Parameter optimization study for unseating prevention device of rc simple-supported girder bridge based on nonlinear static and dynamic analysis methods
JIANG Hui; Li Yu; Xiong Zhi-yang; YANG Qing-Sshan; ZHU Xi; ＮＩＹｏｎｇ-ｊｕｎ1
1.School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China;2.Highway School, Chang’an University, Xi’an 710064, China;3.Changsha Rail Transit Group Co., Ltd, Changsha 410007, China
Abstract：Unseating prevention device is an effective measure to forefend beams from falling from RC girder bridges, so it is necessary to study thoroughly the reasonable range of the stiffness of this rubber-tie bar device. Based on capacity spectra method of FEMA440, a typical railway RC simple-supported girder bridge was taken to discuss the stiffness distribution for different site soils and fortification intensities under the seismic demand of current design spectra and Wenchuan Earthquake. It indicates that the site soil has no obvious influence on the stiffness value of unseating prevention device, and the rational stiffness ratio is between 0.05~0.15 times of the linear stiffness of the adjacent beams for 8 degree of high-level fortification intensity, in which condition the relative displacement between the piers and beams as well as the overall structural response can be effectively repressed. However, the fortification intensity has remarkable influence on the stiffness. When PGA is less than 0.2g, it is not essential to install unseating prevention device, and when PGA is 0.4g and 0.6g, the reasonable stiffness ratio may be 0.1 and 0.2 respectively. The rationality and reliability of above conclusion was validated by nonlinear time history analysis, which can provide reference for the seismic design of RC bridges and the revision of related seismic design codes
2012, Vol. 31 
