Abstract: The stress analysis of sliding surface is the key link to evaluate the stability of slope and predict the risk of landslide. There are many methods to solve the sliding surface stress, but there is no reasonable method to evaluate these methods. In order to solve this problem, a sliding surface stress test device used in landslide model test was proposed. The structural characteristics and design principle of the device were introduced in detail. Three cases were designed to test the sliding surface stress by model test. Based on the correlation analysis and probability P value in the statistical analysis results of paired sample t-test, the applicability of Morgenstern-Price (M-P) method, elastic theoretical solution of sliding surface stress based on slope unloading and numerical analysis method in solving sliding surface stress was evaluated. The main conclusions are as follows: (1) The absolute error between the test results and the theoretical values of the 9 sliding surface test units is within 2.5%. The statistical analysis results show that the difference between the test results and the theoretical values is not significant, and the stability of the test results is good. (2) The elastic theoretical solution and numerical analysis method can accurately calculate the stress state of the sliding surface, but the calculation result of the M-P method has a large deviation from the actual one, which is not suitable for the calculation of slip surface stress in non-limit state. (3) The application of sliding surface stress elastic theory solution based on slope unloading in embankment slope is expanded, but this method still has great limitations. The sliding surface stress test device proposed in this paper expands the new method of sliding surface stress test, and provides a guarantee for the accuracy verification of sliding surface stress calculation and stability analysis theory.

Key words: landslide, sliding surface stress, model test, elastic theoretical solution, numerical analysis, statistical analysis