Study On Seismic Response And Anti-seismic Optimization Measures Of Tianjin Metro Shield Tunnel Structure

In recent years, along with the development of economic construction, the acceleration ofurbanization and the increase of public buildings, which makes the ground transportationbecome very crowded. In order to solve people’s travel problems, all over the provincesdevelop their underground traffic network actively. Shield tunnel is one of the importantstructure form in the utilization of underground space process, especially the important rolein the urban underground rail transit design it played, which make people need to thinkabout not only the basic use function of shield tunnel, also requires to resist the earthquakeand other disaster.Taking tianjin metro line3tunnel lining and surrounding soils as the research object andsetting up three dimensional finite element model by ANSYS software. Getting data fromthe computation and analysis results, as well as comparing the regularity of the tunnelresponse of seismic in different working conditions (thickness, lining tunnel stiffness andburied depth).At last, analysing the three aseismic optimum measures (change liningstiffness, foundation reinforcement and setting up the damping layer).Following detailwork and results:1) Setting up the Tianjin metro line3structure-soil finite element analysis model.Theseismic weak parts of typical section under the action of vertical seismic load is invault, so vault shall be the key parts of the seismic fortification.2) Through comparing the regularity of the tunnel response of seismic in differentworking conditions (thickness, lining tunnel stiffness and buried depth), come to theconclusion that lining structure stiffness has effect on changing structure seismicperformance. But the method that improving the strength of concrete only to improvethe structure seismic performance is not recommended., and reduced the thickness oftunnel lining structure properly is beneficial to the improvement of seismicperformance. Tunnel buried depth difference affect most obvious to the response ofseismic.3) Researching the three resist seismic measures for subway tunnel and analyzing thedifferent effect, at last drawing a conclusion that the anti-seismic effect of foundationreinforcement and setting up the damping layer are better than changing the liningstiffness. When the foundation reinforcement thickness is5m and the modulus ofelasticity increase to double, the seismic effect is best.