Abstract: Soil-rock mixture landslides present obvious features such as wide distribution, high frequency of occurrence and poor regularity, which have become one of the most common geological disaster types in the western mountainous area and its key construction projects. The complex internal soil-rock structure is the critical factor leading to the difficulty of preventing and controlling the landslides. Hence, a new method by combining the geophysical prospecting and trenching was proposed to acquire the nearly realistic geological structure of soil-rock mixture landslides. The prospecting geological structure was conducted by high-resolution geophysical exploration techniques and supplemented using digital image processing of trench section. Thus, the precise geological structure of soil-rock mixture deposit was obtained, and the integration of macroscopic and mesoscopic geological structure was preliminarily achieved by the method. The proposed combination method was applied to investigate the precise detection of geological structure within the soil-rock mixture landslide in Baidian township of Nanyue district in Hunan province, and then the nearly realistic geological structure was obtained. This study provides a basis for revealing the structural control mechanism of the formation and evolution of landslides and makes the prediction and prevention of landslides more reasonably and scientifically.

Key words: soil-rock mixture, geological structure, combination method, geophysical prospecting, digital image processing, precise detection