地震液化区桥台滑坡数值模拟

Numerical Simulation of Abutment-induced Landslides in Seismic Liquefaction Area

摘要:

桥台在桥梁系统中占据重要位置,桥台的稳定性直接影响到桥梁的抗震性能。在国内外大量震害中发现大量由桥台破坏引起的桥梁损坏,而且这些破坏常常伴随着由于液化引起的地面大变形。为研究液化场地中桥台滑坡机理,采用完全耦合的有效应力分析方法,利用修正的 Paster-Zienkiewicz Mark-Ⅲ模型来模拟砂土在地震荷载作用下的液化特性。研究台顶梁重和液化层位置对桥台位移的影响,并分析夯实作用对砂土液化的影响。结果表明:模拟得出结果与振动台试验结果基本一致,而且简单的夯实不能降低砂土液化的风险。

Abstract:

Abutments occupy an important position in a bridge system.The stability of a bridge station directly affects the seismic performance of a bridge.Vast amounts of seismic damage and bridge failure caused by abutment damage have occurred.This damage is often accompanied by large ground deformation induced by soil liquefaction.To study the landslide mechanism of abutment in liquefied sites,the fully coupled effective stress analysis method was used to simulate the characteristics of liquefied sand under a seismic load with a Paster-Zienkiewicz-modified Mark-III model.The effects of beam weight and liquefied layer position on abutment displacement were studied.The compaction effects on sandy soil liquefaction were also analyzed.Numerical simulation produced results consistent with those of the shaking table test suggests the ramming processing alone does not reduce the risk of sand liquefaction.