Geotechnical_Report_-_Service_Dr._between_Temple_St._and_Congress_Ave..pdf

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GEOTECHNICAL ENGINEERING REPORT

PROPOSED VEHICULAR BRIDGE

TEMPLE STREET OVER SERVICE DRIVE

NEW HAVEN, CONNECTICUT

Prepared for:

City of New Haven, Connecticut 200 Orange St. 5th Floor

New Haven, Connecticut 06510

Prepared by:

Down To Earth Consulting, LLC 122 Church Street

Naugatuck, Connecticut 06770

July 2020 File No. 0063-009.00

July 21, 2020 File No. 0063-009.00

Zach Shapiro, P.E.

City of New Haven 200 Orange St. 5th Floor New Haven, Connecticut 06510

Via email: ZShapiro@newhavenct.gov

Re: Geotechnical Engineering Report Proposed Vehicular Bridge Temple Street over Service Drive

New Haven, Connecticut

Dear Mr. Shapiro, Down To Earth Consulting, LLC (DTE) is pleased to submit this geotechnical engineering report for the proposed vehicular bridge that will span Temple Street over Service Drive in New Haven, Connecticut. We appreciate this opportunity to work with you. Please call if you have any questions.

Sincerely, Down To Earth Consulting, LLC

Daniel F. LaMesa, P.E. Raymond P. Janeiro, P.E.

Principal Reviewer/Principal

Temple Street Bridge over Service Drive New Haven, Connecticut

File No. 0063-009.00 – July 21, 2020 Page No. i

TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 BACKGROUND

3.0 SUBSURFACE DATA

3.1 GENERAL SITE GEOLOGY

3.2 TEST BORINGS

4.0 SUBSURFACE CONDITIONS

4.1 SUBSURFACE PROFILE

4.1.1 Fill

4.1.2 Sand Deposits

4.2 GROUNDWATER

5.0 GEOTECHNICAL RECOMMENDATIONS

5.1 FOUNDATIONS

5.2 BACKFILL AND DRAINAGE

5.3 LATERAL EARTH PRESSURES

5.4 SEISMIC DESIGN

6.0 MATERIALS RECOMMENDATIONS

6.1 BACKFILL MATERALS

6.2 COMPACTION REQUIRMENTS

7.0 CONSTRUCTION RECOMMENDATIONS

7.1 FOUNDATION SUBGRADE PREPARATION

7.2 TEMPORARY EXCAVATIONS

7.3 TEMPORARY GROUNDWATER CONTROL

8.0 REVIEW OF FINAL DESIGN, PLANS, AND SPECIFICATIONS

9.0 CONSTRUCTION QUALITY CONTROL

10.0 LIMITATIONS

APPENDICES

APPENDIX 1 – FIGURES

APPENDIX 2 – BORING LOGS

APPENDIX 3 – LIMITATIONS

Page No. 1

1.0 INTRODUCTION

Down To Earth Consulting, LLC (DTE) is pleased to submit this geotechnical engineering report for the proposed vehicular bridge that will span Temple Street over Service Drive in New Haven, Connecticut. Refer to Figures 1 and 2 (in Appendix 1) for the approximate site and proposed bridge locations, respectively.

Our geotechnical engineering services included: reviewing project plans, observing test borings, characterizing subsurface conditions within the project limits, performing geotechnical engineering analyses, and providing geotechnical design and construction recommendations for the proposed bridge. Our services were performed in accordance with our July 5, 2020 proposal.

Our recommendations are based on load and resistance factor design and the following references:

2012 AASHTO LRFD Bridge Design Specifications The Connecticut Department of Transportation (CTDOT) Geotechnical Manual, 2005 edition (revised January 2020) CTDOT Bridge Design Manual, 2003 edition (revised December 2019) CTDOT Standard Specifications for Roads, Bridges, and Incidental Construction, Form

818.

Elevations (El.) provided in this report are in feet and based on the NGVD 29 Datum.

2.0 BACKGROUND

The project site is located immediately north of the Congress Avenue and South Frontage Road intersection. Refer to Figures 1 and 2 (in Appendix 1) for the site location and site plan. Existing site grades generally slope down from South Frontage Road (approximate El. 23.5) to the existing Oak Street Connector (approximate El. 13.5). We understand that the Oak Street Connector will be removed and replaced with the Service Drive Northbound and Southbound Lanes that will convey traffic in and out of a tunnel below the proposed 101 College Street Building.

A vehicular bridge will be constructed directly adjacent to the 101 College Street Building and convey traffic over Service Drive (approximate El. 112) between South Frontage Road and Temple Street. The superstructure will have a clear span of about 55.5 feet with a curb to curb length of about 68 feet and be supported on concrete abutments embedded about 4 feet below Service Drive. The abutment foundations will be about 75 feet wide by 18 feet long with service and strength loads of about 1,760 and 2,242 kips each, respectively.

A modular block wall will be constructed directly east of the proposed south abutment to facilitate grade charges that include raising South Frontage Road up to about El. 31.5. The proposed wall will be about 130 feet long and retain up to about 19.5 feet of soil and South Frontage Road.

Associated walking ramps, stairs, sidewalks, drainage structures, utilities, and landscape areas will also be constructed.

Page No. 2

3.0 SUBSURFACE DATA

3.1 GENERAL SITE GEOLOGY

Published surficial and bedrock geological map data (1:125,000 scale, Surficial Materials Map of Connecticut, Janet Radway Stone, 1992 and Bedrock Geological Map of Connecticut, John Rodgers, 1985) was reviewed. The site surficial materials are mapped as Fill over Stratified Drift Deposits (sand, silt, and gravel). The underlying bedrock is mapped as Arkose (i.e., Brownstone).

3.2 TEST BORINGS

We observed and logged five test borings (DTE-1 to DTE-5) drilled by our subcontractor Associated Borings Company, Inc. on July 9 and 10, 2020. Boring locations are depicted on Figure 2 (Appendix 1) and the logs are included in Appendix 2. Borings were located in the field by taping/pacing from existing site features and should be considered approximate. Elevations at the boring locations were approximated from the Existing Conditions Plan-1, Downtown Crossing Phase 3 - Temple Street, New Haven, Connecticut, prepared by the City of New Haven, undated and should also be considered approximate.

The borings were drilled to explore the soil and groundwater conditions in the project area. Due to site access restrictions and utility conflicts, some borings could not be drilled within the footprints of the proposed southern abutment or retaining wall at the time of drilling. Rotary auger drilling methods were used to advance borings to depths of approximately 14 to 42 feet (approximate El. -0.5 to -28.5) below existing grades. Borings were terminated in natural soil.

Representative soil samples were obtained for soil classification in the borings by split barrel sampling procedures in general accordance with ASTM D-1586. The split-spoon sampling procedure utilizes a standard 2-inch O.D. split-barrel sampler that is driven into the bottom of the boring with a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the sampler the middle 12-inches of a normal 24-inch penetration is recorded as the Standard Penetration Resistance Value (N). The blows (i.e., “N-Value”) are indicated on the boring logs at their depth of occurrence and provide an indication of the relative consistency of the material.

Groundwater levels were measured using a weighted tape in open drill holes.

4.0 SUBSURFACE CONDITIONS

4.1 SUBSURFACE PROFILE

The subsurface conditions from the borings generally consisted of uncontrolled Fill over natural Sand Deposits. The following is a more detailed description of the primary subsurface materials encountered at the site.

Page No. 3

4.1.1 Fill

Fill was encountered directly below an approximate 4 to 12-inch thick layer of Asphalt (and 9 inches of concrete at Boring B-2) at each of the boring locations. This stratum was about 4 to 10 feet thick and extended down to approximate El. 9.5 to 5. This material typically consisted of medium dense, brown/reddish brown/black, fine to coarse sand with varying amounts of gravel and silt. Trace (0 to 10%) amounts of asphalt, brick, and cinders were also observed in the Fill.

The thickness, character, and consistency of the Fill will vary between boring locations.

4.1.2 Sand Deposits

Natural Sand Deposits were encountered directly below the Fill. This material generally consisted of loose to medium dense, reddish brown, fine to coarse sand with trace amounts of silt.

4.2 GROUNDWATER

Groundwater was measured at about 8 to 9.5 feet (approximate El. 5.5 to 4.5) below existing grades in the borings. Groundwater levels measured in the boreholes may not have had sufficient time to stabilize and should be considered approximate. Groundwater levels will vary depending on factors such as temperature, season, precipitation, construction activity, and other conditions, which may be different from those at the time of these measurements.

5.0 GEOTECHNICAL RECOMMENDATIONS

We offer the following geotechnical design recommendations based on the subsurface conditions encountered at the site, available project information, and the proposed construction.

5.1 FOUNDATIONS

The proposed bridge abutments and retaining wall may be supported on shallow footings bearing on natural Sand Deposits or on Structural Fill (hereinafter specified as Compacted Granular Fill (CGF)) over natural Sand Deposits. Asphalt, existing Fill, and existing structures (e.g., utilities) are not considered suitable bearing materials, and must be excavated and removed in the area of the proposed footings during site preparation. Actual bottom of unsuitable bearing material elevations will vary across the site and should be verified during construction excavation by a DTE representative. Prior to construction, we recommended that supplemental test borings be performed under the direction of DTE in the proposed southern abutment footprint and along the proposed wall alignment to verify that subsurface conditions in this area are consistent with the other boring locations.

Abutment and modular block retaining wall foundations should be constructed at a minimum depth of 48 and 24-inches below proposed site grades, respectively. Footings should have a minimum width of 3 feet. The foundations for the proposed Bridge and 101 College Street Building should be coordinated such that they do not overload or cause excessive settlement of one another.

Page No. 4

When CGF is used beneath the footings, we recommend that it be placed one foot beyond the edge of the footings and at a one horizontal to one vertical slope away and down from the bottom outside edge of the footings. Crushed Stone can be used in place of CGF as it is much easier to compact.

We recommend maximum factored service and strength bearing resistances of 2 and 5.5 kips per square foot, respectively, for footings bearing on the recommended bearing materials. If needed, higher bearing resistances can be achieved if the subgrades are improved with rammed aggregate piers or other soil improvement techniques. Based on the recommended bearing materials and anticipated loads and foundation geometries, we estimate that the footings will undergo less than one inch of total settlement and less than a half inch of differential settlement. Settlements will occur as the loads are applied and are expected to be complete at the end of construction.

DTE should be provided with the final foundation loads and geometries once they are available to verify the above bearing capacity and settlement estimates.

5.2 BACKFILL AND DRAINAGE

We recommend backfilling the proposed abutments and retaining wall with Pervious Structural Fill in accordance with CTDOT Standard Specifications Form 818, Section 2.16, and installing footing drains. The limits of backfill should extend upwards from the wall heel at a slope of 1.5H:1V (Horizontal to Vertical) to the intersection of unexcavated, undisturbed materials. The drains should consist of 6-inch diameter perforated PVC pipe, surrounded by 6-inches of Crushed Stone, wrapped in non-woven filter fabric. The drains should be gravity drained and fitted with rodent screens.

5.3 LATERAL EARTH PRESSURES

Computation of lateral forces should be based on AASHTO Section 3.11, Earth Pressure, using the following recommended parameters and the appropriate load factors in AASHTO Section 3.4, Load Factors and Combinations. Assuming that the abutments and wall are backfilled with Pervious Structure Backfill in accordance with CTDOT standards, we recommend the following design parameters:

Total unit weight of backfill above the water table = 125 pcf Effective unit weight of backfill below the water table = 66 pcf Angle of internal friction (Ф’) of backfill = 34° Coefficient of friction for soil against concrete walls (tan delta) = 0.40 Earth pressure calculations should assume a surface traffic surcharge of a minimum of 24 inches of soil depth or 250 psf.

Walls that are free to rotate at the top and are not braced (e.g., modular block wall) should be designed to resist an active earth pressure (Ka). Braced retaining walls (e.g., abutments) should be designed to resist an at-rest earth pressure (Ko). Due to the limited expected wall movement and depth of footings, we do not recommend the use of passive earth pressures (Kp) against the base of walls.

Page No. 5

We recommend a maximum coefficient of friction of 0.45 and using a sliding resistance factor of

0.8 for cast-in-place foundations (0.9 for precast foundations) bearing on the natural Sand deposits or Compacted Granular Fill.

5.4 SEISMIC DESIGN

The site class is “D” (Stiff Profile) per AASHTO 2012 LRFD. Based on the standard penetration test results, visual soil classification, and design peak ground acceleration at this locale, the saturated site soils are not susceptible to liquefaction.

6.0 MATERIALS RECOMMENDATIONS

6.1 BACKFILL MATERALS

We recommend that backfill materials conform to the following CTDOT Standards:

Compacted Granular Fill - CTDOT Standard Form 818, Section M.02.01 Crushed Stone - Size No. 8 per CTDOT Standard Form 818, Section M.01.01 Pervious Structure Backfill - CTDOT Standard Form 818, Section M.02.05

6.2 COMPACTION REQUIRMENTS

Granular Fill and Pervious Structure Backfill should be placed and compacted to a minimum in-place dry density of 95-percent and 98-percent, respectively, of laboratory maximum dry density, as per AASHTO T180, Method D, and within 2% of their optimum moisture content. Granular Fill and Pervious Structure Backfill should be placed in loose layers not exceeding 8-inches and 6-inches, respectively, in thickness. Each layer should be placed horizontal and compacted before placing subsequent layers.

7.0 CONSTRUCTION RECOMMENDATIONS

7.1 FOUNDATION SUBGRADE PREPARATION

The base of footing excavations should be free of debris materials, water, ice, and loose and frozen soils prior placing CGF or concrete. Should the materials at bearing level become disturbed, the affected materials should be removed prior to placing CGF or concrete. We recommend the use of smooth edged excavator buckets or clips (not back-bladed) to make the final subgrade excavations and placing a six-inch-thick layer of compacted crushed stone between foundations and soil subgrades to prevent disturbance during construction.

7.2 TEMPORARY EXCAVATIONS

The Fill and natural site soils are classified as OSHA Class “C” soil and can be cut at a maximum one vertical to one and a half horizontal (1V:1.5H) slope up to a maximum excavation depth of 20 feet. These maximum slope and excavation depths assume no surcharge load (i.e., stockpiles, construction equipment, traffic, etc.) at the top of the excavations or groundwater seepage.

Page No. 6

Care should be taken to not undermine the adjacent roads (e.g., South Frontage Road), structures (e.g., proposed 101 College Street Building), and utilities. If excavations cannot be sloped in accordance with OSHA requirements or will potentially undermine adjacent structures, temporary excavation support systems (e.g., soldier piles and lagging, soil nailing, etc.) and/or underpinning will be required. These systems should be chosen and installed by the contactor and designed by a Professional Engineer registered in the State of Connecticut.

7.3 TEMPORARY GROUNDWATER CONTROL

We expect that temporary groundwater/storm water control can be accomplished by means of shallow trenches and sumps, and grading the excavation to low points. Groundwater/storm water should be discharged in a manner that avoids endangering public health and nearby property and meets applicable local, state, and environmental regulations.

8.0 REVIEW OF FINAL DESIGN, PLANS, AND SPECIFICATIONS

When project plans and specifications are available they should be provided to DTE for review of conformance with our geotechnical recommendations. If any changes are made to the proposed bridge and wall, the recommendations provided in this report will need to be verified by DTE for applicability.

9.0 CONSTRUCTION QUALITY CONTROL

We recommend that DTE make field observations of excavations and foundation preparation to monitor compliance with our recommendations and project specifications. Specifically, we recommend field observation of excavations, removal of unsuitable materials, and Fill placement and compaction to monitor compliance with project specifications. We can also assist in classifying material on-site for the purpose of segregation and/or mixing for re-use on-site.

10.0 LIMITATIONS

This report is subject to the limitations included in Appendix 3.

APPENDIX 1 -

FIGURES

SITE

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AREA PLAN TEMPLE STREET BRIDGE OVER SERVICE DRIVE NEW HAVEN, CONNECTICUT

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REVIEWED BY: DFL

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DATE: 7/17/20

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FIGURE NO. 1

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PROJECT NO. 0063-009.00

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122 CHURCH STREET

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REFERENCE: USGS TOPOGRAPHIC QUADRANGLE: NEW HAVEN, CT

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CONNECTICUT

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QUADRANGLE LOCATION

NAUGATUCK, CONNECTICUT 06770

DESIGNED BY

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TEMPLE STREET BRIDGE OVER SERVICE DRIVE NEW HAVEN, CONNECTICUT

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FILE NO.

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AS NOTED

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SITE AND BORING LOCATION PLAN

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122 CHURCH STREET

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NAUGATUCK, CONNECTICUT 06770

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TEST BORING NO. AND LOCATION

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DTE-1

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APPROXIMATE LIMITS OF PROPOSED 101 COLLEGE STREET BUILDING

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APPROXIMATE LOCATION OF PROPOSED RETAINING WALL

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APPROXIMATE LIMITS OF PROPOSED BRIDGE ABUTMENTS

AutoCAD SHX Text NOTES: 1) BASE MAP DEVELOPED FROM AN ELECTRONIC FILE PREPARED BY THE CITY OF NEW HAVEN ENTITLED "DOWNTOWN CROSSING PHASE 3 TEMPLE STREET", DATED: AUGUST 22, 2019, ORIGINAL SCALE 1:40. 2) BORINGS WERE COMPLETED BY ASSOCIATED TEST BORINGS, CO. AND OBSERVED BY DOWN TO EARTH CONSULTING, LLC ON JULY 9 AND 10, 2020 3) THE LOCATIONS OF THE EXPLORATIONS WERE DETERMINED BY TAPING AND VISUAL ESTIMATES FROM EXISTING SITE FEATURES. THESE LOCATIONS SHOULD BE CONSIDERED ACCURATE ONLY TO THE DEGREE IMPLIED BY THE METHOD USED.

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DTE-2

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DTE-3

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DTE-4

DTE-5

APPENDIX 2 -

TEST BORING LOGS

PROJECT BORING NO.

SHEET 1 of 2

FILE NO.

CHKD. BY

Boring Co. Boring Location See Boring Location Plan

Driller Ground Surface El. Datum

Logged By Date Start Date End

Hammer Type: Groundwater Readings (from ground surface)

Sampler Size: Date Time Depth (ft) Elev. Stabilization Time

Type Drill Rig: 7/9/20 - Drilling Method:

D

E

P Casing

T Blows REC/PEN DEPTH

H (ft) (inches) (feet)

2 10/21 1 to 3

4 5/9 3 to 3.8

6 10/24 5 to 7

11 6/24 10 to 12

16 8/24 15 to 17

21 24/24 20 to 22

26 7/24 25 to 27

31 16/24 30 to 32

36 4/24 35 to 37

1. S denotes split-barrel sampler. 7. WH denotes weight of hammer

2. ST denotes 3-inch O.D. undisturbed sample. 8. WR denotes weight of rods

3. UO denotes 3-inch Osterberg undisturbed sample. 9. PP denotes Pocket Penetrometer.

4. PEN denotes penetration length of sampler. 10. FVST denotes field vane shear test.

5. REC denotes recovered length of sample. 11. RQD denotes Rock Quality Designation.

6. SPT denotes Standard Penetration Test. 12. C denotes core run number.

DTE-1

TEMPLE STREET BRIDGE

OVER SERVICE DRIVE 0063-009.00

NEW HAVEN, CONNECTICUT DFL

Safety hammer driven by cathead with a 30 inch drop

1-3/8" I.D. Split Spoon

Truck Rig CME 55 8 5.5± End of Boring

Associated Borings Company, Inc.

Jamie Lloret 13.5± NGVD 29

Mateusz Fekieta 7/9/2020 7/9/2020

DESCRIPTION

Type BLOWS PER Core Time

& No. 6 INCHES (min./ft)

3.25-inch I.D. Hollow-Stem Augers

SAMPLE INFORMATION SAMPLE DESCRIPTION STRATA

FILL

S-1 9-12-11-24 Medium dense, reddish brown/black, fine to coarse SAND, some fine to coarse Gravel, trace Silt

S-3 6-10-13-14 Medium dense, reddish brown, fine to coarse SAND, trace Silt

S-2 40-50/3" Very dense, reddish brown/red, fine to coarse SAND, trace Silt, trace Brick

5-10-12-14 Medium dense, reddish brown, fine to coarse SAND, trace Silt

S-4 3-4-5-5 Loose, reddish brown, fine to coarse SAND, trace Silt

S-5 3-3-6-8

Medium dense, reddish brown, fine to coarse SAND, trace Silt S-7 5-7-9-14

Medium dense, reddish brown, fine to coarse SAND, trace Silt S-8 6-8-8-16

Medium dense, reddish brown, fine to medium SAND, trace Silt S-9 4-7-10-11

SYMBOL KEY

0 to 4 - Very Loose 0 to 2 - Very Soft Trace = 0 to 10%

SAND

Loose, reddish brown, fine to coarse SAND, trace Silt

S-6

5 to 10 - Loose 3 to 4 - Soft Little = 10 to 20% 11 to 30 - Medium Dense 5 to 8 - Medium Stiff Some = 20 to 35%

SPT N-Values SPT N-Values Proportions

FIELD NOTES: 1) Stratification lines represent approximate boundaries between soil types, transitions may be gradual.

2) Water level readings have been made at times and under conditions stated, fluctuations may occur due to other factors.

3) Running sands observed in auger prior to sampling S-9 and S-10. Running sands were washed out prior to obtaining samples.

31 to 50 - Dense 9 to 15 - Stiff And = 35 to 50% Over 50 - Very Dense 16 to 30 - Very Stiff

Over 30 - Hard

12" Asphalt

0063‐009.00 Boring Logs Page 1 of 7 Down to Earth Consulting, LLC

FILE NO.

CHKD. BY

Boring Co. Boring Location See Boring Location Plan

Driller Ground Surface El. Datum

Logged By Date Start Date End

Hammer Type: Groundwater Readings (from ground surface)

Sampler Size: Date Time Depth (ft) Elev. Stabilization Time

Type Drill Rig: 5/10/20 - Drilling Method:

D

E

P Casing

T Blows REC/PEN DEPTH

H (ft) (inches) (feet)

41 8/24 40 to 42

1. S denotes split-barrel sampler. 7. WH denotes weight of hammer

2. ST denotes 3-inch O.D. undisturbed sample. 8. WR denotes weight of rods

3. UO denotes 3-inch Osterberg undisturbed sample. 9. PP denotes Pocket Penetrometer.

4. PEN denotes penetration length of sampler. 10. FVST denotes field vane shear test.

5. REC denotes recovered length of sample. 11. RQD denotes Rock Quality Designation.

6. SPT denotes Standard Penetration Test. 12. C denotes core run number.

DTE-1

TEMPLE STREET BRIDGE

OVER SERVICE DRIVE 0063-009.00

NEW HAVEN, CONNECTICUT DFL

SAND

Safety hammer driven by cathead with a 30 inch drop

1-3/8" I.D. Split Spoon

Truck CM 55 8 5.5± End of Boring

Associated Borings Company, Inc.

Jamie Lloret 13.5± NGVD 29

Mateusz Fekieta 7/9/2020 7/9/2020

DESCRIPTION

Type BLOWS PER Core Time

& No. 6 INCHES (min./ft)

3.25-inch I.D. Hollow-Stem Augers

SAMPLE INFORMATION SAMPLE DESCRIPTION STRATA

S-10 7-10-11-8 Medium dense, reddish brown fine to coarse SAND, trace Silt

END OF EXPLORATION AT 42 FEET BELOW GROUND SURFACE

SYMBOL KEY

0 to 4 - Very Loose 0 to 2 - Very Soft Trace = 0 to 10% 5 to 10 - Loose 3 to 4 - Soft Little = 10 to 20%

11 to 30 - Medium Dense 5 to 8 - Medium Stiff Some = 20 to 35%

SPT N-Values SPT N-Values Proportions

FIELD NOTES: 1) Stratification lines represent approximate boundaries between soil types, transitions may be gradual.

2) Water level readings have been made at times and under conditions stated, fluctuations may occur due to other factors.

31 to 50 - Dense 9 to 15 - Stiff And = 35 to 50% Over 50 - Very Dense 16 to 30 - Very Stiff

Over 30 - Hard

0063‐009.00 Boring Logs Page 2 of 7 Down to Earth Consulting, LLC

SHEET 1 of 1

FILE NO.

CHKD. BY

Boring Co. Boring Location See Boring Location Plan

Driller Ground Surface El. Datum

Logged By Date Start Date End

Hammer Type: Groundwater Readings (from ground surface)

Sampler Size: Date Time Depth (ft) Elev. Stabilization Time

Type Drill Rig: 7/9/20 - Drilling Method:

D

E

P Casing

T Blows REC/PEN DEPTH

H (ft) (inches) (feet)

2 8/10 1.5 to 2.3

4 12/24 3 to 5

6 14/24 5 to 7

11 12/24 10 to 12

16 16/24 15 to 17

21 12/24 20 to 22

1. S denotes split-barrel sampler. 7. WH denotes weight of hammer

2. ST denotes 3-inch O.D. undisturbed sample. 8. WR denotes weight of rods

3. UO denotes 3-inch Osterberg undisturbed sample. 9. PP denotes Pocket Penetrometer.

4. PEN denotes penetration length of sampler. 10. FVST denotes field vane shear test.

5. REC denotes recovered length of sample. 11. RQD denotes Rock Quality Designation.

6. SPT denotes Standard Penetration Test. 12. C denotes core run number.

FIELD NOTES: 1) Stratification lines represent approximate boundaries between soil types, transitions may be gradual.

2) Water level readings have been made at times and under conditions stated, fluctuations may occur due to other factors.

Medium dense, reddish brown, fine to coarse SAND, trace Silt

31 to 50 - Dense 9 to 15 - Stiff And = 35 to 50% Over 50 - Very Dense 16 to 30 - Very Stiff

Over 30 - Hard

5 to 10 - Loose 3 to 4 - Soft Little = 10 to 20% 11 to 30 - Medium Dense 5 to 8 - Medium Stiff Some = 20 to 35%

SPT N-Values SPT N-Values Proportions SYMBOL KEY

0 to 4 - Very Loose 0 to 2 - Very Soft Trace = 0 to 10%

S-6 5-10-17-17

S-5 3-5-8-11

Loose, reddish brown, fine to coarse SAND, trace Silt S-4 3-3-4-7

26-50/4"

S-3 7-12-18-20 Medium dense, reddish brown, fine to coarse SAND, trace Silt

S-2 15-15-15-15

DTE-2

TEMPLE STREET BRIDGE

OVER SERVICE DRIVE 0063-009.00

NEW HAVEN, CONNECTICUT DFL

3.25-inch I.D. Hollow-Stem Augers

Safety hammer driven by cathead with a 30 inch drop

1-3/8" I.D. Split Spoon

Truck CME 55 9 4.5± End of Boring

FILL

S-1

END OF EXPLORATION AT 22 FEET BELOW GROUND SURFACE

Medium dense, reddish brown, fine to coarse SAND, trace Silt

Medium dense, brown/black/red, fine to coarse SAND, little fine to coarse Gravel, trace Silt, trace Brick

Very dense, brown, fine to coarse GRAVEL and fine to coarse SAND, trace Silt

SAND

Associated Borings Company, Inc.

Jamie Lloret 13.5± NGVD 29

Mateusz Fekieta 7/9/2020 7/9/2020

SAMPLE INFORMATION SAMPLE DESCRIPTION STRATA

DESCRIPTION

Type BLOWS PER Core Time

& No. 6 INCHES (min./ft)

4" Asphalt 9" Concrete

0063‐009.00 Boring Logs Page 3 of 7 Down to Earth Consulting, LLC

FILE NO.

CHKD. BY

Boring Co. Boring Location See Boring Location Plan

Driller Ground Surface El. Datum

Logged By Date Start Date End

Hammer Type: Groundwater Readings (from ground surface)

Sampler Size: Date Time Depth (ft) Elev. Stabilization Time

Type Drill Rig: 7/10/20 - Drilling Method:

D

E

P Casing

T Blows REC/PEN DEPTH

H (ft) (inches) (feet)

2 7/24 1 to 3

4 6/24 3 to 5

6 8/24 5 to 7

8 3/22 7 to 9

11 4/24 10 to 12

13 0/24 12 to 14

16 10/24 15 to 17

21 3/24 20 to 22

26 19/24 25 to 27

1. S denotes split-barrel sampler. 7. WH denotes weight of hammer

2. ST denotes 3-inch O.D. undisturbed sample. 8. WR denotes weight of rods

3. UO denotes 3-inch Osterberg undisturbed sample. 9. PP denotes Pocket Penetrometer.

4. PEN denotes penetration length of sampler. 10. FVST denotes field vane shear test.

5. REC denotes recovered length of sample. 11. RQD denotes Rock Quality Designation.

6. SPT denotes Standard Penetration Test. 12. C denotes core run number.

Associated Borings Company, Inc.

Jamie Lloret 15± NGVD 29

Mateusz Fekieta 7/10/2020 7/10/2020

DTE-3

TEMPLE STREET BRIDGE

OVER SERVICE DRIVE 0063-009.00

NEW HAVEN, CONNECTICUT DFL

3.25-inch I.D. Hollow-Stem Augers

SAMPLE INFORMATION SAMPLE DESCRIPTION STRATA

Safety hammer driven by cathead with a 30 inch drop

1-3/8" I.D. Split Spoon

Truck CME 55 9.5 5.5± End of Boring

DESCRIPTION

Type BLOWS PER Core Time

& No. 6 INCHES (min./ft)

FILL

S-2 19-18-6-4 Medium dense, reddish brown/black, fine to coarse SAND, trace Silt, trace Asphalt, trace Cinders

S-3 1-8-8-7 Medium dense, reddish brown/black, fine to coarse SAND, little fine Gravel, trace Silt, trace Asphalt, trace Cinders

S-1 5-8-18-16 Medium dense, Top 2": gray, fine to coarse SAND, some fine to coarse Gravel, trace Silt Bottom 5": reddish brown, fine to coarse SAND, trace Silt

S-4 9-7-22-50

SAND

S-5 7-2-2-5 Very loose, reddish brown, fine to coarse SAND, trace Silt

Medium dense, reddish brown/red, fine to coarse SAND, some Brick, little fine Gravel, trace Silt

S-6 8-7-10-7 Medium dense, No Recovery

S-7 6-10-14-15 Medium dense, reddish brown, fine to coarse SAND, trace Silt

S-8 2-2-4-6 Loose, reddish brown, fine to coarse SAND, trace Silt

S-9 6-10-15-17

SPT N-Values SPT N-Values Proportions

END OF EXPLORATION AT 27 FEET BELOW GROUND SURFACE

Medium dense, reddish brown, fine to medium SAND, trace Silt

Over 50 - Very Dense 16 to 30 - Very Stiff Over 30 - Hard

FIELD NOTES: 1) Stratification lines represent approximate boundaries between soil types, transitions may be gradual.

2) Water level readings have been made at times and under conditions stated, fluctuations may occur due to other factors.

11 to 30 - Medium Dense 5 to 8 - Medium Stiff Some = 20 to 35% 31 to 50 - Dense 9 to 15 - Stiff And = 35 to 50%

SYMBOL KEY

0 to 4 - Very Loose 0 to 2 - Very Soft Trace = 0 to 10% 5 to 10 - Loose 3 to 4 - Soft Little = 10 to 20%

0063‐009.00 Boring Logs Page 4 of 7 Down to Earth Consulting, LLC

FILE NO.

CHKD. BY

Boring Co. Boring Location See Boring Location Plan

Driller Ground Surface El. Datum

Logged By Date Start Date End

Hammer Type: Groundwater Readings (from ground surface)

Sampler Size: Date Time Depth (ft) Elev. Stabilization Time

Type Drill Rig: 7/9/20 - Drilling Method:

D

E

P Casing

T Blows REC/PEN DEPTH

H (ft) (inches) (feet)

2 8/25 1 to 3

4 6/24 3 to 5

6 12/24 5 to 7

8 14/24 7 to 9

11 19/24 10 to 12

16 16/24 15 to 17

21 14/24 20 to 22

26 0/24 25 to 27

31 15/24 30 to 32

36 12/24 35 to 37

1. S denotes split-barrel sampler. 7. WH denotes weight of hammer

2. ST denotes 3-inch O.D. undisturbed sample. 8. WR denotes weight of rods

3. UO denotes 3-inch Osterberg undisturbed sample. 9. PP denotes Pocket Penetrometer.

4. PEN denotes penetration length of sampler. 10. FVST denotes field vane shear test.

5. REC denotes recovered length of sample. 11. RQD denotes Rock Quality Designation.

6. SPT denotes Standard Penetration Test. 12. C denotes core run number.

DTE-4

TEMPLE STREET BRIDGE

OVER SERVICE DRIVE 0063-009.00

NEW HAVEN, CONNECTICUT DFL

Safety hammer driven by cathead with a 30 inch drop

1-3/8" I.D. Split Spoon

Truck CME 55 8 5.5± End of Boring

Associated Borings Company, Inc.

Jamie Lloret 13.5± NGVD 29

Mateusz Fekieta 7/9/2020 7/9/2020

DESCRIPTION

Type BLOWS PER Core Time

& No. 6 INCHES (min./ft)

3.25-inch I.D. Hollow-Stem Augers

SAMPLE INFORMATION SAMPLE DESCRIPTION STRATA

S-2 7-5-7-7 Medium dense, reddish brown/black, fine to coarse SAND, trace Silt, trace Brick

S-1 9-11-10-12 Medium dense, reddish brown/black, fine to coarse SAND, little fine Gravel, trace Silt, trace Asphalt

S-3 2-4-4-4 Loose, reddish brown, fine to coarse SAND, trace Silt

S-4 5-7-11-9

S-5 3-4-7-7 Medium dense, reddish brown, fine to coarse SAND, trace Silt

Medium dense, reddish brown, fine to coarse SAND, trace Silt

S-8 5-7-11-13

S-6 3-4-5-7 Loose, reddish brown, fine to coarse SAND, trace Silt

S-7 2-4-7-8 Medium dense, reddish brown, fine to coarse SAND, trace Silt

S-9 15-9-8-13

S-10 6-8-19-17

Proportions SYMBOL KEY

0 to 4 - Very Loose 0 to 2 - Very Soft Trace = 0 to 10%

FILL

SAND

FIELD NOTES: 1) Stratification lines represent approximate boundaries between soil types, transitions may be gradual.

2) Water level readings have been made at times and under conditions stated, fluctuations may occur due to other factors.

3) Running sands observed in auger prior to sampling S-10 and S-11. Running sands were washed out prior to obtaining samples.

Medium dense, No Recovery

Medium dense, reddish brown, fine to coarse SAND, trace Silt

Medium dense, reddish brown, fine to coarse SAND, trace Silt

31 to 50 - Dense 9 to 15 - Stiff And = 35 to 50% Over 50 - Very Dense 16 to 30 - Very Stiff

Over 30 - Hard

5 to 10 - Loose 3 to 4 - Soft Little = 10 to 20% 11 to 30 - Medium Dense 5 to 8 - Medium Stiff Some = 20 to 35%

SPT N-Values SPT N-Values

0063‐009.00 Boring Logs Page 5 of 7 Down to Earth Consulting, LLC

SHEET 2 of 2

FILE NO.

CHKD. BY

Boring Co. Boring Location See Boring Location Plan

Driller Ground Surface El. Datum

Logged By Date Start Date End

Hammer Type: Groundwater Readings (from ground surface)

Sampler Size: Date Time Depth (ft) Elev. Stabilization Time

Type Drill Rig: 7/9/20 - Drilling Method:

D

E

P Casing

T Blows REC/PEN DEPTH

H (ft) (inches) (feet)

41 12/24 40 to 42

1. S denotes split-barrel sampler. 7. WH denotes weight of hammer

2. ST denotes 3-inch O.D. undisturbed sample. 8. WR denotes weight of rods

3. UO denotes 3-inch Osterberg undisturbed sample. 9. PP denotes Pocket Penetrometer.

4. PEN denotes penetration length of sampler. 10. FVST denotes field vane shear test.

5. REC denotes recovered length of sample. 11. RQD denotes Rock Quality Designation.

6. SPT denotes Standard Penetration Test. 12. C denotes core run number.

Associated Borings Company, Inc.

Jamie Lloret 13.5± NGVD 29

Mateusz Fekieta 7/9/2020 7/9/2020

DTE-4

TEMPLE STREET BRIDGE

OVER SERVICE DRIVE 0063-009.00

NEW HAVEN, CONNECTICUT DFL

3.25-inch I.D. Hollow-Stem Augers

SAMPLE INFORMATION SAMPLE DESCRIPTION STRATA

Safety hammer driven by cathead with a 30 inch drop

1-3/8" I.D. Split Spoon

Truck CME 55 8 5.5± End of Boring

S-11 10-11-19-25

DESCRIPTION

Type BLOWS PER Core Time

& No. 6 INCHES (min./ft)

SAND

0 to 2 - Very Soft Trace = 0 to 10%

FIELD NOTES: 1) Stratification lines represent approximate boundaries between soil types, transitions may be gradual.

2) Water level readings have been made at times and under conditions stated, fluctuations may occur due to other factors.

Medium dense, reddish brown, fine to coarse SAND, trace Silt

END OF EXPLORATION AT 42 FEET BELOW GROUND SURFACE

31 to 50 - Dense 9 to 15 - Stiff And = 35 to 50% Over 50 - Very Dense 16 to 30 - Very Stiff

Over 30 - Hard

5 to 10 - Loose 3 to 4 - Soft Little = 10 to 20% 11 to 30 - Medium Dense 5 to 8 - Medium Stiff Some = 20 to 35%

SPT N-Values SPT N-Values Proportions SYMBOL KEY

0 to 4 - Very Loose

0063‐009.00 Boring Logs Page 6 of 7 Down to Earth Consulting, LLC

FILE NO.

CHKD. BY

Boring Co. Boring Location See Boring Location Plan

Driller Ground Surface El. Datum

Logged By Date Start Date End

Hammer Type: Groundwater Readings (from ground surface)

Sampler Size: Date Time Depth (ft) Elev. Stabilization Time

Type Drill Rig: 7/9/20 - Drilling Method:

D

E

P Casing

T Blows REC/PEN DEPTH

H (ft) (inches) (feet)

2 5/24 1 to 3

4 11/24 3 to 5

6 0/24 5 to 7

11 1/24 10 to 12

13 20/24 12 to 14

1. S denotes split-barrel sampler. 7. WH denotes weight of hammer

2. ST denotes 3-inch O.D. undisturbed sample. 8. WR denotes weight of rods

3. UO denotes 3-inch Osterberg undisturbed sample. 9. PP denotes Pocket Penetrometer.

4. PEN denotes penetration length of sampler. 10. FVST denotes field vane shear test.

5. REC denotes recovered length of sample. 11. RQD denotes Rock Quality Designation.

6. SPT denotes Standard Penetration Test. 12. C denotes core run number.

SAND

Associated Borings Company, Inc.

Jamie Lloret 13.5± NGVD 29

Mateusz Fekieta 7/9/2020 7/9/2020

DTE-5

TEMPLE STREET BRIDGE

OVER SERVICE DRIVE 0063-009.00

NEW HAVEN, CONNECTICUT DFL

3.25-inch I.D. Hollow-Stem Augers

SAMPLE INFORMATION SAMPLE DESCRIPTION STRATA

Safety hammer driven by cathead with a 30 inch drop

1-3/8" I.D. Split Spoon

Truck CME 55 8 5.5± End of boring

FILL

S-1 9-19-16-15 Dense, reddish brown/black, fine to coarse SAND, little fine to coarse Gravel, trace

Silt

DESCRIPTION

Type BLOWS PER Core Time

& No. 6 INCHES (min./ft)

S-2 7-9-8-8 Medium dense, Top 3": brown/black, fine to coarse SAND, trace Silt Bottom 8": reddish brown, fine to coarse SAND, trace Silt

S-3 5-6-6-6 Medium dense, No Recovery

S-4 2-2-4-4 Loose, reddish brown, fine to coarse SAND, trace Silt

S-5 4-5-8-8

0 to 2 - Very Soft Trace = 0 to 10%

FIELD NOTES: 1) Stratification lines represent approximate boundaries between soil types, transitions may be gradual.

2) Water level readings have been made at times and under conditions stated, fluctuations may occur due to other factors.

Medium dense, reddish brown, fine to coarse SAND, trace Silt

END OF EXPLORATION AT 14 FEET BELOW GROUND SURFACE

31 to 50 - Dense 9 to 15 - Stiff And = 35 to 50% Over 50 - Very Dense 16 to 30 - Very Stiff

Over 30 - Hard

5 to 10 - Loose 3 to 4 - Soft Little = 10 to 20% 11 to 30 - Medium Dense 5 to 8 - Medium Stiff Some = 20 to 35%

SPT N-Values SPT N-Values Proportions SYMBOL KEY

0 to 4 - Very Loose

7" Asphalt

0063‐009.00 Boring Logs Page 7 of 7 Down to Earth Consulting, LLC

APPENDIX 3 -

LIMITATIONS

LIMITATIONS

Explorations

1. The analyses and recommendations submitted in this report are based in part upon the data obtained from subsurface explorations by others. The nature and extent of variations between these explorations may not become evident until construction. If variations then appear evident, it will be necessary to reevaluate the recommendations of this report.

2. The generalized soil profile described in the text is intended to convey trends in subsurface conditions.

The boundaries between strata are approximate and idealized and have been developed by interpretations of widely spaced explorations and samples; actual soil transitions are probably more erratic. For specific information, refer to the boring logs.

3. Water level readings have been made in the drill holes at times and under conditions stated on the boring logs. These data have been reviewed and interpretations have been made in the text of this report. However, it must be noted that fluctuations in the level of the groundwater may occur due to variations in rainfall, temperature, and other factors occurring since the time measurements were made.

Review

4. In the event that any changes in the nature, design or locations of the proposed structures are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report modified or verified in writing by DTE.

It is recommended that this firm be provided the opportunity for a general review of final design and specifications in order that earthwork and foundation recommendations may be properly interpreted and implemented in the design and specifications.

Construction

5. It is recommended that this firm be retained to provide soil engineering services during construction of the earthworks and foundation phases of the work. This is to observe compliance with the design concepts, specifications, and recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction.

Use of Report

6. This report has been prepared for the exclusive use of the City of New Haven, Connecticut for specific application to the project noted in this geotechnical report in accordance with generally accepted soil and foundation engineering practices. No other warranty, express or implied, is made.

7. This soil and foundation engineering report has been prepared for this project by DTE. This report is for design purposes only and is not sufficient to prepare an accurate bid. Contractors wishing a copy of the report may secure it with the understanding that its scope is limited to design considerations only.

8. This report may contain comparative cost estimates for the purpose of evaluating alternative foundation schemes. These estimates may also involve approximate quantity evaluations. It should be noted that quantity estimates may not be accurate enough for construction bids. Since DTE has no control over labor and materials cost and design, the estimates of construction costs have been made on the basis of experience. DTE does not guarantee the accuracy of cost estimates as compared to contractor's bids for construction costs.