ANALYSIS OF COUPLED AXIAL-TORSIONAL POUNDING RESPONSE OF ADJACENT BRIDGE STRUCTURES

摘要

Poundings between adjacent bridge structures were observed in almost all the major earthquakes in the past. Owing to the extreme complexities involved in the contact/pounding phenomenon,previous studies of pounding responses of adjacent bridge structures are usually based on the simplified lumped mass model or beam column element model. Therefore,only point-topoint pounding in ID,usually the axial direction of the structures,is considered. In a real bridge structure under seismic loading,pounding could be between the entire surfaces of the adjacent decks,torsional responses may also induce additional poundings at corners of the adjacent decks besides those at the geometric centre of the deck cross sections. This paper performs the analysis in the time domain by using the transient dynamic element code LS-DYNA. A 3D finite element model of two adjacent bridge structures from a previous study is constructed and studied. The results obtained based on the simplified methods and the proposed detailed modelling are compared and discussed. Numerical results show that detailed 3D finite element model is necessary for a comprehensive analysis of pounding between adjacent bridge structures because surface to surface pounding and torsional response induced pounding are not modelled in the commonly adopted ID models.