三轴抗剪强度参数的粗差剔除与指标确定

三轴抗剪强度指标(粘聚力和内摩擦角)是岩土工程中的重要设计参数,为了更加准确地确定三轴抗剪强度指标,提出了一种基于最小距离平方和的非线性规划求解法。在证明各莫尔应力圆与回归所得强度线的垂直距离服从正态分布的基础上,根据罗曼诺夫斯基准则等小样本异常值判别准则剔除含有粗大误差的数据,获取唯一的强度线,并最终确定岩土体粘聚力和内摩擦角。结合Matlab程序,问题求解显得快速、精确而直观。实例分析验证了本文方法的实用性。

Gross Error Elimination and Index Determination of Shearing Strength Parameters in Triaxial Test

Triaxial shearing strength parameters (including cohesion and friction angle) are essential design parameters in geotechnical engineering. In order to determine the shearing strength parameters of triaxial tests more accurately, the nonlinear programming solution was suggested based on “minimum square sum of distance”. After proving that the vertical distances between Mohr circles and the regressed strength line are distributed normally, the data with gross error would be excluded based on small sample outlier discrimination criterion such as Romanowski criterion; moreover, the exclusive strength line, as well as the cohesion and friction angle, could be determined. Combined with Matlab, the solution process became rapid, precise and intuitive. Some examples have verified the applicability of the suggested method finally.