Shallow Metamorphic Rocks In The Regolith Slope Failure Mode And Its Stability

According to the systematic field surveying, the thesis summarized the engineering properties of the low-grade metamorphosed rock high slopes of Xiamen-Chengdu expressway (from Shuikou to Duyun). The mapping principle of stereographic projection was used to ascertain the dominant orientations of discontinuities, and some parameters such as the RQD (rock quality of designation), JRC (joint roughness coefficient), joint density and rock mass integrity were calculated on the spot. It laid the foundation for ascertaining the mechanical parameters of rock structure.The X-ray diffraction and SEM image methods were used to describe the mineral composition and micro-structural characrteistics of the low-grade metamorphosed rock. The mechanical parameters of rock (c,φ) were given by back analysis, experiment and empirical method.By contrast of the results metioned above, a efficacious method in different circumstances was advanced.Based on the field surveying and analysis, the failure mechanism and common failure mode of the low-grade metamorphosed rock high slope in Guizhou province were proposed. After a statistical analysis of the parameters of the discontinuities and rock mass quality classification, a mathematical model showed the relationship between slope face and discontinuities was established according to stereographic projection. According to Hoek-Bray's theory, the failure mode of slope was identified. A rapid, qualitative assessment of local and overall stability were given based on SMR method and modified CSMR method. For the different failure mode of slope, a appropriate propose of construction, consolidation and protection was given by a simple example.