| The staircase as an integral part of the building,is an important channel that plays a vital role in people's escape during the earthquake.However,from the post-earthquake disaster situation,staircase components and staircase corner column damage was more serious in the frame structure,or even the whole staircase collapse phenomenon,and then lost the proper evacuation function.In this paper,six models are used to study the seismic performance of the staircase in order to solve the problem that the commonly used stairs in the frame structure are prone to damage in the earthquake.Model one uses a common staircase approach,is the basic contrast model.Because there are few studies on the two-way plate system with two-way slab and the staircase through the upper and lower stairs,there is no more consistent conclusion,and the model two and model three are established.Two-way plate system is used in the model of the middle resting platform,and the seismic performance of the two stairways is analyzed in the model three,which provides a reliable basis for the design.In connection with that the problem of shear failure of the stair corner frame is easy to occur,the model four is setting the gap between the rest platform and stair frame frame corners instead of staircase.In connection with that It is easy to cause the shear failure of staircase ladder,the model four is setting rope instead of ladder columns.The four model is the combination of cable and sliding bearing,so that the whole floor slab and platform beam can be moved relative to the frame structure to reduce the internal force of the structure and increase the seismic performance of the whole structure.In order to compare and analyze the seismic performance of different stairways,the finite element analysis software is used to analyze the six models by the mode superposition response spectrum method under multi-event earthquake and the elastic-plastic dynamic time-history analysis under rare earthquakes.The results showed that: the two-way plate system reduced the internal force of the resting platform plate on both sides,but the internal force of the platform beams in the depth direction of the stairway was large and prone to plastic damage;At the the through stair columns model,the staircase columns bear the horizontal load under the earthquake with the corner columns of frame structure at the staircase,reducing the bending moment and shear of the columns;Setting the gap between the rest platform and stair frame frame corners instead of staircase reduces the overall structure of the torsion effect and the overall structure in the Y-side of the lateral stiffness.The internal force of the stair frame beam in the direction of the depth of the staircase between the base shear force,the interlaminar shear force,the interlayer displacement angle,the internal force of the stairframe frame corner column under Y-direction earthquake.In the elastic-plastic time-history analysis,the plasticity of the corner column of the staircase frame is less,which indicates that the stitching between the rest platform and the stair frame frame corner column basically solved the problem of the shear failure;The use of cable instead of ladder columns,although there is no ladder,to avoid the destruction of ladder column.But in the response spectrum analysis and dynamic elastic-plastic analysis,the displacement between the layers is larger,and the plasticity of frame columns,frame beams and platform beams is more;To sat the gap between the middle of the rest platform and the staircase corner pillars,effectively solved the problem of the shear failure at the stair columns and corner columns;In the elastic-plastic dynamic time-history analysis under rare earthquakes,at the model that used the combination of cable and sliding bearing,the plasticity angle and plastic damage of the structural members were less than those of other models,which indicates that this kind of setting method of staircase members had better seismic performance. |
PDF Full Text Request