or directly underlying the existing pavement structure. The contractor should anticipate the possible need to fill and compact voids with select borrow prior to constructing subexcavation sections, and removing decomposing organics from below the design subexcavation depth as directed by the CO. The depth of the subexcavation may be increased by the CO if unsuitable materials are encountered at the bottom of the subexcavation. Consultation with the project geotechnical engineer may be required.

Drainage Station 138 Culvert A 7-foot diameter CMP culvert is located near Station 138 on East Beach Road. The shoulder on both sides of the embankment is very soft. Two small voids (less than a foot in diameter) were encountered within the left shoulder. One void was probed with a steal rod extending about 5 feet below the ground surface. The roadway across this embankment exhibits numerous patching. Boring B14-07 is located east of the existing culvert at approximately station 138+00.

Underlying the pavement structure is loose to medium dense silty gravel between 2.6 feet and

13.5 feet below the ground surface. Two feet of wood was encountered under the silty gravel.

Moderately weak sandstone was encountered between 15.5 feet and 23 feet.

A 10-foot culvert is proposed to replace the existing 7-foot culvert, see Figure 1. The red dashed line is the approximate offset location of B14-07 (not station location) and the dotted horizontal violet line indicates the approximate depth where sandstone bedrock was encountered. The top of the sandstone bedrock elevation may be deeper at the location of the existing culvert. The 70% Plans show the proposed culvert invert about 3 feet below the existing culvert invert and 17.5 feet below the ground surface. Rock excavation may be required to place the 10-foot culvert and keyed riprap embankment protection at the proposed elevations.

Geotechnical Memorandum GM35-15 Page 10

Figure 1: Cross section of the culvert near Station 138.

Culverts There are several sections along East Beach Road where water in the ditches must flow a great distance to reach a culvert. Some of these areas are located within a sag curve. It is possible that culverts may be located within these sections; however, they are not apparent. Table 6 contains approximate locations where culverts and ditches are interpreted to be performing inefficiently. This table should be considered as incomplete as it only contains the interpreted worst-case areas. We recommend that the WFLHD Hydraulics Section be consulted for further evaluation. We recommend that the Project CO make final determination of the locations.

Table 4: Inefficient performing culverts and ditches

Geotechnical Memorandum GM35-15 Page 11 October 2015

Summary This memorandum presents recommendations for East Beach Road and Joyce Piedmont Road in Olympic National Park. For questions regarding this memorandum, please contact Diann Morehouse at 360-619-7609 or diann.morehouse@dot.gov.

References Schasse, H.W (2003) Geologic Map of the Washington Portion of the Port Angeles 1:100,000 Quadrangle Washington Division of Geology and Earth Resources, Open File Report 2003-6, Scale 1:100,000.

Palmer, S., Magsino, S., et al (2004). Liquefaction Susceptibility Map of Clallam County, Washington, Open File Report 2004-20, Map 5A, Washington Division of Geology, and Earth Resources, Scale 1:150,000.

Western Regional Climate Center, Cooperative Climatological Data Summaries Elwha Ranger Station (452548), http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa2548 , Accessed July 27, 2015.

Western Regional Climate Center, Cooperative Climatological Data Summaries Forks 1E, Washington (452914) http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa2914, Accessed July 27, 2015.

Attachments:

A: Vicinity, Location, and Geologic Maps B: Project Pictures C: Boring Locations D: Boring Logs and Rock Core Pictures E: Laboratory Test Results mailto:diann.morehouse@dot.gov http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa2548 http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa2914

Geotechnical Memorandum GM35-15

Attachment A:

Vicinity, Location, and Geologic Maps

Geotechnical Memorandum GM35-15 Page A-1

Figure A-1: Vicinity Map

Figure A-2: Location Map

End of Project

Project

Beginning of Project

End of Joyce Piedmont Road segment

Intersection of East Beach Road and Joyce Piedmont Road

Sol Duc Trailhead Parking Area

WA NPS OLYM 11(9)

Geotechnical Memorandum GM 35-15 Page A-2

Figure A-3: Geologic map of the project vicinity (Schasse, H.W (2003)).

Lake Crescent Beginning of Project

End of Joyce Piedmont Road

End of East Beach Road

Sol Duc Trailhead Parking Area

WA NPS OLYM 11(9)

Geotechnical Memorandum GM 35-15 Page A-3

Figure A-4: Excerpt from Liquefaction Susceptibility Map of Clallam County, Washington (Palmer, S. (2004))

Lake Crescent

Attachment B:

Project Pictures

Geotechnical Memorandum GM 35-15 Page B-1

Picture B-1: East Beach Road Station 102+00, Back (2015)

Picture B-2: East Beach Road Station 102+00, Ahead, (2015)

Geotechnical Memorandum GM 35-15 Page B-2

Picture B-3: East Beach Road Station 106+00, Ahead, (2015)

Picture B-4: East Beach Road 106+00 Back, (2015)

Geotechnical Memorandum GM 35-15 Page B-3

Picture B-5: East Beach Road 112+00, Ahead, (2015)

Picture B-6: East Beach Road Station 116+00, Back (2015)

Geotechnical Memorandum GM 35-15 Page B-4

Picture B-7: East Beach Road Station 120+00, Ahead, (2015)

Picture B-8: East Beach Road Station 120+00, Back (2015)

Geotechnical Memorandum GM 35-15 Page B-5

Picture B-9: East Beach Road Station 122+00, Ahead, (2015)

Picture B-10: East Beach Road Station 122+00, Back (2015)

Geotechnical Memorandum GM 35-15 Page B-6

Picture B-11: East Beach Road Station 130+00, Ahead, (2015)

Picture B-12: East Beach Road Station 130+00, Back, (2015)

Geotechnical Memorandum GM 35-15 Page B-7

Picture B-13: East Beach Road Station 134+70, Ahead, Intersection with Joyce Piedmont Road (2015)

Picture B-14: East Beach Road Station 135+00, Back, Intersection with Joyce Piedmont Road (2015)

Geotechnical Memorandum GM 35-15 Page B-8

Picture B-15: East Beach Road Station 138+00, Ahead, (2015)

Picture B-16: East Beach Road Station 138+00, Back, (2015)

Geotechnical Memorandum GM 35-15 Page B-9

Picture B-17: East Beach Road Station 141+00, Ahead, (2014)

Picture B-18: East Beach Road Station 141+00, Back, (2014)

Geotechnical Memorandum GM 35-15 Page B-10

Picture B-19: East Beach Road Station 150+00, Ahead, (2015)

Picture B-20: East Beach Road Station 150+00, Back, (2015)

Geotechnical Memorandum GM 35-15 Page B-11

Picture B-21: East Beach Road Station 154+00, Ahead, (2014)

Picture B-22: East Beach Road Station 154+00, Ahead, (2015)

Geotechnical Memorandum GM 35-15 Page B-12

Picture 23: East Beach Road Station 158+20, Ahead, (2015)

Picture B-24: East Beach Road Station 162+00, Ahead, (2015)

Geotechnical Memorandum GM 35-15 Page B-13

Picture B-25: East Beach Road Station 162+00, Back, (2015)

Picture B-26: East Beach Road Station 166+00, Ahead, (2015)

Geotechnical Memorandum GM 35-15 Page B-14

Picture B-27: East Beach Road Station 167+30, Back, (2014)

Picture B-28: East Beach Road Station 168+30, Ahead, Possible cobbles close to pavement surface (2014)

Geotechnical Memorandum GM 35-15 Page B-15

Picture B-29: East Beach Road Station 170+00, Back, (2015)

Picture B-30: East Beach Road Station 175+20, Ahead, (2014)

Geotechnical Memorandum GM 35-15 Page B-16

Picture B-31: East Beach Road Station 178+00, Back, (2015)

Joyce Piedmont Road

Picture B-31: Joyce Piedmont Road Station 302+00, Back (2014)

Geotechnical Memorandum GM 35-15 Page B-17

Picture B-32: Joyce Piedmont Road Station 305+00, Back, (2014)

Picture B-33: Joyce Piedmont Road Station 314+40, Ahead, (2014).

Geotechnical Memorandum GM 35-15 Page B-18

Picture B-34: Joyce Piedmont Road Station 314+50, Ahead, (2015)

Picture B-35: Joyce Piedmont Road Station 484+10, Back, (2015)

Attachment C:

Boring Locations

Geotechnical Memorandum GM 35-15

Figure C-1: Overview of boring locations within the project

Geotechnical Memorandum GM 35-15

Figure C-2: Borings B14-01 and B14-02 locations

Geotechnical Memorandum GM 35-15

Figure C-3: Borings B14-03 and B14-04 locations

Geotechnical Memorandum GM 35-15

Figure C-5: Borings B14-04 and B14-05 locations

Geotechnical Memorandum GM 35-15

Figure C-6: Boring B14-05 and B14-06 locations

Geotechnical Memorandum GM 35-15

Figure C-7: Borings B14-06 and B14-07 locations

Attachment D:

Boring Logs and

Rock Core Pictures

Geotechnical Memorandum GM 35-15 Page D-1

ROCK CORE PICTURES

Picture D-1: Boring EBR14-01, 7 to 20 feet

Geotechnical Memorandum GM 35-15 Page D-2

Picture D-2: Boring EBR14-04, 3 to 13 feet

Geotechnical Memorandum GM 35-15 Page D-3

Picture D-3: Boring EBR14-05, 5 to 16.5 feet

Geotechnical Memorandum GM 35-15 Page D-4

Picture D-4: Boring EBR14-06, 16.3 to 19.5 feet

Geotechnical Memorandum GM 35-15 Page D-5

Picture D-5: Boring EBR14-07, 16 to 23 feet

Attachment E:

Laboratory Test Results