SLIDE-IN REPLACEMENT OF TWO I-84 BRIDGES IN NEW YORK STATE

摘要

This project involves the rapid replacement of the existing I-84 Bridges over Dingle Ridge Road in New York State using the slide-in construction method. The existing structures carry two travel lanes in each direction over Dingle Ridge Road and are too narrow to cross over traffic during replacement. I-84 is heavily traveled, with a peak AADT of up to 100,000, with 16% truck traffic. The existing structure has a 3-span steel girder superstructure with a total length of 135’-0”. The new structures utilized 80’-0” single-span concrete NEXT beam superstructures.rnThe superstructure consists of adjacent NEXT beams made composite with one another through longitudinal Ultra High Performance Concrete (UHPC) closure pours for greater durability. The approach slabs consist of precast concrete modules that are also made composite through UHPC closure pours. The bridge replacements were done over two weekend nights using the slide-in construction method. Closure of the I-84 roadway was limited to just 20 hours for each bridge to allow for the rapid demolition of the existing bridge and slide-in of the new superstructure. Conventional bridge replacement would have extended over two years and would have required a temporary bridge in the median estimated to cost about $2.0 Million. Construction was started in March 2013, and the first slide-in was completed on Saturday Sept 21, 2013 between Saturday 5 PM and Sunday 1 PM. The second slide-in was completed on the weekend of October 19, 2013. Approach pavement work was performed during the closure period to raise the widened roadway to the same elevation as the raised section carrying two lanes.