Location: New York, NY
Owner: New York State Department of Transportation
Contractors: China Construction America, Inc./Halmar International, LLC JV

Siefert Associates, LLC designed a temporary structure for ramps 6A and 7A. In addition, we provided construction engineering for substructure and lateral support, jacking plans and crane demolition and erection plans. The erection of Ramp 6A was successfully completed in May 2012 and the demolition plan for the removal of Temporary Ramp 7A was submitted for construction.

Location: Staten Island, NY and Bayonne, NJ
Owner: The Port Authority of New York and New Jersey
Contractors: Skanska Koch-Kiewit, JV

As the fourth largest arch bridge in the world, the Bayonne Bridge connects Bayonne, New Jersey and Staten Island, New York, spanning over the entrance to the Port Newark-Elizabeth Marine Terminal.  The height of ships serving the port was limited by the Bayonne Bridge. This limitation grew more serious with the Panama Canal's 2016 expansion that enabled bigger, New Panamax ships to reach the port from Asia. The Port Authority of NY&NJ awarded the contract to raise the Bayonne Bridge's roadway 65 feet at a cost of around $1.7 billion. The increased navigational clearance to the busiest port on the East Coast was achieved in June 2017, and the overall bridge project was completed in 2019.

Siefert developed a comprehensive strategy for the temporary works including Temporary Supports and Pile Foundations, Engineered Lift Plans for Demolition and Erection of the Main and Approach Spans, Rigging Design, with related Structural and Geotechnical Analysis. The engineered solutions minimized disruptions to the navigational channel below and to the roadway traffic, while maintaining stability of the existing truss arch.

Piers for the new viaduct approach spans had to be constructed directly through the existing roadway, which required selective demolition of the existing structure and pier bents. Temporary shoring towers were engineered to maintain the traffic flow and preserve the structural integrity of the bridge. Weak subsurface soil conditions warranted the design of deep micro-pile foundations with concrete pier caps.

There were 2 different types of temporary support towers designed, a heavy duty tower that supported the 10 feet deep edge girders and a light duty tower that supported the 6 feet deep floor beams. The towers had to be designed to support 2 lanes of live load traffic [HS-20, 36 tons each] and the segment haulers [600 tons] used to transport the precast pier segments across the bridge. Unique solutions were developed by Siefert to take advantage of the existing framing and to save the contractor time and money.

Siefert Associates meticulously formulated, evaluated, and provided detailed lift plans for the removal and replacement of all bridge components. These lift plans entailed extensive dimensional assessments to ensure that cranes with complicated rigging had ample clearance to safely lift and lower loads from the roadway to their final positions. Our teams assumed the responsibility of conducting a comprehensive analysis of the structural capacity of members and connections during all construction phases. This analysis was imperative to confirm the ability of the bridge deck and superstructure to support the substantial loads from cranes, heavy haul transporters, and excavators, all within the existing structure configuration at the time of the operation. Also, a geotechnical analysis was performed and working platforms and temporary roadways were designed for equipment operating on grade below and adjacent to the structure.

Location: Newtown, CT
Owner: State of Connecticut
Contractors: Empire Paving Inc.

An emergency culvert repair project on Mile Hill Road [Route 860] in Newtown, CT quickly transformed into emergency culvert replacement due to the discovery of severe deterioration of the existing culvert pipe. Siefert Associates, LLC supported the deep excavation by designing a combination of temporary support of excavation (SOE) systems, such as GRES walls, braced soldier piles and lagging systems and soil nail walls. Additionally, the project scope included the design of a cantilevered reinforced concrete headwall and endwall, modified to accommodate right-of-way restrictions, and stabilization of existing subgrade soils.

Location: Detroit, MI and Windsor, Ontario

Owner: Windsor-Detroit Bridge Authority (WDBA)

Contractors: BNA Constructors USA JV (ACS Infrastructure, Fluor, and Aecon)

Siefert Associates, LLC is working on a variety of scopes for the construction of this six-lane cable-stayed bridge, including the design of innovative lifting frames for the erection of slanted, asymmetric rebar cages, the design of crane tie systems to brace the tower crane to the bridge concrete tower as it grows in height during the construction process, and the design of a timber-framed building for use by the contractor throughout the project.

Location: Boston, MA
Owner: Massachusetts Bay Transportation Authority [MBTA]
Contractors: GLX Constructors

In support of the extension of Boston’s oldest rapid transit line, Siefert Associates, LLC provided engineered lift plans for several rebar cages and designed the lifting rings to maintain the geometry of the cage. We also collaborated with the contractor on the design of formwork and falsework for the pier caps and columns, providing a third party review of the contractor’s where necessary, and designed temporary utility supports for several bridges within the 4.7-mile project limits.

Location: Queens, NY
Owner: City of New York
Contractors: Skanska Walsh Design-Build JV & Stonebridge Inc.

LaGuardia Airport, located in Queens, New York City, is one of the busiest airports in the United States. Renowned for its proximity to Manhattan, it serves as a vital hub for domestic flights, especially along the East Coast. Despite its small size compared to other major airports, LaGuardia is known for its bustling atmosphere and efficient operations. Recent renovations have aimed to enhance traveler experience, modernize facilities, and alleviate congestion, making it a pivotal gateway for millions of passengers each year.

Siefert Associates has made significant contributions to the LaGuardia Airport Terminal B Replacement Project.  Siefert Associates developed erection and demolition plans for over a dozen bridges within the airport's supporting infrastructure. These plans encompassed staged construction and stability analyses for both straight and curved girders, bracing design, dunnage analysis for crawler cranes, and the design, erection and hydraulic jacking of temporary supports. Besides vehicular bridges, other scope of work included construction engineering for pedestrian, utility and temporary modular bridges including launching operations. Peer review services were performed on demolition and erection plans. Additionally, the construction of the Delta Concourse necessitated a free-standing tower crane, for which Siefert Associates provided assembly plans and designed the concrete foundation upon which it was supported.

Location: Long Island, New York
Owner: Metropolitan Transportation Authority
Contractors: 3rd Track Constructors, JV

To aid in the addition of a third track to a 9.8-mile stretch of the Long Island Railroad, Siefert Associates, LLC has created demolition plans for existing bridges and foundations to be replaced and produced erection plans for multiple items, including track segments, platform panels, foundations, substation units, temporary utility poles, and new station house steel. SALLC also provided the design of support of excavation [SOE] for the placement of new foundations, platforms, and retaining walls.

Location: Middlebury, VT

Owner: State of Vermont

Contractors: Kubricky Construction Corp.

Siefert Associates, LLC provided engineered lift plans for precast tunnel segments, which replaced the deteriorating retaining walls and bridge abutments previously holding back soil from the railroad line 20ft below grade. The size and geometry of the segments called for specialized rigging designed to upend the segments without fracturing the precast or overloading the lifting eyes. SALLC laid out the crane positions for three large cranes within the tight jobsite, each having a capacity upwards of 250T.

Location: Newark, NJ
Owner: City of Newark
Contractors: Stonebridge, Inc.

Newark Liberty International Airport, one of the busiest airports in the United States, serves as a major hub for both domestic and international flights, offering connections to numerous destinations worldwide. Operated by the Port Authority of New York and New Jersey, the airport features three terminals, extensive amenities, and efficient transportation options for travelers. With its proximity to New York City and comprehensive facilities, Newark Airport plays a crucial role in facilitating air travel in the northeastern region of the United States.

Siefert Associates, LLC was involved in the rehabilitation and modernization of Newark Airport's Terminal A’s hub, including 3 concourses and a pedestrian bridge. The project scope included preparing working drawing and supporting calculations tailored to the preferred means and methods of Stonebridge Steel Erection. The erection of the structural steel for all three levels of the Terminal Hub/Concourses were orchestrated using 3 different cranes (Manitowoc M16000 and Liebherr LR1400 and a large hydraulic support crane) during two shifts. Structural analysis included evaluation of the structural stability of the frame during erection, review of the cantilevered condition of roof girders and design/analysis of temporary supports. The roof girders were pre-assembled atop temporary supports that were designed with consideration of the tapered bottom flange and fit-up tolerance of the field-spliced connections. Rigging details were also provided.

The pedestrian truss bridge was erected both in prefabricated sections and stick-built. Several temporary supports were required for each staged sequence of assembly. Two crawler cranes were used for erection. The erection sequence, structural analysis model, erection procedure, and temporary supports were all provided. The crane plan included very detailed information on crane position, operating radii, delivery locations, supporting conditions, assembly/disassembly, and wind action plans, in addition to compliance with all crane operation protocol required by the PANYNJ.

Location: New York, NY
Owner: State of New York
Contractors: Skanska USA Civil Inc.

For this transformation project, Siefert Associates, LLC provided engineering drawings and calculations for the erection and demobilization of the two tower cranes, a derrick, and a Spydercrane used to erect steel within the footprint of the historic James A. Farley Post Office Building. In collaboration with the contractor, SALLC reviewed the calculations and utilized 3D drafting to provide concise drawings of the tower crane support frames. The engineered lift plans strategically distributed loading to avoid the Amtrak Rail Road below grade.

Location: Boston, MA
Owner: Massachusetts Department of Transportation
Contractors: Atlantic Coast Dismantling, LLC

To facilitate the safe demolition of this bridge, Siefert Associates, LLC was hired to perform bridge demolition analysis and prepare engineered lift plans. SALLC analyzed the existing superstructure for construction equipment loading, analyzed the staged removal of sections of the main span truss, and designed temporary bracing of the main span truss and approach span girders. The steel truss mainspan and most of the approach spans were removed with a large crane on a barge.

Location: New York, NY
Owner: Triborough Bridge & Tunnel Authority
Contractors: Restani Construction Corporation

Due to corrosion in the concrete foundations, the Manhattan approach of the bridge needed to be replaced. Siefert Associates, LLC was hired to design an extensive temporary shoring system, up to thirty [30] towers in total, to support the two-level viaduct structure and five [5] lanes of traffic on the bridge during all phases of construction. Extensive SOE designs were also needed to facilitate footing removal to bedrock without interrupting adjacent traffic.

Location: Waterbury, CT
Owner: Connecticut Department of Transportation
Contractors: I-84 Constructors JV

Siefert Associates, LLC was involved in several scopes of work, mainly focusing on the demolition and/or lift plans for the eight highway bridges that were constructed or replaced. The lift plans included rigging design, analysis of temporary supports and bracing as needed, and concise procedures for steel erection and jacking. SALLC also provided geotechnical services for various sites within the project limits, designing geosynthetic reinforced earth system [GRES] walls at the bridge abutments and producing temporary support of excavation [SOE] designs for several bridge foundations, retaining walls, and culverts.

Location: Boston, MA
Owner: Massachusetts Bay Transportation Authority
Contractors: SPS New England, Inc.

At 110-years-old, this structure needed to be strengthened, while preserving the historic façade, to accommodate the future increase in train frequency. Siefert Associates, LLC prepared engineered lift plans to carefully demolish the concrete walkways, parapets, and banding along the 1700-foot bridge with a combination of cranes on barges, cranes on grade, excavators on the superstructure, and hand demolition. Our team also created erection plans for the new floor beams, stringers, and deck panels, and designed shoring posts and a jacking procedure for the repair of girder seats of the bascule span.

Location: Brooklyn and Queens, NY
Owner: New York State Department of Transportation
Contractors: Granite Construction, Inc.

Siefert Associates, LLC was hired to prepare engineered lift plans for the spliced rebar cages of the piers of this bridge replacement, also designing the lifting rings and internal bracing to maintain the cage geometry. We also designed several overhang brackets on the exterior girders of the spans to support personnel, formwork, and concrete. A unique challenge was presented by the guide pipes of the cables, which prompted the design of a specialized overhang bracket to avoid interferences.

Location: Stamford, Connecticut
Owner: Connecticut Department of Transportation
Contractors: Halmar International

The replacement of a vital railroad bridge over a congested street in Stamford, CT required the use of Accelerated Bridge Construction. While the contractor constructed the [6] superstructure spans off-site, Siefert Associates, LLC engineered the self-propelled modular transporter [SPMT] arrangement and monitoring plan to safely and efficiently carry each of the 1.6-million pound superstructure spans into place. SALLC also produced erection plans for the jump spans and the design of temporary support of excavation [SOE] and underpinning as part of the construction of the proposed pier.

Location: Jersey City & Kearny, New Jersey
Owner: New Jersey Department of Transportation
Contractors: George Harms Construction Company & Atlantic Coast Dismantling

Siefert Associates, LLC was hired by the subcontractor to create working drawings, procedures, and calculations to demolish the existing vertical-lift bridge safely and efficiently. SALLC analyzed various equipment on the superstructure during operations, designed temporary support and bracing schemes, and devised alternative methods of demolition as required. The team was also hired by the general contractor to collaborate on the lift plans for the new approach spans and on-ramps, analyzing the stability of straight and curved girders throughout erection and designing bracing, as required.

Location: Tarrytown, NY
Owner: New York State Thruway Authority
Contractors: Tutor Perini Corporation & Tappan Zee Constructors

Siefert Associates, LLC was selected to provide services for the repair of the Tappan Zee bridge and the construction of the 3-mile long new bridge, which included several demolition and erection plans and the design of a 170ft bulkhead, a 1000ft temporary trestle bridge, and cofferdams to support construction. Other services included the analysis and engineered lift plans of curved steel girders, support of excavation, and the design of a temporary storage platform.

Location: Bronx and Queens, New York
Owner: New York State Department of Transportation
Contractors: Skanska Koch, Inc. & Judlau-OHL Group

During an earlier rehabilitation project, Siefert Associates, LLC provided inspection services and engineered designs for temporary construction; designing a horizontal, modular lifeline system and an air compressor platform for use by the contractor during repairs. The most recent rehabilitation consisted of a deck replacement along the full 2,190ft of the bridge, for which SALLC provided designs for the support steel and erection procedure for the 30T overhead gantry cranes, demolition and erection drawings for the main span, tower spans, and anchor spans, the design of temporary supports, platforms, and jacking brackets.

Location: Manhattan, NY
Owner: New York City Department of Transportation
Contractors: GCCOM Construction Company Inc.

Due to site constraints, the two trusses were assembled on a barge in the Hudson River, then lifted by a barge crane onto self-propelled modular transporters, which delivered the spans to a temporary staging location, and a hydraulic crane lifted them into their final position. Siefert Associates, LLC created the lift plans for the initial assembly and final erection of each truss span, as well as the erection of the access stairways at each terminus of the bridge. The team also analyzed the stability of each truss span on-the-hook and in its final position, and provided the contractor with comprehensive drawings depicting the procedure to pre-tension the truss rods.

Location: New York, New York

Owner: The Port Authority of New York and New Jersey

Contractors: American Architectural, Atlantic Hoisting & Scaffolding, DCM Erectors, EE Cruz, Gramercy Group, Granite Construction, Navillus Contracting, O’Kane Electrical, Peri Formwork Systems, Phoenix Construction, Skanska, Tutor Perini Corporation, and Yonkers Contracting Company, Winco Corporation/Sorbara Construction Corporation

Siefert Associates, LLC worked on numerous scopes since 200, including demolition and erection plans, analysis of slurry walls, design of temporary support, crane platforms, and protective shields, analysis of existing structure under construction equipment loading, design of temporary retaining walls and dunnage analysis. Notably, SALLC designed the trestle bridge, locally dubbed “The Siefert Bridge”, which created crane access for the installation of the memorial slab.