Evolution analysis of the Banbiyan dangerous rock mass in the three gorges reservoir area, China

Due to the changing mechanical environment, it is difficult to determine the evolution process of the rocky bank. In this paper, the Banbiyan dangerous rock mass (BDRM) in the Three Gorges Reservoir area was taken as an example to analyze its failure characteristics. As for this specific evolutionary environment, a new judgment system was proposed, involving the comprehensive field survey method and indoor tests. The key information about the steep areas, interior areas, and underwater areas was obtained, which overcomes the limitations of the conventional survey methods. On this basis, combined with a simplified geo-mechanical model and dry-wet cycle tests, the evolution trend of BDRM under variable water levels was predicted. The results show that the stability of BDRM depends on many factors, including the self-weight of overlying rock mass (the location of the broken area), the strength of the broken area, the water pressure of the trailing edge crack (rainfall) and the reservoir water level. According to the calculation results, the BDRM is likely to slip along the broken area after 46 dry-wet cycles. The application of related methods can provide an important reference for judging the evolution trend of unstable rocky banks worldwide.