THE SUPERFICIAL DEFORMATION AND FAILURE MODES OF SMALL AND MEDIUM SCALE SLOPE IN RED BED SICHUAN BASIN

摘要

Red-Bed soft rocks are widely distributed in the Sichuan Basin. There are geological disasters frequently occurs in red bed area. It is difficult to identify the potential hazards. After Wenchuan earthquake, traffic interruption happened frequently by secondary disasters in mountain area, endanger the traffic safety, and result in huge economic losses. Therefore, the study which focuses on the deformation and failure mechanism of this kind of slopes is very important. The project aims at the superficial layer deformation and failure mode of the traffic slope in red bed Sichuan Basin, based on the on-the-spot geological investigation, combined with the features of the lithological association simultaneously. The project classifies three subtypes of small and medium scale slope in red bed area. There are hard sandstone slope, soft shale mudstone slope, and soft and hard sandstone and mudstone interbedded strata slope. And then, the project establishes 8 types of deformation and failure modes. Beside structure type of slope, the shape of bedrock and obliquity can also affect the deform characteristics. Based on all kinds of modes, the project analyzes the disaster-causing mechanism of each slope. The results shows the diversities of deformation and failure characteristics of the small and medium scale slope in red bed. The results provide a basis of calculation of slope structure and stability, and also provide a foundation of designing in red bed area.