GM 08-15 Old Faithful to West Thumb_Final GT Recommendations.pdf

Memorandum Western Federal Lands Highway Division

610 E. Fifth Street Vancouver, WA 98661-3801

Date: March 17, 2015 Reply Refer To: HFL-17 GM 08-15

From: Dustin Woods Geotechnical Engineer

To: Connie Kratovil Project Manager

Subject: Final Geotechnical Recommendations, WY NPS YELL 10(23), West Thumb to Old Faithful

Geotechnical Memorandum 08-15

INTRODUCTION

This memorandum provides the final geotechnical recommendations for the West Thumb to Old Faithful pavement preservation/rehabilitation project and offers the investigation results and boring logs from the 2014 site investigation. Information contained in this memorandum is intended to supplement the preliminary recommendation memo, GM 01-15. GM 01-15 contains background, scope, and other general project information.

RECOMMENDATIONS

Thermally Insulated Roadway Design

On January 29, 2015 Yellowstone National Park Geologist Henry Heasler and Landscape Architect Daniel Rhodes discussed the proposed Thermal Insulation Locations (Table 6 GM 01-15) with Western Federal Lands’ Geotechnical Engineers Dustin Woods and Nathan Jenks;

and Highway Designer Clinton Choy. The park confirmed the thermally insulated roadway design from station 100+00 to 102+50; however they did not have any concerns or evidence of hot ground or a lack of snow with the section between station 412+00 and 423+00. Because of the lack of evidence, this section is no longer recommended.

The Park did recommend two additional locations within the project limits that need to be insulated that were not identified in the drilling program.

The first additional location is located approximately at the culvert at station 1075+00. This site was not investigated during previous site visits or during the September drilling; therefore, the specific limits of this area are unknown. During the teleconference with the park it was determined that a 50 foot long thermal section in this location would sufficiently cover the area of concern, extending approximately 25 feet on either side of the culvert.

The second additional location is located at the intersection of the Black Sand Road and Grand Loop Road. This section of Grand Loop Road is being omitted from this development effort due to the presence of cement concrete pavement along the mainline; however it is possible that the approach of Black Sand Road will be included in the proposed project. Thermal imagery (Figure 1 attached) was provided by Yellowstone National Park in the absence of subsurface temperature information for this section. It is recommended that if the approach at Black Sand Road is rebuilt, the new section include a type 5 thermal sub-excavation with standard sand.

Table 1 provides the final recommended locations for thermally insulated roadway sections for this project . Please see Figure 2 (attached) for typical sections of a type 5 sub-excavation.

Table 1. Thermal Insulation Locations.

Station Length (ft) Sand Type WidthStart End

100+00 102+50 250 Standard Full 1074+75 1075+25 50 Standard Full

Black Sand Road Intersection 100’ SW 100 Standard Full

Sub-Excavations

The sub-excavation locations have not changed from the preliminary memorandum. For convenience, the locations of these recommendations are listed again below in Table 2. The recommended design details for the subexcavation types are presented in Figure 2.

Table 2. Recommended Sub-Excavation Locations Station Length (ft) Type Width Daylight

Side Collector Pipe Side

Outlet SideStart End

93+00 96+20 320 3 Full LT RT 99+95 101+75 180 3 Full LT RT

116+90 118+00 110 2 Full RT RT 177+65 179+05 140 3 Full RT LT 185+85 187+85 200 3 Full LT RT 196+80 200+55 375 2 Full RT RT

204+00 205+40 140 1 1/2 RT RT

207+00 207+70 70 2 Full LT LT

211+40 213+15 175 2 1/2 LT LT LT

240+80 242+30 150 3 Full LT RT 285+25 286+15 90 3 Full LT RT 286+85 287+65 80 2 Full 290+80 292+00 120 2 Full LT LT

Table 2 Continued. Recommended Sub-Excavation Locations Station Length (ft) Type Width Daylight

Side Collector Pipe Side

Outlet SideStart End

293+05 294+25 120 1 1/2 LT LT

296+40 297+40 100 1 1/2 LT LT

297+40 298+80 140 1 Full LT

299+65 302+50 285 1 1/2 LT LT

344+15 347+80 365 2 1/2 RT

347+80 349+25 145 2 Full

349+25 351+70 245 2 1/2 RT

362+80 367+95 515 2 Full LT RT 375+55 378+30 275 3 Full LT LT 290+80 292+00 120 2 Full LT LT

293+05 294+25 120 1 1/2 LT LT

296+40 297+40 100 1 1/2 LT LT

297+40 298+80 140 1 Full LT

299+65 302+50 285 1 1/2 LT LT

344+15 347+80 365 2 1/2 RT

347+80 349+25 145 2 Full

349+25 351+70 245 2 1/2 RT

362+80 367+95 515 2 Full LT RT 375+55 378+30 275 3 Full LT LT 382+80 384+90 210 3 Full RT LT 386+00 387+80 180 2 Full LT LT 403+15 405+25 210 3 Full LT LT 414+05 415+35 130 2 Full LT RT 416+50 418+80 230 2 Full LT RT 419+90 421+30 140 2 Full LT RT

450+60 452+30 170 2 1/2 RT RT RT

511+70 513+20 150 3 Full LT RT 734+75 736+25 150 2 Full RT RT 784+75 787+05 230 2 Full RT RT

9213+85 9218+70 485 2 Full 3097+82 3099+22 140 2 Full RT RT

Underdrains/Ditches

The underdrain and ditch locations have not changed from the preliminary memorandum; these recommendations are listed in Table 3. Please note that there has not been sufficient design work completed to give a more accurate length to the underdrain located at station 164+00 to 163+75. This length will likely change as the design progresses. See Figure 3 (attached) for details of the underdrain design.

Table 3. Underdrain and Ditch Locations.

Station Length (ft) Type Width Daylight

Side Collector Pipe Side

Outlet SideStart End

164+00 163+75 50 UD RT

412+00 422+50 1050 UD LT LT

3082+50 3086+50 400 Ditch RT

Closing

The Soil and Rock Classification Guidelines (Figure 4) and boring logs (Figure 5) have been attached to this memorandum for informational purposes.

Please contact Dustin Woods at (360) 619-7541 or Dustin.Woods@dot.gov with any questions regarding this memorandum.

CC: Clinton Choy, WFLHD Roadway Design Megan Marshall, WFLHD Materials Malcolm Ulrich, WFLHD Geotechnical Team Lead Geotechnical File

Attachments: Figure 1. Thermal Map of Black Sand Intersection Figure 2. Sub-excavation Typical Sections and Details Figure 3. Underdrain Typical Section and Details Figure 4. Soil and Rock Classification Guidelines

Figure 5. Boring Logs

Figure 1. Thermal Imagery of Black Sand Intersection

131.0 F

105.6

88.3

81.3

77.0

73.6

71.2

69.1

67.1

65.1

63.0

60.1

58.8

56.7

54.5

51.8

Figure 2. Sub-excavation Typical Sections and Details

Figure 2. Sub-excavation Typical Sections and Details

Figure 3. Underdrain Typical Section and Details

SOIL DESCRIPTIVE TERMINOLOGY

CONSISTENCY OF COHESIVE SOILS

SPT N-Value (blows/ft) Consistency Field Identification

0 - 1 Very Soft Easily penetrated several inches by first

2 - 4 Soft Easily penetrated several inches by thumb

5 - 8 Firm Moderate effort required to penetrate several inches by thumb

9 - 15 Stiff Readily indented by thumb but penetrated only with great effort

16 - 30 Very Stiff Readily indented by thumbnail

> 30 Hard Indented with difficulty by thumbnail

RELATIVE DENSITY OF

COHESIONLESS SOILS

SPT N-Value (blows/ft) Relative Density

0 - 4 Very Loose

5 - 10 Loose

11 - 30 Medium Dense

31 - 50 Dense

> 50 Very Dense

PARTICLE SIZE

Term Sieve Size Boulder > 12” (>300mm)

Cobble 3” - 12” (75mm - 300mm)

Gravel – coarse ¾” - 3” (19mm - 75mm)

Gravel – fine #4 - ¾” (4.75mm - 19mm)

Sand – coarse #10 - #4 (2.00mm - 4.75mm)

Sand – medium #40 - #10 (0.425mm - 2.00mm)

Sand – fine #200 - #40 (0.075mm - 0.425mm)

Silt & Clay < #200 (<0.075mm)

MOISTURE CONTENT

Dry Dusty, dry to the touch

Moist Damp, but no visible free water

Wet Visible free water, saturated, over optimum

ROCK DESCRIPTIVE TERMS

ROCK WEATHERING

Field Identification Term Crystals are bright. Discontinuities may show some minor surface staining.

No discoloration in rock fabric. Fresh

Rock mass is generally fresh. Discontinuities are stained and may contain clay. Some discoloration in rock fabric.

Slightly Weathered

Significant portions of rock show discoloration and weathering effects.

Crystals are dull and show visible chemical alteration. Discontinuities are stained and may contain secondary mineral deposits.

Moderately Weathered

Rock can be excavated with geologist’s pick. All discontinuities exhibit secondary mineralization. Complete discoloration of rock fabric. Surface of core is friable and usually pitted due to washing out of highly altered minerals by drilling water.

Highly Weathered

Rock mass is completely decomposed. Original rock “fabric” may be evident. May be reduced to soil with hand pressure. Decomposed

DISCONTINUITY SPACING ROCK QUALITY DESIGNATION (RQD)

Spacing (in) Spacing Term RQD % Designation < 2.5 Very Close 0 - 25 Very poor

2.5 – 8 Close 25 - 50 Poor 8 – 24 Moderately close 50 - 75 Fair 24 – 80 Wide 75 - 90 Good

> 80 Very Wide 90 - 100 Excellent (RQD is the percent of a core run with intact lengths greater than 4 inches excluding breaks caused by drilling.)

INTACT ROCK HARDNESS

Field Identification UCS (psi) Hardness Term Indented by thumbnail. 40 - 150 Extremely Weak (R0) Crumbles under firm blows with point of geological hammer, can be peeled by a pocket knife. 150 - 730 Very Weak (R1)

Can be peeled by a pocket knife with difficulty, shallow indentations made by firm blow with geological hammer.

730 – 3,600 Weak (R2)

Cannot be scraped or peeled with a pocket knife, specimen can be fractured with a single blow of geological hammer.

3,600 – 7,300 Medium Strong (R3)

Specimen requires more than one blow of geological hammer to fracture it. 7,300 – 15,000 Strong (R4)

Specimen requires many blows of geological hammer to fracture it. 15,000 – 36,000 Very Strong (R5)

Specimen can only be chipped with geological hammer. > 36,000 Extremely Strong (R6) (UCS – Unconfined Compressive Strength)