The Dynamic Response Analysis Of Liquefaction And Model Test About Underground Structure Of Subway In Sand Stratum

In China,earthquakes are frequent,intense,and widely distributed,and most are shallow earthquakes.With the development of urban rail transit in China,it is of great significance to carry out seismic analysis of underground structures.In the early days,it was generally believed that the seismic safety of underground structures can be guaranteed.Until 1995,serious damage to underground structures Kobe earthquake in Japan caused widespread concern,the seismic design and research of the underground structure have been paid attention to by many scholars.In this paper,the vibration characteristics of the underground structure are summarized.On this basis,the Taiyuan subway line two is used as the engineering background,based on the shaking table test,numerical inversion and numerical simulation,the liquefaction response of underground structure in sandy soil is analyzed.A total of three tests were carried out in this paper,and the shaking table test was carried out for the tunnel structure model,the station structure model and the station model of underground enclosure structure with lateral deformation and liquefaction suppression.In the preparation stage of the experimental design,based on the soil characteristics of Taiyuan sand soil test,the tunnel structure model and the structure form of the model box are prepared according to the geometric similarity ratio and the similar elastic physical relationship.According to the results of shaking table model test,the dynamic response acceleration,pore water pressure and displacement characteristics are analyzed.The dynamic response characteristics of dynamic response acceleration,pore water pressure and lateral displacement are compared and analyzed by model test FLAC3D numerical analysis.On this basis,the dynamic simulation of the prototype field model is generalized,and the dynamic response characteristics of the prototype field are obtained.The model test,model and prototype numerical analysis results are compared and analyzed,and the anti-seismic and anti liquefaction mechanism of diaphragm wall retaining structure is briefly analyzed.