基于非均质流变特性的滑坡时效演化及预警研究

Evolution characteristics and early warning of landslides based on heterogeneous rheological properties

针对滑坡孕育演化过程中岩土体非均质现象,开展滑坡相似材料的强度试验、底摩擦模型试验和扫描电镜试验,从宏观和微观角度深入研究滑坡演化力学机制及其非均质特征。基于上述研究,将强度劣化模型与Burgers模型串联,形成考虑非均质流变特征的本构模型,应用于滑坡时效演化的数值算例分析和预警研究,结果表明:滑坡演化过程中存在时间和空间非均质性,在时间上,岩土体参数劣化速率越快的滑坡,其蠕滑变形到最终失稳破坏所经历的时间越短,在空间上,不同部位的滑坡岩土体的破坏机制和微观结构存在非均质性。考虑非均质流变特征的本构模型能够较好地反映滑坡变形三阶段演化特征,通过实际工程与数值分析相结合,验证了非均质流变模型的准确性,为滑坡失稳破坏的分析和预警提供有益参考。

In view of the heterogeneous of rock and soil during the gestation and evolution of landslides,the strength test,bottom friction model test and scanning electron microscope test of similar materials of landslides were carried out,and the mechanical mechanism of landslide evolution and its heterogeneity characteristics were deeply studied from macro and micro perspectives. In addition,the strain softening model and Burgers model are connected in series to form a constitutive model considering the heterogeneous rheological characteristics,which is applied to the numerical example analysis and early warning study of landslide time evolution. The results show that there are time and spatial heterogeneity. In terms of time,the faster the degradation rate of rock and soil parameters of the landslide,the shorter the time from creep deformation to the final instability failure. There is heterogeneity in the mechanism and microstructure. The constitutive model considering the heterogeneous rheological characteristics can better reflect the three-stage evolution characteristics of landslide deformation. The accuracy of the heterogeneous rheological model is verified through the combination of actual engineering and numerical analysis,which is the analysis of landslide instability and failure,and early warning to provide useful reference.