WESTMINSTER DRIVE UNDERPASS - ACCELERATED BRIDGE CONSTRUCTION USING GIGO (GET IN-GET OUT) BRIDGE CONCEPT

摘要

The Ministry of Transportation Ontario (MTO), in partnership with consultants and contractors, developed a method for accelerated bridge construction called Get in-Get out Bridge or GiGo Bridge. The GiGo Bridge concept is an Accelerated Bridge Construction (ABC) technique for replacing bridges over freeways, in 45 days or less, with a full closure of the crossing road. The concept requires that bridge components be prefabricated in advance of the on-site work. This has the advantage of shifting a substantial portion of the work into the winter months, freeing up staff resources and equipment for the summer months. Additional benefits of GiGo Bridge include shorter disruptions to traffic as well as enhanced safety, since workers have less contact with traffic during the project. In 2014, the Westminster Drive Underpass on Highway 401 in London, Ontario, was successfully replaced using the GiGo Bridge concept. The new, two-span integral abutment bridge consists of a number of prefabricated elements, including precast concrete abutments, wingwalls, and pier cap; and steel box girders. However, the accelerated bridge construction feature that is of primary interest in this project, and that is key to the GiGo Bridge concept, is the use of 6 prefabricated, 95-tonne supermodules, each of which consists of a steel box girder with a cast-in-place concrete deck. Based on the success and lessons learned from the Westminster Drive project, MTO will be using the GiGo Bridge concept on other projects, including the replacement of the Highway 401/Highway 19 Underpass in Ingersoll in 2017.