基于随机有限元的重力坝时变可靠度计算分析

Reliability Calculation of Gravity Dams Considering Material Aging Based on SFEM

我国水库总量较大,病险水库较多,其运行期的溃坝与非溃坝风险分析与处置是水库运行管理的关键技术。针对病险库坝材料老化特性,提出了基于随机有限元法的重力坝可靠度计算分析方法。以HYT电站为例,对左岸非溢流坝段抗滑稳定和坝体强度可靠指标进行了计算分析;并考虑了材料参数随运行时间的变化,进而对运行期的可靠度时程变化规律进行了分析。结果显示,校核洪水位工况层面抗滑稳定可靠指标和坝顶浆砌石部分单轴拉伸准则对应的强度可靠指标小于目标可靠指标,要重点关注;且该坝段的抗滑稳定和强度可靠指标均随着运行时间的增长而有所下降。提出的方法计算效率高,能考虑众多实际影响因素,计算结果符合实际规律,在分析重力坝可靠性时合理有效。

There are a lot of reservoirs in China and the number of dangerous reservoirs is large.The dam break and non⁃dam break risk anal⁃ysis and disposal of dangerous dams during the operation period is the key technology of reservoir operation management.According to the ag⁃ing characteristics of dam materials and based on stochastic finite element method,the method to calculate and analyze the reliability of gravi⁃ty dam was proposed.Taking HYT Hydropower Station as an example,the reliability indexes of anti⁃slide stability and strength of the non⁃o⁃verflow section on the left bank were calculated and analyzed.Meanwhile,how material parameter change with operation time was considered and then the time⁃history variation rule of reliability in operation period was analyzed.The results show that under the check flood level condi⁃tion,the strength reliability index corresponding to uniaxial tension criterion of the masonry part of dam crest and the anti⁃slide stability relia⁃bility index are lower than the target reliability index 3.7,which need special attention.And with the increase of operation time,the reliabili⁃ty indexes of anti⁃slide stability and strength are decreased.This method has high calculation efficiency,many actual influence factors can be considered,and the results are in accordance with the actual law,which is reasonable and effective in analyzing the reliability of gravity dam.