# Risk Analysis of Service Slope Hazards for Highways in the Mountains Based on ISM-BN
## 2 Literature Review  
Highway slope disaster (HSD) risk analysis is an effective method for disaster risk prevention and management, and accurate identification of potential systematic risk influencing factors is a prerequisite for establishing a reliable risk assessment model [7]. The causes of slope hazards are complicated. Geotechnical properties, slope gradient, slope height, heavy rainfall, and human disturbance are all important factors leading to slope disasters [8, 9, 10, 11]. During heavy rainfall, the infiltration capacity of the slope is not sufficient to absorb all the rainwater into the soil. As a result, the rainwater that cannot infiltrate into the soil flows over the surface of the slope in the form of runoff, and it is obvious that both rainwater permeability and runoff undermine the stability of the slope [12, 13]. [PERSON] et al. [14] found that, due to insufficient understanding of slope structures or inaccurate judgments of slope disaster, some slopes have poor protective effectiveness despite the implementation of protective measures. A study by [PERSON] et al. [15] showed that rainfall is the main trigger for landslides and that about 90% of the landslide fatalities worldwide are due to rainfall-induced landslides. In previous studies related to highway slope risk, scholars at home and abroad have explored various methods to quantify slope disaster risks, such as the traditional slope stability evaluation model based on limit equilibrium [16] and finite element numerical simulation [17]. These methods have achieved notable success in slope mechanical behavior analysis and stability assessment. However, the level of slope disaster risk is affected by the joint influence of various uncertain factors inside and outside. It is insufficient to comprehensively capture the complexity and evolutionary characteristics of slope disaster risk using only deterministic mathematical modeling methods based on the principle of geotechnical characteristics design. [PERSON] et al. [18] proposed a risk assessment of the stability of expansive soil slopes based on Fuzzy Hierarchical Analysis (FAHP), but there are deficiencies in the risk evolution analysis of multi-factor coupling. [PERSON] et al. [19] developed a quantitative risk assessment in terms of probabilistic loss for the cutting slope  
Figure 1: The proposed methodology flowchart. risks during the design phase. This approach enabled the quantitative estimation and comparison of potential risk losses under different working conditions, but their study is largely confined to static risk analysis. [PERSON] et al. [PERSON] et al. (2018) constructed a highway slope stability evaluation model integrating Principal Component Analysis (PCA), Genetic Algorithm (GA), and Support Vector Machine (SVM), providing a preliminary theoretical foundation for highway slope management. However, the method exhibits a strong dependency on data and fails to effectively reveal the intrinsic correlation among factors. [PERSON] et al. [PERSON] et al. (2018) carried out spatial prediction of slope stability for mountain highways based on GCG-CNN with the support of the Geographic Information System (GIS), which provided a theoretical basis for improving the disaster resistance of highway and regional disaster prevention and mitigation capacity, but it focuses on spatial distribution characteristics and lacks sufficient analysis of the interactions among multiple factors. BN consists of two parts: Directed Acyclic Graph (DAC) and conditional probability tables (CPTs), which can effectively characterize causal relationships among influencing factors through probabilistic reasoning [PERSON] et al. [PERSON] et al. (2018). [PERSON] et al. (2018) developed a multi-index serviceability assessment model for dams based on BN, and the results showed that it has high reliability in assessing complex systems. [PERSON] et al. showed that the BN model is an effective method for dam risk analysis. However, BN still has certain limitations in practical applications.