Research On The Seismic Performance Of The RC Frames Affected By The Methods Of Connections To The Cranked Slab Stairways

Investigations of previous seismic hazards indicate that the performance of the stairways in the RC frames is unsatisfying. It’s a main factor which aggravates the seismic hazards that the components relevant to the stairways are severely damaged, thus blocking the evacuation and rescue channels. Therefore, it’s of engineering significance to adopt structural measures to improve the seismic performance of the stairways and alleviate their seismic hazards. In the thesis, the method of numerical simulation is adopted to the research of the seismic performance of the frames to which the stairways are connected with the method of resistance and release. The proper connection pattern which suits the RC frames will be discussed via contrast and analysis. The main research work of the thesis is as follows:A brief introduction to SAP2000 and ABAQUS, softwares of finite element analysis will be conducted, which is mainly about the Mander constitutive model, the concept of the lumped plastic hinge and the concrete damaged plastici ty model. By means of the simulation of the existing quasi-static tests on models with stairways, the important details in modeling are stated and the rationality and feasibility of the parameter settings in the models is verified.By the utilization of ABAQUS, the bidirectional elastic-plastic time-history analysis of the two schemes of the release connection will be conducted. The major research is the situation of development of the damage and crack of the structure in different cells under rare earthquakes, meanwhile, the reduction effect of the horizontal earthquake shear force and the vertical braced force beneath the stair plate of the slip connection is discussed as well.In SAP2000, 5 groups of contrast models are established to research, including the situation such as whether to account for the modeling of the starways, the reinforcement of the frame columns around the stairways, the adoption of slip connection and the addition of staircase columns. Modal analysis, standard seismic response spectrum analysis, pushover analysis and elastic time-history analysis under frequent earthquakes are included in the analysis content, and multiple aspects are utilized to study the influence modes and rules of the seismic performance of the frames on account of the aforementioned factors, such as the vibration characteristics of the structure, the interstory drift ratio, the stiffness degradation, the stress state of the components, the displacement ductility and the yield mechanism.By means of the comparision and research of the aforementioned analysis results, the effects, advantages and disadvantages of various kinds of treatment of the stairways are evaluated, and relevant suggestions are proposed, thus providing some reference to the improvement of the sei smic performance of the current stairways design.