AMD 3 EIE439-Geotechnical_2024-10-17.pdf

Geotechnical Data Report Revision 1 Fuel Management and Lab Facility

(EIE439)

Eielson Air Force Base, Alaska

Alaska District, Pacific Ocean Division

27 September 2024

PN: DESC2503

Status: Final

DEPARTMENT OF THE ARMY

U.S. ARMY CORPS OF ENGINEERS, ALASKA DISTRICT

P.O. BOX 6898

JBER, AK 99506-0898

CEPOA-ENG-M 27 September 2024

MEMORANDUM FOR Military Project Management (CEPOA-PM-M), Charles Newman

SUBJECT: Geotechnical Data Report for the Fuel Management and Lab Facility (EIE439), Eielson Air Force Base, Alaska.

1. Enclosed is the Geotechnical Data Report for the Fuel Management and Lab Facility (EIE439) located on Eielson Air Force Base, Alaska. Included with the report are the project Location and Vicinity Map, Test Boring Location Map, a discussion of the geotechnical findings, and exploration logs for the project.

2. Questions should be addressed to Twain Cacek at 907-753-2784 or Amy Steiner at 907-753-

2800.

TWAIN M. CACEK, E.I.T., G.I.T.

Civil Engineer

CEPOA-ENG-M

AMY L. STEINER, P.E.

Chief, Geotechnical and Materials Section

CEPOA-ENG-M

JOHN J. RAJEK, P.E.

Chief, Geotechnical and Engineering Services Branch

CEPOA-ENG

Fuel Management and Lab Facility (EIE439), Eielson Air Force Base, Alaska i

Geotechnical Data Report September 2024 U.S. Army Corps of Engineers

Table of Contents 1 Introduction

2 Location and Project Description

3 Previous Geotechnical Investigations

4 Historical Site Use/Desktop Study

5 Regional Geology

6 Field Exploration

Drilling Operations

Field Soil Sampling

Borehole Locations

7 Laboratory Testing and Soil Classification

8 Site Conditions

Surface Conditions

Subsurface Conditions

8.2.1 Fill Soils Unit

8.2.2 Fine Grained Soils Unit

8.2.3 Coarse-Grained Soils Unit

Groundwater

Seasonally Frozen Soils

Permafrost Soils

Potential Soil Contamination

9 Assessment of Liquefaction Potential and Seismic Settlement

APPENDIX A – LOCATION MAPS

Project Location and Vicinity Map .................................................................................1 Sheet

Test Boring Location Map ............................................................................................. 1 Sheet

APPENDIX B – EXPLORATION LOGS

Key to Exploration Logs ............................................................................................... 1 Sheet

Exploration Logs EIE-BH-2023001 through EIE-BH-2023005 .................................... 6 Sheets

APPENDIX C – LABORATORY TESTING RESULTS

Laboratory Testing Summary ..................................................................................... 2 Sheets

Laboratory Testing Results ......................................................................................... 5 Sheets

APPENDIX D - CALCULATIONS

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Seismic Settlement Calculations ................................................................................. 3 Sheets

TABLE OF FIGURES

Figure 4-1. Historical Imagery from 1949 with approximate project footprint

Figure 4-2. Historical Imagery from 1978 with project footprint

Figure 4-3. Imagery from 2023 with project footprint

Figure 8-1. Typical Fill Soil Unit encountered in EIE-BH-2023002 at 0-2’ bgs

Figure 8-2. Typical Fine-Grained Soil Unit encountered in EIE-BH-2023005 at 5-7’ bgs

Figure 8-3. Typical Coarse-Grained Soil Unit encountered in EIE-BH-2023003 at 10-12’ bgs

TABLE OF TABLES

Table 6-1. Borehole Locations (NAD83(1992), ASPC Zone 3, NAVD88)

Table 7-1. Soils Laboratory Test Standards

Table 8-1. Lithological Description of Fill Soils Unit

Table 8-2. Lithological Description of Fine-Grained Soils Unit

Table 8-3. Lithological Description of Coarse-Grained Soils Unit

Table 9-1. Seismic Design Ground Motion Parameters

Table 9-2. Liquefaction Potential and Estimated Total Settlement of EIE-BH-2023005

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U.S. Army Corps of Engineers

1 Introduction The purpose of this report is to identify surface and subsurface conditions and address geotechnical concerns associated with the proposed Fuel Management and Lab Facility (EIE439) located on Eielson Air Force Base, Alaska. This report presents a summary of the findings based on site observations and results of the field exploration and laboratory testing.

2 Location and Project Description Eielson Air Force Base is located near Moose Creek, Alaska which is about 25 miles southeast of Fairbanks, Alaska in the North Star Borough. The project site is located east of the airfield along Flight Line Avenue approximately 500 feet south of Division Street. The site is located across the street from Fire Station #1. These features are illustrated in the project vicinity map located on sheet A-1 in Appendix A.

The planned project includes the construction of a new Petroleum Operations Building to replace the existing Petroleum Operations Building which is located just north of the proposed site. The propose building will be approximately 3850 sf and will include a fuel testing laboratory, a fuels control center, and other supporting rooms. The single-story facility will be constructed using masonry or a pre-engineered metal building.

3 Previous Geotechnical Investigations Previous geotechnical investigations were performed in the vicinity of the project area. These investigations include the 750-Man EM Barracks completed in 1951 (Eielson AFB 002), the POL Operations and Administration Facility completed in 1964 (Eielson AFB 025), and the Refueling Station completed in 1984 (Eielson AFB 052). These investigations are archived in the Alaska District Geotechnical and Materials Section and are available upon request. The historical subsurface characterizations presented with these projects is not indicative of the subsurface conditions encountered during the August 2023 site investigation. Historical geotechnical investigations in the area indicated a layer of permafrost that was encountered between 5 and 15 feet below ground surface (bgs). This layer of permafrost was not encountered during our investigation. This layer of permafrost likely thawed over time due to the land development in the area.

4 Historical Site Use/Desktop Study The site of the proposed new Petroleum Operations Building has been utilized as a parking lot for the existing Petroleum Operations Building since its construction in 1967. Limited historical imagery and other records indicate that the site may have been used as a parking lot for the 750- Man EM Barracks. The site has had no other development or use besides as a parking lot.

Historical imagery from 1949 in Figure 4-1 indicates no development within the project footprint other than clearing of vegetation. Historical imagery from 1978 and 2023 (Figure 4-2 and Figure 4-3, respectively) show the project site with the existing Fuel Lab and parking lot. There are buried and overhead utilities on the site that must be accounted for during construction of the new Fuel Management and Lab Facility. Historical imagery does not predate development/clearing in the vicinity of the proposed site, and therefore does not indicate whether old stream beds, sloughs, or forests were present at the site prior to development. It is not anticipated that historical site use or natural features will impact the current project.

Fuel Management and Lab Facility (EIE439), Eielson Air Force Base, Alaska 2

Figure 4-1. Historical Imagery from 1949 with approximate project footprint.

Figure 4-2. Historical Imagery from 1978 with project footprint

Fuel Management and Lab Facility (EIE439), Eielson Air Force Base, Alaska 3

Figure 4-3. Imagery from 2023 with project footprint

5 Regional Geology

Eielson Air Force Base (AFB) is regionally located within the Yukon-Tanana Uplands physiographic province, an area bounded by the Alaska Range to the south and the Brooks Range to the north. Within the province, Eielson AFB is more specifically located along the eastern edge of the Tanana River Valley. The bedrock geology of the area consists of the Birch Creek Schist, a Precambrian and Paleozoic age metamorphic rock unit. This rock unit has been intruded by Mesozoic and Cenozoic age granodiorite and quartz monzanite metamorphic rocks. Due to the areas proximity to both the Tanana River floodplain and glacial deposits of the Alaska Range, the bedrock is overlain by younger sedimentary deposits of fluvial gravel and wind-blow silt (loess). These unconsolidated sediments range from approximately 200 to 300 feet thick beneath Eielson AFB. As a result of the thick unconsolidated fluvial deposits, Eielson AFB is underlain by a shallow unconfined aquifer with groundwater typically less than 10 feet below the ground surface.

6 Field Exploration The subsurface exploration for this project was conducted from 22 to 23 August 2023. A total of 5 boreholes were drilled to depths between 20 and 50 feet bgs. These borings were designated permanent numbers EIE-BH-2023001 through EIE-BH-2023005.

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Drilling Operations

GeoTek Alaska, Inc., under contract with the USACE-Alaska District, performed the geotechnical drilling with a Geoprobe 8040DT. Boreholes were drilled using 4.25-inch inside diameter hollow stem auger. Engineers with the Alaska District supervised the drilling operations and field logged samples collected from the boreholes in accordance with ASTM D2488, “Description and Identification of Soils (Visual – Manual Procedure).” Soil samples were assigned frost classifications based on the Unified Facilities Criteria (UFC) 3-250-01 Pavement Design for Roads and Parking Areas, Table 19-2 “Frost Design Soil Classification.” Estimated frost classifications are based on ASTM soil classifications. Exploration logs are presented in Appendix B.

Field Soil Sampling

Soil samples were obtained using an unlined large penetration test (LPT) sampler. The LPT sampler consisted of a three-inch outside diameter and 2.5-inch inside diameter split-barrel sampler typically advanced 24 inches into the undisturbed soils ahead of the auger. Samplers were driven into the soil using a 340-pound automatic trip hammer free-falling a vertical distance of 30 inches on NWJ rods. Soil samples were generally collected at the surface, 2.5 feet, 5 feet,

7.5 feet, 10 feet, and at five-foot intervals thereafter to the limit of the exploration. Sampling procedures were in general accordance with ASTM D1586, “Standard Test Method for Penetration Test and Split-Barrel Sampling of Soils”, with modifications for use of the LPT sampler and 340-pound hammer. The number of blows required to drive each six-inch increment is recorded on the exploration logs and shown in Appendix B. Refusal is defined as 50 blows in less than 6 inches. Refusal was not encountered in any of the boreholes. Soil samples were double sealed in polyethylene bags to preserve natural moisture content.

Soil samples were scanned for volatile organic compounds by Alaska District Engineers using a photoionization detector (PID). Two types of readings were taken on recovered soil samples. The first reading was taken while the material was still on the sampling barrel and was designated as a “cold” reading. The second reading was taken when the sample was placed in a sample collection bag and exposed to some form of heat such as heating the bag with the heater of the service truck used. This second reading was designated as “hot”. All PID readings were below the contamination threshold of 20 parts per million (ppm).

Borehole Locations

The boreholes were located in the field by engineers of the USACE-AD Geotechnical and Materials section using recreational grade handheld GPS. The borehole locations were plotted into the georeferenced CAD drawing prepared by CRW (survey performed 30 May to 1 June 2023) for the project which allowed the determination of approximate horizontal geographical coordinates and vertical elevations. Vertical control from the topographic survey and test boring locations are referenced to North American Vertical Datum (NAVD) 88 in U.S. survey feet.

Horizontal coordinates are based on Alaska State Plane Coordinates Zone 3, North American Datum (NAD) 83 (1992) in U.S. survey feet. A summary of borehole coordinates is provided in Table 6-1 and the Test Boring Location Map is located on Sheet A-2 in Appendix A.

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Table 6-1. Borehole Locations (NAD83(1992), ASPC Zone 3, NAVD88)

Test Boring Location Northing (ft) Easting (ft) Surface Elevation

(ft)

EIE-BH-2023001 3,899,677.07 1,469,739.97 544.8

EIE-BH-2023002 3,899,667.52 1,469,656.75 544.5

EIE-BH-2023003 3,899,711.35 1,469,660.64 544.6

EIE-BH-2023004 3,899,721.22 1,469,725.06 544.7

EIE-BH-2023005 3,899,696.08 1,469,697.99 544.7

7 Laboratory Testing and Soil Classification A laboratory testing program was established to classify the soils encountered and determine their physical and engineering properties. The program consisted of particle-size analysis, moisture content, engineering classification, frost classification, and Atterberg limits tests. WSP, under contract with the Alaska District, performed laboratory tests using the latest version of the ASTM test standards listed in Table 7-1. Laboratory test results are provided in Appendix C.

Soils were assigned frost classifications according to Table 2-1 in EM 1110-3-138. These frost classifications are defined as:

NFS – Non-Frost-Susceptible PFS – Possibly Frost-Susceptible (requires laboratory testing to determine frost design soil classification) S1 and S2 – Possibly Frost-Susceptible Gravels and Sands, respectively.

F1 – Negligible to low frost susceptibility F2 – Low to medium frost susceptibility F3 – Medium to high frost susceptibility F4 – High to very high frost susceptibility

Table 7-1. Soils Laboratory Test Standards

Test Designation Test Description

ASTM D2216

Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

ASTM D6913

Standard Test Methods for Particle-Size Distribution of Soils Using Sieve Analysis

ASTM D7928 / D6913

Standard Test Method for Particle-Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis

ASTM D4318

Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils

8 Site Conditions The soil descriptions and classifications in this report, as well as the exploration logs, are based on the project engineer's interpretation of field logs and laboratory test results. Stratification lines indicate approximate soil type boundaries, and transitions may be subtle or not clearly discernible during drilling.

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Surface Conditions

At the time of the exploration, the proposed site was relatively flat with an approximate elevation of 544.5 feet NAVD88. Surface materials encountered at the site consisted of approximately 3 inches of hot mix asphalt pavement. Overhead utilities are present at the site and run from the power drop along the eastern portion of the site to the passenger vehicle plug in stations to Building 3242 to the north. Underground utilities are present throughout the site. These include water and gas lines running north to south along the eastern portion of the site as well as electrical lines running throughout the site. There is also a utilidor that runs north to south in the middle on the project site. These utilities can all be found in the Test Boring Location Map in Appendix A.

Subsurface Conditions

Details of the subsurface conditions encountered by the boreholes are shown on the Exploration Log sheets in Appendix B. The general subsurface profile consists of approximately 3 feet well graded sand and gravel fill soils over 3 to 5 feet of low plasticity silts transitioning into poorly graded sands and gravels. The details of the subsurface conditions encountered, and their pertinent characteristics, are described in the following sections.

8.2.1 Fill Soils Unit

Fill soils were encountered in all boring locations and extended approximately 3 feet below the existing ground surface. The fill soils are comprised of medium dense to dense gravels with silt and sand. The gravels were subrounded to subangular with a maximum particle size of approximately 2 inches. The fill soils were determined to have a frost classification ranging from non-frost-susceptible (NFS) to low frost-susceptibility. There was no indication of contaminated material such as chemical odor or discoloration of recovered fill soil samples. An example of the fill soils encountered at the project site is shown in Figure 8-1.

Figure 8-1. Typical Fill Soil Unit encountered in EIE-BH-2023002 at 0-2’ bgs.

Laboratory tests were performed on select samples of the fill soils. Natural moisture contents ranged from 2% to 6%. Grain size analysis tests indicated 5% to 8% of material passing a No.

200 sieve. A detailed laboratory summary can be found in Appendix C. The general properties of the fill soils unit are described in Table 8-1.

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Table 8-1. Lithological Description of Fill Soils Unit

Condition Value Description

Classification

GP, GP-GM,

GW-GM

Poorly Graded Gravel with Sand, Poorly Graded Gravel with Silt and Sand, Well Graded Gravel with Silt and Sand

Fines Content (< #200 Sieve) 5% to 8% Non-plastic

Moisture 2% to 6% Moist

Frost Class NFS, F1 Possible to low frost-susceptibility

Soil Relative Density Medium Dense to Dense

N/A

Nominal Maximum Particle Size 2 inches Subrounded to Subangular, fractured while driving

8.2.2 Fine Grained Soils Unit

Fine-grained soils were encountered below the fill soils in all but one test boring location and extended approximately 7 to 8 feet below the existing ground surface. These soils typically consisted of soft to very stiff low plasticity silts. Fine-grained soils had an estimated frost group of F4 indicating they are frost susceptible. There was no indication of contaminated material such as chemical odor or discoloration of recovered fine-grained soil samples. An example of the fine-grained soils encountered at the project site is shown in Figure 8-2.

Figure 8-2. Typical Fine-Grained Soil Unit encountered in EIE-BH-2023005 at 5-7’ bgs.

Laboratory tests were performed on select samples of the fine-grained soils. Natural moisture contents ranged from 22% to 32%. Grain size analysis tests indicated 78% to 85% of material passing a No. 200 sieve, with 24% to 26% of material passing the 0.02mm. A detailed laboratory summary can be found in Appendix C. Fine-grained soil unit properties are described in Table 8-2.

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Table 8-2. Lithological Description of Fine-Grained Soils Unit

Condition Value Description

Classification ML Silt with Sand

Fines Content (< #200 Sieve) 78% to 85% Non to Low Plasticity

Moisture 22% to 32% Moist

Frost Class F4 High frost-susceptibility

Soil Relative Density Soft to Very Stiff N/A

Nominal Maximum Particle Size Fine Sand N/A

8.2.3 Coarse-Grained Soils Unit

Coarse-grained soils were encountered below the fine-grained soils in all test boring locations and extended through the boring termination depths of 20 and 50 feet bgs. These soils typically consisted of very loose medium dense poorly graded gravels with sand, silt, and cobbles. The gravels were subrounded with a maximum particle size of greater than 3 inches. The coarse-grained soils were determined to have a frost classification ranging from NFS to PFS. There was a petroleum odor in one borehole near the water table (PID measurement below reporting threshold). There was no indication of contaminated material such as chemical odor or discoloration of recovered coarse-grained soil samples in the other four boreholes. An example of the coarse-grained soils encountered at the project site is shown in Figure 8-3.

Figure 8-3. Typical Coarse-Grained Soil Unit encountered in EIE-BH-2023003 at 10-12’ bgs.

Laboratory tests were performed on select samples of the coarse-grained soils. Natural moisture contents ranged from 3% to 10%. Grain size analysis tests indicated 2% to 8% of material passing a No. 200 sieve, with 2% of material passing the 0.02mm. A detailed laboratory summary can be found in Appendix C. The general properties of the coarse-grained soils unit are described in Table 8-3.

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Table 8-3. Lithological Description of Coarse-Grained Soils Unit

Condition Value Description

Classification

GP, GP-GM, GW,

GW-GM, GP, GW,

SW, SW-SM, SP

Poorly to Well Graded Gravel with Sand, Poorly to Well Graded Gravel with Sand and Silt, Poorly to Well Graded Sand with Gravel, Well Graded Sand with Gravel and Silt

Fines Content (< #200 Sieve) 2% to 8% Non-plastic

Moisture 3% to 10% Moist to Wet

Frost Class PFS, F1 Possible to Low frost susceptibility

Soil Relative Density Very Loose to Dense

N/A

Nominal Maximum Particle Size 3+ inches Subrounded to Subangular, fractured while driving

Groundwater

Groundwater was encountered while drilling between 8.25 and 8.5 feet bgs, corresponding to elevations of 536.1 to 536.5 feet NAVD88. The groundwater depths recorded while drilling are presented on the exploration logs. Groundwater elevations can fluctuate seasonally with changes in precipitation, snowmelt, and runoff conditions.

Seasonally Frozen Soils

Seasonally frozen soils were not encountered in any test borings drilled August 2023. Seasonal frost at Eielson Air Force Base can penetrate up to 10 feet bgs or deeper during a cold winter in areas of little to no snow cover.

Permafrost Soils

Permafrost was not observed during the geotechnical investigation and is assumed to not be present in the project site to the depths explored.

Potential Soil Contamination

Soil samples were scanned for volatile organic compounds by the Alaska District Engineers using a photoionization detector (PID). All PID readings were reported to be less than the contamination threshold of 20 ppm. The soil was also screened for other forms of contamination by USACE Alaska District chemists, and those findings are contained in the Chemical Data Report.

9 Assessment of Liquefaction Potential and Seismic Settlement Eielson AFB is located in a seismic region of Alaska where large magnitude earthquakes occur.

Structures shall be designed to meet or exceed seismic requirements in the International Building Code (IBC) 2021 and Unified Facilities Criteria (UFC) 3-301-01 Seismic Design of Buildings. This includes the requirement to evaluate the liquefaction potential of the site and address the potential for settlement and/or loss of bearing capacity during a seismic event.

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U.S. Army Corps of Engineers

The proposed structure is assigned a Seismic Design Category D per Section 11.6 of ASCE 7-16 (2018), since the mapped spectral response acceleration parameter at 1-second period, S1, is less than 0.5 at the project site. Note that per ASCE 7-16 section 11.4.8, a site-specific response analysis is required for the project area. Seismic data for Eielson AFB was determined using the probabilistic seismic hazard maps of Alaska provided by the U.S. Geological Survey (USGS) and the ASCE 7 Hazard Tool and is shown in Table 9-1 using a 2% probability of exceedance in 50 years. The specified design ground motions are for Site Class D. Seismic design parameters are given for ASCE 7-16 and ASCE 7-22, pending finalization of the design code.

It is worth noting that sites with potentially liquefiable soils, such as those in this project area, are typically assigned Site Class F which require a site response analysis. However, ASCE 7-22 provides an exception to this requirement for structures that have fundamental periods of vibration equal to or less than 0.5 seconds. If fundamental periods of vibration for proposed structures are greater than 0.5 seconds, an additional site response analysis will be required to establish seismic design parameters.

The proposed facility is assigned a Risk Category II in accordance with Table 2.2 of the UFC 3- 301-01 Structural Engineering (2019), since it represents a low hazard to human life in the event of failure, and is not included in the buildings and structures mentioned under Risk Category I.

Per the UFC 3-220-01 Geotechnical Engineering Section 2-1, the criteria for minimum factor of safety (FOS) for liquefaction of Risk Category II structures is greater than or equal to 1.0. An assessment of liquefaction potential and seismic settlement at the site was conducted based on the methods and procedures provided in the Earthquake Engineering Research Institute (EERI) Engineering Monograph MNO-12, “Soil Liquefaction during Earthquakes” by I.M. Idriss and R.W.

Boulanger. Site-specific seismic ground motion parameter values used for this analysis are provided in Table 9-1. The values used in the analysis were based on mapped values from the American Society of Civil Engineers (ASCE) Minimum Design Loads for Buildings and Other Structures (ASCE 7-16 and UFC 3-301-01 Structural Engineering).

EIE-BH-2023005 was evaluated for liquefaction. Results of this analysis, summarized in Table 9-2, indicate a potential for soil liquefaction to occur during the maximum considered earthquake (MCE). Potentially liquefiable soils are indicated in red. Seismically induced ground displacements, such as settlement, should also be anticipated at the site and could lead to an estimated settlement of 14.9 inches. See Appendix D for liquefaction and seismic settlement calculations.

The findings in Table 9-1 and Table 9-2 are provided to help develop ground improvement measures aimed at reducing liquefaction potential and seismic settlement at the proposed site to a satisfactory level for the facility.

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Table 9-1. Seismic Design Ground Motion Parameters Parameter ASCE 7-16 ASCE 7-22 Site Class D D

Return Period 2475 2475 Maximum Considered Earthquake (MCE) 7.5 7.5

Site-Specific PGAM 0.475 0.48 S1 0.375 0.34

SD1 * 0.57

Ss 0.965 1.0 SDs 0.717 0.81

*site-specific response spectrum required per ASCE 7-16

Table 9-2. Liquefaction Potential and Estimated Total Settlement of EIE-BH-2023005

Factor of Safety (FOS) for Liquefaction vs Depth

Depth (feet)

EIE-BH-2023005

FOS

Settlement

(inches)

0 to 2.5 #N/A 0.00

2.5 to 5 #N/A 0.00

5 to 7.5 #N/A 0.00

7.5 to 10 2.00 0.00

10 to 15 2.00 0.00

15 to 20 0.36 1.79

20 to 25 0.48 1.34

25 to 30 0.15 4.10

30 to 35 0.20 2.71

35 to 40 0.35 1.53

40 to 45 0.54 1.15

45 to 50 0.60 1.08

50 to 55 1.13 0.31

55 to 60 1.14 0.31

60 to 65 1.15 0.30

65 to 70 1.47 0.15

70 to 75 1.52 0.13

Settlement (inches) 14.9

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U.S. Army Corps of Engineers

APPENDIX A

LOCATION MAPS

Project Location and Vicinity Map ......................................................................... 1 Sheet

Test Boring Location Map ..................................................................................... 1 Sheet

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U.S. Army Corps of Engineers

APPENDIX B

EXPLORATION LOGS

Key to Exploration Logs ........................................................................................ 1 Sheet

Exploration Logs EIE-BH-2023001 through EIE-BH-2023005 ........................... 6 Sheets

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APPENDIX C

LABORATORY TEST RESULTS

Laboratory Testing Summary .............................................................................. 2 Sheets

Laboratory Testing Results ................................................................................. 5 Sheets

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APPENDIX D

CALCULATIONS

Seismic Settlement Calculations ......................................................................... 3 Sheets

20231017 EIE439 Liquefaction ASCE 7-22 APPENDIX D

ASCE 7 HAZARD TOOL OUTPUT SUMMARY

Site

Information

Project: DLA Fuel Labs

Location: Eielson Air Force Base, AK

General Elevation: 544 ft (NAVD 88)

Lat: 64.66699

Long: -147.08935

Standard: ASCE/SEI 7-22

Risk Category: III

Soil Class: D

Seismic Data

Moment Magnitude, MW: 7.5

SS: 1.00

S1: 0.34

SMS: 1.22

SM1: 0.85

SDS: 0.81

SD1: 0.57

TL: 6

PGAM: 0.48

VS30: 260

Seismic Design Category: D

Note:

Event 2% PE in 50 years.

Where values of the multi-period 5%-damped MCER response spectrum are not available from the USGS Seismic Design Geodatabase, the design response spectrum shall be permitted to be determined in accordance with Section 11.4.5.2

Date Source: USGS Seismic Design Maps based on ASCE/SEI 7-22 and ASCE/SEI 7-22 Table 1.5-2. Additional data for site-specific ground motion procedures in accordance with ASCE/SEI 7-22 Ch. 21 are available from USGS.

https://asce7hazardtool.online/

Earthquake Parameters Version 20120723 https://asce7hazardtool.online/ https://asce7hazardtool.online/ https://asce7hazardtool.online/ https://asce7hazardtool.online/

EIE-BH-2023005 20231017 EIE439 Liquefaction ASCE 7-22 APPENDIX D

DLA Fuel Labs

Eielson Air Force Base, AK

544.8 Feet (NAVD 88)

EIE-BH-2023005

7.5

0.480

7.5 Feet

62.4 PCF

4 Inches

Automatic-trip hammer

75 %

5 Feet

Yes

No

H:1V

#N/A

1.00

0.0 2.5 27 35 1 GP 120 5 1.3 543.6 0.15 0.15 55.9 55.9 1.00 0.312 1.00 1.10 1.00 2.000 #N/A #N/A 0.0 #N/A #N/A 0.000 0.00 0.000 0.00 #N/A

2.5 5.0 11 14 0 ML 120 85 3.8 541.1 0.45 0.45 22.8 28.3 1.00 0.311 1.00 1.10 1.00 0.396 #N/A #N/A 0.0 #N/A #N/A 0.000 0.00 0.000 0.00 #N/A

5.0 7.5 8 10 0 ML 115 85 6.3 538.6 0.74 0.74 16.6 22.1 0.99 0.309 1.00 1.10 1.00 0.234 #N/A #N/A 0.0 #N/A #N/A 0.000 0.00 0.000 0.00 #N/A

7.5 10.0 25 33 1 GP-GM 120 8 8.8 536.1 1.04 0.96 41.7 42.1 0.99 0.332 1.00 1.10 1.00 2.000 2.200 2.00 2.5 0.006 -0.962 0.000 0.00 0.000 0.00 2.80E-150

10.0 15.0 22 29 1 GP-GM 115 8 12.5 532.3 1.48 1.16 33.7 34.0 0.97 0.385 1.00 1.10 1.00 0.915 1.007 2.00 5.0 0.026 -0.367 0.000 0.00 0.000 0.00 9.72E-15

15.0 20.0 9 12 1 GP-GM 105 8 17.5 527.3 2.03 1.40 13.8 14.2 0.96 0.432 1.00 1.04 1.00 0.149 0.155 0.36 5.0 0.301 0.787 0.301 1.50 0.030 1.79 1.00E+00

20.0 25.0 15 20 1 GP 110 5 22.5 522.3 2.56 1.63 20.8 20.8 0.94 0.461 1.00 1.03 1.00 0.216 0.222 0.48 5.0 0.145 0.475 0.145 0.73 0.022 1.34 1.00E+00

25.0 30.0 2 3 1 GP 90 5 27.5 517.3 3.06 1.81 2.3 2.3 0.92 0.484 1.00 1.01 1.00 0.072 0.072 0.15 5.0 0.500 0.948 0.500 2.50 0.068 4.10 1.00E+00

30.0 35.0 6 8 1 GP 100 5 32.5 512.3 3.54 1.98 7.0 7.0 0.90 0.501 1.00 1.00 1.00 0.098 0.098 0.20 5.0 0.500 0.948 0.500 2.50 0.045 2.71 1.00E+00

35.0 40.0 15 20 1 GP 110 5 37.5 507.3 4.06 2.19 17.6 17.6 0.88 0.507 1.00 0.99 1.00 0.179 0.178 0.35 5.0 0.208 0.640 0.208 1.04 0.026 1.53 1.00E+00

40.0 45.0 21 27 1 GP-GM 115 8 42.5 502.3 4.63 2.44 24.3 24.7 0.85 0.504 1.00 0.97 1.00 0.283 0.274 0.54 5.0 0.092 0.251 0.092 0.46 0.019 1.15 1.00E+00

45.0 50.0 23 30 1 GP-GM 115 8 47.5 497.3 5.20 2.70 25.6 26.0 0.83 0.498 1.00 0.95 1.00 0.316 0.300 0.60 5.0 0.078 0.170 0.078 0.39 0.018 1.08 9.94E-01

50.0 55.0 28 36 1 GP-GM 120 8 52.5 492.3 5.79 2.98 31.2 31.6 0.81 0.489 1.00 0.91 1.00 0.607 0.555 1.13 5.0 0.037 -0.198 0.027 0.14 0.005 0.31 4.02E-03

55.0 60.0 29 38 1 GP-GM 120 8 57.5 487.3 6.39 3.27 31.3 31.6 0.79 0.479 1.00 0.89 1.00 0.608 0.544 1.14 5.0 0.037 -0.199 0.027 0.14 0.005 0.31 2.25E-03

60.0 65.0 30 39 1 GP-GM 120 8 62.5 482.3 6.99 3.56 31.3 31.7 0.76 0.468 1.00 0.88 1.00 0.613 0.537 1.15 5.0 0.037 -0.203 0.027 0.13 0.005 0.30 1.04E-03

65.0 70.0 32 42 1 GP-GM 125 8 67.5 477.3 7.60 3.86 32.9 33.3 0.74 0.457 1.00 0.85 1.00 0.794 0.672 1.47 5.0 0.029 -0.312 0.014 0.07 0.002 0.15 7.35E-08

70.0 75.0 33 43 1 GP-GM 125 8 72.5 472.3 8.23 4.17 33.1 33.4 0.72 0.445 1.00 0.83 1.00 0.820 0.678 1.52 5.0 0.028 -0.325 0.012 0.06 0.002 0.13 5.74E-09

H = 67.5 LDI = 9.66 S = 14.89 Inches

Rod stick-up length (i.e., length above the ground surface)

Sloping Ground Conditions

Slope Ratio 1/m

Standard Split Spoon without room for Liners

Depth to Groundwater

Unit Weight of Water

Borehole Diameter

Hammer Type

Hammer Efficiency Ratio, ERm

Input Parameters

Earthquake Magnitude

Peak Ground Acceleration (PGAM)

Site

Information

LIQUEFACTION INDUCED CALCULATION DURING EARTHQUAKES

Project:

Location:

Ground Surface Elevation at

Borehole:

v

(ksf) g (dry) (pcf)

FC

zmid

(ft) ELmid

(ft) s'v (ksf) su

(ksf)

PL

CRR

M7.5 and v=1at

CRR FS

DHi

(ft) glim Fa evgmax

DLDIi (ft)

Target Factor of Safety ztop

(ft) zbot

(ft) DSi

(in) Ka

(N1)60

(bpf) (N1)60cs

(bpf) rd CSR MSF Ks

LPT N

(bpf)

SPT N

(bpf)

USCS Group Symbol 0 fine 1 coarse

0.0 1.0 2.0

CRR CSR FS

Liquefaction Potential Factor of Safety Depth Chart

CRR

CSR

FS

Groundw ater

0.0 2.0 4.0 Settlement (inches)

Settlement Depth Chart

Settlement

Groundwater

0.0 5.0 10.0 Stress (ksf)

Total Vertical Stress and Effective Vertical Stress

S'v

Groundwater

Sv

SPT Liquefaction Triggering Version 20120825

Multipurpose Machine Gun Range (FTW405), Fort Wainwright, Alaska Appendix D

FOS

Settlement

(inches)

0 to 2.5 #N/A 0.00

2.5 to 5 #N/A 0.00

5 to 7.5 #N/A 0.00

7.5 to 10 2.00 0.00

10 to 15 2.00 0.00

15 to 20 0.36 1.79

20 to 25 0.48 1.34

25 to 30 0.15 4.10

30 to 35 0.20 2.71

35 to 40 0.35 1.53

40 to 45 0.54 1.15

45 to 50 0.60 1.08

50 to 55 1.13 0.31

55 to 60 1.14 0.31

60 to 65 1.15 0.30

65 to 70 1.47 0.15

70 to 75 1.52 0.13

14.9

Factor of Safety (FOS) for Liquefaction vs Depth

Depth (feet)

EIE-BH-2023005

Settlement (inches)

Seismic Settlement Calculations Summary 20231017 EIE439 Liquefaction ASCE 7-22

F A L M O U T H , M E 0 4 1 0 5

4 0 0 U S R O U T E 1

N O R T H S U I T E B

2 0 7 . 8 6 9 . 8 0 0 6

A N C H O R A G E , A K 9 9 5 0 3

3 6 0 1 C S T R E E T

S U I T E 6 5 0

9 0 7 . 5 6 3 . 3 8 3 5

H O N O L U L U , H I 9 6 8 1 9

3 3 7 5 K O A P A K A S T .

S U I T E B - 2 3 2

8 0 8 . 2 6 0 . 1 4 8 1

GEOTECHNICAL RECOMMENDATIONS

REPORT

EIE439 Fuels Management Laboratory Facility

Eielson AFB, Alaska

August 28, 2024

Prepared for:

USACE-Alaska District

PO Box 6898

JBER, Alaska 99506-0898

EEI Project Number: 10097.01

ENTERPRISE ENGINEERING, INC.

Geotechnical Recommendations Report EIE439 Fuels Management Facility

Page 2 August 2024

1.0 PURPOSE AND SCOPE

This report provides recommendations for the geotechnical aspects of this project. The report is based on information provided in Geotechnical Data Report, Fuel Management and Lab Facility (EIE 439), dated

November 9, 2023, prepared by the USACE-AK. This design summary report describes geotechnical analyses conducted, and provides engineering recommendations for geotechnical works, including site preparation, earthwork, foundation support, and pavement sections.

2.0 SITE AND PROJECT DESCRIPTION

This project will provide a fuels management and laboratory facility and associated improvements at Eielson

Air Force Base, located on Flightline Avenue. The building will be one-story, approximately 3800 square feet.

Paved parking areas on 2 sides of the building will provide 27 parking spaces. Other improvements include a service utilidor containing water, sewer , and steam; and other supporting utilities. The new building will be situated about 80 feet south of the existing POL building (#3242), which will be demolished.

Due to site and geotechnical conditions at the site, the foundation type selected for the building is a “raft-slab”, which will serve to distribute building loads and limit soil bearing pressures, and also provide rigidity to bridge uneven ground settlement that may occur in a major seismic event. This foundation offers a considerable cost savings compared to deep soil improvement, and should have acceptable performance in such a seismic event. The raft is made up of a grid of 2-ft wide reinforced concrete grade beams, 2-ft deep

(measured from finished floor) around the perimeter, and 3-ft deep beams elsewhere. The grade slab is 6-inch thick concrete, with 2 layers of reinforcement.

The following building foundation loads were used in assessing foundation performance and developing recommendations of this report:

Total building dead (long term) load: 250 psf

Footing area: 28% of building footprint

Average footing bearing pressure: 1,000 psf

3.0 SUBSURFACE CONDITIONS

The USACE Geotechnical Data Report (GDR) included findings from the project specific exploration. The report included boring logs, results of laboratory tests, and a discussion of findings. Soils conditions are described in general terms in this section. For detailed information, refer to GDR descriptions and test boring logs.

The field exploration was conducted in August 2023. A total of 5 borings were drilled, all in the general proximity of the proposed building location. Four borings extended to a depth of 22 feet, and one boring to a depth of 52 feet. Refer to the GDR for details of the field investigation, and findings including laboratory test results.

The near-surface soil types and layer thicknesses were found to be fairly uniform. All borings were placed in a paved parking area, and encountered fill materials which make up the pavement section.

A layer of 3” asphalt pavement was encountered in all borings, the parking lot surfacing material.

Below the asphalt pavement, a granular fill of generally 3 to 5 feet thick is present. The material is gravel with silt and sand, and is medium dense to dense. Nominal maximum particle size is 2 inches. The fines content ranges from 5%-8%, thus is classified as NFS to low frost susceptibility.

Page 3 August 2024

Underlying the gravel fill layer is a silt, extending to a depth of about 7.5 feet below the ground surface

(bgs). The silt is described as non-plastic, and soft to very stiff. LPT blowcounts (N values) ranged from 4 to 10, with an average of 8. This silt layer was not present in one boring, TB #4.

Below the silt layer, a gravel layer was encountered, extending to the limit of exploration (52 feet). The gravel includes variable fractions of silt and sand, with a generally low (< 8%) fines content. The layer density is variable, being very loose to dense. LPT N-values were primarily in the range of 10-20 blows/foot. Some lower values of 2-6 were recorded, generally between depth of 20 to 32 feet.

Groundwater was encountered in all boings, at a depth of 8.2 to 8.5 feet bgs.

PID screening did not detect the presence of petroleum contaminated soils, since readings were below threshold level. However a petroleum odor was noted in one sample in TB#4, near the water table. Soil samples were further screened by chemists for other forms of contamination; results are included in a separate Chemical Data Report.

4.0 SEISMICITY AND LIQUEFACTION

The GDR presented the following seismic design criteria, as appropriate for the geotechnical conditions encountered, and ASCE 7-22:

Site Class: D

MCE magnitude 7.5

PGAM 0.48

Refer to the GDR for other seismic criteria.

The GDR indicated potentially liquefiable soils, at a depth between 15 and 50 feet, based on data obtained for boring EIE-BH-202305. The predicted settlement during an MCE event was 14.9 inches.

The building design team considered various options for ground improvement and building foundation designs to limit building damage during the design seismic event to an acceptable level. Construction costs were a consideration, including potential damage during construction to adjacent improvements. The current foundation, a “raft-slab”, without deep ground improvements, was selected. Refer to “RFI

Foundation Type” dated 12/22/23 for more details.

5.0 DISCUSSION AND RECOMMENDATIONS

The native inorganic soils at this site appear suitable for support of the proposed development. The proposed “raft-slab” foundation should maintain building settlement within acceptable levels, and allow the building to have acceptable performance during the design seismic event.

5.1a Structure Foundations and Slabs-General

Standard concrete spread footings may be used for support of the structures provided that all unsuitable soils are removed and replaced, and that the earthwork recommendations given below are followed.

Footings should be founded on structural fill placed over native inorganic soil, as defined below. It is intended that base of foundations will be within the gravel fill layer of the existing parking area. Footings should be designed for an allowable soil bearing pressure not to exceed 2,000 pounds per square foot (psf).

Page 4 August 2024

This value may be increased by one-third for loadings including wind or seismic. These recommendations are intended to provide an adequate safety factor against bearing capacity failure, and to limit footing settlement to 1 inch (total) and one-half inch (differential).

5.1b Spread Footing Foundations-Buildings

Minimum footing width should be 16” for strip footings and 18” for isolated footings. Footings should be founded a minimum of 12” below lowest adjacent finish grade. Perimeter footings of heated structures should be founded a minimum of 42 inches below lowest adjacent finish grade, unless designed as a frost-protected shallow foundations, meeting ASCE 32 criteria. Subgrade insulation board, 3” minimum thickness, should be installed against the wall, preferably on the outside face. This insulation helps direct the building heat downward and prevent frost penetration below footings.

Perimeter and interior foundations for unheated structures should be founded a minimum of 5 feet below lowest adjacent grade, be supported on a NFS fill layer a minimum of 12 inches thick, and insulated to prevent frost penetration below the foundation, per ASCE 32 criteria.

5.1c Frost Protected Shallow Foundations

This section provides recommendations for FPSF design, for a heated building with slab-on-grade. These recommendations are to ensure that frost does not penetrate below foundations. Perimeter foundation elements, including footings, grade beams, or thickened slab edges, should be founded a minimum of 16 inches below adjacent exterior finish grade. The following recommendations meet the minimum requirements as presented in ASCE Standard 32, “Design and Construction of Frost-Protected Shallow

Foundations”. In addition, we recommend footing insulation be provided in accordance with the following report: Frost Protected Shallow Foundations (FPSF) for Interior Alaska Freezing Indices Between 4,000 and

8,000 Degree-Fahrenheit-Days.

The insulation recommendations are based on the following assumptions:

• An air-freezing index (AFI) as published by NOAA for Eielson AFB was used for the analysis (7113 °F-days, 50-yr return).

• The building is heated, maintaining an average monthly temperature of at least 63 degrees

Fahrenheit. No insulation is to be placed below the floor slab.

• Subgrade insulation shall be extruded polystyrene (XPS) or expanded polystyrene (EPS) approved for subgrade use and shall have a minimum nominal R-value of 4.0/inch, and a minimum compressive strength of 25 psi per ASTM C578.

The below table provides minimum thickness of vertical insulation against the side of the perimeter foundation, and horizontal (wing) insulation, based on a minimum footing cover (and depth to bottom of wing insulation) of 16 inches, and a maximum projection of foundation wall/finished floor above perimeter finished grade of 12 inches.

Page 5 August 2024

Table 5.1 – Insulation for FPSF Design

Insulation Case

Insulation

R-value 1

Insulation Thickness 2

Wing Width

Extruded (XPS) Expanded (EPS)

Vertical Insulation 9.5 3” 3” N.A.

Wing Insulation, wall 18.5 5” 7” 60”

Wing insulation, within 5 ft of bldg corners (Alt A)

24.1 6” 9” 78”

Wing insulation, within 5 ft of bldg corners (Alt B)

27.8 7” 10” 60”

1. R-value for wing insulation is taken from Fig. 21, for the curve “Poorer Soils (SM or worse)”

2. The insulation thickness variation between XPS and EPS is based on effective R-values provided in above-cited report.

ASCE 32 recommends that any wing insulation not in areas of asphalt or concrete pavement should be overlain with a layer of protective material, such as cementitious board.

5.2 Earthwork - General

All organic material, loose fill, or fill contaminated with organics or other deleterious material should be removed from beneath buildings and other structures sensitive to settlement. Excavations to achieve subgrades for foundations, structural fill, or utilities should be made with care to not disturb the bottom of the excavation. Any material disturbed by earthwork activities should be compacted to achieve density requirements, or should be removed and replaced with structural fill. Any pockets of loose soil that are encountered at subgrade elevation should be compacted with large vibrating rollers, to achieve the densities recommended below.

Care should be taken in compacting the initial lifts over subgrade soils, so as to avoid "pumping" the subgrade soil. Excessive vibration and truck traffic can also lead to pumping conditions. In areas subject to construction traffic, we recommend the use of a geotextile over silty subgrades, to help reduce pumping, and to separate fill material from subgrade soils. If silty subgrade soils are allowed to become wet from heavy rain or runoff, this soil shall be carefully removed and replaced with structural fill.

The project specifications should include cautions regarding fill placement and compaction adjacent to structures. Structures should be supported as required to prevent movement during backfill operations.

Heavy compaction equipment should not be operated immediately adjacent to new or existing structures.

When backfilling against buried structures or walls, compact the fill using hand-operated equipment, and construct each lift on alternate sides to prevent unbalanced loading.

Excavations side slopes shall be sloped as necessary to remain stable until backfilled, and in accordance with safety standards. Excavations that penetrate the groundwater table may require flatter slopes or shoring.

If groundwater is anticipated or encountered, provide dewatering as necessary to maintain the groundwater level below the bottom of the excavation. Bottoms of excavations should be sloped to direct seepage or sschell Cloud sschell Text Box Insulation values revised on following page. This Page is original page is included for reference only.

Page 5 August 2024

Table 5.1 – Insulation for FPSF Design

Insulation Case

Insulation

R-value 1

Insulation Thickness 2

Wing Width

Extruded (XPS) Expanded (EPS)

Vertical Insulation 9.5 3” 3” N.A.

Wing Insulation, wall 18.5 5” 7” 60”

Wing insulation, within 5 ft of bldg corners (Alt A)

24.1 6” 9” 78”

Wing insulation, within 5 ft of bldg corners (Alt B)

27.8 7” 10” 60”

1. R-value for wing insulation is taken from Fig. 21, for the curve “Poorer Soils (SM or worse)”

2. The insulation thickness variation between XPS and EPS is based on effective R-values provided in above-cited report.

ASCE 32 recommends that any wing insulation not in areas of asphalt or concrete pavement should be overlain with a layer of protective material, such as cementitious board.

5.2 Earthwork - General

All organic material, loose fill, or fill contaminated with organics or other deleterious material should be removed from beneath buildings and other structures sensitive to settlement. Excavations to achieve subgrades for foundations, structural fill, or utilities should be made with care to not disturb the bottom of the excavation. Any material disturbed by earthwork activities should be compacted to achieve density requirements, or should be removed and replaced with structural fill. Any pockets of loose soil that are encountered at subgrade elevation should be compacted with large vibrating rollers, to achieve the densities recommended below.

Care should be taken in compacting the initial lifts over subgrade soils, so as to avoid "pumping" the subgrade soil. Excessive vibration and truck traffic can also lead to pumping conditions. In areas subject to construction traffic, we recommend the use of a geotextile over silty subgrades, to help reduce pumping, and to separate fill material from subgrade soils. If silty subgrade soils are allowed to become wet from heavy rain or runoff, this soil shall be carefully removed and replaced with structural fill.

The project specifications should include cautions regarding fill placement and compaction adjacent to structures. Structures should be supported as required to prevent movement during backfill operations.

Heavy compaction equipment should not be operated immediately adjacent to new or existing structures.

When backfilling against buried structures or walls, compact the fill using hand-operated equipment, and construct each lift on alternate sides to prevent unbalanced loading.

Excavations side slopes shall be sloped as necessary to remain stable until backfilled, and in accordance with safety standards. Excavations that penetrate the groundwater table may require flatter slopes or shoring.

If groundwater is anticipated or encountered, provide dewatering as necessary to maintain the groundwater level below the bottom of the excavation. Bottoms of excavations should be sloped to direct seepage or

Revised to account for 2" thick insulation layer below floor slab.

R value of 4.0/inch for XPS, per procedure (8.0 total).

CAB 5/15/25

17.5

26.5

32.1

35.8

4"

6.5"

8"

9"

5"

9.5"

11.5"

13"

Page 6 August 2024 storm water to a collection point or points for removal from the excavation. Grade and/or berm around excavations as necessary to prevent storm water runoff from entering excavations.

5.3 Earthwork - Structures

Remove organics and other unsuitable soil beneath spread footing foundations and grade slabs as described in “Earthwork – General”. Removal of organics and loose fill beneath structures should extend to limits defined by a 1:1 (horizontal:vertical) prism beyond the toe of perimeter footings.

All fill placed below footings or slabs, and against the exterior of foundation walls, should be structural fill as defined in paragraph 5.4 following.