Anti-Seismic Performance Calculation of Luohe Bridge

In order to calculate the seismic response of Luohe bridge exactly,three computation models were put forward based on long-span bridge seismic analysis method.In whole-pile model,pile-soil interaction was considered.In incomplete-pile model,longer piles in soil were cut when their wave speeds were greater than 500 m·s~(-1),pile-soil interaction was considered.In big mass model,the multi-support excitations of different site soils and the traveling-wave effect resulted from limit transmitting earthquake wave were analyzed.Bridge 3-D earthquake wave was studied by finite element program ANSYS.The result shows that the displacement and axial force of longer pier are greater,the shorter pier is,the bigger its transverse and lognitudinal shearing forces and its flexural torque in lognitudinal are,the most deviations of displacement responses for incomplete-pier model and whole-pier model are 7.4% and 8.2% respectively,therefore,incomplete-pile model is adaptively used for the simplified analysis of bridge response when its piles are too long,big-mass model is greatly affected by the capacity of mass block and the length of bridge pier,the bridge is insensitive to traveling-wave effect when its span is below 160 m and its length is below 660 m,shorter pier sectional resisting force design and longer pier ductility design must be strengthened in the seismic design of continuous rigid-framed bridge with high piers and long spans based on considering pile-soil interaction.4 tabs,6 figs,11 refs.