基于非参数统计Hoek-Brown准则的参数敏感性分析

Parameter sensitivity analysis of Hoek-Brown Criterion based on nonparametric statistics

Hoek-Brown强度准则能正确反映岩体强度,描述岩体非线性破坏特征,但其参数获取存在人为因素,数据离散,不利于理论分析和数值计算。基于此,在对不规则Hoek-Brown屈服面处理并数值实现的基础上,提出用非参数统计方法研究Hoek-Brown参数敏感度,用Matlab实现拉丁抽样,借助一巷道模型,研究了参数对其围岩变形的敏感性,得到各参数的敏感度大小顺序,说明围岩塑性区和弹性区的变形受控因素不同,围岩塑性区的变形与GSI值的相关性最大。

The Hoek-Brown strength criterion can be adjusted to provide an estimate of the decreased strength of the rock mass and reflect the intrinsic nonlinear strength criterion of rock and rock-mass failure characteristics. But for estimating material parameters, there are subjective factors and data discretization, which are not conducive to the theoretical analysis and numerical calculation. As a result, on the basis of yield surface treatment on irregular Hock-Brown and numerical realization, this paper proposes using nonparametric statistical method to study Hoek- Brown parameters sensitivity. Latin sampling is applied with the aid of Matlab software. The sensitivity of parame- ters to the deformation of wall rock is studied by tanking a tunnel as an example. The order of the sensitivity of parameters is deduced as well. The study illustrates the controlled factors to the deformation of wall rock are differ- ent for plastic zone and elastic region, and the correlation of the deformation and the GSI value is the highest for plastic zone.