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: 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: 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: 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: 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.