Shaking Table Test Of A Frame Structure Crossing Ground Fissure And Finite Element Analysis Under Multi-stage Loading

Not only destoryed the integrity of the ground soil,ground fissure can also cause adverse effect to the upper and adjacent buildings.Xi'an is one of the city in China which suffered from the most serious ground fissure hazard,to reduce the harm of ground fissure activity,space avoidance principle is in use today.With the development of the city,however,to make full use of the precious land resources,construction of a large number of buildings have to cross the ground fissures.In recent years,with the ground fissure activity tends to be stable in Xi'an,the construction of the ground fissure fields put forward new requirements.A lot of researchers have been conduted on the formation mechanism and characteristic of ground fissure,but the study of the superstructure that crossing ground fissure have not been reported in paper.Shaking table test of the superstructure that crossing ground fissure will fill in the blank of the superstructure dynamic characteristics,and this paper made a comprehensive analysis by the finite element method.First of all,this paper designed and finished the five layers of concrete frame structure,and adopted the shear box filling soil to simulate the soil's shear properties.Jiangyou wave and El-Centro wave and Jiyan wave were selected as seismic input,experiment data analysis showed: after per level loading,beam-column node was firstly cracked,then,cracks appered on the floor.A first and second order natural frequency of the structure were both decresing,and the changing amplitude of the first order natural frequency was greater than the second order.Maximum acceleration and relative displacement and maximum interlayered shear have a big difference under different seismic waves.Acceleration amplification coefficient of each layer was decresing with loading intensity incresing,maximum interlayered shear appeared on the structural bottom.Maximum strain of the column reinforced occurred on the horizontal column which located on the hanging wall and footwall.Secondly,by using ABAQUS finite element software to simulate the prototype structure,soil boundary condition was simulated by the viscoelastic consistent artificial condition,the acceleration response of shaking table was selected as seismic input.Results comparison between the finite element simulation and shaking table test presented that changing tendency of the maximum acceleration and relative displacement and maximum interlayered shear was consistent,numerical difference was smaller.Maximum acceleration and the relative displacement appeared on the substructure,the structural top was minimal.Finally,the structural distribution of the plastic energy dissipation and damping energy dissipation was analyzed by the energy method,and the plastic energy dissipation and damping energy dissipation of the beam that crossing ground fissure on the same floor were minimal,and the plastic energy dissipation of the beam on the top and bottom was bigger,furthemore,the damping energy dissipation of the beam on the bottom was maximal.The plastic energy dissipation of the column that closing to the ground fissure was bigger,and it was also falling from bottom to top.