Seismic Response Analysis Of Large Span Metro Vehicle Without Soil Column Considering Soil Structure Interaction

Columnless long-span subway station structure is a new type of subway structure system.It can greatly improve the space permeability of subway station structure and lower visual field openness.At the same time,it can meet the passengers' demand for large space of subway station.Due to the lack of support of columns in large-span stations without columns,the seismic performance of structures has attracted more and more attention.In view of this,taking Jinqiao Passenger Station of Line 5 of Nanning Metro Station as the engineering background,the shaking table test of large-span subway station without columns is carried out,and the seismic response of the station under various test conditions is analyzed.Combined with the dynamic finite element method,the dynamic response of a large span station without column under seismic loading is analyzed.The main research contents and achievements include the following aspects:(1)On the basis of domestic and foreign research,the dynamic equation of soil-underground structure system is established and solved;then the constitutive relation and contact relation between soil and structure in soil-underground structure system are discussed,and the intercepting range of underground surrounding rock and the establishment and solution of artificial boundary are determined..(2)Based on the principle of model similarity,the dynamic model system of a long-span subway station with a scale of 1/80 am is designed and manufactured,and shaking table tests are carried out.The results show that the peak acceleration of the top,middle and bottom slabs of the station structure increases with the increase of earthquake intensity under the same earthquake amplitude.When the peak acceleration is 0.076 g,the acceleration response of the structure is higher than that of El-Centro wave and Taft wave on the whole;when the peak acceleration is 0.11 g,the acceleration response of the structure to the artificial wave is higher than that of the other two waves.When the peak acceleration is 0.44 g,the response of Taft wave to the acceleration of the structure is lower than that of the other two waves.(3)On the basis of shaking table test,a three-dimensional finite element model of the model structure is established and its numerical analysis is carried out.The numerical results show that the experimental results are in good agreement with the finite element simulation analysis results,and the error is controlled within 20%,and the two are consistent in the acceleration response law of the structure,thus verifying the existence of the model.The correctness of the finite element modeling method.(4)Based on the measured data of subway station,the finite element model of subway station prototype structure is established by using the finite element software ANSYS,and the dynamic response of subway station under unidirectional horizontal,vertical and coupled earthquake is analyzed.The results show that the variable cross-section and the middle span of the structure are both weak positions under earthquake action,and they are easy to be destroyed under earthquake action.It is shown that the bidirectional seismic action has a great influence on the structure,so the seismic action in one direction can not be considered unilaterally in the design of the structure.