Experimental Study On Seismic Performance Of Elevated Station Structure Tianjin Metro Line Z2

With the rapid development of urban rail transit,the application of the bridge-built viaduct station structure system is more and more.It is of great significance to ensure the seismic safety of viaduct station structure and its usability after earthquake.At present,there is still a lack of design standards for bridge-built viaduct station structures in China,and the earthquake damage records are almost blank.Therefore,it is of great significance to study the seismic performance,failure mechanism and seismic weak links of elevated stations.Shaking table test is a more accurate test method to study the seismic performance of structures.Taking Gaoxinyilu Station of Tianjin Metro Z2 Line as the engineering background,this paper conducts a shaking table test study on the seismic performance of the bridged elevated station structure.The main contents and conclusions are as follows:(1)According to the test conditions,the prototype structure is simplified and the test model is made according to the principle of stiffness equivalence;According to the similarity theory,the similarity relation is determined and the shaking table test scheme is developed.The appropriate ground motion records are selected,and the test measurement and loading scheme are formulated.(2)Shaking table test was carried out on the structure model of the bridge-built viaduct station.The results show that the structure is in the elastic stage under the action of octave occurrence and fortifying earthquake.After being subjected to octave rare earthquake,the natural vibration frequency and stiffness of the model structure in the transverse bridge direction decrease the most,which are 9.02% and 17.23%,respectively.The transverse bridge direction is weak axial direction,which is more prone to damage.The acceleration amplification effect of the model structure is obvious,and the acceleration amplification factor of the top platform floor is 2.1～2.5.The maximum interlayer displacement Angle in the transverse bridge direction is 1/250,which all meet the requirements of the code of 1/50.According to the test phenomenon,it is judged that the cantilever beam on the hall floor and the cantilever frame column in the longitudinal middle of the station are weak anti-seismic parts.In practical engineering,support can be set at the cantilever end near the double column side to strengthen.(3)The ABAQUS software was used to simulate the model structure test.Compared with the test results,it was found that the dynamic characteristics of the two models were about 12% different,and the dynamic response errors were both less than15%,which verified the correctness of the finite element simulation.The finite element numerical simulation of the seismic performance of the prototype station structure is carried out to reveal the dynamic response law and plastic development history of the prototype structure.The results show that the prototype station structure has good seismic performance and meets the seismic fortification requirements of "not damaged under small earthquake,repairable under medium earthquake and not collapsed under large earthquake" under octave fortification intensity.