The Vulnerability Analysis Of The Reinforced Concrete Structure Based On The Ground Motion Parameters

The earthquake occurs frequently in recent years all over the world. One of the most concerned problems is how to predict earthquake losses effectively and mitigate damages caused by the earthquake, that is very meaningful importantly. Seismic vulnerability analysis which is the premise of the earthquake damage is the key technology of earthquake damages and loss prediction. Therefore, carrying out the study of structural seismic vulnerability analysis is very necessary.Based on the conclusion of commonly used structural vulnerability analysis method, this paper put forward vulnerability estimation method of lacking earthquake damage experiences and discussed the method of determining the ground motion demand spectrum with the structural capacity curve. Reinforced concrete frame structures and reinforced frame-shear wall structures are the most structure form of civil residence in our country. In this paper, the structures followed above (three layers and six layers) are estimated by theoretical vulnerability analysis.This paper mainly has the following several aspects of content:First, structural vulnerability is the description with respect to all the the ultimate states of probability distribution. The traditional methods include expert judge method, experience statistics, seismic intensity table method, the simplified structural dynamic analysis and seismic performance evaluation method, etc. With regard to the formal structures designed lacking earthquake damage experiences, the main way is to combine with code for seismic design of buildings, structural dynamic analysis method and relevant experiment results. This paper argues that using ground motion peak acceleration response spectrum as input parameters and simplified structural nonlinear static analysis method can undertake structural vulnerability analysis.Second, In order to determine the ground motion spectrum, the paper points out that substitute ground motion input parameters for earthquake intensity can avoid the defects. Then, the method of elastic ground motion demand spectrum is put forward. At last, based on the seven models which domestic and foreign scholars put forward, the spectrum of elastic ground motion demand spectrum is reduced to elastic-plastic ground motion demand spectrum.Third, the paper discussed the method of determining structual capacity curve. Through the nonlinear static analysis method (Push-over analysis), the base shear-toplevel displacement curve can be gotten. According to conversion formula, the push-over curve can be converted to spectrum displacement and spectrum acceleration curve, which is the structural capacity curve.Fourth, using earthquake acceleration response spectrum combined with simplified nonlinear static analysis method, the earthquake displacement under ground motion is calculated by the ground motion demand spectrum and the structural capacity curve. Then the reinforced concrete frame structure and the reinforced concrete frame-shear wall structure are analysed and the vulnerability curve can be established. There are some following conclusions through the analysis of theoretical vulnerability matrix:The lower reinforced concrete frame structure is, the stronger the seismic capacity is; reinforced concrete frame-shear wall structure has stronger seismic capacity than reinforced concrete frame structure; when the suffered earthquake action is bigger than seismic fortification intensity, structure fierce serious damage and collapsed probability are increased. Comparing theoretical vulnerability matrix with obtained actual vulnerability matrix, the results of two matrixes are close. This proves that simple vulnerability analysis method is correct and feasible.