Bid No. 01-26-01 Attachment A.PDF

REPORT

21-0414 S

December 23, 2022

Explorations and Geotechnical Engineering Services

Proposed Bridge Replacement George Street over Beaver Brook Keene, New Hampshire

Prepared For:

McFarland Johnson, Inc.

Attention: Samuel White, P.E.

53 Regional Drive Concord, NH 03301

Prepared By:

S. W. Cole Engineering, Inc.

10 Centre Road Somersworth, New Hampshire 03878 T: 603-692-0088

TABLE OF CONTENTS

1.0 INTRODUCTION

1.1 Scope and Purpose

1.2 Site and Proposed Construction

2.0 EXPLORATION AND TESTING

2.1 Explorations

2.2 Laboratory Testing

3.0 SUBSURFACE CONDITIONS

3.1 Soil and Bedrock

3.1.1 West Abutment (B-1)

3.1.2 East Abutment (B-2)

3.1.3 Environmental Boring (ENV-1)

3.2 Groundwater

4.0 SEISMIC CONSIDERATIONS

4.1 Bedrock Acceleration and Site Response

4.2 Liquefaction Assessment

5.0 FOUNDATION EVALUATION AND RECOMMENDATIONS

5.1 General

5.2 Frost Considerations

5.3 Foundation Options and Discussion

5.4 Foundation Design

5.4.1 Precast Box Culvert

5.4.2 Spread Footing Foundations

5.4.3 Micropiles

5.5 Abutments and Wingwalls

5.6 Excavation and Dewatering Considerations

5.7 Backfill and Compaction

5.8 Design Review and Construction Testing

6.0 CLOSURE

Appendix A Limitations Appendix B Figures Appendix C Exploration Logs & Key Appendix D Laboratory Test Results

McFarland Johnson, Inc.

Attention: Samuel White, P.E.

53 Regional Drive Concord, NH 03301

Subject: Explorations and Geotechnical Engineering Services Proposed Bridge Replacement George Street over Beaver Brook Keene, New Hampshire

Dear Sam:

In accordance with our Revised Proposal dated August 2, 2021, we have performed subsurface explorations for the subject project. This report summarizes our findings and geotechnical recommendations, and its contents are subject to the limitations set forth in Appendix A.

1.0 INTRODUCTION

1.1 Scope and Purpose

The purpose of our services was to explore subsurface conditions at the site in order to provide geotechnical recommendations for design of the proposed bridge replacement.

Our scope of services included two test borings and one environmental test boring, soils laboratory testing, a geotechnical evaluation of the findings relative to proposed construction, and preparation of this report.

1.2 Site and Proposed Construction

The site is located on George Street at its crossing of Beaver Brook in Keene, New Hampshire. The site consists of an existing 13-foot single-span bridge across Beaver Brook in an east-west direction. Based on the provided plans, site grades are relatively flat along George Street at about Elevation 488 feet. Site grades slope downward to

Beaver Brook at the crossing to about elevation 479 to 480 feet.

Based on correspondence with you, we understand proposed construction will include a new bridge spanning 20 to 30 feet across Beaver Brook. We understand replacement structures under consideration include:

• Concrete box culvert recessed into the brook.

• Three-sided rigid concrete frame supported on spread footings; or

• Shallow stub abutments supported on single row of driven piles.

We understand the new bridge will be constructed on the existing horizontal alignment and have a similar vertical grade as the existing bridge.

2.0 EXPLORATION AND TESTING

2.1 Explorations

Two geotechnical test borings (B-1 and B-2) and one environmental test boring (ENV-1) were made at the site on December 5 and 6, 2022, by S. W. Cole Explorations, LLC.

The test borings were advanced utilizing cased rotary-wash drilling techniques.

Standard Penetration Testing (SPT) and split-spoon sampling were performed at 2-foot intervals to a depth of 15 feet than at 5-foot intervals, thereafter. Upon encountering a refusal surface, test borings B-1 and B-2 were advanced 5 feet into bedrock using a NQ2 rock core barrel. The exploration locations were selected by S. W. Cole Engineering, Inc. (S.W.COLE) in consultation with Sanborn, Head & Associates, Inc.

(SHA) (project environmental consultant) and established in the field by S.W.COLE using taped measurements from existing site features.

Soils in the test borings were screened by SHA using a MiniRAE 2000 photoionization detector (PID). PID results are noted on the boring logs.

The approximate exploration locations are shown on the “Exploration Location Plan,” included in Appendix B. Exploration logs and a key to the notes and symbols used on the logs are included in Appendix C. The elevations shown on the logs were estimated based on topographic information shown on the “Exploration Location Plan”.

2.2 Laboratory Testing

Soil samples obtained from the explorations were returned to our laboratory for further classification and testing. Gradation and moisture content testing was performed on two select soil samples. Gradation test results are included in Appendix D. Moisture content test results are shown on the boring logs.

3.0 SUBSURFACE CONDITIONS

3.1 Soil and Bedrock

3.1.1 West Abutment (B-1)

Test boring B-1 was preformed on the west side of the existing bridge and encountered a surficial asphalt pavement layer overlying granular fills consisting of loose to dense, brown sand with varying portions of silt and gravel to a depth of 9 feet. The fill was underlain by alluvial deposits of loose to medium dense, brown sand and gravel, with some silt to a depth of 15 feet. Below the alluvial deposit, the test boring encountered glacial till soils consisting of medium dense, gray gravelly sand some silt to a depth of 20 feet where bedrock was encountered. Bedrock recovery was minimal and consisted of hard, slightly weathered, moderately to slightly fractured, fine to medium grained, gray to black Granodiorite, with very close to close, low to high angle joints with a Rock Quality Designation (RQD) of 10% indicating very poor rock quality.

3.1.2 East Abutment (B-2)

Test boring B-2 was made on the east side of the existing bridge and encountered a surficial 1.5 feet of grassed topsoil overlying granular fills consisting of medium dense silty sand with varying portions of gravel to a depth of 7 feet. Below the fill, the test boring encountered alluvial deposits of medium dense to very dense, brown gravelly sand with varying portions of silt to a depth of 17 feet. Below the alluvial deposit, the test boring encountered glacial till soils consisting of very dense, gray silty gravelly fine to medium sand to a depth of 21 feet, where bedrock was encountered. Bedrock consisted of hard, slightly weathered, moderately to slightly fractured, fine to medium grained, gray to black Granodiorite, with very close to close, low to high angle joints. The bedrock sampled had an RQD equal to 62% indicating fair rock quality.

3.1.3 Environmental Boring (ENV-1)

Environmental boring ENV-1 was performed in an open grassed area to the northwest of the bridge and encountered a surficial 1.5 feet of grassed topsoil overlying granular fills consisting of loose to medium dense sand with varying portions of silt and gravel to a depth of 9 feet, overlying very loose to loose, sand and sandy silt (alluvial deposits) to a depth of 15 feet, where the exploration was terminated.

3.2 Groundwater

Free water was observed at depths ranging from 8 to 9 feet in the test borings at the time of exploration work. Long term groundwater information is not available. It should be anticipated that groundwater levels will fluctuate, particularly in response to periods of snowmelt and precipitation, changes in site use and the water level of Beaver Brook.

4.0 SEISMIC CONSIDERATIONS

4.1 Bedrock Acceleration and Site Response

Seismic site class was evaluated in accordance with AASHTO LRFD 2020 Article

3.10.3.1 using the average SPT N-value method. Based on the information obtained in the explorations, the average N-value was between 15 and 50 blows per foot corresponding to an AASHTO Site Class D as defined in AASHTO Table 3.10.3.1-1.

United States Geological Survey (USGS) Seismic Design Parameters program (Version 2.1) was used to obtain the seismic design parameters for the bridge. Based on the assigned site class (AASHTO Site Class D) and the project site coordinates, the software provides the recommended AASHTO Response Spectrum for a 7 percent probability of exceedance in 75 years. The results for the project site are summarized below:

Site Class D Seismic Design Parameters Site Coordinates: N42.944645°, W72.271597°

Parameter Design Value PGA 0.069 g

Ss 0.150 g S1 0.043 g

Fpga 1.60 Fa 1.60 Fv 2.40 As 0.111 g

SDS 0.240 g SD1 0.103 g

Seismic Zone (based on SD1) Zone 1

Based on the Acceleration Coefficient SD1=0.103 g and AASHTO Article 3.10.6, this site is assigned to Seismic Zone 1. Per AASHTO Article 4.7.4, single span bridges are not required to be analyzed for seismic loads, however the requirements of AASHTO Articles 4.7.4.4 and 3.10.9 shall apply. Per AASHTO Article 3.10.1 the seismic effects for box culverts and buried structures need not be considered except where they cross active faults. There are no known active faults within the site vicinity.

4.2 Liquefaction Assessment

Liquefaction is typically observed in saturated deposits of loose sands and non-plastic silts subjected to ground shaking most commonly from earthquakes. The foundation soils at the proposed abutments are anticipated to consist of native, medium dense to very dense sand or glacial till. Based on the site soils, we anticipate the risk of seismically induced liquefaction below the foundations is low.

5.0 FOUNDATION EVALUATION AND RECOMMENDATIONS

5.1 General

S.W.COLE has conducted geotechnical engineering evaluations in accordance with 2020 AASHTO LRFD Bridge Design Specifications, 9th Edition (AASHTO) and the NHDOT Bridge Design Manual, 2015 Version 2 Edition with November 2020 revisions

(NHDOT BDM).

5.2 Frost Considerations

The 100-year freezing index for the Keene, New Hampshire area is approximately 1,300 Fahrenheit degree-days. Considering this, we recommend spread footing foundations or pile caps and grade beams for the abutments and wing walls have at least 4.5 feet of soil cover to provide frost protection. Riprap for scour protection should not be considered as part of the soil cover.

5.3 Foundation Options and Discussion

We understand the proposed bridge replacement alternatives consist of a box culvert, three-sided rigid frame or pile supported bridge integral abutment bridge.

Subsurface conditions at the site consist of fills overlying native sand and gravel, overlying glacial till mantling bedrock at depths of about 20 to 21 feet. Based on the subsurface findings, it is our opinion that driven piles will be too short to develop lateral resistance depending on the bottom of pile cap elevation. Therefore, we anticipate abutment support by cast-in-place spread footings founded below scour or drilled micropiles are feasible foundation options for the bridge replacement.

Uncontrolled fills were encountered at each abutment extending to depths ranging from 7 to 9 feet below ground surface. Uncontrolled fills and soils containing organic material must be completely removed below foundations and from areas of proposed construction and replaced with compacted fill. It is anticipated that these unsuitable soils will be removed during anticipated excavations for the proposed bridge; however, over-excavations, if needed, should extend out one foot horizontally for each foot of over-excavation (1H:1V bearing splay).

It is anticipated that use of spread footings may require a deeper foundation embedment than frost depth for scour protection, potentially increasing efforts associated with excavation and dewatering. It will be important to properly dewater excavations to allow for observation of the bearing surface.

5.4 Foundation Design

5.4.1 Precast Box Culvert

We anticipate a box culvert will be recessed into the brook and founded on medium dense to very dense sand and gravel (alluvial deposits) or medium dense to very dense glacial till soils. We recommend precast box culvert be recessed below scour and supported on at least 12 inches of compacted Crushed Stone overlying properly prepared subgrades. We recommend the precast box culvert include toe walls at the inlet and outlet ends to prevent undermining. Based on the subsurface conditions and our understanding of the proposed construction, we recommend the following foundation design parameters:

GEOTECHNICAL FOUNDATION DESIGN PARAMETERS

Design Frost Depth 4.5 feet

Strength Limit Sate – Article 10.6.3.1.1 Nominal Bearing Resistance 12.4 ksf Strength Limit Bearing Resistance Factor (AASHTO Table 10.5.5.2.2-1) 0.45 Factored Bearing Resistance 5.6 ksf Estimated Post-Construction Settlement 1.5 inches or less

Service Limit – AASHTO Table C10.6.2.6.1-1 Nominal Bearing Resistance 4.0 ksf Service Limit Bearing Resistance Factor 1.0 Factored Bearing Resistance 4.0 ksf Estimated Post-Construction Settlement 1.5 inches or less

5.4.2 Spread Footing Foundations

We anticipate spread footing foundations will likely be founded on medium dense to very dense sand and gravel (alluvial deposits) or medium dense to very dense glacial till soils. We recommend cast-in-place spread footings be founded below scour and supported on at least 12 inches of compacted Crushed Stone overlying properly prepared subgrades. The purpose of the Crushed Stone layer is intended to create a level and stable working mat and provide a media to sump and pump. Voids left by the removal of cobbles or boulders should be backfilled with additional Crushed Stone.

Based on the subsurface conditions and our understanding of the proposed construction, we recommend the following foundation design parameters:

GEOTECHNICAL FOUNDATION DESIGN PARAMETERS

Design Frost Depth 4.5 feet

Strength Limit Sate – Article 10.6.3.1.1 Nominal Bearing Resistance 11.7 ksf Strength Limit Bearing Resistance Factor (AASHTO Table 10.5.5.2.2-1) 0.45 Factored Bearing Resistance 5.3 ksf Estimated Post-Construction Settlement 1 inch or less

Service Limit – AASHTO Table C10.6.2.6.1-1 Nominal Bearing Resistance 5.0 ksf Service Limit Bearing Resistance Factor 1.0 Factored Bearing Resistance 5.0 ksf Estimated Post-Construction Settlement 1 inch or less

We recommend a minimum footing width of 6 feet. S.W.COLE should be given the opportunity to review the proposed foundation layout during final design to adjust our recommendations based on the actual proposed foundation configuration and dimensions.

It is anticipated that use of spread footings may require a deeper foundation embedment than frost depth for scour protection, potentially increasing efforts associated with excavation and dewatering. It will be important to properly dewater excavations to allow for observation of the bearing surface.

5.4.3 Micropiles

We anticipate micropiles will consist of a cased section from the bottom of pile cap down to the top of competent bedrock with an uncased section below. The micropiles will be reinforced with a single, continuously threaded central bar running the full length of the micropile and filled with 5,000 psi Portland cement grout. In accordance with LRFD Article 10.9.1.2, center-to-center micropile spacing should not be less than 30 inches or 3 pile diameters, whichever is greater.

5.4.3.1 Axial Resistance

Rock-socketed micropiles will generally develop axial resistance through side friction in the rock socket. For design, per LRFD Table C10.9.3.5.2-1, we recommend a presumptive nominal grout-to-ground bond resistance of 20 ksf for the granodiorite bedrock. Per LRFD Table 10.5.5.2.5-1, at the strength limit state, axially loaded micropiles shall be designed using a geotechnical resistance factor ϕstat of 0.70 provided pile load testing is performed.

If no load test is performed, a geotechnical resistance factor ϕstat of 0.55 shall be used.

Micropile axial resistance is dependent on pile diameter and grout-to-ground bond length.

A summary of estimated factored strength-limit axial geotechnical resistances for 7.5 and 9.5-inch diameter micropile with various bond lengths are provided in the following table:

Embedment in Competent Bedrock (ft)

Strength Limit Factored Axial Geotechnical Resistance (kips)1

7.5-inch Uncased Diameter2 9.5-inch Uncased Diameter3 10 274 347 15 411 520 20 548 694

Notes: 1. Resistance factor of 0.7 used for the strength limit state

2. 8.625-inch OD, 7.625-inch ID casing to top of rock, assumed 7.5-inch diameter rock-socket

3. 10.75-inch OD, 9.75-inch ID casing to top of rock, assumed 9.5-inch diameter rock-socket

Additional micropile grout-to-ground bond lengths may be considered depending on the actual factored design axial loads. S.W.COLE can provide additional input on micropile size once abutment loading has been developed for the proposed structure. Final axial design of micropiles shall be performed by the micropile specialty contractor during construction-phase, based on pile load test results and selected means and methods.

5.4.3.2 Downdrag

We anticipate settlement in the native soils generated from the load applied by embankment fills will be elastic and occur during construction with negligible long-term settlement. Therefore, downdrag is not considered to be an issue.

5.4.3.3 Lateral Resistance

The micropiles will be subjected to lateral loading; therefore, the micropiles shall be evaluated for resistance against combined axial compression and flexure in accordance with LRFD Table Article 10.7.3.9. Lateral resistance can also be derived from the use of battered piles.

5.4.3.4 Service and Extreme Limit State Design

The design of micropiles at the service limit state shall consider tolerable transverse and longitudinal movement of piles and pile group movement considering changes in soil conditions due to scour based on the design flood (Q100). For the service limit state, resistance factors of φ = 1.0 should be used in accordance with LRFD Article 10.5.5.1.

The exception is the overall global stability of the foundation which should be investigated at the Service I load combination and a resistance factor, φ, of 0.65.

Extreme limit state design shall include pile axial compressive resistance, overall global stability of the pile group, pile failure by uplift in tension, and structural failure. The extreme event load combinations are those related to seismic forces, ice loads, debris loads, and hydraulic events. Extreme limit state design shall also check that the nominal pile foundation resistance remaining after scour due to the check flood (Q500) can support the extreme limit state loads. Resistance factors for extreme limit states, per LRFD Article 10.5.5.3, shall be taken as φ = 1.0 except for uplift of piles, for which the resistance factor, φup, shall be 0.80 or less per LRFD Article 10.5.5.3.2.

5.5 Abutments and Wingwalls

The material properties will be controlled by the backfill which is anticipated to consist of NHDOT Granular Backfill (Bridge) Item 209. We assume the bridge will be backfilled with free-draining, granular wall backfill resulting in a drained condition (i.e. no hydrostatic pressure) within the wall backfill. Based on the use of a free-draining, granular wall backfill, we recommend design consider the following parameters:

GEOTECHNICAL PARAMETERS FOR ABUTMENT AND WING WALLS

Total Unit Weight of Backfill (γt) 125 pcf Internal Friction Angle of Backfill (NHDOT Granular Backfill Item 209) 32° Active Lateral Earth Pressure Coefficient (Ka) 0.3 At-Rest Lateral Earth Pressure Coefficient (Ko) 0.5 Passive Lateral Earth Pressure (Kp) 3.3

AASHTO recommends that live load surcharge be applied as a uniform lateral surcharge pressure using an equivalent fill height. Recommendations for equivalent lateral surcharge height are provided in AASHTO Article 3.11.6.4 based on wall height and distance from the wall back face to the edge of traffic.

5.6 Excavation and Dewatering Considerations

The excavations to foundation subgrade will generally encounter granular fills overlying native sands with varying portions of silt and gravel, overlying glacial till and bedrock. The foundation should be underlain with a minimum 6 inches of Crushed Stone (NHDOT #57

Crushed Stone). This will help provide a stable surface from which to construct forms and provide a media from which to collect, sump, and pump groundwater.

Excavations below the water level of Beaver Brook will be difficult and will likely need sheetpiles for groundwater cutoff and river flow diversion to help control groundwater.

Controlling the water levels to at least one foot below planned excavation depths will help stabilize subgrades during construction. Surface water should be diverted from entering the foundation excavation.

Excavations must be properly shored and/or sloped to prevent sloughing and caving of the sidewalls during construction. All excavations should be performed in accordance with OSHA requirements. The contractor is responsible for developing an appropriate dewatering and excavation plans to install the foundations and maintain stable subgrades.

5.7 Backfill and Compaction

Embankment fill for approaches and backfill placed adjacent to the new abutments and wing walls should be clean, non-frost susceptible sand and gravel meeting the gradation requirements for NHDOT Granular Backfill (Bridge) Item 209.

Fill should be placed in horizontal lifts and be compacted. Lift thickness should be limited to that which can be thoroughly compacted using small, hand operated compaction equipment to avoid over compaction of material within 3 feet of abutment and wing walls. We recommend fill against the proposed structure and wing walls be compacted to between 95 to 98 percent of its maximum dry density as determined by

AASHTO T-99.

If foundation construction takes place during cold weather conditions, subgrades and foundations must be protected from freezing conditions.

5.8 Design Review and Construction Testing

We recommend S.W.COLE be provided the opportunity to review recommendations in this report and make modifications as necessary once the final design for the replacement structure has been determined. S.W.COLE should be retained to review the final design and specifications to determine that our earthwork and foundation recommendations have been properly interpreted and implemented.

Further, we recommend S.W.COLE be retained to provide soils engineering and testing services during the excavation and foundation phases of the work. This is to observe compliance with the design concepts, specifications, and design recommendations and to allow design changes in the event that subsurface conditions are found to differ from those anticipated prior to the start of construction. S.W.COLE is available to provide testing of soil, concrete, and asphalt construction materials.

6.0 CLOSURE

It has been a pleasure to be of assistance to you with this phase of your project. We look forward to working with you during the construction phase of the project.

Sincerely, S. W. Cole Engineering, Inc.

Tyler S. Demers, P.E.

Project Geotechnical Engineer

TSD:mas tyler.demers

NH

APPENDIX A

Limitations

This report has been prepared for the exclusive use of McFarland Johnson, Inc. for specific application to the Proposed Bridge Replacement on George Street Over Beaver Brook in Keene, New Hampshire. S. W. Cole Engineering, Inc. (S.W.COLE) has endeavored to conduct our services in accordance with generally accepted soil and foundation engineering practices. No warranty, expressed or implied, is made.

The soil profiles described in the report are intended to convey general trends in subsurface conditions. The boundaries between strata are approximate and are based upon interpretation of exploration data and samples.

The analyses performed during this investigation and recommendations presented in this report are based in part upon the data obtained from subsurface explorations made at the site. Variations in subsurface conditions may occur between explorations and may not become evident until construction. If variations in subsurface conditions become evident after submission of this report, it will be necessary to evaluate their nature and to review the recommendations of this report.

Observations have been made during exploration work to assess site groundwater levels. Fluctuations in water levels will occur due to variations in rainfall, temperature, and other factors.

S.W.COLE’s scope of services has not included the investigation, detection, or prevention of any Biological Pollutants at the project site or in any existing or proposed structure at the site. The term “Biological Pollutants” includes, but is not limited to, molds, fungi, spores, bacteria, and viruses, and the byproducts of any such biological organisms.

Recommendations contained in this report are based substantially upon information provided by others regarding the proposed project. In the event that any changes are made in the design, nature, or location of the proposed project, S.W.COLE should review such changes as they relate to analyses associated with this report.

Recommendations contained in this report shall not be considered valid unless the changes are reviewed by S.W.COLE.

APPENDIX B

Figures

B-1

B-2

ENV-1

MCFARLAND JOHNSON, INC.

PROPOSED BRIDGE REPLACEMENT

GEORGE STREET OVER BEAVER BROOK

KEENE, NEW HAMPSHIRE

EXPLORATION LOCATION PLAN

Job No.:

Date :

21-0414 12/22/2022

Scale:

Sheet:

1" = 20'

S.W.COLE

E N G I N E E R I N G , I N C .

LEGEND:

APPROXIMATE BORING LOCATION

NOTES:

1. EXPLORATION LOCATION PLAN WAS PREPARED FROM A

SCALE PLAN OF THE SITE ENTITLED "EXISTING

CONDITIONS SURVEY," PREPARED BY GM2 ASSOCIATES,

INC., DATED 10/3/2022.

2. THE BORINGS WERE LOCATED IN THE FIELD BY TAPED

MEASUREMENTS FROM EXISTING SITE FEATURES.

3. THIS PLAN SHOULD BE USED IN CONJUNCTION WITH THE

ASSOCIATED S. W. COLE ENGINEERING, INC.

GEOTECHNICAL REPORT.

4. THE PURPOSE OF THIS PLAN IS ONLY TO DEPICT THE

LOCATION OF THE EXPLORATIONS IN RELATION TO THE

EXISTING CONDITIONS AND PROPOSED CONSTRUCTION

AND IS NOT TO BE USED FOR CONSTRUCTION.

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MN-5

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SP-8=2

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BENCHMARK MNS IN UPW ELEV.=488.40

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PSNH 120/4 NETT 4

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8" APPLE

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APPENDIX C

Exploration Logs and Key

1-3

3-5

5-7

7-9

10-12

12-14

15-17

20-25

Asphalt Pavement

Dense, brown, Gravelly Silty fine to medium

SAND (FILL)

Loose, brown, SILT and fine SAND (Fill)

Medium dense, brown, Gravelly Silty SAND

(FILL)

Loose to medium dense, brown, SAND and GRAVEL some silt

Medium dense, gray, Gravelly SAND some silt (Glacial Till)

Bedrock: Hard, slightly weathered, moderately to slightly fractured, fine to medium grained, gray to black, Granodiorite.

Joints are very close to close, low to high angle. RQD = 10%

Bottom of Exploration at 25.0 feet Probable Boulder or Bedrock

24/18

24/15

24/8

24/3

24/2

24/7

24/1

60/15

1D

2D

3D

4D

5D

6D

7D

1R

29-21- 19-13

5-6-4-6

13-17- 11-7

7-9-7-

5-4-6-4

5-7-7-

15-12- 10-5

PID=0 ppm

PID=0 ppm

PID=.1 ppm

PID=0 ppm

PID=0 ppm

PID=0 ppm ID 22365s w =12.3 %

PID=0 ppm

Pen. = Penetration Length Rec. = Recovery Length

LOGGED BY: Sean Hlywa

CORE BARREL: NQ2

At time of Drilling At Completion of Drilling After Drilling

D = Split Spoon Sample

CASING ID/OD: N/A /N/A

Water Level

AUGER ID/OD: N/A / N/A

ELEVATION (FT): 488' +/-

bpf = Blows per Foot

TOTAL DEPTH (FT): 25.0

U = Thin Walled Tube Sample

DRILLER: Matt Bussey

KEY TO NOTES

AND SYMBOLS:

Sv = Field Vane Shear Strength, kips/sq.ft.

Drilling Information

RIG TYPE: Track Mounted Mobile Drill B-48

HAMMER TYPE: Automatic

GENERAL NOTES:

HAMMER WEIGHT (lbs): 140

R = Rock Core Sample V = Field Vane Shear mpf = Minute per Foot

WOR = Weight of Rods WOH = Weight of Hammer RQD = Rock Quality Designation

HAMMER DROP (inch): 30

DRILLING CO.: S. W. Cole Explorations, LLC

PID = Photoionization Detector N/A = Not Applicable

SAMPLER: Standard Split-Spoon qU = Unconfined Compressive Strength, kips/sq.ft.

Ø = Friction Angle (Estimated)

DRILLING METHOD:

WATER LEVEL DEPTHS (ft): 9 ft Water observed at 9.0 feet on 12/6/2022

HAMMER EFFICIENCY FACTOR: 0.91

LOCATION: See Exploration Location Plan

Depth (ft)

Depth (ft)

Casing Pen.

(bpf)

Stratification lines represent approximate boundary between soil types, transitions may be gradual. Water level readings have been made at times and under conditions stated.

Fluctuations of groundwater may occur due to other factors than those present at the time measurements were made.

SAMPLE INFORMATION

H20 Depth Remarks

Sample Description & ClassificationT yp e

Elev.

(ft)

G ra ph ic

L og

Pen./ Rec.

(in)

Sample No.

Blow Count or

RQD

Field / Lab Test Data /

PID

Readings

B O

R

IN

G

W E

LL

-1

2-

-0

4.

G P

J S

W C

E T

E M

P

LA

T E

.G D

T

2/

3/

DATE FINISH: 12/6/2022

BORING NO.: B- 1

BORING NO.: B- 1

PROJECT NO. 21-0414

SHEET: 1 of 1

DATE START: 12/6/2022

BORING LOG

PROJECT: Proposed Bridge Replacement CLIENT: McFarland Johnson, Inc.

LOCATION: George Street, Keene, New Hampshire

1.0

3.7

5.0

9.0

15.0

20.0

0-2

2-4

5-7

7-9

10-12

12-14

15-17

20-21

21.1- 26.1

Grassed Topsoil

Medium dense, brown, Gravelly Silty SAND (Fill)

Medium dense, brown Silty fine to medium SAND some gravel (Fill)

Medium dense, brown, Silty Gravelly SAND

Dense, brown, Gravelly SAND some silt

Very dense, brown, SAND trace gravel trace silt

Cobbles

Very dense, gray, Silty Gravelly fine to medium SAND (Glacial Till)

Bedrock: Hard, slightly weathered, moderately to slightly fractured, fine to medium grained, gray to black, Granodiorite.

Joints are very close to close, low to high angle. RQD = 62%

Bottom of Exploration at 26.1 feet Bedrock

24/8

24/2

24/13

24/13

24/13

24/16

24/1

12/2

60/58

1D

2D

3D

4D

5D

6D

7D

8D

1R

6-6-7-7

10-8-6-

20-12- 13-17

27-11- 15-13

17-13- 19-20

14-33- 21-16

20-15- 9-9

11-7- 50/0"

PID=0 ppm

PID=0 ppm

PID=.7 ppm

PID=.3 ppm

PID=.8 ppm

PID=.1 ppm ID 22366s w =18.1 %

Pen. = Penetration Length Rec. = Recovery Length

LOGGED BY: Sean Hlywa

CORE BARREL: NQ2

At time of Drilling At Completion of Drilling After Drilling

D = Split Spoon Sample

CASING ID/OD: 4 in / 4 1/2 in

Water Level

AUGER ID/OD: N/A / N/A

ELEVATION (FT): 488' +/-

bpf = Blows per Foot

TOTAL DEPTH (FT): 26.1

U = Thin Walled Tube Sample

DRILLER: Matt Bussey

KEY TO NOTES

AND SYMBOLS:

Sv = Field Vane Shear Strength, kips/sq.ft.

Drilling Information

RIG TYPE: Track Mounted Mobile Drill B-48

HAMMER TYPE: Automatic

GENERAL NOTES:

HAMMER WEIGHT (lbs): 140

R = Rock Core Sample V = Field Vane Shear mpf = Minute per Foot

WOR = Weight of Rods WOH = Weight of Hammer RQD = Rock Quality Designation

HAMMER DROP (inch): 30

DRILLING CO.: S. W. Cole Explorations, LLC

PID = Photoionization Detector N/A = Not Applicable

SAMPLER: Standard Split-Spoon qU = Unconfined Compressive Strength, kips/sq.ft.

Ø = Friction Angle (Estimated)

DRILLING METHOD: Cased Boring

WATER LEVEL DEPTHS (ft): 8 ft Water observed at 8.0 feet on 12/5/2022

HAMMER EFFICIENCY FACTOR: 0.91

LOCATION: See Exploration Location Plan

Depth (ft)

Depth (ft)

Casing Pen.

(bpf)

Stratification lines represent approximate boundary between soil types, transitions may be gradual. Water level readings have been made at times and under conditions stated.

Fluctuations of groundwater may occur due to other factors than those present at the time measurements were made.

SAMPLE INFORMATION

H20 Depth Remarks

Sample Description & ClassificationT yp e

Elev.

(ft)

G ra ph ic

L og

Pen./ Rec.

(in)

Sample No.

Blow Count or

RQD

Field / Lab Test Data /

PID

Readings

B O

R

IN

G

W E

LL

-1

2-

4.

G P

J S

W C

E T

E M

P

LA

T E

.G D

T

2/

3/

DATE FINISH: 12/5/2022

BORING NO.: B- 2

BORING NO.: B- 2

PROJECT NO. 21-0414

SHEET: 1 of 1

DATE START: 12/5/2022

BORING LOG

PROJECT: Proposed Bridge Replacement CLIENT: McFarland Johnson, Inc.

LOCATION: George Street, Keene, New Hampshire

1.5

5.0

7.0

10.0

12.0

15.0

17.0

21.0

0-2

2-4

5-7

7-9

10-12

12-14

Grassed Topsoil

Loose, brown, Silty fine SAND (Fill)

Medium dense to dense, brown, Gravelly fine to medium SAND some silt (Fill)

Loose, brown, SAND some gravel some silt

Very loose, gray, fine Sandy SILT Loose, brown, Silty SAND Very loose, gray, fine Sandy SILT

Bottom of Exploration at 15.0 feet

24/8

24/6

24/12

24/6

24/24

24/17

1D

2D

3D

4D

5D

6D

2-3-2-2

2-5-3-3

9-12- 19-19

12-10- 14-8

3-4-4-2

3-3- 2/12''

PID=0 ppm

PID=0 ppm

PID=.5 ppm

PID=.2 ppm

PID=.1 ppm

PID=0 ppm

Road Box

Drill Spoils

Filter Sand

Pen. = Penetration Length Rec. = Recovery Length

LOGGED BY: Sean Hlywa

CORE BARREL: N/A

At time of Drilling At Completion of Drilling After Drilling

D = Split Spoon Sample

CASING ID/OD: N/A /N/A

Water Level

AUGER ID/OD: 2 1/4 in / 5 5/8 in

ELEVATION (FT): 488' +/-

bpf = Blows per Foot

TOTAL DEPTH (FT): 15.0

U = Thin Walled Tube Sample

DRILLER: Matt Bussey

KEY TO NOTES

AND SYMBOLS:

Sv = Field Vane Shear Strength, kips/sq.ft.

Drilling Information

RIG TYPE: Track Mounted Mobile Drill B-48

HAMMER TYPE: Automatic

GENERAL NOTES:

HAMMER WEIGHT (lbs): 140

R = Rock Core Sample V = Field Vane Shear mpf = Minute per Foot

WOR = Weight of Rods WOH = Weight of Hammer RQD = Rock Quality Designation

HAMMER DROP (inch): 30

DRILLING CO.: S. W. Cole Explorations, LLC

PID = Photoionization Detector N/A = Not Applicable

SAMPLER: Standard Split-Spoon qU = Unconfined Compressive Strength, kips/sq.ft.

Ø = Friction Angle (Estimated)

DRILLING METHOD: Hollow Stem Auger

WATER LEVEL DEPTHS (ft): 9 ft Water observed at 9.0 feet on 12/5/2022

HAMMER EFFICIENCY FACTOR: 0.91

LOCATION: See Exploration Location Plan

Depth (ft)

Depth (ft)

Casing Pen.

(bpf)

Stratification lines represent approximate boundary between soil types, transitions may be gradual. Water level readings have been made at times and under conditions stated.

Fluctuations of groundwater may occur due to other factors than those present at the time measurements were made.

SAMPLE INFORMATION

H20 Depth

Sample Description & ClassificationT yp e

Elev.

(ft)

G ra ph ic

L og

Pen./ Rec.

(in)

Sample No.

Blow Count or

RQD

Field / Lab Test Data /

PID

Readings

B O

R

IN

G

W E

LL

-1

2-

4.

G P

J S

W C

E T

E M

P

LA

T E

.G D

T

2/

3/

DATE FINISH: 12/5/2022

BORING NO.: ENV-1

BORING NO.: ENV-1

PROJECT NO. 21-0414

SHEET: 1 of 1

DATE START: 12/5/2022

BORING LOG

PROJECT: Proposed Bridge Replacement CLIENT: McFarland Johnson, Inc.

LOCATION: George Street, Keene, New Hampshire

Well Diagram

1.5

5.0

9.0

11.7 12.0

13.0

APPENDIX D

Laboratory Test Results

Project Name KEENE NH - GEORGE STREET OVER BEAVER BROOK BRIDGE

REPLACEMENT - GEOTECHNICAL ENGINEERING SERVICES

Project Number 21-0414

Lab ID 22365S

Material Source B-1, 6D, 12.0'-14.0' Date Completed 12/19/2022

Tested By BRADLEY GERSCHWILER

Date Received 12/13/2022

ASTM C-117 & C-136

Client MCFARLAND JOHNSON INC.

Report of Gradation

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.00100.01000.10001.000010.0000100.0000

SIEVE SIZE - mm

A M

O U

N T

P A

S S

IN

G

3" 2" 1" #10 #20 #40 #100 #2001/2" 1/4"

SIEVE SIZE AMOUNT PASSING (%)STANDARD

DESIGNATION (mm/µm)

1" 10025.0 mm 3/4" 8419.0 mm 1/2" 7512.5 mm 3/8" 679.5 mm 1/4" 566.3 mm

No. 4 48.4% Gravel524.75 mm No. 10 402.00 mm No. 20 27850 um No. 40 46.4% Sand17425 um No. 60 12250 um

No. 100 8150 um No. 200 5.2% Fines5.275 um

SheetComments: Moisture Content = 12.3%

Project Name KEENE NH - GEORGE STREET OVER BEAVER BROOK BRIDGE

REPLACEMENT - GEOTECHNICAL ENGINEERING SERVICES

Project Number 21-0414

Lab ID 22366S

Material Source B-2, 6D, 12.0'-14.0' Date Completed 12/19/2022

Tested By BRADLEY GERSCHWILER

Date Received 12/13/2022

ASTM C-117 & C-136

Client MCFARLAND JOHNSON INC.

Report of Gradation

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.00100.01000.10001.000010.0000100.0000

SIEVE SIZE - mm

A M

O U

N T

P A

S S

IN

G

3" 2" 1" #10 #20 #40 #100 #2001/2" 1/4"

SIEVE SIZE AMOUNT PASSING (%)STANDARD

DESIGNATION (mm/µm)

1/4" 1006.3 mm No. 4 4.4% Gravel964.75 mm

No. 10 832.00 mm No. 20 55850 um No. 40 91% Sand29425 um No. 60 14250 um

No. 100 8150 um No. 200 4.6% Fines4.675 um

SheetComments: Moisture Content = 18.1%

3.2 Groundwater