Analysis Of Main Cable Shape And Construction Of Main Girder Hoisting Of Steel Girder Suspension Bridge In Mountain Area

The erection of main cable and girder hoisting are the key process in the construction of suspension bridge.After the main cable is installed,the hollow cable shape determines whether the bridge line is in accordance with the design.The control of the hoisting process of the steel truss girder in the bridge deck,especially the new construction technology of the girder with girder,which influences the initial state of the bridge.Therefore,it is of great significance to study the key process of main cable frame and girder hoisting in mountain suspension bridgeThe paper first introduces the analysis theory of suspension bridge.It briefly introduces the hypothesis reasoning of deflection theory,elastic theory and finite displacement theory.The parabolic method,catenary method and numerical finite element method are used to analyze and the calculation of the main cable's alignment.The parabolic method,catenary method and numerical finite element method are used to analyze the calculation of the main cable's alignment.The calculation of the cable shape is analyzed by catenary method and finite element method.The construction theory of main girder hoisting is explained through the forward analysis,backward analysis and the correction of backward analysis.Secondly,based on the actual project engineering,MIDAS/Civil and analytic method are used to calculate the influence of temperature,unstressed cable length,main cable saddle pre-elevation and horizontal force of main cable on mid-span and mid-span.The results of the two methods are verified with each other,and the results are accurate.According to sensitivity coefficient,the corresponding construction suggestions for main cable erection are given.Based on the measured two methods of the measured main cable saddle deviation and the main cable line shape,the position of the balance point of the main cable saddle of the actual air cable line is obtained respectively.Through the correction of the balance point deviation of the main cable saddle and the influence deviation of the air cable line shape,the line shape of the air cable under the reference state is obtained by the linear superposition,which is compared the elevation of the characteristic point with the theoretical air cable line and analyzed the reason of deviation to get the final cable alignment that is used to install cable clamp and baiting the length of suspender.By analyzing the advantages and disadvantages of several common crane beam technology of suspension bridge and the new construction technology of the cross-cable crane walking with beam,the new technology can be used to solve the problems of the geographical environment and engineering economy of bridge.The working principle,control safety and structure safety of the crane beam walking construction technology are studied and analyzed to demonstrate the feasibility analysis of this construction technology.The mechanical characteristics of the crane truss structure are calculated and analyzed with the finite element software.In the deck steel truss girder hoisting construction process,connection of top chord and bottom chord of freedom are adopted by beam segment.In this paper,considering the effect of the load effect of the cable crane,the finite element software is used to simulate the hoisting construction process of the beam section which maximum temporary hinge force is designed to provide the theory design basis for the temporary connection in the field,and the calculation results are studied and analyzed.It provides a reference for the calculation and analysis of the construction process of the cable crane's walking beam construction technology.After the steel truss was successfully assembled,the reasons for the effect of the beam walking technique in the construction process and the damage of the main cable are analyzed and the corresponding suggestions are givenWith the help of practical engineering,this paper that summarizes some experience on the line shape sensitivity of the main cable and the analysis of the line shape of the air cable,and studies the construction technology of the leading international technical cross cable crane with beam walking,which can provide some reference for the construction of other similar projects.