混凝土重力坝薄弱面分布范围的确定方法

Determination of weak interface distribution range of concrete gravity dam based on reliability analysis

客观存在的诸多不确定性因素使得高坝系统不可避免地存在风险,因此研究不确定性因素对碾压混凝土重力坝安全性的影响意义重大,其中一个重要内容就是确定在随机因素下坝体最不利薄弱面的分布范围。对于碾压混凝土重力坝来说,层面的特性对坝体结构安全的影响至关重要,最不利薄弱面一般发生在层面上,如何确定最不利薄弱面的分布高程及分布范围是工程中较为关心的重要问题。以国内某一碾压混凝土重力坝为例,首先对不利薄弱面的高程进行搜索计算,然后运用随机有限元的方法进行整个坝段的随机分析,对比规范给定的可靠指标编制程序搜索失效单元,进而确定出最不利薄弱面的分布范围,为工程的施工设计及安全校核提供了一定的参考依据。

Many uncertain factors such as loads,boundaries,material parameters can cause unavoidable risk for the high dams.It is of great significance to study on uncertainties in RCC gravity dam safety.One of the most important questions is to determine the dam's weak interface distribution under the random factors.For the RCC gravity dams,the properties of weak interface are very important to dam safety,usually the most unfavourable weak interface is dam layer plane.How to decide the weak interface elevation and weak interface distribution range are the key questions to dam engineering.In the paper,an RCC gravity dam as an example is researched.Firstly weak interface elevation is decided,then the whole dam section including the weak interface is calculated by the stochastic finite element method,comparison of reliability index of calculated result and reliability index given by code,the most unfavorable weak interface distribution range can be determined.