Research On Seismic Performance Of Frame-shear Wall Structure Of Tall Buildings With Single Tower Offsetting

The large chassis high-rise building structure, which is one of the forms of high-rise buildings, is more popular in recent years. In order to meet the requirement of the building facade, more and more such structures do not tend to set joints to tear off the podium and tower, which result in the deviation of the tower centroid and the large chassis center of mass of the structure. When the both centroid eccentricity are more than20%which is beyond the specification limits, it proves to be the high-rise building structure biased a single tower and therefore the response becomes more complex under the earthquake. Traditional seismic design methods can not completely guarantee the security of ultra-high-rise buildings, it is particularly important to conduct a in-depth study of the seismic performance of such structure and make efforts to provide improved method for the seismic design.This paper taking a frame-shear wall structure of tall building with single tower offsetting for example focuses on in-depth exploration and study on the overall stress analysis and the strengthen measures of the weak parts. The main work can be concluded as follows:1. Corresponsive macroeconomic indicators could be deduced from response spectrum analysis and comparison of differential responses to the different bias rate on the structure under the role of multi-earthquake.2. The necessity of the time history analysis on such structure is pointed out and the recommendations about selection of the duration of the seismic waves are proposed through the elastic time history analysis and by comparison with results of the response spectrum analysis.3. Elastic-plastic response indicators under strong earthquake are deduced from nonlinear static analysis on the structure under rare earthquake, and the weak parts of the structure are pointed out according the distribution and the development of plastic hinge.4. By combination with the results of response spectrum analysis, the elastic time history analysis and nonlinear static analysis, starting from the structural arrangement by changing the skirt layers and setting additional shear wall at the podium corner, the optimum proposal of the structure is put forward as a result of comparing the influence of a variety of programs on the seismic performance.The research results indicate that the effect on the main modes translational torsion coupling of towers bias tall superstructure is more obvious. There is a sudden increase on the displacement of the floor layer whose body is received and the relative story of the top structure, and the envelope value of time-history results and response spectrum calculations should be taken into account when designing. The inelastic response to the eccentric direction of this structure is more obvious in the rare earthquake. The most serious region of structural damage is mainly in the height range of the podium, and focus on the structural corner, edge, eccentric direction of electric hole around and the location at the junction of tower chassis, especially the vertical component of the tower chassis junction. At the same time the destructive type of plastic hinge turns up earlier on the corner posts of remote tower chassis and on the frame side column of the top tower chassis, so the reinforcement ratio should be increased in design. In the design of the large chassis tall superstructure of tower offsetting should control podium layers in order to reduce the interlayer displacement and interlaminar shear of the structure under earthquake effect. Meanwhile additional shear wall at the podium of the tower remote corner can also be built to improve the displacement reaction of the structure.