Progress and prospect of failure mechanism and stability analysis of soft rock slope under wet-heat-force action

The soft rock has low strength and is easy to deform and is easily disintegrated under the influence of factors such as wet-heat-force, etc., which will lead to instability and failure of the slope. Many scholars have carried out researches on the disintegration mechanism of soft rock, the law of strength degradation and the stability of slopes. In order to summarize the existing research results and deepen the understanding of the failure mechanism and stability analysis of soft rock slopes, the disintegration mechanism of soft rock under the action of wet-heat-force, the law of strength degradation and the analysis methods of slope stability were reviewed. Firstly, the macroscopic disintegration characteristics of various soft rocks were discussed. Using SEM and CT scanning test, the disintegration mechanism of soft rocks was revealed from a microscopic point of view. Secondly, the results of the existing unconfined compression and triaxial shear tests of the existing soft rock were summarized, and the strength degradation law of the soft rock under the conditions of wet-heat-force was discussed. Finally, the application of research methods such as model tests, theoretical analysis and numerical simulations of soft rock slope stability was introduced. It is pointed out that setting the initial conditions correctly is a key factor that needs to be considered in model tests and numerical simulation analysis. Based on the above research results, the development direction of the failure mechanism and stability analysis of soft rock slopes under the action of wet-heat-force was prospected as follows. The types of soft rock should be furtherly refined, and the proportion of factors such as wet-heat-force and other factors in the process of soft rock disintegration should be quantitatively analyzed based on the initial state, and thus predicting its disintegration characteristics. The strength testing methods under the coupling effect of moisture, heat and force should be improved, and carrying out research on the strength deterioration can of soft rocks that is more in line with the multi-factor and multi-variation paths in the natural state. A slope model test device should be designed that can realize the coupled effect of wet-heat-force, and a new theoretical analysis method must be derived that can adapt to a variety of situations and can fully consider the expansion, contraction characteristics of soft rock, the distribution of initial pores and cracks of the slope in the numerical simulation technology. © 2021, Central South University Press. All right reserved.