CSX HOFFMAN'S SPAN REPLACEMENT OVER THE MOHAWK RIVER

摘要

CSX Transportation has completed replacement of four spans and stringer structural steel modifications to the Mohawk River Bridge located at mile post QG 40.81 in Rotterdam Junction, New York. The existing bridge spans had numerous fatigue issues resulting in restricted speeds and future maintenance issues on this high traffic volume double track mainline. OCCI, Inc. was contracted for the work in 2010. The contracted work included design and fabrication of the false work support system, a proprietary hydraulic sliding system to slide the two existing 150-foot trusses out and new plate girders spans back into position during a limited time outage, erection of the new plate girder spans utilizing floating plants, modification of existing stringers, and rock drilling and joint repair to existing stone piers. This paper presents the challenges associated with erecting the two new 150-foot spans parallel to the existing spans on falsework supports and the slide out/slide in of old and new spans with the contractor designed hydraulic slide system during two scheduled 20-hour closures. The paper also discusses the additional challenges of the project brought about by Hurricane Irene and the resulting record flood event in the middle of the project prior to the new spans being slid into place.