拉索减震支座在近断层城市高架桥梁中的应用

Application of Cable-sliding Friction Aseismic Bearing(CSFAB) in Urban Elevated Bridges under Near-fault Ground Motion

处于近断层地震威胁下的城市高架桥梁需要引入减隔震设计方案解决抗震问题,拉索减震支座由于其良好的适应性较好地解决这一难题。以某城市高架桥中的4×30 m跨径连续梁桥为工程背景,建立全桥有限元模型,基于不同特性的地震动输入,进行拉索减震支座减隔震方案的桥梁结构非线性时程分析。计算结果表明,无论是近断层脉冲型地震动、还是非脉冲地震动或一般远场地震动作用,拉索减震支座均能起到很好的减震作用,满足结构的抗震需求,是高架连续梁桥减隔震体系的理想设计结构。

Under the threat of near-fault earthquakes,urban elevated bridges should require the isolation design scheme to solve seismic problems.The cable-sliding friction aseismic bearing(CSFAB) can solve problems effectively because of its great adaptability.With the background of an urban elevated bridge project,its continuous girder bridge with 4 × 30 m span is made a full-bridge finite element model based on different characteristics of ground motions input and then,the nonlinear time history analysis of bridge structure with the CSFAB is carried out.The results show that the CSFAB has an excellent earthquake mitigation effect whether under near-fault pulse ground motions,non-pulsed ground motions or generally far-field ground motions.It is an ideal solution for isolation system in urban elevated continuous girder bridges.