桥梁在移动车辆荷载作用下的影响系数.pdf

The 12th International Symposium on Structural Engineering IMPACT FACTORS OF THE BRIDGE UNDER MOVING VEHICULAR LOADS Xinfeng Yin 1*, Xiao Hu 1 , C.S.Cai1,2, Yang Liu1 1 School of Civil Engineering and Architecture, Changsha University of Science Technology, Changsha 410004, Hunan, P.R.China 2 Dept. of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA * Corresponding author: yinxinfeng@163.com Abstract: This paper presents a new method to study the impact factor of a bridge based on the model updating technique. Using the genetic algorithm (GA) by minimizing an objective function of the residuals between the measured and predicted responses, the bridge and vehicle coupled vibration models were updated. The simulated results show that compared with the other bridge codes, the impact factor specified by the bridge code of AASHTO (LRFD) is the most conservative one, and the value of Chinese highway bridge design code (CHBDC) is the lowest; for the large majority of old bridges whose road surface conditions have deteriorated, calculating the impact factor with the bridge codes cannot obtain the reliable results. Keywords: Bridge, moving vehicle, model updating, impact factor, vibration 1 INTRODUCTION and the interaction force relationship at the contact patches, the vehicle-bridge coupled system can be established by combining the The bridge-vehicle interaction has attracted equations of motion of both the bridge and much attention over the last two decades due to