隧道-土-桥桩相互作用体系振动台试验与数值模拟研究

Shaking table test and numerical simulation of tunnel-soil-bridge pile interaction system

以大连实际工程为背景,通过振动台试验研究了双隧道-砂土-桥桩系统在地震作用下的动力相互作用(SSSI),得到结构、场地的动力响应规律,并与ABAQUS数值模拟结果进行对比。数值模型引入Kelvin本构模型子程序,利用等效线性方法处理砂土在计算过程中的非线性问题。将试验结果与数值模拟结果进行对比,验证了数值模拟的可靠性。在此基础上设计了8种工况,通过对比分析研究了体系内各结构之间的相互作用规律。结果表明,隧道会放大桥桩、临近隧道的峰值加速度,而桥桩却会对侧穿隧道的峰值加速度起到减弱作用;隧道与桥桩的存在均会增大彼此的截面剪力与弯矩,其中受影响的区域主要集中在隧道上下拱,桥桩的桩底与桩-土交界面。

Based on the actual project in Dalian,this paper studies the dynamic interaction(SSSI)of the double tunnel sand bridge pile system under earthquake through shaking table test,obtains the dynamic response law of structure and site,and compares it with ABAQUS numerical simulation.The Kelvin constitutive model subroutine is introduced into the numerical model,and the equivalent linear method is used to deal with the nonlinear problem of sand in the calculation process.The experimental results are compared with the numerical model to verify the reliability of the numerical simulation.On this basis,eight working conditions are designed,and the interaction law between structures in the system is studied through comparative analysis.The results show that the tunnel will amplify the peak acceleration of the bridge pile and adjacent tunnel,but the bridge pile will weaken the peak acceleration of the side tunnel;the existence of the tunnel and bridge pile will increase each other's section shear force and bending moment.The main affected areas are concentrated in the upper and lower arches of the tunnel and the interface between the pile bottom of the bridge pile and the pile-soil.