PSC Constructing Method of Continuous PSC Girder Bridges Using Multi-stepwise Thermal Prestressing Method

摘要

PURPOSE: A continuation method of a PSC beam bridge using a multi-stage temperature prestressing method is provided to offset the stress caused by dead load and live load on an inner spot of continuous PSC beam bridges and to continue PSC beam bridges by increasing structural section by a lateral gusset plate. CONSTITUTION: The continuation method of a PSC beam bridge using a multi-stage temperature prestressing method comprises the steps of: installing a high-tensile bolt fixing plate(2) to anchor a steel lateral gusset plate(5) on the top of a PSC beam for continuation; placing the PSC beam attached with the high-tensile bolt fixing plate(2) on the spot for continuation; placing the steel lateral gusset plate(5), then supplying a heat source to generate artificial multi-stage temperature distribution to cause temperature transformation; continuing PSC beams by fastening the high-tensile bolt fixing plate(2) and the lateral gusset plate in a job site, removing the artificial temperature distribution by stopping heating up, offsetting the section force by dead load and live load which act on an inner spot of the continuous PSC beams by the section force by shrinkage of the lateral gusset plate caused by a fall in temperature, and increasing structural section of a continued part by the lateral gusset plate; replacing a temporary support of the PSC beam with a regular support installed on the continued spot if necessary; arranging reinforcing bars for a floor slab, placing a high-tensile bolt fixing plate(2) to be installed on the top of a floor slab, then placing floor slab concrete; and installing a lateral gusset plate on the side of the PSC beam or the floor slab, then applying temperature prestress again.