Study On Dynamical Analysis Of Prefabricating Beam On Bridge Floor In Mountain Difficult Terrain

Precast yard is an important temporary site for the prefabricated concrete beambridge and continuous beam bridge, which not only affect construction cost, but alsoaffect the construction period. In recent years, it’s very difficult to find a properprecast yard in some mountainous highway in China, an alternative method is toprefabricate beam on bridge floor.This paper, based on the Sichuan provincetransportation department technology program of “research on technology ofprefabricating T-beam in mountain difficult terrain” and the Sichuan province ba-shanhighway program of “research on technology of prefabricating beam on bridge floorin mountain difficult terrain”,has carried out the following work:①The construction methods of prefabricating beam in mountain difficult terrainand its usage place are summarized;②The vibration characteristics of tool girders are analyzed by using ANSYSfinite element software, the influences of upper and lower factors of tool girders onthe fundamental frequencies and mode of vibration are studied, the upper factorscontain”without prefabricated T-beams”、”symmetrical arrangement”and”asymmetricarrangement”,and the lower ones contain”pier forms”、”pier height”and”transverseconnecting beam of high pier”;③Because of moving load conditions(concrete mixer tanker and beam carrier)that appear in the process of prefabricating beam on bridge floor, the influences ofcoupling effect of speed and factors which contain spans(25m、30m and40m)、pierheights(0m、10m、20m、30m and40m) and load cases(pedestal longitudinalarrangement along the bridge and Perpendicular to the bridge) on dynamic responseof precast yard are analyzed, then doing a simulation analysis to the concrete mixertanker and beam carrier;④The influences of beam carrier with different axle types、spring stiffness、loadof prefabricated beam and pavement roughness(amplitude and wavelength) oncoupling effect of vehicle-bridge are analyzed.The research results have been successfully used in G75Guangyuan highwayand Ba-shan highway of Sichuan,and have achieved good economic and socialbenefits.