Research On The Effects Of Vertical Layout To Seismic Performance Of RC Frame

With the development of economy level, building using function of the demand is higher and higher for people. All kinds of comprehensive building emerge in an endless stream. The vertical layout of the building structure changes can’t be avoidable due to site conditions, the use of functional requirements and other restrictions. The floor height and the number of layers changes are the most notable features of vertical layout. In the earthquake, the story mutated floor due to stiffness mutation lead to stress increased and deformation concentrated of the floor to form a weak layer, causing severe damage or even collapse. How to correctly foresee the structures’ force, failure modes in the earthquake, identified the weak components and the weak parts reasonably to ensure better seismic performance has become an important research direction of the engineering.In this paper, multi-storey RC frame structures were designed according to the current standard. Their seismic performances were studied when the vertical layout changed, for example the floor height and the number of the floors. The structures were made elasticity analysis in the earthquake, static elastic-plastic analysis and dynamic elastic-plastic analysis in the rare earthquake with the help of PUSH&EPDA. This paper investigated the structural deformation, failure modes, the weak layer and weak components, evaluated the seismic performance synthetically. The purpose is to summarize the impact of change on the vertical layout of multi-seismic performance of RC frame structure. In this paper, the following conclusions are:(1) Relative stiffness is sensitive to changes on the story, the smaller relative stiffness, the sooner edge members into plastic state in the earthquake. The relative stiffness can be used to judge which component produced plastic hinge firstly.(2) Floors yield strength is sensitive to changes on the bearing capacity of the floor, Floors yield strength coefficient can be used to judge structural weak layer position.(3) Through the elastic-plastic analysis under rare earthquake of five conditions, the weak layer showed that the lateral force resisting member formed the largest number of plastic hinges and the elastic-plastic layer angle is largest.Our work in this paper enriches the study on changes in the structural vertical layout, and provides reference for the future framework of conceptual design and structural design.