重力坝服役期间,渗流作用会对大坝稳定及应力产生不利影响,研究重力坝在渗流作用下的可靠度具有重要意义。本文将响应面法与随机有限元法结合,提出了考虑渗流作用的重力坝稳定与应力高效可靠度分析方法。依托某水电站工程,通过敏感性分析确定影响重力坝抗滑稳定与应力的关键不确定性参数；基于响应面法构建考虑渗流作用下重力坝抗滑稳定安全系数的功能函数,计算了多破坏模式的失效概率,并与不考虑渗流作用情况下的结果进行对比分析；采用概率失效分析方法定量分析了关键不确定性参数对重力坝失效概率的影响。结果表明：考虑渗流作用计算得到的失效概率较高,忽略渗流作用导致低估重力坝失效概率；比较三种失效模式,坝踵拉裂与沿坝基面滑动失稳最容易发生,其次是坝趾压坏。相关研究成果可为实际大坝工程可靠度评价提供理论依据和技术支撑。

During the service lifetime of gravity dams, seepage flow could adversely affect the stability and stress distribution of dams. In investigating the reliability of gravity dams, it holds paramount importance to account for the seepage effects. In this study, an efficient reliability analysis is conducted to evaluate the stability and stress distribution of gravity dams incorporating the influence of seepage effects. This analysis involves integrating the response surface method and random finite element approach. For a hydropower station project, the key uncertainty parameters affecting the stability and stress distribution of gravity dams are identified through a parametric sensitivity analysis. Using the response surface method, the performance function for the anti-sliding stability safety factor of gravity dams under the seepage effects is established, and the failure probability considering multiple failure modes is calculated. Meanwhile, the simulated results are compared with those obtained without considering the seepage effects. The influence of key uncertainty parameters on the failure probability of gravity dam is quantitatively analyzed by the probabilistic failure analysis approach. These findings show that accounting for seepage effects leads to higher failure probabilities, indicating that neglecting these effects may underestimate the likelihood of dam failure. In comparison with the three failure modes, the heel cracking of the gravity dam and sliding instability along dam-foundation interface are most likely to occur, followed by the dam toe cracking. The results could provide a theoretical foundation and technical guide for evaluating the reliability of practical dam projects.

TV37

国家自然科学基金（42002287）