Seismic Analysis Of A High-Rise Structure With A Basement Supported By Stepped Foundation And Research On The Influence Of The Basement Supported By Stepped Foundation On Structure

With the development of urbanization,growth of the population and the increasing people pursuit for beauty,building is becoming higher and higher,structure is becoming more and more complex,There appears a lot of new structure system,such as step-terrace structure,transfinite high-rise structure,etc.In this paper,the project I study is a transfinite high-rise structure with a step-terrace basement in Chongqing.In this paper,based on the analysis of the structure,combined with the structure scheme design,the preliminary design and the seismic fortification special examination of the structure,I systematic research and summary the results of its selection of structure form and components size,the design of seismic performance,the analysis of its dynamic elastic-plastic time history,etc.I built a simple plane model to analyze the influence of the Step-Terrace Basement for Structure and put forward a design proposal for the questions of the Step-Terrace Basement present by the engineers.â‘  Under the current Code for seismic design of building and Technical specification for concrete structures of tall building,Using modal decomposition response spectrum method for seismic design by Midas Building,compared with the results analyzed by SAP2000,Analyze the overrun of the structure,and determine the seismic performance requirements according to the situation of overrun.â‘¡ I use Midas Building analysis software to do elastic-plastic time history analysis of the structure under design earthquake and rare earthquake,at the same time,I use SAP2000 analysis software to do elastic-plastic time history analysis of the structure under rare earthquake.With the structure of the three-dimensional model as the basis,I use the default frame beam column plastic hinge model and define the elastic-plastic restoring force characteristics to do elastic-plastic time history analysis.Compared with the results of two kind of analysis software,I find that the results are basically the same,so the results are Highly credible.â‘¢ In order to meet the predetermined performance objectives I take some necessary aseismatic measures according to the above analysis.I do the elastic-plastic time history analysis of the structure with the design idea of performance.The results show that the structure meets the requirements of seismic performance.On the basis of the result,suggestions of the design of this structure are put forward.â‘£ According to the discussion about step-terrace basement during engineering design and the request of fixed end put forward by Code for seismic design of building and Technical specification for concrete structures of tall building.I built a simple plane model to analyze the influence of the Step-Terrace Basement for Structure and I find that the influence on inter-layer displacement of the upper grounding layer is greater and the top of the Step-Terrace Basement can not be the fixed end.I proposed that the level of Seismic grade of the components of upper grounding part can be raised one level to design.