汉源昔格达组半成岩微观结构与宏观力学的相关性

Correlation between Semi-diagenetic Microstructure and Macroscopic Mechanics of Xigeda Formation in Hanyuan

地层岩性是滑坡产生的物质基础。为更清晰地认识半成岩微观结构变化对宏观物理力学性质的影响,通过对“8.21”中海村滑坡进行调查分析,表明:相比较于低含水率的昔格达组半成岩,高含水率的颗粒形态更趋向于有序性,但颗粒排列却更加无序,表明结构稳定性变差,昔格达组半成岩更易滑动。运用灰色关联度分析方法研究了汉源昔格达组半成岩宏观强度特征参数与微观结构参数之间的关联性,发现对黏聚力C、内摩擦角φ影响最大的是颗粒平均直径。随着含水率的增大,昔格达组半成岩微观颗粒接触不连续,颗粒间孔隙增多,结构发生较大变化,整体密实度降低,导致昔格达组半成岩强度降低,使得滑坡更易发生。

Formation lithology is the material basis of landslide.In order to more clearly understand the influence of semi-diagenetic microstructure on macroscopic physical and mechanical properties,through the investigation and analysis of‘8.21’Zhonghaicun landslide,it is shown that compared with the semi-diagenetic Xigeda Formation with low water content,the particle morphology of high water content tends to be more orderly,but the particle arrangement is more disordered,indicating that the structural stability is worse,and the semi-diagenetic Xigeda Formation is more likely to slide.The grey correlation analysis method was used to study the correlation between the macroscopic strength characteristic parameters and the microstructure parameters of the semi-diagenetic Xigeda Formation in Hanyuan.It was found that the average diameter of the particles had the greatest influence on the cohesion C and the internal friction angleφ.With the increase of water content,the contact of semi-diagenetic microscopic particles in Xigeda Formation is discontinuous,the pores between particles increase,the structure changes greatly,and the overall compactness decreases,which leads to the decrease of semi-diagenetic strength of Xigeda Formation and makes landslide more likely to occur.