| Earthquake is the natural phenomena that human beings cannot avoid.At the same time,earthquake is the most serious natural disaster that damages hunam lives and causes property loss.As the most popular shock absorption method,seismic isolation technology has been widely used for high-rise or super-high-rise buildings in the world.Some important buildings have also adopted seismic isolation technology.Among them,the frame-shear wall high-rise buildings are common in China.So the seismic dynamic analysis of frame-shear wall high-rise buildings is very significant for society.When performing seismic response analysis on an isolated structure,the structural response results are affected by the following factors:the error in establishing the finite element model,the selection of material parameters,the definition of the analysis method,and the impact of inputting ground motion.Among them,inputting ground motion of time-history analysis is the key to the entire analysis process.In spite of three basic factors of ground motion,the selected ground motion is affected by site characteristics.By fully considering site effects on ground motions,seismic time-history analysis of the high-rise frame-shear wall isolation structure is essential for seismic response analysis and research of seismic performance of the isolation structures.This paper conducts the calculation and analysis of a frame-shear wall isolation high-rise building as an example.A finite element model for seismic time-history analysis is built to study the seismic performance of the frame-shear wall isolation high-rise building,which considers the site effect.The main research work can be given as follows:(1)This study uses the finite element analysis software,Open Sees,to establish a three-dimensional nonlinear model of the isolated structure,and make a comparative analysisof the selected material constitutive models and their elements.Firstly,the performance of simulating the response of the actual structure by using selected element model is verified.Then,the comparison of dynamic characteristics between the established model and the ETABS model provided by a design company is performed to verify the rationality of the established model.The result shows that the natural vibration period of the frame-shear wall isolation building strutures is about 2 times greater than the one of the non-isolated frame-shear wall structure.Besides,the result is consisit with the one of the ETABS model,which proves that the established elastoplastic model of Open Sees is correct.(2)The static elastoplastic Pushover analysis is conducted,which uses the horizontal load of the inverted triangular horizontal mode as equivalent seismic action.By comparing the results of the displacement angles and shear forces of interlayer before and after the isolation of the frame-shear wall structure,the seismic performance prediction of the frame-shear wall isolation building is obtained.(3)This study considers Chinese "Standard for Seismic Design" for the classification of sites,and then makes a comparison with the specification of FEMA450.This study uses a certain number of ground motion records for four types of sites according to the shear wave velocity of Vs(30)value.Then,the finite element model of seismic isolation is subjected to two-way ground motion,and its dynamic time-history analysis is conducted to study the seismic performance of high-rise buildings with frame-shear wall isolation under different site conditions.Moreover,the maximum interlayer displacement angle of the upper structure and the horizontal displacement of the isolation layer are used as damage indicators to mark the curve of earthquake vulnerability. |
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