# Comprehensive Method to Test the Stability of High Bedding Rock Slope Subjected to Atomized Rain
## 1 Introduction  
High rock slopes are inevitable in the construction of high dams, and the problem of slope stability is a key issue for engineering safety. For high dam projects with characteristics of high water head, large flood discharge, and narrow canyon, there is a class of bedding rock slope instability problems that is induced by rainfall and flood discharge atomized rain. Here, atomized rain refers to the rain produced by the discharge of flood from high dams. Due to rainfall infiltration being the most frequent triggering factor for natural bedding rock slope failure, substantial research has been carried out to study the failure mechanisms of rainfall-induced landslides. Various relevant aspects have been investigated, such as those concerned with causes, triggering factors, and their impact priority under rainfall. This class of bedding rock slope stability problems is mainly affected by the mechanical parameter reduction of structural planes and the internal pore water pressure [1; 2; 3]. At present, numerical simulation and physically based tests are widely used to study slope stability [4; 5; 6]. Finite element method (FEM) simulation has been extensively used to study the complex problem of slope stability subject to rainfall, rising/lowering water levels, and earthquakes. For example, [PERSON] and [PERSON] [7] used FEM based on the shear strength reduction method to simulate and analyze the stress, displacement, friction on contact surface, and stability of bedding rock cutting slope in different excavated stages. Numerical simulation methods are not overly costly to undertake. These methods have provided improved insight into slope failure mechanisms [8; 9; 10; 11]. However, it is difficult for these numerical methods to reliably simulate all the details of the failure mode and mechanism. Physically based tests can provide an improved insight into the failure mode and mechanism of slopes. For example, the steel frame lifting technique was first used by [PERSON] [12] to study the sliding and toppling failure mechanism of jointed rock slopes. [PERSON] et al. [13] adopted the same method to study the global stability of the high slope in the Jinping Power Station project. Based on the centrifuge method, [PERSON] et al. [14; 15; 16; 17] studied the failure mechanism of a slope by increasing the unit weight of the rock mass. However, in an actual project, besides an increase in the rock mass unit weight and slope sliding force, the slope failure is also affected by rainfall, reservoir water level fluctuations, etc. [1; 2; 3; 18]. [PERSON] and [PERSON] [19] proposed a physically based distributed cell model to predict regional rainfall-induced shallow slope failures in two-layer soils under realistic rainfall conditions. [PERSON] and [PERSON] [3] analyzed the seepage characteristics, mechanical characteristics, and deformation laws of a slope under the conditions of long-time heavy rain and short-time rainstorm. However, as far as the authors know, none of the existing physically based methods consider multifactor impacts that may lead to high rock slope failure. Additionally, the safety factor expression of a rock slope by a physically based test needs further study and establishment. In this paper, based on the steel frame lifting technique and strength reduction materials, a comprehensive method is proposed to study the stability of high bedding rock slope subjected to atomized rain. Safety factor expression of the comprehensive method and the evaluation method for deformation instability were established according to the similarity theory of geomechanical model, failure criterion, and mutation theory. Using the high bedding rock slope in the Baihetan Hydropower Station, this paper presents the details of the comprehensive method as well as an analysis of the test results. Load-displacement characteristics and the macroscopic failure process were recorded during the strength reduction and uplift stage. The failure modes of high bedding rock slope subjected to atomized rain were examined.