拱坝坝肩稳定的随机分析

以有限元法为基础,利用子结构法分析拱坝坝体和岩体的相互作用问题.利用Bayes法对错动带的力学随机参数进行了估计,将裂隙岩体材料参数看作是空间随机场,引入区域化变量以反映其在空间上的随机性和相关性,用变异函数反映了岩石力学参数区域化特征,用克里格方程对各单元材料参数进行了估计.据此,可充分利用地质资料,人为判断最大可能滑动的部分结构面,对不易判断的滑动面,利用破坏追踪搜索获得.该方法可充分考虑各种不确定性以及各种破坏失稳模式的相关性,利用可靠度理论对坝肩的稳定性进行评价.应用该方法对某高拱坝的拱肩稳定进行分析,结果表明,本文提出的计算方法简单,计算结果合理可靠.

Probability analysis on stability of arch dam abutment

The substructure method is applied to study the interaction between arch dam and its abutment and the stochastic mechanical parameters of the fault belt are estimated by means of Bayes method. The distribution of parameters is regarded as a spatial stochastic field and the localized variables are introduced to reflect the spatial stochastic characteristic and orrelations among the parameters. The parameters of every element are obtained from sample data by using Kringing formula. Geological condition is used to judge the sliding plane. The cracking trajectory is utilized to help searching the sliding plane which can not be judged by geological condition. This method can sufficiently consider all uncertainties and all correlations of fracture mode and apply the reliability theory to estimate the stability of abutment. The example of application of this method shows that the calculation is simple and the result is reliable.