Study On The Dynamic Response Numerical Simulation Of Tunnel And Stratum Due To Subway Moving Loads In Ground Fissures Area

With the continuous expansion of city size, the ground traffic pressure is also increasing,the development of underground space is to represent the general trend, in recent years，inorder to alleviate the city traffic congestion，the construction of subway is springing up in thebig city.In Xi’an，the construction of subway has entered a new period.At present,Xi’an metroline1and2have been operating，the construction of other lines are in full swing.Due to thespecial geological conditions in Xi’an and the existence of the ground fissures，a series of newproblems are brought to the subway construction，such as the problems of subway tunnel-stratum–ground fissure dynamic interaction and the subway vibration in ground fissure area，have become the important topics of concern，and whether the subway moving loads willaffect the safety operation of subway tunnel in ground fissure area is an important topic inurgent need to study in subway construction.This paper is on the basis of Xi’an metro line2，relying on the National Natural ScienceFoundation project“study on the interaction of the stratum–ground fissure–tunnel under thesubway dynamic load”，focusing on the vibration response of the tunnel and stratum inground fissure area，the propagation law of the subway vibration and the dynamic stress anddeformation characteristics of the tunnel and stratum under dynamic loading.The researchmethod in this article is numerical simulation，the main research contents are as follows：（1）Through consulting literature, the mechanism of subway vibration，the general rulesof vibration propagation and the influence factors of vibration strength are summarized；（2）The three-dimensional vibration response numerical simulation method oftunnel-stratum-ground fissure model is proposed based on ABAQUS and the method torealize subway moving loads is given；（3）Through the simulation of vibration response of the integral tunnel model，thesectional tunnel model and the tunnel model without ground fissure，the propagation law ofthe subway vibration is studied.The vibration response of ground fissure model and the noground fissure model，the integral tunnel model and the sectional tunnel model are compared，the influence of the ground fissure and the section of the tunnel on the vibration response areexpounded.And according to the sectional tunnel model, analyzed the influence of the velocity on the vibration response；（4）Based on the study of the dynamic stress and deformation of the integral andsectional tunnel model，the transmission and distribution law of dynamic stress in soil andtunnel lining，and the rules of deformation and distribution of soil are analyzed.The research achievements of this paper have some reference value to the research ofsubway vibration in special site,provides reference for the subway security operationmonitoring，lays the foundation for the formulation of vibration control standards，andprovides reference for the following experiments and field tests.