NJ TRANSIT BRIDGE REPLACEMENT USING ACCELERATED BRIDGE CONSTRUCTION WITH SELF-PROPELLED MODULAR TRANSPORTERS

摘要

NJ TRANSIT'S Raritan Valley Line (RVL) carries 27 trains and more than 27,000 passengers daily over two historic commuter rail bridges at Park and Watchung Avenues in Plainfield, NJ. Replacement of the two 100-year-old bridges provided each bridge with a new main roadway span, bordered on each side by new sidewalk spans, and higher vertical under-clearance. NJ TRANSIT and HNTB selected an innovative Accelerated Bridge Construction (ABC) technique using Self-Propelled Modular Transporters (SPMTs) and a roll-in/roll-out replacement method. SPMTs use multi-axle platforms operated through state-of-the-art, computer-controlled systems, and are capable of pivoting 360 degrees to lift, carry and set large, heavy loads. Key factors determining the decision to use the roll-in/roll-out method included: 1. New bridges could not be built alongside on temporary bents due the given the close proximity of the bridge location to local businesses and the high volume of traffic on each roadway. 2. With both bridges directly adjacent to Plainfield Station, one bridge located at each end of the station platforms, staging construction by switching tracks between structure bays was not viable. 3. SPMTs allowed the majority of demolition and construction to take place at an off-site staging area. 4. SPMTs enabled the ability to precisely time the switch-out to coincide with railroad operations and to minimize impact to the surround community. Each bridge was replaced and operating in one weekend - compared with the traditional method which would have taken weeks or months. The contractor finished its portion of the work with a few hours to spare during each weekend outage, allowing NJ TRANSIT more time to get the tracks and signals back up and running before the Monday morning commute.