Study Of Seismic Performance Of Stairs In Masonry Structure

Masonry structure is one of the traditional types of building structures.The previous earthquake disaster showed damage of staircase in masonry structures was more serious than the main structure under earthquake action.Based on the analysis of stairs under earthquake disaster,it illustrated the necessity that stairs are required consider seismic design.By using PKPM software to establish whole structure model and finite element analysis software ANSYS to establish masonry structure staircase finite element model,it analyzes the influencing factors of seismic performance of stairs under earthquake disaster and put forward some suggestions on stairway design.The main contents are as follows:(1)This paper analyzes the damage which is masonry structure stairs under earthquake action,and is devoted to the related researches at home and abroad,and is analyzed that the problem of stairs on seismic design.(2)This paper takes reinforced concrete block masonry structure for example,and is analyzed by using PKPM software to establish whole structure model 1 of neglecting stair,model 2 of considering stair,model 3 of considering stair.By comparing that stairs Participate whether in whole structure and changing staircase position,it analyzes the stairs have some effect on seismic performance of structure.Through these analyze of basic characteristics of structure,structure vibration mode,natural vibration period,structural displacement,story shear force,seismic force,structural moment,it conclude that participation stairs increases the integral rigidity of the structure,and changes stiffness distribution of structure,and reduces natural vibration period of structure,and makes structural deformation reduced.In addition,the different staircase positions on the integral rigidity of the structure is different.And the nearer staircase positions,the larger the staircase on integral rigidity of structure.(3)Using ANSYS to establish a separate staircase,and applying respectively to the displacement of the four directions,and analyzing the stress characteristics of platform ridge,platform plate,bench plate,and two side wall in detail can be drawn that platform ridge at mid-span,position platform ridge and bench plate connected,position platform ridge and platform plate connected,1/3-1/4 position of bench plate,and the position of wall near platform ridge easily deformed or destroyed under earthquake action.