Study On Performance Based Seismic Analysis Method Of Concrete Frame Structures

In recent years, force-based seismic design has reduced the casualties caused byearthquake, but the economic loss caused by building damage has been still too high to accept.In this context, American scholars proposed the performance-based seismic analysis methodin the early90’s. At present, this method has become the main trend for amendment ofseismic design code in21stcentury. The method is mainly realized by means of Pushoveranalysis with gradually applying lateral loads to the structure according to a particular loadmode, in order to get the response spectrum and demand spectrum which are superimposed tobe the bases of the structure performance evaluation and design. This method remains to beimprovement in many aspects, among which the structure performance affected by lateralload distribution and higher modes are important aspects. Centering round this, thedissertation involves the following work.The application background, development process are system elaborated. The mainfunction and basic principle of the main means to realize performance based seismicanalysis Pushover analysis is discussed in detail. Several commonly lateral load patternsused in Pushover and its defects analysis are introduced. Four frame structures which thenumbers of floor are8.10,12,15are adopted to be calculation models of reinforced concreteframe structures. Load patterns of triangle，even and multi modes inertial force combinationare used in Pushover analysis, getting the capacity spectrum, storey displacement and plastichinge analysis，in order to research the influence to the results of Pushover analysis whichcaused by different lateral load patterns. For the defect of traditional Pushover analysis thatvibration vector is controlled by basic model, the influence caused by high modes isresearched and structural dynamic equation with high modes is deducted in detail. Thecalculation models are analyzed by Modal Pushover Analysis and time history analysis, getting the interlayer drift angel in order to campared with that get by Pushover analysis usedload patterns of triangle, multi modes inertial force combination and basic mode. The researchshows that higher modes have significant impact on the dynamic performance of the structure,and adopting the method of Modal Pushover Analysis could improve the accuracy of structureperformance evaluation.The paper analyzes the seismic performance of structure in the view of lateral loadpattern and the method of MPA, getting the conclusion which has a certain reference value forthe performance based seismic analysis of reinforced concrete frame structures, and alsolaying a good foundation for the further research.