Nonlinear analysis of pounding between decks of multi-span bridge subjected to multi-support and multi-dimensional earthquake excitation

ZHANG Hai(张海), JIAO Li(焦莉), LIN Jun-nan(林君南)

(School of Civil Engineering, Shenyang Jianzhu University, Shenyang 110168, China)

Abstract:The nonlinear analysis of pounding between bridge deck segments subjected to multi-support excitations and multi-dimensional earthquake motion was performed. A novel bottom rigid element (BRE) method of the current displacement input model for structural seismic analysis under the multi-support excitations was used to calculate structural dynamic response. In the analysis, pounding between adjacent deck segments was considered. The seismic response of a multi-span bridge subjected to the multi-support excitation, considering not only the traveling-wave effect and partial coherence effect, but also the seismic non-stationary characteristics of multi-support earthquake motion, was simulated using finite element method (FEM). Meanwhile, the seismic response of the bridge under uniform earthquake was also analyzed. Finally, comparative analysis was conducted and some calculation results were shown for pounding effect, under multi-dimensional and multi-support earthquake motion, when performing seismic response analysis of multi-span bridge. Compared with the case of uniform/multi-support/multi-support and multi-dimensional earthquake input, the maximum values of pounding force in the case of multi-support and multi-dimensional earthquake input increase by about 5-8 times; the absolute value of bottom moment and shear force of piers increase by about 50%-600% and 23.1%-900%, respectively. A conclusion can be given that it is very necessary to consider the pounding effect under multi-dimensional and multi-support earthquake motion while performing seismic response analysis of multi-span bridge.

Key words:pounding; bridge; bottom rigid method (BRE); multi-dimensional and multi-support earthquake motion