Report_Canarsie_Pier_Inspection.pdf

GATEWAY NATIONAL RECREATION AREA

JAMAICA BAY UNIT, BROOKLYN, NEW YORK

CANARSIE PIER

GATE 154876

LEVEL III INSPECTION

November 2012

NATIONAL PARK SERVICE

CANARSIE PIER (GATE 154876)

GATEWAY NATIONAL RECREATION AREA

JAMAICA BAY UNIT, BROOKLYN, NEW YORK

LEVEL III INSPECTION

November 2012

Submitted By:

Moffatt & Nichol

104 West 40th Street, 14th Floor

New York, New York 10018 ii

EXECUTIVE SUMMARY

During June 2012, Moffatt & Nichol performed an above and below water Level III Inspection of

Canarsie Pier located in Brooklyn, New York. The purpose of this inspection was to assess the general overall condition of the Pier, estimate the load carrying capacity of the structure, recommend necessary repairs, and provide a “Class C” concept level cost estimate for the recommended repairs. The inspection was performed at the request of the U.S. Army Corps of

Engineers on behalf of the National Park Service and was completed in accordance with the Unified

Facilities Criteria guideline 4-150-07 Maintenance and Operation: Maintenance of Waterfront

Facilities.

Overall, Canarsie Pier is in fair condition and exhibits deterioration which is consistent with what is typically observed in marine structures of similar age. The Pier is structurally sound and observed deficiencies occur at localized areas.

Repairs are recommended to be completed in order to ensure that operations at the Pier can continue without interruption and to extend the useful service life of the structure. M&N has categorized repair recommendations for the structures as Immediate, Priority, and Routine Actions in order to prioritize the repairs required to extend the service life of the facility. Immediate actions are recommended for completion as soon as possible in order to prevent an existing deficiency from becoming a more severe safety hazard. Priority recommendations are repairs which should take precedence over all other scheduled work. Routine recommendations are repairs which can be undertaken as part of a routine scheduled maintenance program.

Table 1 provides a summary of repair recommendations for the Canarsie Pier.

iii

Table 1. Summary of Recommended Repairs for Canarsie Pier

Element Repair Category

Immediate Priority Routine

Concrete Piles None Repair 64 piles with severe or major deterioration.

None

Concrete Bent Caps None Repair 12 locations with large spalls and wide cracks.

None

Concrete Fascia Beam and Back Beam None

Repair 29 locations with large spalls and wide cracks.

None

Apron Deck None None None

Pier Topside Repair 4.5’x12’ sinkhole in Pier Topside.

None

Repair spalls and cracks at 5 locations in the concrete curb.

Replace 11 panels on the railing pedestals.

Pier Bulkhead None None None

Estimated Repair Cost $38,852 $971,214 $19,175

One condition requiring immediate action was identified during this inspection. There is a large sinkhole which has developed in the deck at the northwestern end of the West Wing Apron. The sinkhole area is approximately 4.5 ft by 12 ft in plan and is approximately 2 ft deep. In two locations above the sinkhole, the pavers have collapsed into the hole. The sinkhole has developed due to loss of backfill through the concrete end wall. The sinkhole is currently cordoned off from pedestrians, but is recommended for repair on an immediate basis so that it does not continue to increase in size. Recommended repairs would generally consist of removing the fill in the area of the sinkhole, repairing the concrete end wall where fill is currently escaping, backfilling the excavated area, and replacing the pavers.

There were several deficiencies that were identified during this inspection that are recommended for repair on a priority basis. These deficiencies include: concrete piles with significant loss of cross-section, and large spalls and wide cracks in the concrete bent cap and fascia beam. Recommended repairs for the piles would consist of installing a concrete encasement around the deteriorated iv portion of the pile. Repairs to the spalls and cracks on the bent caps and fascia beams would consist of localized concrete patch repairs.

Deficiencies that were identified during this inspection that are recommended for repair on a routine basis include: spalls and cracks in the concrete curb and missing or broken pedestal panels on the deck topside.

In addition to repair recommendations, a Class C cost estimate for repairs is provided. All costs associated with the estimate are in 2012 dollars and include a 20% contingency.

v

CANARSIE PIER

GATEWAY NATIONAL RECREATION AREA

LEVEL III INSPECTION

TABLE OF CONTENTS

Page

TITLE PAGE I

EXECUTIVE SUMMARY II

TABLE OF CONTENTS V

LIST OF FIGURES VII

LIST OF PHOTOGRAPHS VIII

LIST OF TABLES X

1. INTRODUCTION 1-1

1.1 BACKGROUND 1-1

1.2 OBJECTIVES 1-2

1.3 INSPECTION EXIT BRIEFING 1-2

2. DESCRIPTION OF FACILITY 2-1

2.1 LOCATION 2-1

2.2 STRUCTURE 2-1

2.2.1 PILES 2-1

2.2.2 BENT CAPS , FASCIA BEAM, AND BACK BEAM 2-2

2.2.3 APRON DECK AND PIER TOPSIDE 2-2

2.2.4 BULKHEAD 2-3

3. CANARSIE PIER LEVEL III INSPECTION 3-1

3.1 INSPECTION SCOPE AND TERMINOLOGY 3-1

3.2 OBSERVED CONDITIONS 3-1

3.2.1 PILES 3-1

3.2.2 CONCRETE BENT CAPS 3-6

3.2.3 CONCRETE FASCIA BEAM AND BACK BEAM 3-8

3.2.4 APRON DECK 3-11

3.2.5 PIER TOPSIDE 3-16

TABLE OF CONTENTS (CONT’D)

Page vi

3.2.6 PIER BULKHEAD 3-21

3.3 STRUCTURAL CONDITION ASSESSMENT 3-23

3.3.1 BASIS FOR STRUCTURAL ASSESSMENT 3-23

3.3.2 EVALUATION OF THE APRON STRUCTURE 3-24

3.4 RECOMMENDATIONS 3-28

3.4.1 IMMEDIATE ACTIONS 3-28

3.4.2 PRIORITY ACTIONS 3-28

3.4.3 ROUTINE ACTIONS 3-29

APPENDIX A – KEY PERSONNEL A-1

APPENDIX B – INSPECTION PROCEDURE B-1

APPENDIX C – DEFICIENCY PLANS C-1

APPENDIX D – STRUCTURAL DATA D-1

CONCRETE CORE LABORATORY RESULTS (TOURNEY CONSULTING GROUP)

GROUND PENETRATING RADAR REPORT (CITYSCAN CORP.)

APPENDIX E – PERTINENT BACKGROUND INFORMATION E-1

ACOE CANARSIE PIER SITE VISIT ASSESSMENT REPORT

CANARSIE PIER REHABILITATION AS-BUILTS (HAN-PADRON ASSOCIATES)

PROPOSED REPAIR LETTER (LEONARD ENGINEERING, P.C.)

APPENDIX F – CALCULATIONS FOR STRUCTURAL ASSESSMENT F-1

APPENDIX G – COST ESTIMATES G-1

APPENDIX H – REFERENCES H-1

vii

LIST OF FIGURES

Figure Title Page

Figure 2-1. Typical Apron Deck Cross-Section 2-3

Figure 2-2. Location Plan 2-5

Figure 2-3. Site Plan 2-6

Figure 2-4. Typical Cross-Section 2-7

Figure 3-1. 14 in. Pile Axial Load Capacity with Cross-Section Loss vs. Live Loads 3-26

Figure 3-2. Overall Repair Recommendation Plan – Sheet 1 of 7 3-32

Figure 3-3. Repair Recommendation Plan – West Wing Apron – Bents 1 to 24

– Sheet 2 of 7 3-33

Figure 3-4. Repair Recommendation Plan – West Apron – Bents 25 to 62 – Sheet 3 of 7 3-34

Figure 3-5. Repair Recommendation Plan – West & South Apron – Bents 63 to 102 – Sheet 4 of 7 3-35

Figure 3-6. Repair Recommendation Plan – South & East Apron – Bents 103 to 142 – Sheet 5 of 7 3-36

Figure 3-7. Repair Recommendation Plan – East Apron – Bents 143 to 180 – Sheet 6 of 7 3-37

Figure 3-8. Repair Recommendation Plan – East Wing Apron – Bents 181 to 204 – Sheet 7 of 7 3-38

Figure 3-9. Repair Recommendation Details 3-39

Figure C-1. Pile Deficiency Plan – Sheet 1 of 6 C-2

Figure C-2. Pile Deficiency Plan – Sheet 2 of 6 C-3

Figure C-3. Pile Deficiency Plan – Sheet 3 of 6 C-4

Figure C-4. Pile Deficiency Plan – Sheet 4 of 6 C-5

Figure C-5. Pile Deficiency Plan – Sheet 5 of 6 C-6

Figure C-6. Pile Deficiency Plan – Sheet 6 of 6 C-7

Figure C-7. Deck Underside Deficiency Plan – Sheet 1 of 6 C-8

Figure C-8. Deck Underside Deficiency Plan – Sheet 2 of 6 C-9

Figure C-9. Deck Underside Deficiency Plan – Sheet 3 of 6 C-10

Figure C-10. Deck Underside Deficiency Plan – Sheet 4 of 6 C-11

Figure C-11. Deck Underside Deficiency Plan – Sheet 5 of 6 C-12

Figure C-12. Deck Underside Deficiency Plan – Sheet 6 of 6 C-13

Figure C-13. Deck Topside Deficiency Plan – Sheet 1 of 1 C-14

LIST OF PHOTOGRAPHS

Photo Title Page viii

Photo 2-1. Aerial View of Canarsie Pier (photo courtesy of Microsoft Bing) 2-8

Photo 2-2. View Looking South from the East Apron of the Pier 2-8

Photo 2-3. Typical reinforced concrete pile encasement with stay-in-place timber form (1970 repair) 2-9

Photo 2-4. Typical reinforced concrete encasement with stay-in-place fiberglass reinforced polyester forms (1990 repair) 2-9

Photo 2-5. Reinforced concrete partial encasement with stay-in-place fiberglass reinforced polyester forms 2-10

Photo 2-6. Typical portion of a bent cap, supporting the pier apron 2-10

Photo 2-7. Concrete fascia beams, cast-in-place around the perimeter of the pier 2-11

Photo 2-8. Pier surface treatment, consisting of asphalt pavers on an asphalt setting bed as seen at the sinkhole (northwest corner of pier). 2-11

Photo 2-9. Bollard from the original pier construction 2-12

Photo 2-10. Asphalt parking area (supported by the earth-filled core of the pier) as seen from the vehicle entrance 2-12

Photo 2-11. Batter piles beneath the pier apron provide lateral support for the bulkhead 2-13

Photo 3-1. Concrete Pile – Severe Loss of Concrete at the Pile Top 3-4

Photo 3-2. Concrete Pile – Major Loss of Concrete at the Pile Top 3-4

Photo 3-3. Pile exhibiting Moderate section loss 3-5

Photo 3-4. Pile exhibiting Minor deterioration after removal of timber stay-in-place forms 3-5

Photo 3-5. Concrete Bent Cap – Large Spall in Bottom Corner of Cap 3-7

Photo 3-6. Concrete Bent Cap – Major Spall in Bottom Corner of Cap 3-7

Photo 3-7. Severe crack and spall in concrete fascia beam with exposed rebar 3-9

Photo 3-8. Major spall in bottom corner of concrete fascia beam 3-9

Photo 3-9. Deterioration of the concrete fascia beam due to corrosion of anchors for the removed timber fender system 3-10

Photo 3-10. Concrete deck core sample NW-3 3-14

Photo 3-11. Severe delamination of concrete and severe loss of bottom reinforcing on the underside of the pier apron 3-14

LIST OF PHOTOGRAPHS

Photo Title Page ix

Photo 3-12. Concrete deck core sample NE-1. Deteriorated wearing course crumbled during coring activity and could not be recovered 3-15

Photo 3-13. Typical GPR test results, showing reinforcement in the top slab 3-15

Photo 3-14. Deck Topside – Large Sinkhole at the Northwest Corner of the West Wing Apron with Two Openings in the Pavers, Looking West 3-18

Photo 3-15. Sinkhole at the west end of the west apron 3-18

Photo 3-16. Gap in end wall joint at the west end of the west apron, where fill loss is occuring at the location of the sinkhole 3-19

Photo 3-17. Major topside deficiency, consisting of a large spall 3-19

Photo 3-18. Deck Topside – Large Spall in the Curb and Missing Pedestal Panel 3-20

Photo 3-19. Minor subsidence is typical on the pier, likely the result of soil consolidation 3-20

Photo 3-20. Severe loss of concrete section and exposed rebar in the original concrete sheet pile bulkhead 3-22

Photo 3-21. Steel sheet pile bulkhead is visible through a gap in the original concrete sheet pile bulkhead 3-22 x

LIST OF TABLES

Table Title Page

Table 1. Summary of Recommended Repairs for Canarsie Pier iii

Table 3-1. Summary of Pile Conditions 3-2

Table 3-2. Summary of Bent Cap Conditions 3-6

Table 3-3. Summary of Fascia Beam Conditions 3-8

Table 3-4. Summary of Pier Topside Conditions 3-16

Table 3-5. Summary of Recommended Actions for Canarsie Pier 3-29

Table 3-6. Recommended Actions Cost Summary 3-31

1-1

1. INTRODUCTION

This report summarizes the findings of the Level III Inspection performed by Moffatt & Nichol (M&N) during June of 2012 for the Canarsie Pier facility located in Brooklyn, New York. The inspection was performed at the request of the U.S. Army Corps of Engineers (ACOE) on behalf of the National Park

Service (NPS) and was completed in accordance with the Unified Facilities Criteria (UFC) guideline 4-

150-07 Maintenance and Operation: Maintenance of Waterfront Facilities.

This Level III Inspection Report presents the observed and noted conditions of the facility, an assessment of the structural condition of the pier, repair recommendations and an associated Class

C cost estimate for the recommended repairs. In addition to the Introduction, this report includes three additional chapters and associated appendices. Chapter 2 describes the overall facility, its current use and a description of the location and structure type. Chapter 3 presents the conditions observed during the inspection, a structural assessment of the pier, recommendations for repairs and associated cost estimates. Appendices A through H contain information on the key personnel involved in the project, inspection procedure, deficiency plans, structural data, background information, structural analysis calculations, the Class C cost estimate, and references.

1.1 BACKGROUND

Canarsie Pier was constructed in 1926 by the City of New York as an industrial waterborne freight facility. The pier is connected to mainland Brooklyn and extends approximately 600 feet into the northwest portion of Jamaica Bay. The City’s plan to turn Jamaica Bay into a seaport never materialized and Canarsie Pier was converted into a fishing and recreational pier as it operates today. The NPS assumed control of the pier in 1973 and it is now part of the Gateway National

Recreation Area. In the past, the pier hosted a restaurant and timber dock which was used for ferry service. Currently, the restaurant has been abandoned and remains fenced off on the pier and the ferry floating docks have been removed.

The pier has undergone two major rehabilitations since its original construction. In approximately

1970, the pier was rehabilitated by the New York City Department of Parks. The rehabilitation included the encasement of the majority of piles with 20 in. square concrete encasements with stay in place timber forms, repairs to the bent caps and the installation of a new reinforced concrete apron deck slab on top of the original deck slab.

1-2

In 1990, Canarsie Pier was rehabilitated by the NPS. This project included the removal of the timber fender system, encasement of piles, repairs to bent cap and the fascia beam, and the installation of a steel sheet pile bulkhead to replace the existing concrete bulkhead.

Additionally, the ACOE performed a visual below-deck/above-water and topside inspection in 2009 identifying the need for a Level III Condition Assessment.

Information regarding the previous rehabilitation efforts and inspections has been included in

Appendix E.

1.2 OBJECTIVES

The primary purpose of this project is to determine overall condition of the pier and provide repair recommendations. The detailed objectives were to provide a highly detailed Level III inspection of the elements which comprise the structure, estimate the load carrying capacity of the pier’s concrete apron in its existing condition, recommend repairs to the pier structure, and provide a

Class C cost estimate for recommended repairs.

1.3 INSPECTION EXIT BRIEFING

On July 16, 2012, M&N provided an exit briefing presentation for the ACOE and NPS at the ACOE offices. The objective of the exit briefing was to discuss the inspection, present and discuss the initial findings from the field work, and discuss the approach for developing this inspection report.

2-1

2. DESCRIPTION OF FACILITY

Canarsie Pier is rectangular pier that is approximately 600 ft long by 400 ft wide and projects South into Jamaica Bay. The pier structure consists of an earth-filled core surrounded by a 27 ft wide, pile-supported, concrete high-level platform apron. A steel sheet pile bulkhead has been installed around the perimeter of the core to retain the earth fill.

A Location Plan, Site Plan, and Typical Cross-Section are presented in Figures 2-2, 2-3, and 2-4, respectively. Photos 2-1 and 2-2 provide general overall views of the facility.

2.1 LOCATION

Canarsie Pier is a part of the Gateway National Recreation Area, Jamaica Bay Unit, located in the neighborhood of Canarsie in Brooklyn, New York. The pier is located at the end of Rockaway

Parkway just off Exit 13 of the Belt Parkway.

The mean tide range at Canarsie Pier is approximately 5.2 ft and Mean Higher High Water falls just below the bent caps, which are approximately 0.82 ft below NAVD 88. Average currents do not exceed 1.0 knot and are typically less than 0.5 knot at the southern end of the pier which was confirmed during the inspection. Water depths along the pier perimeter range from 0 ft to 25 ft

(relative to Mean Lower Low Water) and are shown on Figure 2-3.

2.2 STRUCTURE

2.2.1 Piles

The high-level platform apron is supported by precast, reinforced concrete piles that frame into concrete bent caps. There are 1,002 14 in. square concrete piles which are part of the original pier construction. The piles are arranged in bents consisting of 3 plumb piles spaced 8 ft apart and 2 batter piles at the bulkhead. The pile bents are spaced approximately 10 ft from center-to-center.

Two generations of pile repairs have been installed at the pier:

1) The first generation of pile repairs which were completed in the 1970s consist of 20 in.

square, cast-in-place, reinforced concrete pile encasements with stay-in-place timber forms.

The encasements typically extend from just below the bent cap to just above the mudline

(Photo 2-3).

2-2

2) The second generation of pile repairs, completed in 1990, typically consist of:

a. full length (bent cap to 1 ft below mudline), 24 in. diameter cast-in-place, reinforced concrete encasements with stay-in-place fiberglass reinforced polyester (FRP) forms

(Photo 2-4); and

b. 36 in. diameter cast-in-place, reinforced concrete partial encasements with stay-in-place

FRP forms, which are only a few feet in length, that were installed at either the mudline or just below the bent caps (Photo 2-5).

Please see the drawings in Appendix E for additional details related to these encasements.

2.2.2 Bent Caps , Fascia Beam, and Back Beam

The cast-in-place, reinforced concrete bent caps are 33 in. high by 24 in. wide and are approximately

22 ft long. There are approximately 204 bent caps which span above each pile bent (Photo 2-6).

Continuous reinforced concrete fascia beams were cast monolithically with the original deck around the offshore perimeter of the pier (Photo 2-7). The fascia beams are approximately 57 in. high by 18

in. wide and span between the concrete bent caps. Similarly, there is a continuous reinforced concrete back beam which extends along the inshore perimeter of the pier apron. The batter piles frame into the back beam and this system provides a means of lateral restraint for the pier apron and bulkhead.

2.2.3 Apron Deck and Pier Topside

The apron deck consists of a cast-in-place reinforced concrete slab which has three discrete layers.

There is an original deck slab that was constructed with the pier (bottom deck), a grout wearing course which was installed on top of the original slab, and a structural overlay (top slab) which was installed as part of a rehabilitation effort in the 1970s. A typical apron deck cross-section is shown in Figure 2-1.

The original deck slab is a reinforced concrete slab which is approximately 12 in. thick. On top of the original slab, there is a grout wearing course which is approximately 2 in. thick. During the rehabilitation in the 1970s, a cast-in-place, reinforced concrete slab was installed as an overlay on top of the original deck. This “top slab” is approximately 9 in. thick and reinforced with two layers

(top and bottom) of #6 longitudinal (spanning from cap to cap) rebar spaced at approximately 9 in.

and #4 transverse (perpendicular to longitudinal reinforcement) rebar spaced at 12 in. The concrete cover for the top reinforcing is approximately 3 in., and 1 in. for the bottom reinforcing. It appears

2-3 that the top slab was installed during the 1970s rehabilitation to replace the deteriorated original deck slab, and that the original deck slab was left in place as a sacrificial element.

The surface treatment of the platform consists of 4 in. thick asphalt pavers (Photo 2-8). There is an asphalt setting bed between the pavers and top slab, which is approximately 1 in. thick for the majority of the pier. The pier perimeter is completed by a steel handrail with intermittent pedestals and light poles. Bollards from the original pier construction are installed adjacent to the railing and are no longer in use (Photo 2-9).

Figure 2-1. Typical Apron Deck Cross-Section

On top of the earth-filled portion of the core are a park and an asphalt parking lot (Photo 2-10). The finished grade of the parking lot is approximately 6 in. below the top surface of the pier apron. The park’s recreational landscaping amenities include trees, benches, tables, and water fountains.

2.2.4 Bulkhead

The original pier construction included a concrete sheet pile bulkhead that functioned to retain fill in the core of the pier as well as along the shoreline. As a part of the 1990 rehabilitation of the pier, the concrete bulkhead was replaced by a steel sheet pile bulkhead. The steel sheet pile bulkhead was installed adjacent to the inland side of the concrete bulkhead and acts as a retaining structure, replacing the need of the original concrete bulkhead. The original concrete bulkhead was left in place as a sacrificial element. The steel sheet pile bulkhead has a concrete cap which connects to

2-4 the back beam of the pier apron. The batter piles beneath the pier apron provide lateral support for the bulkhead (Photo 2-11).

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Photo 2-1. Aerial View of Canarsie Pier (photo courtesy of Microsoft Bing)

Photo 2-2. View Looking South from the East Apron of the Pier

2-9

Photo 2-3. Typical reinforced concrete pile encasement with stay-in-place timber form (1970 repair)

Photo 2-4. Typical reinforced concrete encasement with stay-in-place fiberglass reinforced polyester forms (1990 repair)

2-10

Photo 2-5. Reinforced concrete partial encasement with stay-in-place fiberglass reinforced polyester forms

Photo 2-6. Typical portion of a bent cap, supporting the pier apron

2-11

Photo 2-7. Concrete fascia beams, cast-in-place around the perimeter of the pier

Photo 2-8. Pier surface treatment, consisting of asphalt pavers on an asphalt setting bed as seen at the sinkhole (northwest corner of pier).

ASPHALT PAVERS

ASPHALT SETTING BED

2-12

Photo 2-9. Bollard from the original pier construction

Photo 2-10. Asphalt parking area (supported by the earth-filled core of the pier) as seen from the vehicle entrance

2-13

Photo 2-11. Batter piles beneath the pier apron provide lateral support for the bulkhead

3-1

3. CANARSIE PIER LEVEL III INSPECTION

3.1 INSPECTION SCOPE AND TERMINOLOGY

The scope of this Level III Highly Detailed inspection included three primary inspection activities:

• An Underwater and Above Water inspection of all accessible structural elements which comprise the pier.

• Concrete coring of the apron deck slab and associated laboratory testing of the cores to determine the mechanical properties of the concrete, as well as possible mechanisms for deterioration.

• A Ground Penetrating Radar (GPR) Survey of the apron deck to determine the size and spacing of the reinforcing steel installed in the concrete top slab.

The terminology in this report which is used to describe the observed conditions of the structures and elements are based on the ratings systems provided in UFC 4-150-07 Maintenance and

Operation: Maintenance of Waterfront Facilities and the American Society of Civil Engineers

Manuals and Reports on Engineering Practice No. 101: Underwater Investigations Standard Practice

Manual. A detailed description of the inspection procedure, including excerpts from each of these guidelines providing the definitions of the terminology used in this report has been included in

Appendix B.

3.2 OBSERVED CONDITIONS

Overall, Canarsie Pier is in fair condition and exhibits deterioration which is consistent with what is typically observed in marine structures of similar age. All of the primary structural elements are sound, with minor to moderate deterioration generally observed throughout the pier. There are localized areas of moderate to advanced deterioration, but these areas do not significantly reduce the overall load bearing capacity of the structure.

Figures illustrating the locations of the observed deficiencies are presented in Appendix C.

3.2.1 Piles

The concrete piles supporting the Canarsie Pier apron deck are generally in fair condition. Typically, the piles exhibit deterioration consisting of spalls, cracks, and general loss of concrete cross-section.

3-2

A summary of the observed conditions for the concrete piles is presented in Table 3-1.

Table 3-1. Summary of Pile Conditions

Element Total No. No.

Inspected

Condition Major

(10%-15% Concrete Cross- Section Loss)

Severe (> 15% Concrete Cross-

Section Loss; Avg. = 30%) No. (%) No. (%)

Concrete Piles 1,002 1,002 28 2.8% 36 3.6%

Of the 1,002 piles, 36 are rated “Severe” for concrete cross-section loss greater than 15% and/or exposed rebar with steel cross-section loss greater than 50% (Photo 3-1). Of the 36 piles rated

“Severe”, 14 have loss of cross-section at the mudline, 20 have loss of cross-section at the pile top, and 2 exhibit section loss at various locations along the full length of the pile. Piles rated “Major” are for concrete cross-section loss between 10%-15%, spalls 6 in. or larger and/or deep wide cracks

(Photo 3-2). Of the 28 piles rated “Major”, 2 have loss of cross-section at the mudline, 24 have loss of cross-section at the pile top, and 2 exhibit section loss at various locations along the full length of the pile. The remaining piles exhibit “Minor” to “Moderate” defects including small to medium spalls and fine cracks (Photo 3-3).

The majority of the piles that exhibited severe or major deterioration were those which were originally encased as part of the 1970 rehabilitation. In general, these piles had two primary deficiencies which were typically observed. First, many of the encasements installed on the piles did not extend completely into the mudline, leaving an exposed length of the original 14 in. square pile, typically ranging from approximately 2 in. to 12 in. In this region, the original pile is unprotected and has continued to deteriorate with time. The second commonly observed deficiency consists of section loss of the encasement, and corresponding exposure of the original pile at the location just below the pile bent cap. Potential causes for this deficiency consist of improper construction techniques for the concrete encasement which resulted in the wash-out of the concrete prior to initial set, or seawater intrusion into the fresh concrete resulting in a poor quality concrete which has since deteriorated. In either case, the exposed original pile at these locations has continued to deteriorate with time.

As part of the inspection, the timber form work was removed from 8 piles to inspect the condition of the concrete encasement. In all locations, the pile encasements were in good condition with only minor deterioration (Photo 3-4).

3-3

The piles that were encased during the 1990 rehabilitation are in good condition with no notable defects.

Pile plans for Canarsie Pier indicating deficiencies are presented in Figure C-1 through Figure C-6 in

Appendix C.

3-4

Photo 3-1. Concrete Pile – Severe Loss of Concrete at the Pile Top

Photo 3-2. Concrete Pile – Major Loss of Concrete at the Pile Top

3-5

Photo 3-3. Pile exhibiting Moderate section loss

Photo 3-4. Pile exhibiting Minor deterioration after removal of timber stay-in-place forms

3-6

3.2.2 Concrete Bent Caps

The concrete bent caps at Canarsie Pier are generally in satisfactory condition with isolated major and severe deficiencies. Typical deterioration includes spalls, cracks, and scaling in the bottom 1 ft –

2 ft of the cap resulting from exposure to tidal wetting and ice abrasion.

A summary of the observed conditions is presented in Table 3-2 below.

Table 3-2. Summary of Bent Cap Conditions

Element Total No. No.

Inspected

Condition Major Severe

No. (%) No. (%)

Concrete Bent Caps 204 204 9 4.4% 3 1.5%

Of the 204 bents of bent caps, 3 are rated “Severe” for concrete cross-section loss greater than 15% and/or exposed rebar with steel cross-section loss greater than 50% (Photo 3-5). There are 9 bent caps rated “Major” for concrete cross-section loss between 10%-15%, spalls 6 in. or larger and/or deep wide cracks (Photo 3-6). The remaining bent caps exhibit “Minor” to “Moderate” defects.

Bent cap plans for Canarsie Pier indicating deficiencies are presented in Figure C-7 through Figure C-

12 in Appendix C.

3-7

Photo 3-5. Concrete Bent Cap – Large Spall in Bottom Corner of Cap

Photo 3-6. Concrete Bent Cap – Major Spall in Bottom Corner of Cap

3-8

3.2.3 Concrete Fascia Beam and Back Beam

The concrete fascia beam and back beam at Canarsie Pier are generally in satisfactory condition with localized major and severe deficiencies. Typical deterioration includes large spalls and cracks.

A summary of the observed conditions is presented in Table 3-3 below.

Table 3-3. Summary of Fascia Beam Conditions

Element Total No.

(LF)

No.

Inspected

(LF)

Condition Major Severe

No. (LF) (%) No. (LF) (%)

Concrete Fascia and Back Beams 4,000 4,000 56 1.4% 390 9.8%

Of the 4,000 lf of perimeter fascia and back beams, 390 lf of the fascia beam are rated “Severe” for concrete cross-section loss greater than 15% and/or exposed rebar (Photo 3-7). There are 56 lf where the fascia beam is rated “Major” for concrete cross-section loss between 10%-15% and spalls

6 in. or larger (Photo 3-8). The remaining portion of perimeter fascia and back beams exhibit

“Minor” to “Moderate” defects.

One of the typical conditions prevalent in the fascia beams are spalls and cracks in the bottom 1 ft.

This condition is due to through bolts that were left in the fascia beam after the timber fenders were removed as a part of the 1990 rehabilitation work. The bolts have corroded and expanded causing the concrete to crack and spall (Photo 3-9).

Fascia and back beam plans for Canarsie Pier indicating deficiencies are presented in Figure C-7 through Figure C-12 in Appendix C.

3-9

Photo 3-7. Severe crack and spall in concrete fascia beam with exposed rebar

Photo 3-8. Major spall in bottom corner of concrete fascia beam

3-10

Photo 3-9. Deterioration of the concrete fascia beam due to corrosion of anchors for the removed timber fender system

3-11

3.2.4 Apron Deck

The concrete deck is generally in satisfactory condition. As identified in Section 2.2.3, the apron deck typically consists of three layers: a) the original bottom slab, b) a grout wearing course, and c) a cast-in-place reinforced concrete top slab which was installed as a structural overlay slab to replace the bottom slab during the pier rehabilitation in the 1970s.

As a part of the detailed Level III inspection, M&N extracted 10 concrete cores at 4 locations on the pier deck. The primary purpose of this investigation was to determine the mechanical properties of the concrete as well as possible mechanisms for deterioration. However, the coring program also confirmed that the deck was indeed comprised of three discrete layers. A typical core is shown in

Photo 3-10.

(A) BOTTOM SLAB AND WEARING COURSE

The concrete bottom slab is in serious condition. Typically the slab exhibits deterioration, including severe delamination of the concrete and severe corrosion or complete loss of the bottom reinforcing (Photo 3-11).

Approximately 60% of the bottom slab is rated “Severe” for concrete cross-section loss greater than

15% and/or exposed rebar with cross-section loss greater than 50%. In these areas, the rebar has either completely deteriorated or is severely corroded. Approximately 8% of the bottom slab is rated “Major” for concrete cross-section loss between 10%-15%. In these areas the rebar is exposed and severely deteriorated. The bottom face of the remaining portion of bottom slab, approximately

32%, has been covered with shotcrete. From a concrete core taken in the area where shotcrete was applied, conditions typical to the rest of the bottom slab were observed, showing that the lower 2

in. to 3 in. of the slab has deteriorated (Photo 3-12). Therefore, it is likely that even in these areas the bottom rebar is severely corroded and the structural capacity of the bottom slab has been compromised. Approximately 3 in. to 4 in. of shotcrete was applied in various locations.

Based on inspection of the cores, there is a 2 in. to 3 in. grout wearing course that has been installed on top of the bottom slab. It is likely this material was installed as part of the original construction to protect the bottom slab from damage due to vehicular operations on the pier. The wearing course has been covered by the top slab and is no longer functional.

3-12

As previously noted, the top slab has been installed as a replacement for the bottom slab, and the bottom slab has been left in place as a sacrificial element. Therefore, while this section of the slab is in serious condition due to severe deterioration, its condition does not impact the overall load carrying capacity of the pier.

Deck underside plans for Canarsie Pier indicating deficiencies in the bottom slab are presented in

Figure C-7 through Figure C-12 in Appendix C.

(B) CONCRETE TOP SLAB

Since the top slab was installed on top of the original bottom slab and an asphalt paver surface treatment is installed on the top slab, the concrete top slab is not accessible for visual inspection.

As a result, M&N conducted a concrete coring program, associated laboratory testing of the concrete cores, and a Ground Penetrating Radar survey of the top slab in order to determine its composition (i.e., slab thickness, concrete strength, steel reinforcing, etc.) and condition.

Using a hand-operated drilling rig, 10 concrete cores were extracted from the deck slab which allowed for a visual inspection of the complete cross-section of the top slab at multiple locations throughout the platform. The cores confirmed that the concrete top slab was approximately 9 in.

thick, included two layers of steel reinforcing, and by visual observation was generally in good condition with no signs of corrosion in the reinforcing.

The concrete cores were sent to a laboratory for testing. The following tests were performed:

chloride ion concentration, compressive strength, and a petrographic examination. The laboratory report containing details related to the testing of the cores are provided in the laboratory report provided in Appendix D. The results from the chloride ion test showed that the concentrations were above the threshold point at which the chlorides have a higher potential to react (corrosion) with the steel reinforcing. However, the steel present in the core samples showed no visible signs of corrosion onset. The compressive strength tests completed on the cores yielded an approximate compressive strength of 6,400 psi, which is greater than the typically specified minimum compressive strength (4,000 psi – 5,000 psi) of most cast-in-place concrete constructed today. The petrographic examination indicates two separate but similar degrading conditions present in the top slab: alkali-silica reaction (ASR) and delayed-ettringite formation (DEF). While the reactionary causes of these two conditions are different, the effects from ASR and DEF are similar which is volumetric expansion and cracking in the concrete which leads to overall loss of concrete strength.

3-13

The results of the laboratory analyses of the top slab are consistent with those observed for similar concrete structures installed during the 1990s. The fact that chloride ion concentrations are exceeding the minimum threshold for inducing corrosion indicates that it will be important to continue to periodically inspect the pier and monitor its condition. However, since the rebar observed in cores obtained during this inspection does not show any signs of significant corrosion, it is not recommended that any rehabilitation of the top slab take place at this time. Additionally, the presence of ASR and DEF can result in concrete durability issues and loss of strength. However, since the concrete appears sound and has a high compressive strength, there are no deficiencies to note at this time.

There were no existing drawings available to M&N indicating the extent of the size and spacing of the rebar in the top slab nor the extents of where the structural slab was installed. However, M&N obtained a letter from the NPS (see Appendix E) which alluded to the fact that the structural top slab may not have been installed over the entire pier apron. As a result, M&N completed a Ground

Penetrating Radar survey of the pier apron to confirm the extents of where the top slab was installed, and determine the size and spacing of the rebar in the slab. The results of the survey confirmed that the structural top slab was indeed installed on the entire pier apron platform area

(excluding the portion of the apron above the drainage culvert on the northwest corner of the pier), and there was reinforcing steel as described in Section 2.2.3 installed throughout the entire top slab

(Photo 3-13). Additional details regarding the GPR survey are included in Appendix D.

Based on the comprehensive results of the inspection and testing, the top slab is considered to be in satisfactory condition.

3-14

Photo 3-10. Concrete deck core sample NW-3

Photo 3-11. Severe delamination of concrete and severe loss of bottom reinforcing on the underside of the pier apron

Top Slab Bottom Slab Wearing Course

3-15

Photo 3-12. Concrete deck core sample NE-1. Deteriorated wearing course crumbled during coring activity and could not be recovered

Photo 3-13. Typical GPR test results, showing reinforcement in the top slab

Top Slab Bottom Slab Shotcrete Repair

Wearing Course (missing)

3-16

3.2.5 Pier Topside

The topside of Canarsie Pier is generally in fair condition. Typically, the topside deterioration includes medium to large spalls and cracks in the concrete curb (water side of steel handrail) and missing or broken façade panels in the pedestals which line the steel handrail. There is one severe deficiency which consists of a sinkhole located at the northwest corner of the west wing apron

(Photo 3-14 and Photo 3-15).

A summary of the observed conditions is presented in Table 3-4 below.

Table 3-4. Summary of Pier Topside Conditions

Element Condition

Minor Moderate Major Severe No. No. No. No.

Concrete Curb (water side of handrail) - - 5 -

Railing Pedestals 11 - - -

Surface Treatment - - - 1

The sinkhole occurs overtop of the drainage culvert which is installed under the pier at the west end of the west apron. The culvert supports fill, an unreinforced concrete floating slab, a 4 in. asphalt setting bed, and pavers. The fascia beam extends over the top of the culvert and confines the fill along with a concrete end wall and back wall. Based on observations during the inspection, it appears that fill is being lost through a joint between the end wall that bears on the culvert and the top of the culvert (Photo 3-16). It appears that this interface was not sealed properly during construction allowing water and fill to escape through the joint, and thereby creating a sinkhole.

The culvert ceiling was determined to be in good condition, confirming that no fill is being lost through the culvert ceiling.

There are 5 locations in the deck topside where there are “Major” deficiencies. These deficiencies include concrete spalls which are 6 in. or larger and wide cracks in the concrete curb (Photo 3-17).

There are 11 locations where the deck topside exhibits “Minor” defects which consist of missing or broken granite façade panels on the pedestals on the pier surface (Photo 3-18).

The paved, tree-lined sitting area and asphalt parking lot which lie on top of the earth-filled core portion of the pier are in good condition with no notable defects. There is minor subsidence of the

3-17 pavers at locations around the pier surface. The minor subsidence appears to be related to the consolidation of fill material as it settles over time, and is not indicative of fill loss through the bulkhead (Photo 3-19).

The original pier construction included mooring bollards spaced at approximately 60 ft increments around the pier perimeter. Since Canarsie Pier was converted into a recreational pier around 1973, commercial and recreational mooring has been prohibited. The bollards are currently installed on the land side of the safety handrail and are no longer in use.

A deck topside plan for Canarsie Pier indicating deficiencies is presented in Figure C-13 in Appendix

C.

3-18

Photo 3-14. Deck Topside – Large Sinkhole at the Northwest Corner of the West Wing Apron with Two Openings in the Pavers, Looking West

Photo 3-15. Sinkhole at the west end of the west apron

3-19

Photo 3-16. Gap in end wall joint at the west end of the west apron, where fill loss is occuring at the location of the sinkhole

Photo 3-17. Major topside deficiency, consisting of a large spall

3-20

Photo 3-18. Deck Topside – Large Spall in the Curb and Missing Pedestal Panel

Photo 3-19. Minor subsidence is typical on the pier, likely the result of soil consolidation

3-21

3.2.6 Pier Bulkhead

Overall, the bulkhead is in good condition.

The original pier construction included a concrete sheet pile bulkhead which was installed to retain fill in the core of the pier, as well as along the shoreline. As a part of the 1990 rehabilitation of the pier, the concrete bulkhead was replaced by a steel sheet pile bulkhead. The steel sheet pile bulkhead was installed adjacent to the inland side of the concrete bulkhead and acts as a retaining structure, replacing the need of the original concrete bulkhead. The original concrete bulkhead was left in place as a sacrificial element.

(A) CONCRETE SHEET PILE BULKHEAD

The concrete sheet pile bulkhead is abandoned, has been left in place and is in serious condition.

Typically the concrete bulkhead exhibits deterioration, including severe loss of concrete section and severe corrosion or complete loss of the reinforcing.

The majority of the concrete bulkhead is rated “Severe” for concrete cross-section loss greater than

15% and/or exposed rebar with cross-section loss greater than 50% (Photo 3-20). In some cases, through holes have formed revealing the steel sheet pile bulkhead behind it. The remaining portion of concrete bulkhead is rated “Major” for concrete cross-section loss between 10%-15% and exposed rebar.

However since this bulkhead has been replaced by the steel sheet pile bulkhead, the noted deterioration does not impact the function of the pier.

(B) STEEL SHEET PILE BULKHEAD

Since the steel sheet pile bulkhead was installed inboard of the concrete sheet pile bulkhead the majority of the bulkhead was not accessible for inspection. However, at locations where there where there were holes or gaps in the concrete bulkhead, the steel sheeting is visible (Photo 3-21).

At these locations, the bulkhead was inspected and is in good condition with no notable defects.

3-22

Photo 3-20. Severe loss of concrete section and exposed rebar in the original concrete sheet pile bulkhead

Photo 3-21. Steel sheet pile bulkhead is visible through a gap in the original concrete sheet pile bulkhead

Gap in abandoned concrete sheet pile bulkhead

Steel sheet pile bulkhead behind

3-23

3.3 STRUCTURAL CONDITION ASSESSMENT

M&N has performed a structural condition assessment of the pier to evaluate the load capacity of the structure in its existing condition. In general, the overall global capacity of the pier is adequate for supporting loads associated with current operations, as defined below. However, repairs to localized deterioration, as noted in Section 3.4, should be completed in order to ensure there are no localized failures of the pier structure. Additionally, given the age of the pier and the proclivity for rapid deterioration in the marine environment, it is recommended that a routine inspection and maintenance program be established for the pier in order to monitor the performance of the structure and extend its useful service life.

3.3.1 Basis for Structural Assessment

Canarsie Pier was originally designed as a general cargo pier which was to be used for loading and unloading of cargo from ships. While the original design criteria for the pier is not available for this assessment, general cargo piers from this era were typically designed to accommodate at least a

400 psf distributed live load on the deck, so that the pier could support typical port activities such as storage of cargo and the operation of mobile cranes used to load and unload ships. The relatively large size of the pier elements and close spacing of the piles at the pier are consistent with marine structures designed to support relatively high loads.

Canarsie Pier now serves as a park, parking area, and place of public assembly. Loads associated with this type of use are significantly lower than those associated with general cargo piers. The New

York City Building Code recommends that plaza areas accessible to the public should be designed to support a minimum uniform live load of 100 psf. Additionally, for pier designs accessible to the public, it is common to design the structure to support ambulance and maintenance vehicles. For the purposes of this assessment, the threshold for acceptability has be defined as being able to support a 100 psf uniformly distributed live load, and an H15-44 vehicle load as defined by the

Standard Specifications for Highway Bridges, published by the American Association of State

Highway and Transportation Officials (AASHTO). Additionally, the assessment included a 30 psf vertical distributed snow load.

The calculations and associated load ratings included in this report are based on field observations and information shown in the reference documents in Appendices D and E. In the event that details of the existing structure were unknown or unavailable, M&N based the calculations on an assumed configuration and made note of the assumption in the detailed calculations. All concrete members

3-24 were analyzed using the Load and Resistance Factor Design method described in the 2011 Edition of the Building Code Requirements for Structural Concrete (ACI 318-11) and Commentary published by the American Concrete Institute (ACI).

The detailed calculations for the assessment are presented in Appendix F.

3.3.2 Evaluation of the Apron Structure

(A) PILES

As mentioned above, the original pier was designed as a robust cargo pier with relatively close pile spacing for concrete piles, indicative of piers which support in excess of 400 psf live loads. In addition, most of the piles were rehabilitated in the 1970s (approximately 98% of the piles) and more piles were rehabilitated again in 1990 (approximately 45% of the piles) giving all of the piles a greater cross-sectional area, and likely a greater axial capacity, than the original 14 in. piles.

However, the reinforcing details for the 1970s’ repairs are unknown and therefore the capacity of these encasements could not be directly calculated. Therefore, to determine the axial capacity of the piles, it was assumed that the encasements constructed in the 1970s were designed to at least meet the capacity of the original 14 in. piles.