黄土颗粒流宏细观对应关系与参数标定方法研究

Study on macro-mesoscopic corresponding relationship and parameter calibration method of loess particle flow

针对黄土颗粒流模型细观参数标定过程中试错法计算量大的现状,采用敏感性分析与回归分析相结合的方法,在分析了黄土细观因素与宏观力学响应对应关系和多因素非线性联合反演的基础上,快速确定了黄土的细观参数,并得出如下结论:黄土的抗剪强度^(-)τ_(c)随半径乘子^(-)λ的增大呈指数函数规律增大,随摩擦系数μ的增大呈线性增大,随法向黏结强度^(-)σ_(c)的增大呈幂函数规律增大;内摩擦角φ′随摩擦系数μ的增大呈对数函数规律增大;黏聚力C随半径乘子^(-)λ的增大呈线性增大,随法向黏结强度^(-)σ_(c)的增大呈对数函数规律增大。数值试验与室内试验结果误差较小,证明了此方法在黄土细观参数标定中的可行性,为其他材料的细观力学参数标定提供了新思路,也为黄土地区滑坡、泥石流和融水降水侵蚀等地质灾害的颗粒流模拟分析提供了参数参考。

Aiming at the status quo of the large calculation amount of trial-and-error method during the calibration process of the microscopic parameters for the loess particle flow code model,the mesoscopic parameters of loess are rapidly determined by means of combining sensitivity analysis with regression analysis on the basis of the analysis of the corresponding relationship between mesoscopic factors and macroscopic mechanical response of loess and the multi-factor nonlinear joint inversion,and then the following conclusions are obtained:the shearing strength ^(-)τ_(c) of loess increases in exponential function law with the increase of the radius multiplier ^(-)λ,linearly increases with the increase of the friction coefficientμand increases in power function law with the increase of normal bonding strength ^(-)σ_(c),while the internal friction angle increases in logarithmic function law with the increase of friction coefficientμand the cohesion C increases linearly with the increase of the radius multiplier ^(-)λ and logarithmically with the increase of normal bonding strength ^(-)σ_(c).The error between the numerical experiment result and the indoor experiment result is small,thus the feasibility of this method for calibrating the mesoscopic parameters of loess is demonstrated,and then not only a new idea for calibrating the mesoscopic mechanical parameters of the other materials is provided,but the relevant references of the parameters for the simulative analysis of particle flow code on the geological disasters such as landslide,debris flow,meltwater and rainwater erosions,etc.in the loess region are also provided.