Study On Seismic Reliability For Urban Brick Building Group

The feature of city is " population concentration, buildings concentration, production concentration and wealth concentration", once encountered destructive natural disasters of earthquake, will suffer a heavy casualties and great financial losses inevitably. At present, we cannot predict the exact time and location of earthquake occurrence, the main work we can do is the earthquake prevention approach. China's earthquake environmental hazard is very execrable, the seismic reliability estimation of city's buildings is received more attention by the earthquake engineering, study theory and approach about it with great theoretical and practical significance. Traditional evaluate approach exist some weakness, which is need to invest substantial labor, material resources, financial ability, and data too detailed, the timeliness of the results is subjected to investigate also.The randomness of earthquake ground motion process and the uncertainty of structural system itself, lead to a random process of the seismic response inevitably. Estimating seismic response and seismic reliability of building in the sense of probability is very necessary and reasonable. Therefore, this paper put forward a probabilistic method to estimate the seismic reliability of urban building group. This study includes the following aspects:1. Seismic reliability of urban building group estimation model is studied in this paper. It proposed a probabilistic method to estimate the seismic reliability of urban building group quantitatively, established total probability model and conditional probability model. The model is consisted of seismic hazard analysis and seismic vulnerability analysis. It considered the randomness of the earthquake action and the uncertainty of building group structures synthetically, which in favor of theory apply of seismic reliability, has very important practical significance.2. During the analysis of seismic hazard, the relationship between intensity of earthquake ground motion and peak acceleration of the correspondence is given by studying specification. It obtained the probability distribution function of the peak acceleration of ground motion by fitting peak ground acceleration exceeding probability curve, and combined with the existed probability model of ground motion, given the segment continuous function for calculating the probability of seismic intensity, which can lay the foundation for seismic reliability estimation of building group.3. During the analysis of seismic vulnerability of building group, it collected practical seismic damage data of urban brick building group in Wenchuan earthquake area, obtained the average damage probability matrix and vulnerability enveloping curve. The vulnerability function is given by fitting the average vulnerability curve, and further got vulnerability matrix. Although the raw date cannot classify detail, it is favor to dynamic administrate and renew for database system, and the practical apply. It can overcome the disadvantage that have existed matrix cannot represent the current building seismic capacity.Finally, take the urban brick building group in Wenchuan earthquake area as an example, it described the use for probability model of seismic reliability, and discussed the advantage. The author considered the model can represent seismic reliability estimating relationship of any area, which has generality. It can be used for estimating and comparing seismic reliability of building group in different areas. Furthermore, it proposes that study the property and character of the 5 parameters, can get seismic reliability estimate result of building group in different areas by analogy. It will lay the foundation for seismic resistance estimation of building subarea in overseas.