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| A novel method for solving the location and depth of tension cracks at the rear edge of rock slopes under stress analysis mechanism |
| DENG Dongping，PENG Yihang，CHEN Haoyu |
| (College of Civil Engineering，Central South University，Changsha，Hunan 410075，China) |
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Abstract Tension cracks at the rear edge of a slope often have a significant impact on the stability of rock slopes，how to effectively predict the location and depth of tension cracks becomes a key prerequisite for reliable analysis of the stability of rock slopes with tension cracks. Thus，a novel method is developed to solve the location and depth of tension cracks at the rear edge of rock slopes，specifically focusing on rock slopes without joints or with four or more sets of joints，based on the formation mechanism of tension cracks. The present method begins by applying the nonlinear generalized Hoek-Brown(GHB) strength criterion，which incorporates the influence of joints into the calculation of rock mass strength. Furthermore，given the approximate vertical development of tension cracks at the rear edge of the slope，the horizontal stress state of the rock mass becomes a crucial factor in the formation and development of tension cracks. Consequently，a micro-wedge unit mechanical analysis model is introduced to determine the horizontal stresses of the rock mass at the rear edge of slope. Thereafter，based on the top-down development pattern of vertical tension cracks at the rear edge of slope and the relationship between the terminal stress level of the tension crack and the rock mass’s tensile strength，a discriminant formula is formulated to calculating the location and depth of tension cracks at the rear edge of slope. The rationality and effectiveness of the present method is verified by comparing with the numerical simulation method，laboratory test results，and engineering measured data. The research findings provide a theoretical basis for predicting the location and depth of tension cracks at the rear edge of rock slope and establish necessary conditions for a reliable stability analysis of rock slopes with tension cracks at the rear edge.
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