闵浦大桥浦西段上横梁底模支撑桁架设计与施工

Design and Construction of Supporting Truss for Upper-beam Bottom Formwork in Minpu Bridge Puxi Segment

由于施工前期动迁延误等原因,闵浦大桥浦西段施工进度比浦东段落后3个月。为保证2009年底通车总体目标,采用底部设置钢桁架作为底模支撑系统,结合钢桁架操作平台和模板平台,钢桁架在下横梁顶部拼装完成后整体提升至高空安装的施工方案。确定桁架系统选型后,用有限元软件Midas/civil计算其应力和变形,确保满足要求,并提出桁架提升应急预案。桁架现已提升就位,与传统施工工艺比较可加快将近1个月的施工进度。

Because of delay induced by removal, Puxi segment of Minpu Bridge is constructed three monthes later than Pudong segment. New construction scheme is adopted in the upper-beam construction of Puxi segment in order to ensure general goal that the bridge should be finished before 2010, that is taking steel truss as supporting system of bottom formwork, and assembling the steel tress on the top of lower-beam according to operation platform and formwork platform, then lifting the truss integrally and installing it at high altitude. After selecting the truss system, its stresses and deformations are calculated by Midas/civil software to satisfy requirements. Furthermore, emergency response plans during lifting are suggested. Compared with traditional construction technology, the new scheme can shorten construction schedule by about one month.