基于模拟退火的重力坝最危险滑动面全局搜索

Global search algorithm of critical slip surface for gravity dam based on annealing simulation

为了弄清地震荷载作用下重力坝坝头部位的失稳规律,采用有限元非线性时程分析方法,得到重力坝在地震作用过程中的应力场,进而应用模拟退火算法进行重力坝临界滑动面的全局搜索。该方法可以在所有增量步的应力场中搜索出坝头区域的最脆弱滑动面,并得到与之对应的抗滑稳定系数及出现时刻。分析结果表明,重力坝在地震荷载作用下更容易向上游方向失稳。在一条特定的地震波作用下,即使调整了其幅值,坝头部位最危险软弱滑动面出现的时刻几乎仍是相同的,且同一时刻下滑动面形式非常相近。

For investigating the instability law of upper part of a gravity dam under seismic load, the time-history nonlinear fi-nite element method is adopted to analyze the stress fields in gravity dams under seismic loads, and then a global optimization method to search the critical slip surface in gravity dams is proposed by simulated annealing algorithm. The presented algorithm could search the critical slip surface in the stress field of all the increment steps, compute anti-slide safety coefficient of the dam upper part and the corresponding occurrence moment are also obtained. An important conclusion is that the gravity dam tends to slide upstream under seismic loads. For a specific earthquake wave, the profile of the sliding surface and the corresponding oc-currence moment are very close even if the amplitude of the seismic waves is not the same.