近场地震动对桩基础高墩摇摆反应的影响

为明确桩基础高墩自复位隔震装置的适用范围,研究了近场地震动特性对桩基础高墩摇摆反应的影响．以断层距作为识别近场地震动的主要参数来选取地震动,采用两弹簧模拟桥墩的提离摇摆,基于某铁路高墩桥梁,采用非线性时程分析方法,讨论了近场地震动对高墩摇摆反应的影响．结果表明,近场水平地震动显著增大墩顶的摇摆位移,竖向地震动对桩基础高墩的摇摆反应有不利影响．在近断层地震区桩基础高墩应谨慎采用摇摆隔震装置．

Effect of near-field ground motion on the rocking response of tall pier with pile foundations

To determine the scope of self-centering for the tall pier with pile foundations, the effect of near-field ground motion on rocking response was investigated. Fault distance was used as parameters identifying near-field to select ground motion. Two springs simulated the uplift and rocking of the pier. Rocking response of a railway tall pier was investigated through nonlinear time history analysis by inputting strong ground motions. The results show that the displacement at pier top is significantly increased by near-field horizontal ground motion. It is also observed that vertical ground motion is unfavorable to the rocking response of tall pier with pile foundations. Rocking devices for tall piers in near-fault zones should be cautious.