基于随机模糊理论的节理面抗剪强度参数的确定

Determinations of Shear Strength Parameters of Jointed Rock with Fuzzy Random Theory

针对岩石抗剪强度参数c,φ的确定具有模糊性及随机性,首先,利用非对称三角模糊系数式表示参数c,φ最可能取值及其可能性分布,再通过非对称三角模糊数在特定截集水平下的宽度之和与测试值和计算分析最可能取值加权系数的方差作为目标函数进行模糊优化分析,同时通过"3σ"原则合理地确定非对称三角模糊数截集水平h,从而为岩土工程设计的优化提供了一种新的方法,该方法不仅可有效减少较大离散性数据对分析结果的影响,又真实地反映了实际工程中参数c,φ取值的不确定性特征。通过与最小二乘法的对比,表明该方法较符合工程实际。

The shear strength parameters of jointed rock mas have the characteristics of fuzziness and randomness. In this paper, the possible values and their distribution pattern can be represented by an asymmetric triangular fuzzy formula. The fuzzy optimization can be achieved by using the area of the triangular function under certain region and using the weighted average of bet possible strength parameter values as the targeted function. The truncated set level h of the asymmetric triangular fuzzy number can be determined through 3 sigma method. This provides a new approach for the optimization of the geotechnical engineering projects. The least square linear regression analysis indicate that his method can be reasonably applied in the practical projects.