Seismic Response Analysis Of Ventilation Shaft Crossing Island For Submarine Tunnel

As the economy develops rapidly in the world,regional links have become increasingly close,especially the increasing demand for traffic along the gulf and across the strait.Among many cross-sea passages,the submarine tunnel has the outstanding advantages of strong disaster prevention ability,strong timeli ness,small marine navigation and ecological environment impact.Therefore,the submarine tunnel has become the preferred scheme of cross-sea passage.As an important part of submarine tunnels,especially long submarine tunnels,ventilation shafts play an important role in ventilation,vehicle aerodynamic effect adjustment and disaster prevention and rescue.Compared with the water ventilation shaft,the ventilation shaft crossing island is more safe and stable,so the ventilation shaft crossing island is often the first choice for the construction of the ventilation shaft.At present,there are few large and long submarine tunnels in the world,and the study of seismic response of submarine tunnel ventilation shafts is still in its infancy.Therefore,the response of submarine tunnel ventilation shafts under seismic effect needs to be further studied and supplemented.In view of the large scale of submarine tunnel and the complexity of surrounding rock,it is difficult to study through test.In this pap er,the seismic response of ventilation shaft crossing island for submarine tunnel is simulated and analyzed by ABAQUS,a large-scale finite element analysis software,combined with other necessary software and related theory,which provides a reference fo r the design and construction of ventilation shaft crossing island for submarine tunnel.Before modeling,basic assumptions are made to simplify the model.Appropriate interaction,loading mode,boundary conditions and material constitutive model are selected.The seismic response characteristics of ventilation shaft crossing island for submarine tunnel are studied by equivalent linear dynamic time history analysis.At the same time,the influcence of different site,tunnel depth and earthquake amplitude for ventilation shaft with is studied.Finally,the quasi-static analysis method is used to calculate,and the results are compared with those of dynamic time-history analysis method to prove the accuracy of the results.The structural response characteristics of ventilation shaft crossing island for submarine tunnel under the effect of horizontal earthquake are obtained through the calculation of the dynamic time-history analysis method.Through the analysis of different influencing factors,the influence characteristics of the site shear wave velocity,the tunnel depth and the amplitude of earthquake motion on the seismic response of the ventilation shaft are obtained.Finally,through the quasi-static analysis,the accuracy of dynamic time-history analysis is proved and it is found that the dynamic time history analysis is more accurate than the quasi-static analysis when the elastic modulus of the site is less than that of the lining of the ventilation shaft.