Analysis Of Seismic Performance And Vibration Response Under Subway Excitation For High-rise Building With Silk Podium Roof

The special-shaped space steel roof between the main building and podium gradually appears with the continuous development of high-rise buildings.Suzhou Taiping high-rise building adopted an innovative structural form,which was silk-shaped podium steel roof.However,the seismic performance of this structure has not been studied at home and abroad.In addition,to alleviate the ground traffic pressure in large and medium-sized cities in recent years,the subway construction has entered the intensive period,and there are many complex high-rise buildings close to the subway line.However,there is still a lack of research on the dynamic response of the surrounding basement structure and high-rise buildings with special-shaped podium steel roof caused by subway operation.Based on the Suzhou Taiping high-rise building,the analysis of the seismic behaviour and subway vibration response for the high-rise building with silk-shaped podium steel roof was carried out in this paper,the main research work was as follows:(1)The free vibration analysis of the silk-shaped podium steel roof composed of the bending and torsion box steel members was carried out using finite element software,and the vibration modes,period and torsion effect of the roof were obtained.Subsequently,the linear buckling and nonlinear stability analysis of this structure were performed and the buckling modes and global stability of the roof were studied.(2)The numerical analysis model of the high-rise building with silk-shaped podium steel roof was established.The influence of the spherical seismic bearings on the connection between the main building and the podium was considered,the constitutive relation models of materials were defined and the simplified calculation methods were given.Compared to the model quality,period and vibration mode calculated by two finite element softwares,the reliability and accuracy of the finite element model was verified.(3)The natural and artificial seismic waves selected accoding to the specification were input into the elastic and elastic-plastic analytical models.The base shear force,elastic and elastic-plastic story drift,floor acceleration were analyzed according to the Chinese specification.Subsequently,the damping effect of podium roof and seismic response at the connection between main building and podium after setting the spherical seismic bearings were compared and analyzed.(4)The underground two-dimensional(2D)model including the subway station and basement structure was established.Then,the subway vibration excitation load was input into this model.The dynamic response of the basement structure was analyzed according to the corresponding evaluation method.At last,the acceleration time-history of the surface points was input to the three-dimensional(3D)model and the analysis of the dynamic response caused by subway vibration for the main building and damping effect for the podium steel roof was carried out.(5)The parametric analysis of the dynamic characteristics for the underground and overground structures caused by subway vibration was performed using the 2D and 3D models.The parameters included the property of foundation soil,subway running speed,subway station burial depth,distance between station and basement structure,thickness of raft foundation and whether there was underground continuous wall,etc.The influence rules of the different parameters on the vertical vibration of basement and main building were obtaioned and the evaluation formulas on the vertical vibration applied for the basement and main building of practical engineering were given.