Stability Analysis of a High-Steep Dump Slope under Different Rainfall Conditions

Abstract

The existing slope stability research, which is based on the fluid–solid coupling theory, is mainly focused on the slopes of central and eastern China. The impact of rainfall on the stability of the dump slope has often been ignored. It is worthwhile to reveal the mechanism of the fluid–solid coupling mechanics of dump slopes in the arid desertification area of northwest China under the maximum precipitation. The method of combining the seepage mechanics theory with the geomechanics theory was adopted. Darcy’s law and the mass conservation law were introduced to derive and establish the fluid–solid coupling analysis method. Taking the Xinxing Coal Mine in Wuhai City, China, as an example, the finite element software ABAQUS was used to construct the fluid–solid coupling model for slope stability analysis with unsaturated soil. The equivalent rainfall intensity of 68 mm/h for 1 h and 18 mm/h for 24 h was designed in the simulation, respectively. Four different types of initial water content (i.e., 1.72%, 7.34%, 14.69%, and 22.03%) of the dump slopes were defined as the initial conditions. The high-steep slope was compared to the standard slope. Therefore, a set of sixteen rainfall schemes was proposed. The variation regularity of slope stability was thoroughly discussed in regards to four areas: vertical deformation, pore water pressure distribution, equivalent plastic strain, and safety factor. As was expected, the research showed that the slope height and angle have a significant effect on the slope stability. When high-intensity rainfall occurs for a short duration, the slope tends to be more stable as the initial water content increases on the slope. When low-intensity rainfall occurs over a long period, the slope stability reduces if the initial water content is too high or too low in the slope.

Investigation on the disaster mechanism and dynamic evolution of a dump slope using experimental and numerical methods: Case study, Kunyang phosphate mine, China

“…Currently, a large number of scholars have carried out research on the instability characteristics and mechanism of dump slopes. S. Li, Qiu, et al (2022) proposed an improved region growing segmentation method (IRGSM), which can automatically monitor the deformation region of rock dump with high precision. Moreover, the progressive failure law of rock slope under variable rainfall intensity is analysed based on the data of water content and pore water pressure.…”

“…Currently, a large number of scholars have carried out research on the instability characteristics and mechanism of dump slopes. S. Li, Qiu, et al (2022) established a balanced equation regarding the interaction mechanism between seepage field and stress field. The influence of maximum storm intensity and rainfall duration were investigated.…”

Probabilistic Approach to Transient Unsaturated Slope Stability Associated with Precipitation Event

“…Various authors have developed or applied specific numerical solutions under adjusted conditions and simplifications for each case of stability study, highlighting the need for closed mathematical solutions for understanding the unsaturated flow that would facilitate the computational implementation, the validation of numerical models, and a better representation of the physical phenomenon [2][3][4][5][6][7][8][9].…”

The Characteristics and Seepage Stability Analysis of Toppling-Sliding Failure under Rainfall

“…Rainfall is an important factor in triggering landslides [19][20][21][22][23]. It often leads to a rise in groundwater level or the development of the perched water zone, both of which may result in the reduction in soil matric suction (an increase in pore-water pressure).…”