Appendix D - Geotechnical Engineering Report - Buffalo Outer Harbor1.pdf

Rochester: 2110 South Clinton Avenue, Suite 1, Rochester, NY 14618 P: 585-223-3660 F: 585-697-1764 Buffalo, NY Albany, NY Binghamton, NY Allentown, PA www.ravieng.com info@ravieng.com

August 7, 2020

Trowbridge Wolf Michaels Landscape Architects LLP 1001 West Seneca Street Suite 201 Ithaca, New York 14850

Attention: Margot D. Chiuten, RLA ASLA

Subject: Geotechnical Engineering Investigation

Buffalo Outer Harbor Phase 2 Fuhrmann Boulevard City of Buffalo, Erie County, New York

Ms. Chiuten:

Ravi Engineering & Land Surveying, P.C. is pleased to submit the revised Geotechnical Engineering Report for the above referenced project. If you require additional information please contact the undersigned at (585) 703-9932. Thank you.

Respectfully submitted, RAVI ENGINEERING & LAND SURVEYING, P.C.

James D. MacKecknie, P.G.

Project Manager

Attachment: Geotechnical Engineering Investigation Report

REPORT

GEOTECHNICAL ENGINEERING INVESTIGATION

BUFFALO OUTER HARBOR PHASE 2

FUHRMANN BOULEVARD

CITY OF BUFFALO, ERIE COUNTY, NEW YORK

For

Trowbridge Wolf Michaels Landscape Architects

August 2020

August 7, 2020

Trowbridge Wolf Michaels Landscape Architects 1001 West Seneca Street, Suite 201 Ithaca, New York 14850

Attention: Margot Chiuten

Subject: Geotechnical Engineering Investigation

Buffalo Outer Harbor Phase 2 Fuhrmann Boulevard City of Buffalo, Erie County, New York

Readers:

This report presents the results of a geotechnical engineering investigation for the project identified above. Information regarding the proposed construction was provided to us by Trowbridge Wolf Michaels Landscape Architects, and by WSP.

UNDERSTANDING OF PROPOSED CONSTRUCTION

The proposed construction includes three one-story buildings, one or more decks, a landscaped amphitheater, several light poles, two pylons, and areas of pavement.

Additional comments regarding the proposed construction are presented in subsequent sections of this report.

SUBSURFACE EXPLORATIONS

Subsurface explorations for this investigation consisted of 18 test borings, identified as B-1-20 through B-18-20. The quantity and locations of the borings were determined by others. Because of field conditions, it was necessary to shift some of the borings from their originally requested locations. The as-drilled locations of the borings are shown on the plans in Appendix A. The approximate ground surface elevations, at the boring locations, are presented in attached Table 1.

Also presented in Table 1 are the proposed features at or near each boring location, as provided to us by others.

TWMLA, 8/7/20

The borings were performed by Earth Dimensions, Inc., using rotary drilling equipment, between 7/1/20 and 7/14/20.

Of the 18 borings, 14 were each advanced to a depth of 27 feet below the ground surface.

Four of the borings (B-3-20, B-4-20, B-10-20, and B-15-20) were advanced to the top of apparent bedrock. Two of these borings (B-4-20 and B-15-20) were each cored an additional 10 feet into bedrock.

The logs of the borings, as prepared by Earth Dimensions, Inc., are presented in Appendix B.

Detailed descriptions of the subsurface conditions encountered, as well as a concise summary, are presented on the log of each boring.

Selected subsurface information is also presented in attached Table 1.

COMMENTS ON SUBSURFACE CONDITIONS

All of the borings encountered random fill materials. The depth of the random fill, at the boring locations, ranged from approximately 4 feet to approximately 22 feet below the ground surface.

The approximate depths and elevations of the bottom of random fill are presented in attached Table 1.

The natural soils, underlying the random fill, are variable. Some of these soils are relatively weak and compressible. Organic matter is present at some locations and depths.

As previously noted, four of the borings were advanced to the top of apparent bedrock. Two of these borings were also advanced into bedrock. The bedrock, within the depths explored, is described as limestone. The depth to the top of bedrock, where encountered, ranged from approximately 52 feet to approximately 66 feet below the ground surface. In general, the depth to bedrock appeared to decrease from south to north. The approximate depths and elevations of the top of bedrock, where encountered, are presented in attached Table 1.

Observations of down-hole groundwater and sample moisture were made during the test boring program. It should be noted that short-term observations may not be representative of actual groundwater levels, and that groundwater levels will vary with factors including location, time, precipitation, season, and site activities. In general, it is likely that groundwater will be encountered near or above the level of nearby Lake Erie.

It should be noted that objects too large to be retrieved by the sampling equipment (including cobbles, boulders, and concrete fragments) are likely to be present. Such objects are especially likely to be present in the random fill.

More detailed descriptions of the subsurface conditions, as encountered by the borings, are provided on the logs in Appendix B. Selected subsurface information is also presented in attached Table 1.

DESIGN AND CONSTRUCTION

General

All design and construction should meet or exceed the requirements of all applicable codes.

With regard to the International Building Code, a seismic Site Class of “E” should be applied to this project. This corresponds to a “Soft soil profile.”

Foundations for Three Proposed One-Story Buildings

It is understood that the floors of the buildings in the south and south-central parts of the site will be at or near existing grade. It is also understood that the floor of the building in the north part of the site will be approximately 2 feet higher than existing grade.

It is recommended that each of the three proposed one-story buildings be supported by a reinforced concrete mat foundation. The top of each mat foundation would serve as the building’s floor. All of the following requirements should be satisfied:

No topsoil, existing utilities, or other unsuitable materials should be left in place. It is anticipated that much of the existing fill, however, including trace amounts of organic matter, may be left in place.

Compacted granular fill should be placed below each foundation. The thickness of the compacted granular fill should be at least 12 inches. Greater thicknesses of compacted granular fill are likely to be necessary.

Subgrades should be prepared, and granular fill should be placed and compacted, as described elsewhere in this report.

Drained, unsaturated conditions should be maintained within the compacted granular fill.

Design of each foundation should be based on a maximum net allowable bearing pressure of 500 pounds per square foot, and a subgrade modulus (K) not exceeding 25 pounds per cubic inch.

Each mat foundation should be haunched/thickened along its perimeter, and perhaps elsewhere as necessary, to provide additional stiffness.

Exterior haunches or frost walls should consist of reinforced concrete, and should extend at least 4 feet below final adjacent exterior grade.

The final grading should be such that surface water is conducted away from each structure.

For a mat foundation properly designed and installed in accordance with this report, the post-construction settlement is not expected to exceed 1 inch. The post-construction shear strain (angular distortion) resulting from differential settlement is not expected to exceed 0.2 percent.

Deck Foundations

Based on the conditions encountered by boring B-3-20, the proposed decks are not well suited to conventional spread footings, mat foundations, or drilled shafts. A preferable foundation system would be steel piles driven to bedrock. It might be possible to reduce the number of piles, by stiffening the beams atop the piles.

The piles could be H piles, open-end pipe piles, or closed-end pipe piles filled with concrete.

H piles and open-end pipe piles may be designed for a maximum allowable axial stress of 35 percent of the yield strength, or 17,500 pounds per square inch, whichever is less.

Closed-end pipe piles, if driven to refusal and filled with good-quality concrete (at least 4,000 psi), may be designed for an allowable load of 1,200 pounds per square inch of total pile cross-sectional area.

Piles should be driven, using a suitable hammer, to practical refusal on or in bedrock.

The ultimate capacity of each pile should be at least twice the allowable load. Pile capacities should be verified by the use of a pile-driving analyzer (PDA), by load testing, or by a combination of the two. Applicable code requirements should be followed.

The minimum center-to-center spacing of piles should be 30 inches or 2.5 pile widths, whichever is greater.

Lateral loads, buckling, the need for cross-bracing, and the need for batter piles should all be considered.

Piles should be installed by a contractor experienced in this specialized work. Obstructions and other installation difficulties should be anticipated. All piles should be installed in such a way that they are not overstressed or otherwise damaged during installation.

Landscaped Amphitheater

It is understood that the landscaped amphitheater will be constructed in the south part of the site, in the area of borings B-1-20, B-2-20, and B-3-20. It is also understood that grade increases as great as approximately 6 feet will be required.

It is recommended that the grade increases be achieved using compacted common and/or granular fill. Subgrades should be prepared, and fill should be placed and compacted, as described elsewhere in this report.

Final slopes should be no steeper than 1 vertical on 3 horizontal.

The proposed grade increases are likely to cause compression of the underlying soft soils, resulting in settlement. It is estimated that a settlement of roughly 1 inch per each foot of grade increase is possible. Grade increases, therefore, should be achieved as early as possible in the construction sequence.

Foundations for Light Poles and Pylons

It is understood that the vertical loads from light poles and pylons will be modest, and that the primary concern is overturning.

The design and construction of the light pole and pylon foundations will be strongly controlled by the existing random fill materials.

It is recommended that the light pole and pylon foundations consist of drilled shafts, and that the existing random fill materials generally be left in place.

Each drilled shaft should be designed for a tip bearing pressure not exceeding 1,000 pounds per square foot.

Each drilled shaft should be at least 2.5 feet in diameter.

The resistance to lateral load and overturning moment should be computed using the method proposed by Broms (1964), or a similar method. Analysis should be based on a soil unit weight of 60 pounds per cubic foot, and a passive lateral earth pressure coefficient of 2.50. A safety factor of at least 3.00 should be applied.

It is anticipated that the drilled shafts will be installed using conventional rotary drilling methods and temporary casings. Drilling difficulties should be expected. Dewatering is likely to be necessary. All concrete should be placed in the dry, or by a suitable tremie method.

Pavement

A practical pavement design is based on factors including subgrade quality, frost action, traffic loads, traffic frequency, design life, and the relative importance of initial costs versus future maintenance.

At this site, the subgrade quality for flexible pavement should be represented using a California Bearing Ratio (CBR) not exceeding 5.

For auto parking areas, the recommended minimum flexible pavement section consists of a 1-inch asphaltic top course, a 2-inch asphaltic binder course, and a 12-inch subbase course of compacted granular fill.

For areas subjected to more frequent and/or heavier vehicles, the minimum combined thickness of asphaltic top and binder courses should be increased to 5 inches. The minimum thickness of the granular subbase should be increased to 16 inches.

The subgrade quality for rigid pavement should be represented using a subgrade modulus (K) not exceeding 75 pounds per cubic inch. The rigid section should consist of reinforced concrete, and should be at least 6 inches thick. At least 12 inches of compacted granular fill should be placed below the slab.

For all pavement sections, compacted common fill may be placed as required below the granular fill.

No existing topsoil or other unsuitable materials should be left in place. Complete removal of the existing fill materials, however, should not be necessary. Subgrades should be prepared, and fill should be placed and compacted, as described elsewhere in this report.

Drained, unsaturated conditions should be maintained within all pavement sections. Surface water should be conducted away from paved areas and structures.

The project designers may wish to consider pavement sections that are more or less conservative than those presented. This could depend on the traffic and cost factors described above, as well as the performance of existing and previous pavement sections at the site.

Excavation and Construction Dewatering

Excavation should be performed in accordance with all applicable local, state, and federal requirements. The sides of all excavations should be sloped or supported as required by safety regulations. Existing structures, utilities, and other property should be protected.

With regard to the current OSHA regulations, Type C soil should be assumed. This would apply to adequately dewatered soil.

To minimize subgrade disturbance, excavation should be performed with increasing care as subgrade levels are approached.

All work should be performed in the dry. In addition, the dewatering should be sufficient to permit suitable preparation of the subgrade and compaction of any subsequent fill materials.

The contractor should be prepared to dewater as necessary, and should choose and employ an appropriate type of dewatering system. Any dewatering system should be operated in such a way that disturbance or removal of the subgrade soil does not occur.

Subgrade Preparation

It is cautioned that the soils at this site contain fine-grained material, and that they will be sensitive to disturbance. Subgrades should be kept free of water, subjected to a minimum amount of construction traffic, exposed no longer than necessary, and not permitted to freeze.

Subgrades should be carefully prepared and thoroughly examined by qualified personnel.

Subgrades should also be tamped using vibratory equipment, to the greatest extent possible without loosening or softening the subgrade soils.

Where space permits, subgrades should be thoroughly proofrolled with both a large vibratory roller and a fully-loaded ten-wheel dump truck. The primary objective of this additional effort is to identify and/or compact any voids or loose zones in the existing random fill materials.

No new fill or foundation concrete should be placed over material that is loose, soft, wet, frozen, or otherwise unsuitable with respect to the design recommendations. No more than trace amounts of organic matter should be left in place.

Fill and Backfill

Granular fill should consist of a durable sand and gravel or crusher-run stone, free of any organic matter. The plasticity index should be less than 5. Granular fill should have 100 percent finer than 3 inches, 20 to 60 percent finer than the Number 4 sieve, and no more than 10 percent finer than the Number 200 sieve.

Granular fill could also be specified as meeting the NYSDOT requirements for Subbase Course Type 1, 2, or 4.

Common fill should consist of durable soil material, free of any organic matter. The plasticity index should be less than 15. Common fill should have 100 percent finer than 6 inches, at least 90 percent finer than 3 inches, and at least 20 percent finer than the Number 4 sieve.

It should be noted that granular fill meets all of the requirements of common fill, and that granular fill can generally be placed and compacted with less difficulty.

All load-bearing fill should be compacted, in lifts of 9 inches or less, to at least 95 percent of the maximum dry density determined by ASTM D 1557.

The in-place density and water content of compacted fill should be determined by ASTM D 6938. At least one test should be performed per 2,500 square feet, per lift.

CLOSING COMMENTS AND RECOMMENDATIONS

Professional services for this investigation were performed in accordance with generally accepted geotechnical engineering practices, exclusively for the subject project. No warranty, expressed or implied, is made.

Subsurface conditions are inferred from the logs of subsurface explorations. Conditions between, beyond, and below these explorations are likely to vary. It should also be noted that subsurface conditions are often described on the basis of visual examinations of recovered samples, that these visual descriptions may not always agree well with descriptions made on the basis of laboratory tests, and that the distinction between fill and naturally-deposited soil can not always be readily determined on the basis of recovered samples. If subsurface conditions are subsequently revealed that appear to be significantly different or less favorable than those described, we should be given the opportunity to revise the statements in this report.

Designers and contractors are advised that this report was prepared primarily for design purposes, and that it may not contain sufficient information for bidding. Contractors should visit the site, review this report and the related exploration logs, and evaluate potential construction difficulties on the basis of their own knowledge and experience.

It is recommended that qualified personnel be retained to review the geotechnical portions of the contract drawings and specifications, and to provide monitoring services during construction.

It has been a pleasure assisting you with this investigation. If you have questions or comments regarding this report, please contact the undersigned.

Yours truly, RAVI ENGINEERING & LAND SURVEYING, P.C.

Nagappa Ravindra, P.E. Ray M. Teeter, P.E.

President Geotechnical Engineer

Attachments: Table 1 – Selected Subsurface Information

Appendix A – Test Boring Location Plans

Appendix B – Test Boring Logs

Table 1 Selected Subsurface Information

Buffalo Outer Harbor Phase 2 Fuhrmann Boulevard

City of Buffalo, Erie County, New York

Approx.

Ground Approximate Approximate Boring Surface Bottom of Fill Top of Bedrock Number Elevation Depth Elevation Depth Elevation Proposed Feature

B-1-20 580 6 574 not encountered light pole

B-2-20 585 14 571 not encountered pylon

B-3-20 580 4 576 66 514 deck

B-4-20 585 15 570 64 521 south building

B-5-20 586 14 572 not encountered south building

B-6-20 585 11 574 not encountered light pole

B-7-20 585 20 565 not encountered light pole

B-8-20 586 22 564 not encountered light pole

B-9-20 585 22 563 not encountered light pole

B-10-20 584 21 563 52 532 south-central building

B-11-20 583 22 561 not encountered south-central building

B-12-20 581 12 569 not encountered north building

B-13-20 581 12 569 not encountered north building

B-14-20 581 12 569 not encountered north building

B-15-20 581 13 568 53 528 north building

B-16-20 581 12 569 not encountered north building

B-17-20 581 13 568 not encountered north building

B-18-20 582 7 575 not encountered pylon

Note: All elevations and depths are in feet, and are approximate. Elevations and depths at other locations will vary. See accompanying report and boring logs for additional information.

Appendix A

Test Boring Location Plans

& LAND SURVEYING, P.C.

2110 South Clinton Avenue, Suite 1 Rochester, New York 14618

TL: (585) 223-3660 FX: (585) 223-4250

COPYRIGHT © 2020, RAVI ENGINEERING & LAND SURVEYING.

ALL RIGHTS RESERVED.

RAVI ENGINEERING

Test Boring Location Plan Borings B-1-20 through B-11-20 Buffalo Outer Harbor - Phase 2

Fuhrmann Boulevard City of Buffalo, Erie County, New York

AutoCAD SHX Text B-10-20

AutoCAD SHX Text B-11-20

AutoCAD SHX Text B-9-20

AutoCAD SHX Text B-8-20

AutoCAD SHX Text B-7-20

AutoCAD SHX Text B-6-20

AutoCAD SHX Text B-3-20

AutoCAD SHX Text B-2-20

AutoCAD SHX Text B-5-20

AutoCAD SHX Text B-4-20

AutoCAD SHX Text B-1-20

AutoCAD SHX Text Drawn By : JFF

AutoCAD SHX Text Date : 7/29/20

AutoCAD SHX Text Scale : 1"=150'

AutoCAD SHX Text

DWG # 20-16-204

AutoCAD SHX Text 0'

AutoCAD SHX Text 150'

AutoCAD SHX Text 300'

AutoCAD SHX Text 450'

Test Boring Location Plan Borings B-12-20 through B-18-20 Buffalo Outer Harbor - Phase 2

Fuhrmann Boulevard City of Buffalo, Erie County, New York

& LAND SURVEYING, P.C.

2110 South Clinton Avenue, Suite 1 Rochester, New York 14618

TL: (585) 223-3660 FX: (585) 697-1764

COPYRIGHT © 2020, RAVI ENGINEERING & LAND SURVEYING.

ALL RIGHTS RESERVED.

RAVI ENGINEERING

AutoCAD SHX Text B-18-20

AutoCAD SHX Text B-17-20

AutoCAD SHX Text B-16-20

AutoCAD SHX Text B-15-20

AutoCAD SHX Text B-14-20

AutoCAD SHX Text B-13-20

AutoCAD SHX Text B-12-20

AutoCAD SHX Text Drawn By : JFF

AutoCAD SHX Text Date : 7/29/20

AutoCAD SHX Text Scale : 1"=150'

AutoCAD SHX Text

DWG # 20-16-204

AutoCAD SHX Text 0'

AutoCAD SHX Text 150'

AutoCAD SHX Text 300'

AutoCAD SHX Text 450'

Appendix B

Test Boring Logs