## 4 Instance Analysis
### Stability Analysis  
In order to obtain the mechanical properties of the sliding body soil layer, a certain number of undisturbed soil samples were taken from different boreholes on the sliding body for natural and saturated fast shear tests and natural and saturated shear tests. In order to facilitate the statistics of the physical and mechanical properties of the slip body, the strata of the slide body revealed in the exploration area were re-stratified and divided into:  
1. Malan Loess (Q\({}_{3}\)\({}^{\text{eol}}\)): It is light yellow; the soil is mainly silty soil, low density and humidity. It contains a small amount of calcium nodules and calcium streaks, and its layer thickness is 0.80-19.80 m.
2. Paleosol (Q\({}_{3}\)\({}^{\text{eol}}\)): It is brown, the soil is mainly silty clay and the humidity and density are moderate. White calcareous streaks and a few calcareous nodules are seen. Its layer thickness is 1.30-13.80 m.
3. Lishi loess (Q\({}_{2}\)\({}^{\text{eol}}\)): The soil is yellowish-yellow and mainly silt. Contains small amounts of calcareous nodules and ferromanganese streaks, containing mica. The soil layer is 1.70-36.40 m thick. 4. Paleosol (Q\({}_{2}\)\({}^{\text{eol}}\)): The soil is yellowish-brown, mainly silty clay. There are a few white stripes and iron and manganese stripes, and the bottom contains a small amount of calcium nodules. The soil layer is 3.30-13.00 m thick. 5. Lishi loess (Q\({}_{2}\)\({}^{\text{eol}}\)): The soil is yellowish-yellow, mainly silty soil. Inside can be seen wormhole, pinhole development, iron and manganese spots. The soil layer is 3.20-15.60 m thick. On the basis of stratification of the sliding body, according to the requirements of _Code for Investigation of Geotechnical Engineering_, the indoor soil test data of each layer in the sliding body are analyzed by mathematical statistics after individual discrete data are  
Figure 7: Landslide plane topographic map and displacement monitoring point layout. deleted. The statistical results of the shear strength index of each layer of the sliding body are presented in Table 1.  
The stability calculation equation is calculated using the equation in GB/T38509-2020 Design Code for Landslide Prevention and Control [14], and two working conditions are selected for this calculation. Condition 1: natural state, that is, the limit equilibrium state of the slope under natural conditions. This condition is used to evaluate the stability of the current slope and calculate the physical and mechanical parameters of the slide surface. Condition 2: saturated state, which is the most unfavorable case for continuous heavy rainfall. Under this condition, the slope body gained weight and the strength of the sliding surface decreased obviously, and the slope body was most likely to slide again under this condition. Since the landslide threat object is the resident gathering area at the foot of the slope and contains the power project, the importance level of the facilities threatened by landslide is important. According to DZ/T0219-2006 \"Technical Code for Design and Construction of Landslide prevention and control engineering\", the landslide control and control engineering should be grade I, and the safety factor under the natural condition is 1.3; the safety factor under the saturated condition is 1.15. The transfer coefficient method is used to calculate and analyze the stability and safety of the landslide after excavation, and the results are shown in Table 2.  
As can be seen from Table 2, the stability coefficient of the slope under natural conditions is 1.387, which is greater than the design safety factor 1.3 stipulated in the Technical Code for Design and Construction of Landslide Prevention Engineering. However, the stability coefficient of the slope under saturation conditions is 1.089, which is less than the specified value of 1.15. According to the results of slope stability analysis, its stability level is poor, and it is in urgent need of engineering treatment.