Research On Dynamic Response Characteristics Of Lining Structure At The Entrance Of Biased Mountain Tunnel Under Earthquake And Its Shock Absorption Technology

Southwest China has complex geological conditions and frequent earthquakes.The construction of mountain tunnels is usually limited by objective conditions such as geological structure,environmental conditions,and engineering costs.It is ineviTablele that bias tunnels will be built at the entrance of the tunnel.Frequent earthquakes and openings The complex geology of the bias causes the tunnel structure to be easily damaged.Due to the uneven load on the surrounding rock of the deep buried side and the shallow buried side of the biased tunnel structure,there is also a large difference in its seismic response when an earthquake occurs.Therefore,it is urgent to carry out in-depth research on the seismic damage mechanism and mitigation measures of the lining structure at the entrance of the biased mountain tunnel.This paper comprehensively applies theoretical analysis,numerical simulation and other research methods,and relies on the biased opening section of the Jiu-Mian high-speed flat ground spiral tunnel,from the damage mechanism of the lining structure of the biased mountain tunnel opening,seismic response characteristics,and seismic mitigation techniques.Direction of research.The main research contents and research results are as follows:(1)Study on the mechanism of earthquake damage at the entrance of a biased mountain tunnelThe geological characteristics of the biased tunnel are summarized by consulting relevant literatures,and the damage method of studying the seismic damage of the tunnel section of the biased tunnel is analyzed.The quasi-static method is proposed to calculate the pressure of the surrounding rock pressure of the biased tunnel,revealing The earthquake damage mechanism of the biased tunnel is analyzed,and the pressure distribution rules of the shallow buried side and the deep buried side of the biased tunnel under earthquake are analyzed from the aspects of surrounding rock type and ground dip angle,and the mechanism of earthquake damage at the entrance of the mountain tunnel is revealed.(2)Research on the seismic response characteristics of the lining structure at the entrance of a biased mountain tunnelThe internal force of the lining structure on the shallow and deep burial sides of the biased mountain tunnel opening section is based on the characteristics of the surrounding rock and the inclination angle of the tunnel by using the MIDAS-GTS finite element analysis software based on the biased opening section of the Jiu-Mian high-speed flat ground spiral tunnel.This paper studies the stress response characteristics of stress,and compares the pressure distribution law of the surrounding rock of a biased tunnel under pseudo-static earthquake,and summarizes the seismic response characteristics of the lining structure of the tunnel section of a biased mountain tunnel.(3)Research on seismic mitigation technology of tunnel lining structure at the entrance of a biased mountain tunnelThrough theoretical analysis and literature analysis,the advantages and disadvantages of the current tunnel vibration reduction technology are studied,and the surrounding ring grouting reinforced surrounding rock is used to damp the biased tunnel.MIDAS-GTS finite element analysis software The analysis and analysis of the effect of the whole ring interval grouting to strengthen the shock absorption are carried out,and the optimal grouting shock absorption scheme based on the working conditions is optimized.