土石混合体材料强度特性及其滑坡灾变机理研究

The mesostructure characteristics significantly affect the macromechanical characteristics of soil-rock mixture(S-RM) material under external force. Based on S-RM landslide along the Mianzhu to Maoxian highway, granular flow model of S-RM reflecting inner structural feature is obtained using digital photography with the help of digital image processing technology and the finite element mesh fuction on the basis of the field investigation and lab large-scale shear test with visual reconstruction. By selecting appropriate particle contact model, a series of numerical simulations of shear test under real microfabric are carried out to study the strength and shear deformation characteristics of S-RM, and the relationship between meso parameters and macro parameters of S-RM material can be built. Combined with the results of shear test, micromechanical parameters consistent with the macro mechanical characteristics can be obtained by repeated trial calculation and adjustment. On this basis, the whole process of the movement of the S-RM landslide is simulated to reveal landslide disaster mechanism based on micromechanics method, which can provide the basis for prediction and prevention of S-RM landslide.

土石混合体材料的细观结构特征在很大程度上影响了其在外力作用下的宏观力学行为。本项目拟以绵竹至茂县公路沿线土石混合体滑坡为背景，在现场调研、室内大型直剪试验及其可视化改造基础上，基于高清数码照相、图像处理技术及有限元网格划分功能构建能够准确表征土石混合体细观组构的颗粒流模型；通过选择适宜的颗粒接触模型，开展一系列真实细观组构下直剪试验的数值模拟，以深入研究土石混合体强度特性及剪切变形特征，并建立对应组构下土石混合体宏、细观力学参数的相关性；结合室内直剪试验结果，通过对细观参数的试算和调整，获得与其宏观力学特征相一致的细观力学参数；在此基础上，从细观角度揭示土石混合体滑坡的滑动灾变机理，为该类滑坡的预测及防治提供理论依据与技术支持。

本项目以绵竹至茂县公路沿线土石混合体滑坡为背景，在现场调研、室内大型强度试验及其可视化改造基础上，基于高清数码照相、图像处理技术及有限元网格划分功能构建了能够准确表征土石混合体细观组构的颗粒流模型；通过选择适宜的颗粒接触模型，开展了一系列真实细观组构下强度试验的数值模拟，建立了对应组构下土石混合体宏、细观力学参数的相关性，从细观角度揭示了土石混合体滑坡的滑动灾变机理。研究结果表明，土石混合体的力学性质与其块石含量密切相关；其宏细观力学参数会随着剪切破坏的形态不同而呈不同的相关关系；边坡稳定性随着含石量的增加而有所提高并呈现不同的破坏模式。项目资助已发表核心论文11篇，其中SCI论文3篇，EI论文3篇。协助培养博士生、硕士生各1名。项目投入经费23.0万元，支出22.75万元，各项支出与预算基本相符。