关键词: 重力坝抗滑, 相关非正态变量, 二阶矩矩阵法, 可靠指标

Abstract: In order to study the influence of correlated non-normal random variables to the reliability index of stability against sliding of gravity dam foundation, the reliability index of stability against sliding of gravity dam foundation for independent non-normal random variables is calculated using JC method, Mapping Transformation method and Practical Analysis method in the paper. At the same time, the reliability index of stability against sliding of gravity dam foundation is also calculated when the correlation between the non-normal variables shear friction coefficient and cohesion is considered. The conclusions are obtained as: (1) although in the JC method, Mapping Transformation method and Practical Analysis method, different theoretical methods are used to transfer the non-normal variables to normal variables, the resultant reliability indexes of engineering example are almost the same; (2) method of second moment matrix degenerates into JC method when the correlation between variables are not considered; and (3) the reliability index of stability against sliding of gravity dam foundation increases along with the decreasing of negative correlation factor between f' and c' , and the reliability index obtained on the basis of f' and c' by normal distribution probability model is smaller than by lognormal distribution probability model.

Key words: stability against sliding of gravity dam, correlated non-normal variable, method of second moment matrix, reliability index