Seismic Response Analysis on Conventional Bridges in Different Terrains of Mountainous Areas with High Intensity
Highway bridges in mountainous areas with high intensity earthquake limited by complex terrain conditions are permanently located in deep ravines,river valleys or half-filled and half-excavated steep slopes,and the seismic response and damage mechanisms of bridges in different terrains may be inconsistent.In order to study the influence of terrain and structural seismic design on the seismic response and damage mechanism of bridges,the mountainous terrain is summarized into three types of typical terrain,based on the finite element software Midas Civil and the projects under construction,the finite element models of prefabricated pre-stressed concrete T-beam bridges with ductile seismic system and seismic isolation system were established respectively,and the nonlinear dynamic time history analysis of the bridge is carried out by ground acceleration recording.The results show that:1)The seismic response of bridges in high seismic intensity areas is significantly affected by the terrain and seismic system,and the seismic performance of bridges is as follows:"groove"type terrain>"W"type terrain>"V"type terrain,seismic isolation system>ductility seismic system:2)When the average pier height in the tandem is greater than 32 m,the bridge may fail using the seismic isolation design,and the failure is related to the stiffness of the adjacent link,i.e.the smaller the stiffness of the adjacent link,the greater the probability of failure;3)Setting the transverse high-low piers can reduce the shear force of the cross bridge at the bottom of the pier,increase the bending moment along the bridge,and make the low pier under the same cover beam more vulnerable to damage.
high intensity mountain areaductility seismic designseismic isolation designmountainous terrain
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