Longitudinal Direction Seismic Response Analysis Of Multi Line Intersecting Underground Tunnel

With the continuous development of economy, city urbanization becomes fasterand faster.The traffic problem of first-tier cities is deteriorating. All the supermetropolis around the world take the development of city underground rail transit as animportant way to ease the traffic pressure. So developing underground space will be thetrend in the future. At the same time,China is an earthquake prone country, as theprevious earthquakes brought huge losses to the lives and property of the people and thetunnel occupies an important position in the city infrastructure, so the tunnelengineering need strict seismic response analysis to ensure reliable seismic performanceafter the completion. In this respect, Japan has long-term accumulated experience in theunderground engineering seismic areas and is worth to learning. Based on the abovebackground, these aspects will be analyzed individually in this paper.(1) The related theories and methods to study the seismic response analysis oftunnel.Discussing the application of the response displacement method in tunnel seismicresponse analysis.Solving some key parameters in detail and summarizing therequirements of seismic properties specified in code for seismic design andgemeralizing the general steps of tunnel seismic design.(2) Based on the response displacement method, modeling a city undergroundtraffic tunnels according the design and doing the seismic analysis of structure. Thetunnel structure is simulated by beam element. Using soil-structure interaction springsto simulate the interaction between soil and structure. Using connect springs to simulatethe connection between piecewise structure. Getting the results of force reaction anddeformation reaction of the junction between the structure body. Based on the seismicspecification to judge the safety of tunnel design.(3) To propose optimization proposals and reflect it to the structure model andcalculate until get the ideal reaction result. If the design of tunnel is unable to achievethe reliable seismic performance, recommendations will be put forward, mainly throughadjusting steel amount of box body connection or increasing the structure piecewisequantity or changing the sectional connection mode between the box body to reduce theseismic response of tunnel structure.In this paper, some conclusions are obtained through analyses results: The dynamicreaction of the time history analysis which combined with response displacement method theory and the finite element modeling method has good practicality inperformance-based seismic design; The entirety of tunnel structure is contradict with theseismic performance; The seismic performance of tunnel can be effectively improvedwith segment structure and suitable connection mode.