Technology Of Overhead Jacking Construction Of Frame Bridge With Large Span And Deep Foundation Pit For Existing Multi-tracks Railway

As increasing the proportion of Frame Bridge with large span,to meet the rigidity requirement of large span frame bridge,thickening structure section makes the self-weight and jacking force larger,and increases the construction difficulty and cost.Also,there are many factors making the force condition more complicated during construction.Therefore,it becomes an urgent problem how to reduce the influence on train traffic,make the frame bridge in place rapidly and accurately,solve the any problems in the overhead and jacking process,and reduce the negative mechanical impact during the construction of Frame Bridge.The paper based on the project of railway closed conduit in west of PingDingShan of JiaoZhi line,the main channel of South-to-North water diversion,adopts a special structure and construction method to satisfy the project's requirements,mainly studies the structure design and construction method of overhead jacking construction of Frame Bridge with large span and deep foundation pit for existing multi-tracks railway.This paper applies the finite element software of Midas GTS to simulate.Firstly,it establishes the model and determines a variety of relative factors.Then it defines and applies all kinds of loads and boundary conditions.Combining with actual engineering,the paper has analyzed the structural displacement and stress in different working condition through software calculation and filed monitoring,aim to demonstrate the rationality and feasibility of the proposed method in this paper.The paper based on reference for conventional overhead jacking method,combined with the practical situation of project,decentralizes the structure.Creatively adjusting the single-layer structure to double-layer and upgrading the mature single-overhead jacking method for twice-overhead and multiple-jacking,ensures the smooth implementation of the project.The content of this research not only has scientific significance,but also can be used to guide the engineering practice,and has great reference to similar engineering.