Study On Seismic Dynamic Response And Vibration Absorbing Measures For Portal Of Double-Arch Tunnel

With the west of China greatly exploiting, a mass of tunnels for highway, railway,and water and electricity projects have been constructing. It is inescapable to construct tunnels near active fault or in high earthquake intensity regions.The seismic response analysis of underground structures is of great economic and social significance. As a special structure of tunnel constructed in high earthquake intensity regions, it is necessary to study on double-arch tunnels in seismic response and the corresponding measures of shock absorption. This paper is research on seismic dynamic response of portal of double-arch tunnel, and numerical modeling is applied to analyzing seismic dynamic response rules of portal of double-arch tunnel. This paper's contents are summarized as following:Firstly, the spectrum or frequency components with Xu dianzi tunnel seismic wave are analyzed; due to the baseline drift in the seismic wave, baseline correction has been applied.Secondly, the effects of many factors on seismic dynamic response of double-arch tunnel, such as depth of burial, parameters of surrounding rock, earthquake intensity, are numerical modeled, and rules of variation in corresponding parameters are analyzed and compared.Thirdly, the effects of shock absorptions are analyzed by way of changing material properties of shock absorption layer,space between anti-seismic joint and material properties of anti-seismic joint, and the influences of variations of material properties of shock absorption layer,space between anti-seismic joint and material properties of anti-seismic joint are summarized.Then, the effects of shock absorptions are analyzed by way of changing depth of grouting and changing location of grouting , and the influences of variations of depth of grouting and location of grouting are summarized.In the final chapter of this thesis, conclusion and expectation are given.