Seismic Performance Analysis Of Fixed Force Sliding Staircase In RC Frame

Reinforced concrete frame structure(RC frame structure)is a kind of structure with beams and columns as the main load-bearing members.The bracing effect of stairs is considered in the design of stairs,and the seismic performance of the stairs is analyzed,as well as the impact on the structure as appropriate.The main shock-absorbing staircases are sliding and friction staircases.Fixed-lift staircase is a new type of shock-absorbing staircase designed and invented by combining the advantages of the two staircases.Firstly,the fixed-force lifting staircase connects the staircase platform plate with the stepped plate with the fixed-force lifting device,so that it can provide the inclined brace from the direction of the stepped plate for the whole structure when it does not reach the lifting force,so as to improve the seismic performance of the structure;when the lifting force is reached,the stepped plate begins to slide,and the action force from the frame will be released through the lifting device,thus ensuring the stepped plate.Safety.This paper preliminarily conceives the structure diagram of the fixed-force lifting device,and determines the size of the lifting force according to the different bearing capacity limit of the stepped plate.Among them,the slipping force is less than a certain bearing capacity limit of the stepped slab,so the staircase will begin to slide before the failure occurs.Secondly,this paper also analyses the influence of the fixed-force sliding staircase on the performance of the overall frame.In this paper,SAP2000 software is used to simulate the static sliding staircase.The frame of the static sliding staircase is compared with the pure frame structure and the ordinary staircase frame structure.The results show that the fixed-force lifting staircase is a kind of vibration-absorbing staircase.On the premise of ensuring the safety of the staircase itself,it can also improve the ductility of the structure and have good seismic performance under earthquake.Finally,the aseismic performance of two kinds of fixed-force takeoff stairs with different performance objectives are compared(performance objectives 1: small-shock takeoff,i.e.to ensure that stairs begin to slide when the members are at 0.8 times the deformation bearing capacity;performance objectives 2: mid-shock takeoff,i.e.,when the stepped plate reaches 0.8 times the damage bearing capacity).The results show thatthe mid-earthquake fixed-force sliding staircase is more conducive to the overall seismic resistance of the structure,but in order to ensure the safety of staircase components,it is necessary to adjust the sliding force reduction factor and further find the optimal sliding force.