Study On Safety Analysis Of Steel Box Girder During The Incremental Launching Construction Stage

ABSTRACT:With expansion of railway lines, more and more situations which across existing lines appear. The incremental launching construction is a common construction method of new line bridges which across existing lines. The mechanical behavior of steel girder and pier was researched during incremental launching construction. The main contents are as follows.(1) The development application of incremental launching method, technological characteristics of incremental launching construction and mechanical characteristics of girder during incremental launching construction were elaborated in detail.(2) The mechanical behavior of steel box girder during incremental launching construction stage was simulated by using Midas/Civil, which contained the size and variation of reaction force, deformation and combined stress. The scaffold simulation including chute beam and steel tube column was also calculated and checked. The size and variation of internal force or stress and overall deformation of scaffold were analyzed.(3) The stability cosfficient against longitudinal overturning of steel box girder was calculated by constructing simple supported beam models. The stability cosfficient against transverse overturning under wind loads was also calculated.(4) The local strss of steel box girder was analyzed by using finite element analysis software Midas/FEA. The local stress of girder on the pier and bracket was analyzed. The maximum value and position of stress of top plate, bottom plate, web, stiffening rib and diaphragm plate was obtained.(5) The pier was simulated by using ANSYS. The mechanical property of pier was analyzed under different level force.