Shaking Table Model Test Scheme Optimization Of Transverse Seismic Response Of Tunnel In Complex Site

The 1995 Kobe earthquake underground structure has suffered serious damage to the world.People begin to study the seismic response characteristics and seismic performance of underground structures.This paper takes Mother Bay Tunnel as an engineering background and develops shaking table model test scheme optimization of transverse seismic response of tunnel in complex site.In this paper,the characteristics of seismic damage of underground structures are summarized.Then,the research status of shaking table test of soil structure interaction system is reviewed.According to the purpose of the test,combined with the experimental conditions,the geometric similarity ratio of the test is determined to be 1/50.The model box is made of laminated shear boxes.The stones and sand,clay simulate soft hard soil.It is proved that it is reasonable to simplify the complex formation into three layers of soil through numerical simulation.It makes tunnel model by using silica gel material.At the same time,according to the results of numerical simulation analysis on tunnel seismic response,the sensor selection and layout schemes are analyzed.Finally,the selection of ground motion and the loading system are described in detail.In this paper,combined with the finite element software ABAQUS,equivalent linear model is used for soil and liner model is for lining materials.With rigid bedrock boundary conditions,considering the soil structure contact,we build up the analysis model of nonlinear seismic response of tunnel.Firstly,the vertical and horizontal acceleration time history of the soil at the monitoring points under different seismic waves are given.Results show that peak of vertical acceleration will gradually increase with the soil layer from the bottom to the surface.At the soft and hard junction of the soil,the peak acceleration of the soil layer will change.Horizontal peak acceleration becomes stable;and then gives the tunnel monitoring point strain time history.The results show that the maximum strain appears near the vault and invert,the minimum value appears at the arch waist within a range of 45 degrees.At the same time,we find that the seismic amplification effect in soft soil is larger than that in hard soil,and the strain will change at the boundary of soft and hard soil.The model can be used for seismic analysis of underground structures in complex sites,which can be used as a reference for subsequent similar tests.