地震作用下桥台非线性力-位移能力预测及其应用

Prediction and Application of Nonlinear Force-displacement Capacity of Bridge Abutment Under Earthquakes Action

为给考虑桥台非线性行为的桥梁整体抗震设计提供参考,针对非线性土-桥台-桥梁结构相互作用,采用土的双曲线应力-应变关系,给出了桥台纵桥向非线性力-位移行为;并基于全尺寸桥台试验数据,提出了一种桥台非线性力-位移关系的双曲线简化适用计算公式;将此简化公式应用于有限元模型中,分析了桥梁上部结构-桥台背墙-回填土相互作用对桥梁结构地震反应的影响。结果表明:给出的预测模型和简化公式可准确评估桥台纵桥向非线性力-位移能力,且便于应用到桥梁抗震设计中;桥台非线性力-位移滞回性能对桥梁结构地震反应影响显著,在桥梁抗震设计中应合理考虑。

In order to provide a reference for the overall seismic design of bridge considering the nonlinear behavior of abutment,aimed at interactions among soil-abutment-bridge structures,the nonlinear longitudinal force-displacement behavior of abutment was given based on hyperbolic stress-strain relationship of soil.According to full-scale abutment test data of abutment,a simplified and applicative formula was proposed to calculate the nonlinear force-displacement hyperbolic curve of abutment.By applying this simplified formula to finite element model,the influence of interactions among superstructure-abutment-fill on the seismic response of bridge structure was analyzed.The results show that both the proposed prediction model and the simplified formula can accurately evaluate longitudinal non-linear force-displacement capacity of abutment and can be conveniently applied into seismic design of bridges;the non-linear hysteretic behaviors of abutments have significant effect on the seismic response of bridge structure,which should be reasonably considered in the seismic design of bridges.