AMEND3 ATTACH4 Geotechnical Report 10.1.2025.pdf

respec.com

USCG SEWARD HOUSING PROJECT

GEOTECHNICAL REPORT

PREPARED BY

Jacob Tiessen, EIT

Cody J. Kreitel, PE

RESPEC

2700 Gambell Street, Suite 500

Anchorage, Alaska 99503

PREPARED FOR

BDS Architects

701 W 8th Ave

Suite 420

Anchorage, Alaska 99501

OCTOBER 2025

Project Number I0154.25001

10/01/2025

I0154.25001 USCG Seward Housing Project i

EXECUTIVE SUMMARY

RESPEC has evaluated the subsurface conditions at the project site of the proposed USCG Seward

Housing project in Seward, Alaska. The subsurface conditions were evaluated at the project site by advancing 4 geotechnical boreholes in Lots 17B-4 to 29B-4 in the Gateway Subdivision. All the collected soil samples were sent to RESPEC’s materials laboratory in Juneau for further identification and analysis.

The subsurface explorations indicate that the stratigraphy at the project site generally consists of native gravel. Approximately the western half of the site has been covered with roughly 5 to 10 feet of gravel fill;

the fill is difficult to distinguish from the underlying native soil since it came from the nearby development.

The eastern portion of the site has a berm of topsoil that has been stored on site which will be removed during development and the eastern edge of the site is native ground with most of the surficial organics removed during electrical utility installation. No bedrock or groundwater was encountered during the explorations.

Design and construction recommendations are provided in the following report for earthworks, shallow foundations, drainage, underground utility connections, retaining walls, and pavement sections.

ii

TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 PROJECT SITE OVERVIEW

3.0 SUBSURFACE EXPLORATIONS

4.0 LABORATORY TESTING

5.0 DESCRIPTION OF SUBSURFACE CONDITIONS

5.1 General Subsurface Profile

5.2 GroundWater

6.0 ENGINEERING CONCLUSIONS

6.1 Earthworks

6.2 Foundations

6.3 Settlements

6.4 Seismic Design Parameters

7.0 DESIGN AND CONSTRUCTION RECOMMENDATIONS

7.1 Earthworks

7.2 Shallow Foundations

7.2.1 Foundation Bearing Capacity

7.2.2 Foundation Uplift Capacity

7.2.3 Floor Slabs

7.3 Winter Construction

7.4 Underground Utilities

7.5 Retaining Walls

7.6 Pavement Sections

8.0 CONCLUSION

APPENDIX A EXPLORATION LOGS AND SELECTED FIELD PHOTOS..................................................................................... A-1

APPENDIX B LABORATORY TEST RESULTS ........................................................................................................................... A-1

APPENDIX C SEISMIC DESIGN PARAMETERS ....................................................................................................................... A-1 iii

LIST OF TABLES

Table Page

Table 7-1. Equivalent Fluid Pressures for Retaining Wall Loads

Table 7-2. Recommended Pavement Section

LIST OF FIGURES

FIGURE Page

Figure 2-1. Approximate Site Location

Figure 3-1. Subsurface Exploration Location Map

1.0 INTRODUCTION

This report presents the results of the geotechnical investigation conducted at Lots 17B-4 to 29B-4 of the Gateway Subdivision in Seward, AK; hereafter referred to as the “project site”. The subsurface conditions were evaluated in support of the United States Coast Guard (USCG) Seward housing project.

The proposed development consists of 4 buildings (3 duplexes and a support facility) and associated driveways, parking areas, and underground utilities. In addition, a retaining wall may be required on the south side of Lot 17-B4 to allow for a pedestrian easement. We provided our professional services in accordance with our geotechnical services fee dated 13th February 2025. The scope of service was authorized by BDS Architects on 7th April 2025.

The geotechnical scope of service is intended to provide the necessary subsurface information for the engineering design and construction of the foundations and retaining wall for the housing project. In this report, the results the field explorations and laboratory testing are provided, as well as engineering conclusions and recommendations for the design and construction of the proposed development.

2.0 PROJECT SITE OVERVIEW

The project site is located northeast of the intersection of Olympia Road and Phoenix Road in Seward, Alaska. The project site consists of relatively flat pad composed of fill on the western side on Pheonix

Road, that then has a steep slope down to the native soil near the middle of the site. Currently there is a stockpile of topsoil from a different project site on the eastern side of the site, which is due to be removed as development continues. The project site has an overall slope to the southeast from an elevation of approximately 210 feet to approximately 187 ft.

The project site is bounded Phoenix Road to the west, underneath which are water and sewer utilities.

To the north there are residential developments under construction in adjacent lots. East of the project site, there is an electrical utilities easement, with powerlines currently installed along the eastern border of the site. Beyond the electrical utility easement, is undeveloped woodland, which also borders the project site on the south. The approximate project location is illustrated in Figure 2-1.

Figure 2-1. Approximate Site Location

3.0 SUBSURFACE EXPLORATIONS

Subsurface explorations were conducted at the project site on 28th and 29th April 2025. Discovery

Drilling, Inc. (DDI) was contracted to provide the drilling services required for subsurface explorations.

DDI mobilized a Geoprobe 6712DT drilling rig to the project site. RESPEC’s Senior Geotechnical

Engineer oversaw the advancement of 4 boreholes at the project site at the approximate locations shown in Figure 3-1. The local weather during the explorations consisted of temperatures between 41 and 49 °F, variable winds of up to 13 mph, and sunny skies on April 28th. On April 29th, the weather consisted of light rain, and cloudy skies.

The 4 boreholes, designated as B-1 through B-4, were advanced to depths between 22 and 31.5 feet below the ground surface (bgs) using air rotary drilling methods. Modified Penetration Tests (MPTs) were performed at regular intervals during the drilling of each borehole. A MPT can be used to assess the consistency of soil intervals and to collect representative soil samples. MPTs are performed by driving a 3.0-inch O.D (2.4-inch I.D.) split-spoon sampler at least 18 inches past the bottom of the advancing augers with blows from a 340-lb drop hammer, free falling 30 inches onto an anvil attached to the top of the drill rod stem. The number of blows required to drive the modified split spoon sampler the entire length of each sample interval was recorded. For this project, the sampler was advanced an additional 6 inches for a total of 24 inches of penetration, to facilitate the collection of representative soil samples. The field blow count data for each sample interval (in 6-inch increments) are provided in the borehole logs in Appendix A of this report.

Each sample that was collected during the subsurface exploration was sealed inside of an air-tight bag to preserve the moisture content of the sample and then submitted to the materials laboratory in

Juneau for analysis.

Once the subsurface exploration was complete, DDI was directed to backfill each borehole with its respective drill cuttings.

DRAFT I0154.25001 USCG Seward Housing Project

Figure 3-1. Subsurface Exploration Location Map

4.0 LABORATORY TESTING

A total of 32 soil samples from 4 boreholes and the soil samples were submitted to RESPEC’s materials testing laboratory in Juneau for further identification and analysis. Selected soil samples were tested in general accordance with the relevant ASTM standard test methods including:

/ Moisture Content (ASTM D2216)

/ Sieve Analysis (3” minus material)

The laboratory test results assist with the evaluation of subsurface conditions and with assessing the suitability of proposed improvement for the soils located at the project site. The results of the laboratory analyses are provided in the borehole logs contained in Appendix A of this report and in laboratory test data sheets contained in Appendix B of this report.

5.0 DESCRIPTION OF SUBSURFACE CONDITIONS

The field observations recorded during the subsurface exploration were compiled along with the laboratory results to produce a graphic log of each borehole which can be found in Appendix A of this report. The graphic logs depict the subsurface conditions that were identified at each borehole location and are used to interpret and extrapolate the subsurface conditions for areas adjacent to, and immediately surrounding, each exploration location.

5.1 GENERAL SUBSURFACE PROFILE

The subsurface conditions across the project site generally consist of well graded gravel, with the native material being overlayed by a gravel fill in boreholes B-2 and B-4. The boundary between the fill and native soil was difficult to distinguish due to a similar composition. The fill was observed in the western half of the site from the surface to an average 6 feet bgs and was composed of well graded gravel with sand and cobbles. The native soil was similar in composition to the gravel fill, being well graded gravel with sand, and cobbles. The native gravel was observed to the maximum exploration depth in all boreholes. On the eastern edge of the site, a layer of silty sand with organics was encountered overlying the gravel from the surface to 2.5 feet bgs in borehole B-3.

6.0 ENGINEERING CONCLUSIONS

With proper design and construction practices, the site is generally suitable for the proposed development. Based on the conditions observed in the boreholes, the soils below the proposed footing depth are generally dense to very dense and are suitable for the expected foundation loads in their current condition. As such little to no ground improvements are required.

6.1 GROUNDWATER

The groundwater table was not encountered during the subsurface exploration, suggesting that the groundwater table at the project site is likely below 30 feet bgs. Groundwater levels are, however, highly variable based on precipitation patterns and seasonal conditions.

6.2 EARTHWORKS

Earthworks will be required for the foundations, utility service connections, paved driveways and parking areas, and any retaining walls. Detailed recommendations are provided in Section 7.1.

6.3 FOUNDATIONS

Traditional shallow concrete foundations are suitable based on the observed site conditions. Detailed recommendations are provided in Section 7.2.

6.4 SETTLEMENTS

The design and construction recommendations provided in Section 7.0 are intended to limit foundation settlement to less than ¾ of an inch in total settlement with differential settlement comprising approximately 50% of the total settlement. Considering the soils at the project site are predominately granular soils (sand and gravel), most of the settlement should occur quickly as the design loads are applied and settlement due to long-term consolidation is not expected.

6.5 SEISMIC DESIGN PARAMETERS

In accordance with ASCE/SEI 7-22 risk, the seismic site classification is D, “Stiff Soil”. The ASCE Hazard

Tool, developed by the American Society of Civil Engineers (ASCE) was used to calculate the seismic design parameters for the project site, which are Ss = 1.5, and S1 = 0.69. A copy of the ASCE Hazards

Report is attached to this report in Appendix C.

7.0 DESIGN AND CONSTRUCTION RECOMMENDATIONS

7.1 EARTHWORKS

It is expected that the building foundations will bear on the existing granular fill present at the project site or newly imported gravel fill from the same source as the existing fill. Imported structural fill should be well graded and non-frost susceptible (NFS) with less than 6% passing the #200 sieve and a minimum of 45% gravel sized particles. For an imported structural fill, the material should be placed in lifts that do not exceed 12 inches in uncompacted thickness and the material should be moisture conditioned as required and compacted to 95% of the modified Proctor density per ASTM D-1557.

While no groundwater was encountered during the subsurface exploration, groundwater levels can fluctuate significantly with precipitation patterns. If groundwater is encountered during excavation, dewatering will be required to allow for proper excavation and fill placement.

All earthworks should be completed with a quality control inspection, including bottom-of-hole inspections, imported fill gradation testing, and in-situ compacting testing (as appropriate). A bottom-of-hole inspection should be conducted by a qualified geotechnical engineer, engineering geologist, or special inspector following site excavation activities (and before any fill placement begins) to visually confirm the findings of this report and provide recommendations for any non-conforming conditions encountered during the excavation activities.

The topsoil stockpile described in Section 2.0 should be completely removed from the site prior to any work occurring in the areas now covered by the stockpile. Any gravel fill used to construct the pad, or the fill slope should be placed on the native gravel described in Section 5.1. If the fill were to be placed on the topsoil, there may be increased settlement and reduced bearing capacity in the areas where this occurred. In addition, the silty sand observed in borehole B-3 should also be removed prior to placing fill in any area where that material is found.

A fill slope is to be constructed on the eastern edge of the fill pad, where the backyards of the housing units will be located. The fill slope can be a 1:1 slope if it is made from the same angular gravel fill that has been used to construct the pads, and it is compacted to a minimum of 90% of the modified Proctor density. Should other material be used, RESPEC should be contacted to assess the applicability of these recommendations.

7.2 SHALLOW FOUNDATIONS

It is expected that building foundations will bear on the gravel fill as described in Section 5.1.

7.2.1 FOUNDATION BEARING CAPACITY

Where the underlying soils are as described in Section 5.1, the allowable bearing capacity for heated foundations placed at a depth of 3.5 feet bgs shall be 3500 psf. For cold foundations placed a depth of

5 feet bgs, the foundations may be designed for a bearing capacity of 5000 psf. The allowable bearing capacity may be increased by 1/3 to accommodate short-term wind and seismic loads.

7.2.2 FOUNDATION UPLIFT CAPACITY

Shallow foundations should be buried deep enough to resist any anticipated uplift or overturning forces

(e.g. wind, seismic, etc.). The uplift capacity of a foundation is a function of its weight, configuration, and depth. The ultimate uplift capacity can be calculated by using 80 percent of the weight of the foundation plus 80 percent of the weight of the effective soil mass located above the footing. An effective unit weight of 120 pcf can be used for the backfill material. The ultimate uplift load includes any short-term load factors, so no increase in uplift capacity should be added for short-term loading.

7.2.3 FLOOR SLABS

The preparation of the subgrade for floor slabs should be similar to that for footings, as described in

Section 7.1 A vapor barrier should be placed between the slab and the underlying fill materials.

Concrete slabs constructed directly on properly constructed granular fill pads, as described in Section

7.1, may be designed using a modulus of subgrade reaction of k1 = 300 pci (k1 is the value for a 1-ft × 1-ft rigid plate). For this project, the following equations can be used (with standard English units) to calculate the appropriate modulus of subgrade reaction for slabs bearing on properly placed structural fill:

(1)

Where :

B = the slab width of a square slab in feet k1 = the modulus of subgrade reaction for a 1-ft × 1-ft rigid plate in pci k(B x B) = the modulus of subgrade reaction for a square slab of width B in pci

The following equation (2) can be used for a rectangular slab having the dimensions B × L (in feet) with similar bearing soils as the slab loading equation above (1).

�.� (2)

Where:

k(B x B) = the modulus of subgrade reaction for a B × B square slab k(B x L) = the modulus of subgrade reaction for B × L rectangular slab

B = the least horizontal dimension of a rectangular slab

L = the larger horizontal dimension of a rectangular slab

7.3 WINTER CONSTRUCTION

Proper placement or compaction of native soil or fill is not possible when fill material is frozen, and as such, frozen fill material should never be used for structural support unless it has been subsequently thawed and properly compacted (throughout its vertical extent). Furthermore, subgrade soils (fill or native) need to be completely thawed prior to the placement and compaction of additional lifts of thawed fill material. In our professional experience, ambient soil temperatures need to be above 37 °F in order to achieve efficient compaction. It is extremely difficult to achieve proper compaction in fill material that is between 32 °F to 37 °F

7.4 UNDERGROUND UTILITIES

It is expected that utility trench wall stability in the granular fill or the native gravel will be moderate. No unusual difficulties are foreseen provided standard design and construction techniques are employed, such as proper bedding of buried pipes, compacting trench backfill to 95% of the modified proctor density, and sufficient pipe embedment to prevent freezing (5 feet minimum to top of waterline). The contractor should be responsible for trench safety and regulation compliance. Trench safety should be planned for utilizing OSHA type C soils.

7.5 RETAINING WALLS

Restrained walls, such as basement walls restrained by a floor diaphragm, should be designed for at-rest pressure conditions. Unrestrained walls (i.e. walls that are allowed to deflect/rotate such as cantilevered retaining walls) should be designed for active pressure conditions. The lateral load capacity of foundation stem walls for resisting seismic loads or wind loads should be calculated using passive pressure conditions. The equivalent fluid unit weights presented in Table 7-1 may be used for at-rest, active, and passive pressure assuming that structural backfill compacted to a minimum of 90% of the modified Proctor density is used as backfill against the walls and that proper wall drainage is provided.

Table 7-1. Equivalent Fluid Pressures for Retaining Wall Loads

Material Pressure Condition Equivalent Fluid

Unit Weight (pcf)

Granular Fill

(0’ to 5’ bgs)

At-rest 55

Active 36

Passive 405

7.6 PAVEMENT SECTIONS

A recommended pavement section is presented in Table 7-2. Considering that the existing gravel fill is

NFS and that the loads on any pavement sections in the housing development are likely to be light, no additional base or subbase layers are considered necessary. If any organic materials are present, they should be completely removed from the footprint of any planned pavement sections. The surface of the existing gravel fill subgrade should be compacted to a minimum of 95% of the modified Proctor density, prior to the laying of the levelling course. If additional structural fill is required to bring the pavement sections up to grade, NFS fill should be used and compacted as directed in Section 7.1.

Table 7-2. Recommended Pavement Section

Material Thickness (inches)

A.C. Pavement 2

D-1 Levelling Course 2

Existing Gravel Fill --

8.0 CONCLUSION

This report was prepared exclusively for the use of BDS Architects and their consultants and contractors for use in the design and construction of the proposed USCG Seward housing project. We should be notified if significant changes are to occur in the nature, design, or location of the proposed improvements so that we may review our conclusions and recommendations that we present in this report and, if necessary, modify them to satisfy the proposed changes.

This report should always be read and/or distributed in its entirety (including all figures, exploration logs, appendices, etc.) so that all the pertinent information contained within is effectively disseminated.

Otherwise, an incomplete or misinterpreted understanding of the site conditions and/or our engineering recommendations may arise. Our recommended best practice is to make this report accessible, in its entirety, to any design professional and/or contractor working on the project. Any part of this report (e.g., exploration logs, calculations, material values, etc.) which is presented in the design/construction plans and/or specifications for the project should have an adequate reference which clearly identifies where the report can be obtained for further review.

Due to the inherent variability of earth materials, variations in the subsurface conditions across the project site may exist other than those we identified during our geotechnical assessment. Therefore, a qualified geotechnical engineer, geologist, and/or special inspector should be on-site during construction activities to provide corrective recommendations for any unexpected conditions revealed during construction. Furthermore, the construction budget should allow for any unanticipated conditions that may be encountered during construction activities.

We conducted this evaluation following the standard of care expected of professionals undertaking similar work in the State of Alaska under similar conditions. No warranty, expressed or implied, is made.

A-1

APPENDIX A

Exploration Logs and Selected Field Photos

2700 Gambell St., Ste 500, Anchorage, Ak 99503 Office: 605-394-6400

USCG Seward Housing

Lat/Lon: 60.129750/-149.446116 SOIL BORING: B-1

Date Started: 04/30/2025 Date Completed: 04/30/2025 Project Number: I0154.25001

Drilling Firm: Discovery Drilling Inc. Hammer Type: Auto Hammer Weight: 340

Rig Type: Geoprobe 6712DT Surface Elevation: 186.6020' Location

Accuracy: Surveyed

Depth: 22' Logged By: CJK Checked By: -

D ep th (f t)

G ra ph ic

L og

U

SC

S

Visual Classification and Remarks

22.0

Loose to compact, brownish grey, Well-graded Gravel with Sand, some broken rock

End of Boring

Samples

D ep th o f S am pl e

(f t)

2.5 ft

0 ft

15 ft

20 ft

5 ft

7.5 ft

10 ft

Sa m pl e

N um be r

S1

S2

S3

S4

S5

S6

S7

Sa m pl e

G ra ph ic

Bl ow

C ou nt s

Lab

M oi st ur e C on te nt

8.80

4.30

3.30

4.20

6.30

6.70

4.90

G ra ve l

53.00

48.70

S an d

40.00

42.00

F in es

7.00

9.30

W el l

Well-graded Gravel LSS - Large Split Spoon - -

B-1 S1 Depth Range: 0.0 - 2.0'

B-1 S2 Depth Range: 2.5 - 4.5'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

CLIENT BDS Architects LOG: B-1

LOCATION Seward, AK FIGURE NO. Appendix

B-1 S3 Depth Range: 5.0 - 7.0'

B-1 S4 Depth Range: 7.5 - 9.5'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

B-1 S5 Depth Range: 10.0 - 12.0'

B-1 S6 Depth Range: 15.0 - 17.0'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

B-1 S7 Depth Range: 20.0 - 22.0'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

Office: 605-394-6400

USCG Seward Housing

Lat/Lon: 60.130214/-149.446539 SOIL BORING: B-2

Date Started: 04/30/2025 Date Completed: 04/30/2025 Project Number: I0154.25001

Drilling Firm: Discovery Drilling Inc. Hammer Type: Auto Hammer Weight: 340 lbs

Rig Type: Geoprobe 6712DT Surface Elevation: 203.2060' Location

Accuracy: Surveyed

Depth: 22' Logged By: CJK Checked By: -

D ep th (f t)

G ra ph ic

L og

U

SC

S

Visual Classification and Remarks

5.0

22.0

FILL, compact, grey, moist, Well-graded Gravel with Sand, some broken gravel

Compact to very dense, grey, moist, Well-graded Gravel with Sand, some broken rocks

End of Boring

Samples

D ep th o f S am pl e

(f t)

0 ft

7.5 ft

5 ft

15 ft

20 ft

10 ft

2.5 ft

Sa m pl e

N um be r

S1

S2

S3

S4

S5

S6

S7

Sa m pl e

G ra ph ic

Bl ow

C ou nt s

50/5"

Lab

M oi st ur e C on te nt

7.20

9.80

5.80

6.60

7.70

3.70

8.80

G ra ve l

51.40

51.60

S an d

42.10

40.30

F in es

6.50

8.10

W el

B-2 S1 Depth Range: 0.0 - 2.0'

B-2 S2 Depth Range: 2.5 - 4.5'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

CLIENT BDS Architects LOG: B-2

B-2 S3 Depth Range: 5.0 - 7.0'

B-2 S4 Depth Range: 7.5 - 8.9'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

B-2 S5 Depth Range: 10.0 - 12.0'

B-2 S6 Depth Range: 15.0 - 17.0'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

B-2 S7 Depth Range: 20.0 - 22.0'

Office: 605-394-6400

USCG Seward Housing

Lat/Lon: 60.130543/-149.446085 SOIL BORING: B-3

Date Started: 04/30/2025 Date Completed: 04/30/2025 Project Number: I0154.25001

Drilling Firm: Discovery Drilling Inc. Hammer Type: Auto Hammer Weight: 340 lbs

Rig Type: Geoprobe 6712DT Coordinates: 60.130543, -149.446085

Location Accuracy: Surveyed

Depth: 22' Logged By: CJK Checked By: -

D ep th (f t)

G ra ph ic

L og

U

SC

S

Visual Classification and Remarks

2.5

22.0

Very loose, brown, moist to wet, Silty Sand with Organics

Compact to very dense, grey, moist, Well-graded Gravel with Sand, some broken rocks

End of Boring

Samples

D ep th o f S am pl e

(f t)

20 ft

7.5 ft

10 ft

0 ft

2.5 ft

5 ft

15 ft

Sa m pl e

N um be r

S1

S2

S3

S4

S5

S6

S7

Sa m pl e

G ra ph ic

Bl ow

C ou nt s

20/5"

Lab

M oi st ur e C on te nt

4.70

4.70

5.10

5.10

4.50

G ra ve l

55.30

58.90

S an d

37.90

33.40

F in es

6.80

7.70

W el

Well-graded Gravel Silty Sand LSS - Large Split Spoon -

B-3 S1 Depth Range: 0.0 - 2.0'

B-3 S2 Depth Range: 2.5 - 4.5'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

CLIENT BDS Architects LOG: B-3

B-3 S3 Depth Range: 5.0 - 7.0'

B-3 S5 Depth Range: 10.0 - 12.0'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

B-3 S6 Depth Range: 15.0 - 16.9'

B-3 S7 Depth Range: 20.0 - 22.0'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

Office: 605-394-6400

USCG Seward Housing

Lat/Lon: 60.130976/-149.446336 SOIL BORING: B-4

Date Started: 04/29/2025 Date Completed: 04/29/2025 Project Number: I0154.25001

Drilling Firm: Discovery Drilling Inc. Hammer Type: Auto Hammer Weight: 340 lbs

Rig Type: Geoprobe 6712DT Surface Elevation: 209.6330' Location

Accuracy: Surveyed

Depth: 31.5' Logged By: CJK Checked By: -

D ep th (f t)

G ra ph ic

L og

U

SC

S

Visual Classification and Remarks

7.5

31.5

FILL, compact to dense, grey, moist, Gravel with Sand, broken oversized gravels and cobbles

Compact to very dense, dark grey, moist, Well-graded Gravel with Sand, max 2" gravels, some broken rock

End of Boring

Samples

D ep th o f S am pl e

(f t)

10 ft

15 ft

7.5 ft

2.5 ft

30 ft

0 ft

25 ft

20 ft

5 ft Sa m pl e N um be r

S1

S2

S3

S4

S5

S6

S7

S8

S9

Sa m pl e

G ra ph ic

Bl ow

C ou nt s

50/4"

50/5"

Lab

M oi st ur e C on te nt

12.70

11.40

9.80

9.50

7.80

8.00

8.50

G ra ve l

46.60

51.80

S an d

43.10

41.20

F in es

10.30

7.00

W el

B-4 S1 Depth Range: 0.0 - 2.0'

B-4 S2 Depth Range: 2.5 - 4.5'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

CLIENT BDS Architects LOG: B-4

B-4 S3 Depth Range: 5.0 - 7.0'

B-4 S4 Depth Range: 7.5 - 9.5'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

B-4 S5 Depth Range: 10.0 - 12.0'

B-4 S8 Depth Range: 25.0 - 27.0'

PROJECT USCG Seward Housing PROJECT NO. I0154.25001

B-4 S9 Depth Range: 30.0 - 31.4'

I0154.25001

B-1

APPENDIX B

Laboratory Test Results

3" 2" 1 1/2" 1" 3/4" 1/2" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200

BH1,S1 100 83.8 79.9 71.2 64.6 59.2 47 38 35.9 30.3 22.6 19.2 15.6 10.6 7.0 8.8

BH1, S2 4.3

BH1, S3 3.3

BH1, S4 4.2

BH1, S5 6.3

BH1, S6 100 92.3 79.8 73.7 67.7 62.5 51.3 41.6 39.4 32.6 23.6 19.9 16.4 12.1 9.3 6.7

BH1, S7 4.9

BH2, S1 7.2

BH2, S2 100 92 83 71 62 49 39 36 30 22 19 15 10 6.5 9.8

BH2, S3 5.8

BH2, S4 6.6

BH2, S5 100 97 91.2 81.5 70.9 63.4 48.4 37.3 34.9 28.9 21.2 18.1 14.9 11 8.1 7.7

BH2, S6 3.7

BH2, S7 8.8

BH3, S2 4.7

BH3, S3 100 90 75 68 62 57 45 35 33 27 20 17 13 9 6.8 4.7

BH3, S5 5.1

BH3, S6 5.1

BH 3, S7 100 84.1 72.5 66.7 59 53.3 41.1 31.5 29.4 23.9 17.6 15.1 12.8 10 7.7 4.5

BH4, S1 100 96 87 81 71 66 53 43 40 34 26 23 19 14 10.3 12.7

BH4, S2 11.4

BH4, S4 100 92 80 68 63 48 37 34 28 20 17 14 10 7.0 9.8

BH4, S5 9.5

BH4, S6 7.8

BH4, S8 8.0

BH4, S9 8.5

Project: USCG Seward Housing Design RESPEC Project No. I0154.25001

Date: 5/13/25

Sheet 1 of 1

Prepared by: RB

Client: BDS Architects

Moisture

Sieve

Moisture

Sieve

Sieve0-2'

10-12'

2.5-4.5'

Moisture

15-17'

Sieve

Moisture

Sieve

Moisture

Moisture

Moisture

Moisture

Sieve

Sieve

Sample ID Depth Test

NMC

Organic

Content

2.5-4.5' Moisture

7.5-9.5'

10-12'

20-22'

Moisture5-7'

Moisture

Moisture

Sieve

Moisture

10-12'

Moisture

0-2'

15-17'

2.5-4.5'

5-7'

7.5-9.5'

0-2'

Moisture

20-22'

2.5-4.5'

5-7'

10-12'

15-17'

20-22'

7-9'

15-17' Moisture

LL PL

Grain Size Distribution

(% Passing Sieve No.) PI

9109 Mendenhall Mall

Road, Suite 4, Juneau

Alaska, 99801

30-32' Moisture

25-27' Moisture

SUMMARY

OF

BOREHOLE

TEST

RESULTS

Client

Project

Location Sta/Offset

Material/Source

Sampled by/date

Moisture

SIEVE SIZE

1 1/2 "

3/4 "

1/2 "

3/8 "

No

No

No

No

No

No

No

No

No

9109 Mendenhall Mall Road Suite #4, Juneau, Alaska, 99801

RB - 5/12/25

Required specs

Required specs

90-100

Required specs

CBJ

Section

02709

7.0 10-60 9.3

50 16

#DIV/0!

#####95-100

100 80

10-30

80-100

50-85

0-8

#####0-1 #####

5-30

0-10 0-3

25-60

Received Date 5/7/2025

Seward, AK Reported Date 5/12/2025

Borehole #1 Tested by/date

8.8% 6.7%

95-100 #####

BDS Architects Project # I0154.25001

#DIV/0!

Percent passing Percent passing Percent passing

Sieve Analysis

AASHTO T 27 / T 11

0AK DOT

703-7

Column E

ASTM

C-33

Cobbles and Gravel Sand Silt and Clay

CK - 4/29/25

USCG Seward Housing Design

Percent passing Required specs

5 " 100

BH 1, S1, 0-2'

BH 1, S6, 15-

17'

/2

/4

/2

/8

0.010.1110100 p a s s in g i n d iv id u a l s ie v e s

Particle Size in mm

BH 1, S1, 0-2'

BH 1, S6, 15-17'

Grain Size Distribution

C:\Users\ricky.bass\Desktop\250512 BH1 - Gradation

Location Sta/Offset

Material/Source

Sampled by/date

Moisture

SIEVE SIZE

1 1/2 "

3/4 "

1/2 "

3/8 "

No

No

No

No

No

No

No

No

No

5 " 100

BH 2, S2, 2.5-

4.5'

BH 2, S5, 10-

12'

Cobbles and Gravel Sand Silt and Clay

BH - 4/29/25

USCG Seward Housing Design

Percent passing Required specs

#DIV/0!

Percent passing Percent passing Percent passing

Sieve Analysis

AASHTO T 27 / T 11

0AK DOT

703-7

Column E

ASTM

C-33

95-100 #####

BDS Architects Project # I0154.25001

Received Date 5/7/2025

Seward, AK Reported Date 5/12/2025

Borehole #2 Tested by/date

9.8% 7.7%

0-3

25-60

0-8

#####0-1 #####

5-30

0-10

10-30

80-100

50-85

95-100

100 91

#DIV/0!

50 15

6.5 10-60 8.1

Required specs

CBJ

Section

02709

90-100

9109 Mendenhall Mall Road Suite #4, Juneau, Alaska, 99801

RB - 5/12/25

Required specs

Required specs

/2

/4

/2

/8

0.010.1110100 p a s s in g i n d iv id u a l s ie v e s

Particle Size in mm

BH 2, S2, 2.5-4.5'

BH 2, S5, 10-12'

C:\Users\ricky.bass\Desktop\250512 BH2 - Gradation

Location Sta/Offset

Material/Source

Sampled by/date

Moisture

SIEVE SIZE

1 1/2 "

3/4 "

1/2 "

3/8 "

No

No

No

No

No

No

No

No

No

9109 Mendenhall Mall Road Suite #4, Juneau, Alaska, 99801

RB - 5/12/25

Required specs

Required specs

90-100

Required specs

CBJ

Section

02709

6.8 10-60 7.7

50 13

#DIV/0!

#####95-100

100 72

10-30

80-100

50-85

0-8

#####0-1 #####

5-30

0-10 0-3

25-60

Received Date 5/7/2025

Seward, AK Reported Date 5/12/2025

Borehole #3 Tested by/date

4.7% 4.5%

95-100 #####

BDS Architects Project # I0154.25001

#DIV/0!

Percent passing Percent passing Percent passing

Sieve Analysis

AASHTO T 27 / T 11

0AK DOT

703-7

Column E

ASTM

C-33

Cobbles and Gravel Sand Silt and Clay

BH - 4/29/25

USCG Seward Housing Design

Percent passing Required specs

5 " 100

BH 3, S3, 5-7'

BH 3, S7, 20-

22'

/2

/4

/2

/8

0.010.1110100 p a s s in g i n d iv id u a l s ie v e s

Particle Size in mm

BH 3, S3, 5-7'

BH 3, S7, 20-22'

C:\Users\ricky.bass\Desktop\250512 BH3 - Gradation

Location Sta/Offset

Material/Source

Sampled by/date

Moisture

SIEVE SIZE

1 1/2 "

3/4 "

1/2 "

3/8 "

No

No

No

No

No

No

No

No

No

5 " 100

BH4, S1, 0-2' BH 4, S4, 7-9' 0

Cobbles and Gravel Sand Silt and Clay

BH - 4/28/25

USCG Seward Housing Design

Percent passing Required specs

#DIV/0!

Percent passing Percent passing Percent passing

Sieve Analysis

AASHTO T 27 / T 11

0AK DOT

703-7

Column E

ASTM

C-33

95-100 #####

BDS Architects Project # I0154.25001

Received Date 5/7/2025

Seward, AK Reported Date 5/12/2025

Borehole #4 Tested by/date

12.7% 9.8%

0-3

25-60

0-8

#####0-1 #####

5-30

0-10

10-30

80-100

50-85

95-100

100 92

#DIV/0!

50 14

10.3 10-60 7.0

Required specs

CBJ

Section

02709

90-100

9109 Mendenhall Mall Road Suite #4, Juneau, Alaska, 99801

RB - 5/12/25

Required specs

Required specs

/2

/4

/2

/8

0.010.1110100 p a s s in g i n d iv id u a l s ie v e s

Particle Size in mm

BH4, S1, 0-2'

BH 4, S4, 7-9'

C:\Users\ricky.bass\Desktop\250512 BH4 - Gradation

I0154.25001

C-1

APPENDIX C

Seismic Design Parameters

ASCE Hazards Report Address:

No Address at This Location

Standard: ASCE/SEI 7-22 Latitude: 60.13092

Risk Category: II Longitude: -149.448062

Soil Class: D - Stiff Soil Elevation: 236.35171660524944 ft ()

Page 1 of 4https://ascehazardtool.org/ Wed Oct 01 2025 https://ascehazardtool.org/

PGA M : 0.53

SMS : 1.62

SM1 : 1.95

SDS : 1.08

SD1 : 1.3

TL : 16

SS : 1.5

S1 : 0.69

VS30 : 260

Seismic Design Category: D

Multi-Period Design Spectrum

S (g) vs T(s)a

Multi-Period MCE SpectrumR

S (g) vs T(s)a

Two-Period Design Spectrum

S (g) vs T(s)a

Two-Period MCE SpectrumR

S (g) vs T(s)a

Design Vertical Response Spectrum

Vertical ground motion data has not yet been made available by USGS.

MCE Vertical Response SpectrumR

Vertical ground motion data has not yet been made available by USGS.

Seismic

D - Stiff SoilSite Soil Class:

Results:

Page 2 of 4https://ascehazardtool.org/ Wed Oct 01 2025

Data Accessed: Wed Oct 01 2025

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.

Page 3 of 4https://ascehazardtool.org/ Wed Oct 01 2025

The ASCE Hazard Tool is provided for your convenience, for informational purposes only, and is provided “as is” and without warranties of any kind. The location data included herein has been obtained from information developed, produced, and maintained by third party providers; or has been extrapolated from maps incorporated in the ASCE standard. While ASCE has made every effort to use data obtained from reliable sources or methodologies, ASCE does not make any representations or warranties as to the accuracy, completeness, reliability, currency, or quality of any data provided herein. Any third-party links provided by this Tool should not be construed as an endorsement, affiliation, relationship, or sponsorship of such third-party content by or from ASCE.

ASCE does not intend, nor should anyone interpret, the results provided by this Tool to replace the sound judgment of a competent professional, having knowledge and experience in the appropriate field(s) of practice, nor to substitute for the standard of care required of such professionals in interpreting and applying the contents of this Tool or the ASCE standard.

In using this Tool, you expressly assume all risks associated with your use. Under no circumstances shall ASCE or its officers, directors, employees, members, affiliates, or agents be liable to you or any other person for any direct, indirect, special, incidental, or consequential damages arising from or related to your use of, or reliance on, the Tool or any information obtained therein. To the fullest extent permitted by law, you agree to release and hold harmless ASCE from any and all liability of any nature arising out of or resulting from any use of data provided by the ASCE Hazard Tool.

Page 4 of 4https://ascehazardtool.org/ Wed Oct 01 2025