Theoretical And Experimental Study On The Mechanical Properties Of The Staircase Rubber Isolator

Staircase plays an irreplaceable role in our daily lives. It is important or even the only vertical emergency escape passage in fire, earthquake and other disasters,however, serious damage occurred in staircases both at home and abroad in the previous earthquakes. In order to improve the staircase's seismic performance, a novel staircase rubber isolator is developed for staircase isolation in this thesis. The staircase rubber isolator has the advantages of lightweight, cost-effective, easy to construction etc for the engineering-plastics plate is used to replace steel sheet.This thesis first reviews both domestic and foreign research progress on staircase and rubber isolator and two kinds of staircase rubber isolators based on the correlative theories are designed. Then a systematic experimental study on the isolator is done,including isolator's vertical stiffness, ultimate vertical bearing capacity, horizontal stiffness, ultimate horizontal deformation capacity, horizontal stiffness of shear strain dependency, horizontal stiffness of pressure dependency and horizontal stiffness of temperature dependency, etc. The basic mechanical properties test of engineering-plastics plate used in the rubber isolator is done, including tensile strength, tensile modulus of elasticity, compressive strength and compressive modulus of elasticity.Two types of staircase rubber isolators' finite element models are established by ABAQUS finite element software. By applying the same experimental conditions to the finite element models, the vertical and horizontal properties of the isolators are analyzed. And the analysis results are compared with the experimental results, the distribution of the internal engineering-plastics layers' stress and rubber layers' stress are analyzed at the same time.Three frame structure models are established by SAP2000 finite element software, frame structure model without staircase, frame structure model with fixed staircase, frame structure model with staircase used seismic isolation technology,respectively. Then time history analysis of these frame structures in two directions aredone with eight ground motion records. It is found that the structural stiffness and elemental stress become uniform with the compare of these results for the eliminate of staircase slabs' bracing effect.Finally, a set of simple and feasible construction methods and replacement methods of the staircase rubber isolator are proposed for the promotion of the staircase rubber isolator applied to the actual construction projects.