Albhaisi and Bashir 1

THE REHABILITATION OF THE ALEXANDER HAMILTON BRIDGE

Suhail Albhaisi*, P.E., Ph.D.

Jacobs Engineering Group

2 Penn Plaza Suite 603, New York, NY 10121

Phone: (212) 946-2325, Fax: (212) 302-4645

Suhail.albhaisi@jacobs.com

Tariq Bashir, P.E.

New York State Department of Transportation

47-40 21st Street, 5

th Floor, Long Island City, NY 11101

Phone: (718) 482-4691, Fax: (718) 482-6319

tariq.bashir@dot.ny.gov

* Corresponding Author

Revision No.: 01

Word count: 3,326

Abstract: 247 < 250

Figures & Tables: 8 x 250 = 2,000

Total: 5,573

Submission Date: 11/15/2014

Albhaisi and Bashir 2

ABSTRACT 1

The Alexander Hamilton Bridge (AHB) is considered a vital link in the New York City 2

(NYC) and the regional Northeast. The 1,525-foot bridge, which includes a 505-foot steel 3

arch main span, was opened to traffic on January 15, 1963. The current Average Annual 4

Daily Traffic (AADT) on the bridge is estimated at 190,000 vehicles. After more than 40 5

years in service with heavy truck traffic, the bridge was in need of major rehabilitation. The 6

scope of the rehabilitation included the strengthening, widening, and complete deck 7

replacement of the main bridge and the rehabilitation and/or replacement of eight other 8

existing ramp structures. Constructing a new state of the art skateboard park, redesigning and 9

improving the parklands, and reconstructing the existing playgrounds were also part of this 10

project. With a construction cost of $413 million, the project is the largest single-contract 11

construction project in the history of the New York State Department of Transportation 12

(NYSDOT). Construction began in the spring of 2009 and was completed on time and within 13

budget in the spring of 2014. Among the many challenges in this bridge improvement project 14

was the need to maintain the current flow of traffic during construction. To overcome this 15

challenge, the design was carried out with mobility in mind. Extensive use of sizeable 16

temporary structures, with a construction cost exceeding $150 million, was utilized during 17

construction. This paper presents an overview of the project, the design and construction 18

challenges, the environmental commitment, and the lessons learned from the project. 19

Albhaisi and Bashir 3

INTRODUCTION 1

The Alexander Hamilton Bridge (AHB) and its associated Highbridge Interchange Ramps are 2

considered vital links in the New York City (NYC) and the regional Northeast highway 3

systems. The location of the bridge is shown in Figure 1. The bridge was opened to traffic on 4

January 15, 1963. It carries eight lanes of traffic over the Harlem River between Manhattan 5

and the Bronx. It also connects the Trans-Manhattan Expressway (TME) in the Washington 6

Heights section of Manhattan and the Cross-Bronx Expressway (CBE), as part of Interstate 7

95 (I-95). The bridge also carries significant traffic on to and off of the George Washington 8

Bridge (GWB). A recent aerial of view of the bridge and the surrounding transportation links 9

is shown in Figure 2. The 1,525-foot bridge, which includes a 505-foot steel arch main span 10

and the approach structures, were in need of major rehabilitation. Subsequent to the in-depth 11

inspections performed in 1993 for all the bridge structures on or spanning the CBE and 12

within the Highbridge Interchange, NYSDOT decided to initiate the major rehabilitation 13

project for the majority of these bridge structures. The replacement option was found to be 14

more feasible for two (2) of the eight (8) ramp structures (1). 15

With a construction cost of $413 million, the project is the largest single-contract 16

construction project in the history of the New York State Department of Transportation 17

(NYSDOT). Construction began in the spring of 2009 and was completed on time and within 18

budget in the spring of 2014. Among the many challenges in this bridge improvement project 19

was the need to maintain the current flow of traffic during construction. To overcome this 20

challenge, the design was carried out with mobility in mind. Extensive use of sizeable 21

temporary structures (bridges), with a construction cost exceeding $150 million, was utilized 22

during construction. This paper presents an overview of the major rehabilitation work that 23

was completed on the AHB, the design and construction challenges, the environmental 24

commitment, and the lessons learned from the project. 25

FIGURE 1 Alexander Hamilton Bridge Project Location. 26

Albhaisi and Bashir 4

FIGURE 2 Aerial View of the AHB and Ramps during Rehabilitation 1

BRIDGES IN THE PROJECT 2

The AHB and Highbridge Interchange Ramps rehabilitation/replacement project includes a 3

total of nine existing bridge structures on or spanning the CBE from Amsterdam Avenue in 4

New York County to Undercliff Avenue in Bronx County, New York City as shown in 5

Figure 3. The project is under the jurisdiction of NYSDOT Region 11. The nine bridges in 6

this construction package include the Alexander Hamilton Bridge, Ramp “TE” over the CBE, 7

the Highbridge Interchange Connector Ramps including three bridges on “Ramp D”, two 8

bridges on “Ramp A”, and a Ramp “B & L” bridge, and the Undercliff Avenue Bridge over 9

the CBE. The on-grade roadways included the segments of Ramps “D” and “A” roadways 10

between the bridge structures and the segments of the AHB, Ramp “TE”, Ramp “B” and 11

Ramp “F” approach roadways. Refer to Figure 3. 12

Bridge 1 – Alexander Hamilton Bridge, (AHB) 13

The superstructure for 505-foot steel deck-arch main span consists of a total of four steel box 14

arch ribs supporting the spandrel columns which support the four lines of longitudinal 15

girders. The ends of each steel box arch rib are anchored into the concrete skewbacks located 16

at both sides of the arch span. The longitudinal girders in the Main Arch Span support the 17

transverse floorbeams and cantilevered brackets which support the stringers. The stringers 18

support the concrete deck slab of the AHB. There are two west approach spans and seven 19

east approach spans at the ends of the Main Arch Span. The existing superstructure for two 20

west approach spans and six east approach spans of AHB consists of non-redundant steel 21

girders, floorbeams, and stringers framing supporting the concrete deck slab. Only the last 22

span in the east approach, 7E, consists of redundant multi-girders framing supporting the 23

concrete slab. Figure 4 shows the AHB south elevation. 24

25

GWB

AHB

(I-95)

Harlem River

Hudson River

New York

Manhattan

Bronx

TME

High

Bridge

Washington

Bridge

Ramp TE

New Jersey

Albhaisi and Bashir 5

FIGURE 3 General Plan – Alexander Hamilton Bridge and Interchange Ramps.

Albhaisi and Bashir 6

The original AHB consists of two independent structures divided by a longitudinal deck joint 1

along the center median and carries six through traffic lanes of the CBE (I-95), three 2

northbound lanes and three southbound lanes in each half of the bridge, an additional 3

acceleration lane for On-Ramp “A” on the southbound side of the bridge, and a deceleration 4

lane for Off-Ramp “D” on the northbound side of the bridge. The bridge spans (total length = 5

452.7m; 1,485.4 ft.) over the Highbridge Park and the Harlem River Drive in Manhattan, the 6

Harlem River, the Metro-North Commuter Railroad tracks, On-Ramp “A”, Off-Ramp “D”, 7

the Major Deegan Expressway and Sedgwick Avenue in the Bronx. 8

Bridge 2 – Ramp TE 9

Ramp “TE” over I-95 is located at the west end of the AHB. It was constructed in 1952 and 10

carries one lane of Off-Ramp traffic from the northbound CBE (I-95) to the eastbound 11

Washington Bridge (181st Street Bridge or Route US1). Ramp “TE” spans over the 12

Highbridge Park, the Trans Manhattan Expressway Connector Ramps, and the Cross Bronx 13

Expressway (I-95). The elevation of the existing structure is shown in Figure 5. 14

Albhaisi and Bashir 7

1

FIGURE 4 Alexander Hamilton Bridge Elevation, Looking South 2

FIGURE 5 Ramp “TE” – Existing Elevation 3

Albhaisi and Bashir 8

Highbridge Interchange Ramp – Bridge 3, 4 & 5 – Ramp “D” 1

These three bridges are segments of the circular Ramp “D,” which was constructed in 1962 2

and carries two lanes of Off-Ramp traffic from the northbound CBE (I-95) to the Major 3

Deegan Expressway (I-87), both northbound and southbound. The bridges span over the 4

Major Deegan Expressway and Sedgwick Avenue. The two segments of Ramp “D” between 5

Bridge 3 and Bridge 4 and between Bridge 4 and Bridge 5 and a segment of Ramp “F” (north 6

approach roadway of Bridge 4) are on-grade roadways. These segments of roadway were also 7

rehabilitated as part of this project. 8

Highbridge Interchange Ramp – Bridge 8 – Ramp “B & L” 9

This structure, a segment of Ramps “B & L,” was constructed in 1962 and carries two lanes 10

of traffic from the northbound Major Deegan Expressway (I-87) to the northbound CBE (I-11

95) and southbound CBE (I-95). The bridge spans over Sedgwick Avenue. The segment of 12

Ramp “B” (south approach roadway of Bridge 8) is an on-grade roadway. This segment of 13

roadway will also be rehabilitated as part of this project. 14

Bridge 9 – Undercliff Avenue Bridge 15

This structure, which carries Undercliff Avenue over I-95, was constructed in 1962 and has 16

one lane of one direction vehicular traffic, two parking lanes, and two wide sidewalks for 17

pedestrian traffic. 18

PROJECT OBJECTIVE AND SCOPE 19

The need for improvements on this section of the CBE was evident in the structural 20

deficiencies caused by age and deterioration of the existing structures as found in the In-21

depth Inspections for the bridge structures that were conducted during the period of 1993-22

1994. In general, the existing steel superstructures were found in fair to good conditions; 23

however, the concrete deck slabs, deck joints, bearings, and substructure concretes for all 24

structures were found in poor conditions. The objective of this bridge rehabilitation and 25

improvement project was to upgrade the existing deteriorating bridge structures to current 26

standards and to extend their service life for an additional fifty years or to replace the existing 27

bridge structure entirely where feasible. Included in the project was also the rehabilitation of 28

the associated segments of on-grade approach roadways for the bridges. The scope of work 29

for the bridge rehabilitation work includes the strengthening, widening, and complete deck 30

replacement of the main bridge and the rehabilitation and/or replacement of eight other 31

existing ramp structures (bridges). The project also includes the rehabilitation of on-grade 32

approach roadways for all nine bridges. Constructing a new state of the art skateboard park, 33

redesigning and improving the parklands, and reconstructing the existing playgrounds within 34

the project limits were also part of this project. 35 36

37

Albhaisi and Bashir 9

DESIGN AND CONSTRUCTION 1

The design on the project was completed at the end of 2006. NYSDOT solicited construction 2

bids in early 2007, but no contractor came forward because of their unwillingness to accept 3

the challenge of designing the complex temporary supports for the AHB and the other 4

temporary ramp structures required during the reconstruction of Ramps “A” and “D”. A 5

decision was made to advance the design of for all the temporary supports and ramp 6

structures, which the contractor usually designs during construction. Upon completion of the 7

design of all the temporary structures, NYSDOT re-advertised the project on January of 8

2009. Five bids were received and the joint venture team CCA Civil/Halmar International 9

was selected based on their lowest bid of $407 million. Additional rehabilitation work worth 10

$6 million was added later to the project. 11

Alexander Hamilton Bridge (AHB) – Steel Arch Span Bridge and approach spans 12

The rehabilitation designs of the Main Arch Span and its approach spans took into 13

consideration the difficulty of staged deck replacement as well as a 3.353m (11.0ft) widening 14

(at each side) to introduce standard shoulders and modifications to the existing superstructure 15

framing. This included the retrofit of the existing substructure to meet the current seismic 16

requirements while maintaining all through lanes of traffic in each direction during 17

construction. The feasibility of using prefabricated components was also investigated 18

intensively. The sections for the existing and proposed arch spans are shown in Figure 6. 19

In order to minimize the duration of construction and the number of traffic detours, it was 20

determined that new longer cantilever brackets in the Main Arch Span and addition of new 21

fascia girders in the approach spans would be the most structurally sound and economical 22

method to increase the existing roadway width for the maintaining and shifting of existing 23

traffic lanes. Based on the existing and new superstructure framing configurations, the 24

proposed work on AHB could be minimized to six construction stages. Furthermore, based 25

on the reduced number of construction stages, it was estimated that due to the irregular 26

framing and geometry for the proposed staged construction, using prefabricated components 27

for the new construction offered no advantages as compared to the cost of conventional 28

construction. In fact, the cost of using prefabricated components would be higher than the 29

cost of conventional construction. Consequently, a cast-in-place concrete deck slab was 30

selected for the proposed deck slab replacement for AHB. In addition, stainless steel rebars 31

were used to attain the desired service life for the deck slab. Smaller concrete cover was used 32

to protect the stainless steel rebar and as a result, the total required depth for the slab was 33

reduced. That reduction in the mass of the superstructure reduced the seismic forces on the 34

substructure elements. Numerous seismic alternatives were investigated during the final 35

design phase to avoid less desired responses from the existing bridge and to limit 36

strengthening to only few existing substructure elements. 37

Albhaisi and Bashir 10

FIGURE 6 AHB – Existing and Proposed Arch Span Section. 1

Ramp “TE” & Undercliff Avenue Bridge 2

The design of the new twin curved box girder Ramp “TE” and Undercliff Avenue Bridge 3

accounted for the complexities in replacing the existing bridge structures while maintaining 4

AHB Traffic flow below. A pier column of the existing Ramp “TE” penetrates through the 5

median of the AHB at the west approach spans, and the center pier of the Undercliff Avenue 6

Bridge is located in the median of the CBE, a short distance from the east end of the AHB 7

approach slab. These two piers interfered with the implementation of staged shifting of traffic 8

required to maintain the existing number of lanes of the CBE (I-95) traffic in each direction 9

on the AHB during its rehabilitation. As a result the removal of these obstructions was 10

essential. Consequently, due to the removal of piers, the span lengths of the existing two 11

bridges over the CBE mainline were doubled. Therefore, for the Ramp “TE” and the 12

Undercliff Avenue Bridge, the only feasible solutions was to replace both existing bridge 13

structures. It should be noted that for the Ramp “TE,” some existing substructure elements 14

were reused. The cross section for the proposed ramp is shown in Figure 7. 15

Site Constraints 16

The construction on this project took several years to complete and had major impacts on the 17

daily lives of motorists who use the CBE (I-95) corridor. Since the CBE operates at or near 18

capacity during peak hours, the existing three Expressway lanes of through traffic in each 19

direction had to be maintained for the AHB during construction. Temporary lane closures 20

were implemented only within the permissible off-peak hours. Accordingly, it was required 21

to remove the center median of the AHB to enable shifting of traffic in order to maintain the 22

same number of travel lanes on the bridge during construction. For the access ramp work 23

(other than Ramp “TE”) and for the Undercliff Avenue Bridge work, short-term closures with 24

reasonable detours and staged construction were employed, respectively. Ramp “TE” was 25

closed to traffic for the duration of replacement construction. 26

Existing

Proposed

Albhaisi and Bashir 11

FIGURE 7 Ramp TE over I-95 - Proposed Section. 1

Construction Stages 2

There were six construction stages for the AHB. 3

Stage 1 – Modification of the existing median 4

Stage 2 – Rehabilitation and widening of the north portion of the bridge 5

Stage 3 – Rehabilitation and widening of the south portion of the bridge 6

Stage 4 – Rehabilitation of the south inner portion of the bridge 7

Stage 5 – Rehabilitation of the north inner portion of the bridge 8

Stage 6 – Rehabilitation of the median portion of the bridge 9

Communication and Agency Coordination 10

Extensive inter-agency coordination, radio ad campaign, and outreach efforts significantly 11

reduced the impacts of construction on the flow of traffic. To ensure the successful 12

completion of the project and to minimize impacts on the commuters and the surrounding 13

communities due to unforeseen delays, specific responsibilities were assigned to each agency 14

involved or affected by the project. The Port Authority of New York and New Jersey 15

(PANY&NJ) supervised truck traffic restrictions for the George Washington Bridge (GWB) 16

lower deck and closures of GWB. They were also responsible for counter-flow lanes within 17

the areas under PA jurisdictions. The New York City (NYC) Parks ensured there was limited 18

disturbance to parklands under the bridge constructions and oversaw the construction of the 19

new skateboard park and playgrounds, as well as the restoration of other facilities within the 20

parkland. The New York City Department of Environmental Protection (NYCDEP) 21

coordinated with the on-going DEP project within the project limits and managed any impact 22

to the existing DEP facilities due to the implementation of new construction. The New York 23

City Department of Transportation (NYCDOT) was responsible for restricted lane closures 24

on I-95 and detours to City local streets. The MetroNorth Railroad (MNR) supervised the 25

coordination of construction works over and within the railroad R.O.W. 26

Albhaisi and Bashir 12

Miscellaneous Field Issues 1

At the beginning of the project, numerous unanticipated field conditions and issues resulted 2

in the project falling behind schedule by many months. However, as the construction 3

progressed, the project was able to recoup much of this lost time and got back on the original 4

schedule. Some of the unanticipated conditions and issues are listed below: 5

- Encountered unexpected utility lines and features that interfere with the proposed 6

construction activities 7

- Field Surveys of existing structures did not meet the As-Built and Contract Plans 8

- Top of existing steel elements varied from the theoretical values shown on the As-Built 9

and Contract Plans requiring adjustments of haunches 10

- Existing drainage pipes system was either non-existent or non-functioning 11

- Existing structural details differed from the details shown on the As-Built and Contract 12

Plans. 13

Temporary Structures

14

Among the many challenges in this bridge improvement project was the need to maintain the 15

current flow of traffic during construction. To overcome this challenge, the design was 16

carried out with mobility in mind. Extensive use of sizeable temporary structures (bridges), 17

with a construction cost exceeding $150 million, was utilized during construction. 18

Temporary spread footings were used for the support of all temporary bridge structures. 19

Reinforced earth walls were used extensively for temporary structures/roadways. 20

ENVIRONMENTAL COMMITMENT 21

Extensive evaluations and studies for the disturbances and environmental impacts within 22

Highbridge Park in upper Manhattan and Washington Bridge Park parcels in the Bronx from 23

the construction activities of the project demonstrated that there were no prudent and feasible 24

alternatives to avoid such impacts on the parklands, and mitigation measures were included 25

all possible planning to minimize harm to both the Highbridge Park and Washington Bridge 26

Park parcel. The project included $20 million in enhancements to Highbridge Park. The most 27

prominent restoration/mitigation work within is the construction of the new state-of-art 28

skateboard park under the reconstructed Ramp TE in Highbridge Park. Figure 8 shows Ramp 29

TE and the new skateboard. 30

FIGURE 8 The New Ramp TE Over I-95 and the Skateboard Park

Albhaisi and Bashir 13

LESSONS LEARNED 1

Below is a summary of the main lessons learned from this project: 2

- Projects of this magnitude require the involvement of all local and regional transportation 3

agencies to discuss the implications of the construction and to obtain their approval on the 4

measures that will be implemented to alleviate impacts on the local communities and the 5

commuters. 6

- The use of sizeable temporary structures is a vital and feasible option to keep traffic flow 7

during construction. For complex temporary structures, the contract plans shall include 8

detailed designs of these structures. 9

- A recent in-depth inspection is needed before the commencement of the design of the 10

rehabilitation work. In addition, Non Destructive Testing (NDT) should be employed for 11

accurate assessment of location and extent of concrete deterioration. 12

- For the rehabilitation of complex bridges, it is recommended that an experienced bridge 13

engineer with a good background of the design work be available in the field office on a 14

full time bases to expedite the response to any Request For Information (RFI) and to 15

expedite the revisions to contract drawings that arise from unexpected field conditions. 16

- Providing detailed Maintenance and Protection of Traffic (MPT) plans for existing 17

conditions, final conditions, and intermediate stages is vital to avoid delays during 18

construction. The detailed plans shall include MPT plans during the erection or 19

construction of major steel and concrete elements. The MPT plans shall be developed in 20

close coordination with engineers from all disciplines who are working on the project to 21

resolve issues related to exiting obstacles, substandard conditions, concrete curing times, 22

and other unforeseen issues. 23

- An effective communication plan that advises motorists of diversion options can convince 24

motorists to change their routes. 25

- The design shall take into consideration existing geometric alignment and conditions. 26

Special considerations shall be given to the deck slab haunches and the locations where 27

two independent structures meet. 28

- Development of a reliable traffic model showing construction impacts in the early stages 29

of the design facilitates inter-agency coordination and community outreach. 30

31

Albhaisi and Bashir 14

CONCLUSIONS 1

With a construction cost of $413 Million, the Alexander Hamilton Bridge Rehabilitation 2

Project is the largest single-contract construction project in the history of the New York State 3

Department of Transportation (NYSDOT). Construction on the project began in the spring of 4

2009 and was completed on time and within budget in the spring of 2014. Among the many 5

major design and construction challenges in this project were the complex geometry of the 6

main bridge and ramp bridges and the need to maintain the current flow traffic, which is 7

estimated at of 190,000 vehicles. To complete a project of this size and complexity within 8

both the planned schedule and the available budget was also a great challenge. This 9

achievement was made possible primarily due to the open and constant lines of 10

communication and cooperation between the NYSDOT personnel, the design team, the 11

contractor, and the inspection team. By working together, they were able resolve the 12

difficulties presented in the field in both a time and cost efficient manner. Extensive Inter-13

agency coordination, incentive and disincentive provisions in the construction contract, radio 14

ad campaign, and the outreach efforts ahead of every construction stage all resulted in 15

significantly alleviating the impacts of construction on the traffic flow. This extremely 16

complex, sensitive, and vital project represents an outstanding achievement in innovation in 17

the restoration and rehabilitation of bridges of a historic nature. The project rejuvenated a 18

major link in the New York metropolitan area’s transportation infrastructure, leading to 19

enhanced mobility throughout the region, improved safety and a structure that will endure for 20

generations. 21

Acknowledgments 22

The authors would like to acknowledge the contributions of Johnny Ho, M.T. Shaikh, and 23

Robert J. LaMagna to this paper. 24

References 25

1. New York State Department of Transportation (NYSDOT) 1995-2004, Bridge 26

Rehabilitation Project Reports (9 Reports), Rehabilitation of 16 Bridges on or Spanning 27

The Cross Bronx Expressway (I-95) Corridor Between Amsterdam Avenue in New York 28

County and Undercliff Avenue in Bronx County, NYSDOT, 1995-2004. 29