Seismic Analysis On SRC Frame-RC Tube Structure With Steel Truss Strengthened Stories

Based on its perfect force and deformation performance, SRC frame-RC tubestructure was more used in some landmark high-rise building. When the structure is toohigh, horizontal strengthened stories were often set to control its displacement. The mainparameters of SRC frame-RC tube structure with steel truss strengthened stories werealways out of code limits, for this reason, this paper carried out the research on Seismicperformance of the structure and how to achieve performance-based seismic design of thestructure. The main contents are listed as follows:The object being studied in this parper was a SRC frame-RC tube structure, whichwas in8degree earthquake intensity zone, at a height of45floors or175.5meters, and ofwhich the aspect ratio was5.85. This research employed ETABS software to make theresponse spectrum analysis of several model examples which were different in the numberand the position of strengthened stories，and further to analysis the impact of structurevibration characteristics, stiffness, lateral displacement and stress by the strengthenedstories under earthquake.We determined transfinite situation of the model example and made the objective ofseismic performance. By means of running ETABS software and SATWE program, wemade elastic analysis and design of the structure under frequent earthquake, and madeadditional calculation of time history analysis. With the help of SATWE program, wecompleted elastic analysis or un-yielding analysis under medium earthquake. Meanwhile,we carried out static elasto-plastic analysis under rare earthquakes by PUSH program ofPKPM software.Analyzed the results of model example, it was demonstrated that: strengthenedstories was playing significant roles in reducing the vibration period, enhancing structuralrigidity and controlling displacement when it was set in the middle height of the structure. A relatively larger number of strengthened stories was berrer for reducing the structuralstiffness and force mutation. The structure with strengthened stories should be madeperformance-based seismic design and determine the appropriate performance targets inaccordance with the relevant engineering properties, if it was out of code limits. To ensurethe good seismic performance, structural strengthening measures should be taken at thebottom of the shear wall and the area near strengthened stories.