基于概率估计方法的立式储罐地震易损性研究

Investigation on seismic vulnerability of vertical storage tanks based on probability estimate method

结合储罐的震害资料和震害特点,提出了基于概率估计方法的立式储罐地震易损性研究。考虑了结构的随机性及荷载作用的随机性,给出了各随机变量的概率分布模型及给定烈度下地震发生的概率。从可靠度指标的几何意义入手,提出了储罐的地震易损性计算方法。通过2×103m3和5×104m32种高矮罐的地震易损性研究,结果表明:通过概率方法和绘制地震易损性曲线的方式,更能直观的给出储罐各失效模式的地震易损性。储罐的地震易损性与地震烈度、高径比的关系很大,地震易损性随着地震烈度的增大逐渐增大;与2×103m3储罐相比,5×104m3储罐各失效模式地震易损性明显较小;从多种失效模式进行储罐地震易损性研究更具有科学性。

Combined past earthquake disaster data with earthquake disaster characters of storage tanks, seismic vulnerability of vertical tanks based on probability estimate method is discussed. Considering the randomness of structures and loads, probability models of random variables and exceeding probability under a given seismic intensity are represented. The calculation method of seismic vulnerability of vertical tanks based on the reliability index＇ s geometry significance is given out. The seismic vulnerability of two 2 × 10^3m^3 tall tanks and a 5 ×10^4m^3 low tank is analyzed. The numerical result shows that： the seismic vulnerability of all failure modes of storage tanks is more visual by using probability method and drawing vulnerability curves. The seismic vulnerability of tanks is closely related to the seismic intensity and the ratio of height to radius, which intensity. The seismic vulnerability of all failure modes of 5 ×10^4m^3 gradually increases with the increase of seismic tanks is smaller than that of 2×10^3m^3 tanks. Evaluating seismic performance of tanks from various failure modes is more scientific.