跨高铁800m半径PC连续箱梁顶推施工控制研究

Research on the Jacking Construction Control of PC Continuous Box Girder with 800 m Radius across High-speed Rail

研究目的:桥梁结构施工日趋大型化和复杂化,给施工控制技术带来新的挑战。为克服这一难题,一种有效的施工方法——顶推施工法应用前景越来越广阔。本文依托厦深联络线位于R=800 m圆曲线上PC连续箱梁的顶推施工控制,采用数值模拟与有限元仿真模拟的方式,施工前模拟计算出顶推法施工方案是否满足安全要求。研究结论:(1)导梁在顶推过程中,最大拉压应力和最大剪应力都出现在导梁根部;(2)分别在导梁根部最大负弯矩和最大正弯矩工况下,埋入混凝土部分的钢导梁各向正拉压应力、竖向剪应力均小于Q345钢材相应的许用应力,满足规范要求;(3)导梁翼缘和腹板高强螺栓连接在顶推荷载作用下,高强螺栓连接最不利截面受力满足要求,仅腹板螺栓连接安全储备略小;(4)本研究结果可为今后为圆曲线上PC连续箱梁桥顶推施工控制提供参考。

Research purposes:As the construction of bridge structures becomes larger and more complex,it brings new challenges to construction control technology.In order to overcome this problem,an effective construction method is the application of the jacking construction method.In this paper,based on the circular curve of R=800 m,relying on the Xiamen-Shenzhen tie line,numerical simulation and finite element simulation are used to simulate whether the construction method of the jacking method meets the safety requirements before construction.Research conclusions:(1)The maximum tensile and compressive stresses and shear stresses occur at the root of the guide girder during the pushing process of the guide girder.(2)Under the conditions of maximum negative moment and maximum positive moment at the root of the guide girder,the tensile and compressive stresses and vertical shear stresses of the steel guide girder embedded in the concrete part are less than the corresponding allowable stresses of Q345 steel,which meets the requirements of the code.(3)Under pushing load,the most disadvantageous section of high-strength bolted connection meets the requirement.Only the safety reserve of web bolted connection is slightly smaller.(4)The research results can provide a reference for the construction control method of PC continuous box girder bridge on circular curve in the future.