Rock mass material parameters.

Under the influence of natural weathering and excavation in human engineering, slopes in nature have various slope shapes. In human engineering activities, the stability of different types of slopes formed by manual excavation must be affected by multiple factors such as geologic setting, lithology and environment. Therefore, to understand the impact of slope shape, geologic setting, and other conditions on slope stability of artificial slopes, calculation models for straight slope, concave slope, and convex slope are constructed based on the three slope shape characteristics. By changing the angles of upward and downward slope angles and analysing the parameters of slope shape, joint spacing, and joint angle, discrete element software is used to calculate the slope safety factor. The calculation results show that the slope shape, joint spacing, and joint inclination affect the safety of slopes. In straight slopes with large joint spacing, the smaller the slope angle, the greater the safety factor. However, in the interval of small joint spacing, the safety coefficient of slopes with slight joint inclination has the opposite variation characteristics. When a<90°, the straight slope has a dominant joint inclination angle that minimises the slope safety factor. In concave slopes, the more concave the slope shape is, the smaller the safety factor is; For concave slopes with small joint spacing, the slope with slight joint inclination has a more significant safety factor; Under the condition of large joint spacing, there is a dominant joint inclination in the joint inclination range of 30° to 70° for concave slopes, which minimises the safety factor of the slope. In convex slopes, the smaller the joint inclination angle of the slope, the smaller the safety factor of the slope, and the smaller the upslope angle of the slope, the greater the safety factor of the slope.