Att 9 - Bronx Boiler Replacement Investigation Report.pdf

PILLORI ASSOCIATES, P.A.

Geotechnical Engineering

GEOTECHNICAL INVESTIGATION REPORT

Bronx Boiler Replacement Project

30,000 Gallon Fuel Oil Tank Bronx, NY

(revised)

Prepared For:

Miller-Remick, LLC 1010 Kings Highway South – Bldg. #2

Cherry Hill, NJ 08034

Prepared By:

Pillori Associates, P.A.

71 Route 35 Laurence Harbor, New Jersey 08879

January 2025

Project # 220409

PILLORI ASSOCIATES, P.A.

71 Route 35, Laurence Harbor, NJ 08879 • Tel: (732) 335-0059 • Fax: (732) 335-8515 www.pilloriassociates.com • e-mail: office@pilloriassociates.com

January 14, 2025 Via email: DJewell@miller-remick.com

Miller-Remick, LLC 1010 Kings Highway South – Bldg. #2 Cherry Hill, NJ 08034

Attn: Dan Jewell, PE, Project Manager

Re: Geotechnical Investigation Report 30,000 Gallon Fuel Oil Tank

Bronx Boiler Replacement Project, Bronx, NY

Gentlemen:

Presented herein is the geotechnical engineering report for the referenced project. We are confident that the subsurface information and engineering recommendations contained herein will meet the needs of the project. Thank you for the opportunity to be of service.

Please call if you have any questions or if we can be of further assistance.

Sincerely, Pillori Associates, PA greg

GP NYS PE

TABLE OF CONTENTS

INTRODUCTION

PROJECT DESCRIPTION

GEOTECHNICAL INVESTIGATION

STRATIGRAPHY

SEISMIC EVALUATION AND CRITERIA

GEOTECHNICAL ENGINEERING EVALUATION

ENGINEERING RECOMMENDATIONS

CONVENTIONAL SPREAD/STRIP FOOTINGS & RETAINING WALLS

EXCAVATION AND DEWATERING

BACKFILL

ROCK REMOVAL AND STABILIZATION

CLOSURE

LIST OF ATTACHMENTS

Boring Location Plan Drawing No. 1 Boring Logs B-1 and B-2 Soil Classification Chart

71 Route 35, Laurence Harbor, NJ 08879 • Tel: (732) 335-0059 • Fax: (732) 335-8515 www.pilloriassociates.com • e-mail: office@pilloriassociates.com

Introduction

This report presents the results of our supplemental geotechnical engineering investigation conducted for the 30,000 Fuel Oil Tank (location D-2) Bronx Boiler Replacement project. This work was performed in general accordance with the consultant service agreement included under Purchase Order # Pillori 0499-0154 #00, dated November 5, 2024. The purpose of this investigation was to identify the subsurface soil/rock conditions at an alternative location in order to determine the relative soil parameters for the design and construction of new foundations for the fuel tank project.

Project Description

The project site is located on the southwest quadrant of the Bronx Veterans Hospital campus, in the Bronx, New York, as shown in Figure 1. Specifically, the additional borings associated with this supplemental geotechnical engineering report were located across from Building 16 in a wooded area above a retaining wall.

Geotechnical Investigation

The geotechnical investigation consisted of drilling 2 borings. PG Environmental Services, Inc drilled borings, B-1 and B-2, on November 26, 2024, using a portable drill rig. Both borings were advanced through a surface layer of controlled fill, terminating upon refusal on decomposed bedrock at completion depths of 8'-11" and 13'-9" below the existing grade. In the borings, Standard Penetration Tests (SPTs) were performed within the overburden soil at continuous 2-foot intervals in accordance with procedures specified in ASTM D1586.

Full-time special inspection was provided by Pillori Associates to locate the explorations in the field, direct drilling and sampling activities, and maintain continuous logs of the explorations. Soil/rock types observed in the borings were visually classified according to the Unified Soil Classification System (USCS) and the New York City Building Code (NYCBC). The boring locations are shown on the Boring Location Plan, Drawing No. 1, attached to this report.

At the conclusion of the investigation program, the soil samples were delivered to our soil laboratory for re-examination and further classification. The individual sample classifications were combined according to soil group and geologic origin, and their descriptions were recorded on finalized logs. The final logs of the borings are attached to this report along with the Unified Soils Classification System chart.

Figure 1 Site Vicinity Map

SITE

Pillori Associates 2 220409

Stratigraphy

In general, the subsurface conditions consisted of a surface layer of miscellaneous fill, overlying very dense glacial till and/or decomposed Gneiss bedrock. Detailed descriptions of the subsurface stratigraphy encountered in the borings are presented on boring logs attached to this report. Generalized descriptions are presented below in order of increasing depth.

Fill (F): A miscellaneous fill layer was encountered at the ground surface at both boring locations. The heterogeneous mixture of sand, silt and gravel was loose to compact in terms of relative density and was classified as nominally unsatisfactory bearing material, Class 7 material, in accordance with the NYCBC.

Glacial Till (GT): Glacial till was encountered below the fill layer in boring B-2. The layer was 2 feet thick, compact to very compact in terms of relative density, and was classified as SP, 3a material, in accordance with the USCS and the NYCBC, respectively.

Decomposed Rock (DR): The top of decomposed bedrock was encountered at the termination depth in both borings. This was the same decomposed rock layer encountered in the borings during the previous investigation on March 15, 2023. The decomposed rock was previously classified as “Soft Rock” Class 1d material, in accordance with the

NYCBC.

Groundwater: Groundwater was found trapped above the decomposed bedrock in each of the borings. We believe groundwater levels and will generally vary from 1 to 2 feet above the decomposed rock layer during heavy rains and seasonal wet periods.

Seismic Evaluation and Criteria

The proposed structure must be designed in accordance with all applicable New York City Building Code seismic design criteria. The site classes are based on the average soil/rock properties in the upper 100 feet. The soil and rock encountered in the borings most closely resembles “Hard Rock,” Site Class A. The profile is based on Section

1613.3.2 and Table 1613.3.4.1 of the 2022 NYCBC. Peak accelerations may be estimated using Table 1816.2.1 of the 2022 NYCBC and values for site coefficients Fa and Fv may be estimated using Tables 1613.3.3(1) and 1613.3.3(2), respectively. The soil underlying the site was classified as “Liquefaction Evaluation Not Required” in accordance with Section 1816 of the NYCBC.

Geotechnical Engineering Evaluation

A substantial fill layer was encountered at the ground surface in both borings. Given the proximity of the borings to existing retaining walls, we suspect the fill was placed as backfill subsequent to the wall construction. Blow counts from the SPT sampling indicated that the fill was placed and compacted in a controlled manner, and as such the fill material was considered suitable for support for the new tank and containment walls.

Pillori Associates 3 220409

Footing elevations for the proposed construction were not know at the time of this writing, so allowable bearing pressures and other geotechnical design parameters are provided below for each of the soil materials encountered in the borings. A minimum footing depth of 40 inches below finished outside grade is recommended for all new foundations for frost protection.

Excavations for footing subgrades are expected to encounter a variety of materials, including controlled compacted fill, dense glacial till, and/or decomposed bedrock, depending on selected design subgrade elevations. Based on the SPT blow counts, the surface fill possesses an allowable bearing pressure of 4 tons per square foot, the glacial till possesses an allowable bearing pressure of 6 tsf, and the underlying decomposed rock possesses an allowable bearing pressure of 8 tsf. For consistency and ease of construction, we recommend that all foundations be dimensioned for an allowable bearing pressure of 4 tsf, given the nature of the proposed construction.

Because the glacial till and underlying decomposed rock are relatively impermeable, water will tend to collect within foundation excavations that extend below the fill layer.

Foundation subgrades that become wet can be dewatered locally by pumping from trenches or sump pits located throughout the excavations.

Ground slabs can be designed as a slabs-on-grade, provided the subgrade soils are re-compacted after final excavation. A crushed stone layer and suitable vapor barrier should be installed beneath the slabs to act as a capillary break and prevent groundwater from permeating through the slabs.

Engineering Recommendations

Conventional Spread/Strip Footings & Retaining Walls

As mentioned above, new footings can be designed for a variety of soil/rock conditions that may be encountered across the construction footprints. The geotechnical engineer performing the controlled inspections of the footing subgrades should make the final footing selection in the field. The following parameters may be utilized in the design of footings and containment walls.

Table 1 – Earth Pressure Design Criteria

Allowable Bearing Pressure – (Class 7) 4 tsf

Allowable Bearing Pressure – (Classes 3a,) 6 tsf Allowable Bearing Pressure – (Class 1d) 8 tsf

Equivalent Fluid Pressure - Below Top of Rock (γKO) 80 pcf Equivalent Fluid Pressure - Above Top of Rock (γKO) 50 pcf

Prior to the placement of reinforcing steel, the footing subgrades should be thoroughly cleaned of loose soil and rock fragments, mud, debris and all other deleterious material.

Pillori Associates 4 220409

An engineer licensed in the State of New York should inspect the prepared subgrade.

Foundation settlements will be negligible for footings designed for the recommended bearing pressures.

Excavation and Dewatering

Temporary, shallow excavations with vertical sides less than 4 feet high will generally be stable, although there is a potential for sloughing. Temporary excavation sides greater than 4 feet in depth may be sloped back at an inclination of 1.5:1 (horizontal to vertical).

Some sloughing or erosion of surface soils should be anticipated. All applicable safety requirements and regulations, including OSHA requirements should be met.

Dewatering, if required, during construction can be handled by periodic pumping from low spots or seepage pits installed below subgrade elevation.

Backfill

All compact fill and backfill placed beneath the floor slabs, sidewalks, and used for backfilling foundation walls and utility trenches should be performed in a controlled manner using the onsite natural soil free of organic matter debris or imported Select Fill meeting the grainsize requirements in Table 2 below. The fill material should be placed in 8-inch loose lifts and compacted to 95% of the maximum dry density as determined in ASTM D1557. Compaction can be performed using walk-behind-vibratory plate, vibratory roller, or “jumping jack” type compactors. Lift thickness may be increased to 12 inches for larger compaction equipment. Imported fill material, if required, should be approved prior to its use.

Table 2 – Select Fill

Sieve Size Percent Passing 4 in 100

3/4 in 100 - 80 No. 4 80 – 60 No. 40 60 – 30 No. 200 <15

Rock Removal and Stabilization

Conventional excavation equipment will be able to penetrate the decomposed rock and about 1 or 2 feet into the underlying sound bedrock; however, deeper excavations will require chipping, and/or drilling and splitting. Line drilling will be required to reduce vibrations and control breakouts along the property lines and/or limits of excavation. Line drilling should not be performed above the footing elevations adjacent to the neighboring foundation walls – only below the footing elevations and along open lot lines.

Pillori Associates 5 220409

Closure

This report presents the results of the geotechnical investigation performed for the Bronx Boiler Replacement project, New York. This report is not a bid document, and any contractor reviewing this report must draw his own conclusions regarding specific construction techniques to be used on this project.

A

35'-11

40.1 2'-4"

4'-0"

6'-5"

B3

B6

B4

13'-10

17'-2"

39.8

39.6 39.5

39.3

2'-4"

5'-8"

17'-0"

6'-0"

71 Route 35, Laurence Harbor, NJ 08879 Geotechnical Engineering

PILLORI ASSOCIATES, P.A.

AutoCAD SHX Text B-1

AutoCAD SHX Text B-2

AutoCAD SHX Text B-1

AutoCAD SHX Text

BORING LOCATION

AutoCAD SHX Text

SCALE: 1" = 20'

AutoCAD SHX Text

LEGEND

AutoCAD SHX Text Job No.:

AutoCAD SHX Text Date:

AutoCAD SHX Text Dwg No.

AutoCAD SHX Text Title:

AutoCAD SHX Text Project:

AutoCAD SHX Text

BORING LOCATION PLAN

AutoCAD SHX Text

BRONX VA NEW GAS TANK

AutoCAD SHX Text

BRONX, NEW YORK

AutoCAD SHX Text 1/6/2025

AutoCAD SHX Text 220409

AutoCAD SHX Text

S-1

S-2

S-3

S-4

S-5

1-2-10-50/6"

FILL

(7)

8'-11" 139.08'

F

PILLORI ASSOCIATES, P.A. Geotechnical Engineering

SOIL DESCRIPTIONSAMPLES

Blows / 6"

Depth Feet Number

Classification Depth

Elevation

Project No.:

Project:

Date:

Contractor:

Strata

Boring No.:

Sheet:

Ground El:

Groundwater Depth:

220409

Bronx VA New Gas Tanks Bronx, New York

11/26/2024 PG Environmental

B-1 +148 +/-

NA

Dark Brown coarse to fine Sand, some Silt with medium Gravel in tip

Tan coarse to fine Sand, trace Silt, some medium to fine Gravel

Tan coarse to fine Sand and medium to fine Gravel, trace Silt

Medium to fine Gravel, some Tan coarse to fine Sand, trace Silt

Refusal on possible Decomposed Rock at a depth of 8'-11" from grade

End of Boring

32-28-25-23

29-23-35-18

22-26-28-21

65/5"

S-1

S-2

S-3

S-4

S-5

2-2-15-24

FILL

(7)

13'-9" 138.25

F

PILLORI ASSOCIATES, P.A. Geotechnical Engineering

SOIL DESCRIPTIONSAMPLES

Blows / 6"

Depth Feet Number

Classification Depth

Elevation

Project No.:

Project:

Date:

Contractor:

Strata

Boring No.:

Sheet:

Ground El:

Groundwater Depth:

220409

Bronx VA New Gas Tanks Bronx, New York

11/26/2024 PG Environmental

B-2 +152 +/-

NA

Brown coarse to fine Sand, little Silt, little medium to fine Gravel

Brown medium to fine Sand, little Silt, little medium to fine Gravel

Brown coarse to fine Sand and medium to fine Gravel, little Silt

32-28-25-23

33-15-14-16

12-8-12-11

12-17-15-11

S-6 18-15-12-12

S-7 7-11-25-50/3"

Brown medium to fine Sand, little Silt, little medium to fine Gravel

Brown coarse to fine Sand, some Silt with Schist fragments

Refusal on possible Decomposed Rock at a depth of 13'-9" from grade

End of Boring

GT

SP

(3a)

12'-0" 140.0

Soil Classification Chart