Research On The Seismic Performance Of High Damping Rubber Bearing In Staircase

Stairs play a vital role in buildings.In an earthquake,damaged stairs can seriously affect escape and rescue.Therefore,it is very important to protect the stairs from damage.However,the behavior of the staircase is very complicated,and the staircase has not performed well in the earthquakes.Investigations on earthquake damage in recent years have shown that stairwells are very susceptible to damage under the action of earthquakes,and the damage is far more serious than other parts of the building.The stairwell is an important channel for escape and rescue.It is of great significance to protect the staircase from damage under the action of earthquakes.Therefore,for the study of the seismic performance of the stairwell,protecting the safety of the stairwell under the action of earthquake is an urgent problem to be solved.In order to improve the seismic performance of the stairwell,this paper proposes a high-damping rubber isolation bearing,that is,by installing the high-damping rubber isolation bearing in the stairwell,the slanting effect of the flight on the overall frame structure is reduced,and improved the dynamic characteristics of the structure which can reduce the force of the staircase members and improve the seismic performance of the structure.For the purpose of studying the impact of the placement of the high-damping rubber isolation bearing for the seismic performance of the structure,the effect that the location of high-damping rubber isolation bearing is also investigated.This paper mainly studies the influence of high-damping rubber isolation bearings on the seismic performance of the frame structure from the following three aspects:(1)The numerical analysis and finite element simulation are conducted to verify the correctness of the modeling method of high-damping rubber pads in the finite element software ABAQUS and the input of constitutive parameters of high-damping rubber materials.The mechanical properties of high-damping rubber isolation bearings under different shear strains,different loading frequencies,different compressive stresses and repeated loading times are calculated by modeling and analysis of high-damping rubber isolation bearings.The parameters such as pre-yield stiffness,post-yield stiffness and yield force of the high-damping rubber isolation bearing are calculated by selecting a suitable high-damping rubber isolation bearing restoration force model,which is convenient for the input of parameters of the high-damping rubber isolation bearing in the ETABS engineering analysis software to study the high-damping rubber bearing.(2)The response spectrum analysis through ETABS software was conducted by analyzing the model of frame structure without staircase,the model of frame structure with cast-in-place staircase and the model of frame structure with high damping rubber isolation bearing at the lower end of the flight.Compared to parameters such as natural vibration period,base shear and storey drifts,the influence of stairs on the frame structure and the high-damping rubber isolation bearing on the seismic performance of the frame structure were analyzed;The static elastoplastic analysis of the frame model without staircase,the frame structure with cast-in-place staircase and the frame model with high-damping rubber isolation bearing at the lower end of the flight shows that the installation of high-damping rubber isolation bearing at the lower end of the staircase can obviously decrease internal force of the stairwell,the high-damping rubber isolation bearing can effectively weaken the inclined bracing effect of the flight and improve the seismic performance of the structure.(3)Through nonlinear dynamic time history analysis,the frame structure model of the cast-in-place staircase,the frame structure model with high-damping rubber isolation bearings on the upper part of the flight and the high-damping rubber isolation bearings on the lower end of the flight were analyzed,Compared to the apex acceleration,floor acceleration,base shear,floor shear,storey drift and other parameters of the overall frame structure,the seismic performance of different locations of the high-damping rubber isolation bearing were conducted.Comparing and analyzing the internal force of landing column and landing beam,the influence of different location of the high-damping rubber isolation bearing on the mechanical performance of the staircase members is studied.