East 175th Street Bridge Demolition
As part of NYCDOT Project No. HBX1215, “Rehabilitation of the East 175th Street Bridge over Metro-North railroad (MNRR)”, Siefert Associates LLC (SALLC) worked with Beaver Concrete Construction to prepare a lift plan for the Stage 1 removal of the existing bridge girders. Careful preparation and planning allowed for all girders within the Stage 1 work zone to be removed within a single track outage. A 550-ton mobile crane (Liebherr 1450-8.1) was used to safely lift the girders from their bearings to the disposal areas, and was strategically placed in the intersection of East 175th Street and Park Avenue [Northbound] to limit outrigger surcharge impacts on the adjacent structures. Large dunnage pads were required to spread the large outrigger forces produced by the lift, specifically the lift of the fully encased fascia beam weighing nearly 80,000 lbs that was picked at a radius of 75’-0”. SALLC also provided rigging and temporary stability bracing design as part of the final submittal package. With Stage 1 demolition complete, SALLC and Beaver Concrete Construction prepare for the erection of the new pre-cast concrete box beams.
Figure 1: Liebherr LTM 1450-8.1 assembled and ready to commence lifting.
Figure 2: Fascia girder being lifted and moved to disposal location.
