Key Control Technology Of The Construction For Long Span Steel Truss Bridges

With the continuous development of traffic construction in China,the structural system of the bridge is becoming more and more new and the construction technology is progressing.In recent years,the construction of long-span bridges is endless,and its structure is more complex,and the difficulty of construction is increasing,higher requirements for construction control are put forward.According to the largest span and simply supported steel truss beam of Chinese high speed railway,namely Xi'an-Chengdu railway passenger dedicated line acrossing Xi'an-Baoji railway passenger dedicated line oversize bridge 132 m steel truss girder construction example,we analysis the construction control of large span simply supported steel truss girder,propose the method of erecting large span steel truss girders by side assembly and jacking transverse movement.It can effectively solve the technical problems such as narrow construction site,complex terrain across high speed rail,highway and so on,and cantilever erection of cantilever erection.It greatly reduces the risk of safety and provides experience for similar projects.First of all,this paper briefly describes the structural characteristics of large span steel truss girder and application of the bridge construction in modern times,and lists examples of construction accidents caused by the instability of bridge structures at home and abroad,and puts forward the important significance of key link control for bridge construction.Secondly,taking the construction control of the 132 m steel truss beam as an example,the paper briefly introduces the key control techniques of the stability of steel tube temporary piers,the process of steel truss beam assembling,steel truss beam transversal and pre-arch in the construction of long span steel truss girder,and put forward the key contents and control measures for the construction control of such long-span bridges,combining with the construction control examples of the bridges.Thirdly,the stress and deformation of the steel truss beam and temporary transversal facility are calculated by the finite element software,and the structural stability is analyzed under the construction state,which provides the theoretical basis and data support for the actual construction.In the end,the article analysis and researches the monitoring and monitoring results of the steel truss beam transversal process.Through the monitoring of the stress and displacement value of the control position of the steel tube temporary pier and the slideway beam in the construction of steel truss beam,and compared with the theoretical calculation value,the difference between the measured data and the theoretical calculation is controlled within the allowable range,so as to achieve the target for the control of the steel truss beam transversal construction.It proves that the analytical method adopted in this paper is scientific and effective.