Overall Risk Assessment Method for Construction Safety of Expressway Reconstruction and Expansion Projects

To accurately evaluate the overall safety status of the project before the construction of the highway renovation and expansion project, an overall safety risk assessment method of expressway reconstruction and expansion projects based on analytic hierarchy process (AHP) and cloud model was proposed. Firstly, the evaluation index system was constructed based on engineering characteristics, traffic conditions, construction traffic organization, construction technology, and natural environmental conditions. The cloud model theory was introduced to improve the traditional analytic hierarchy process, to determine the cloud digital characteristics of the relative weights of each index. Then, the overall risk assessment cloud model of expressway reconstruction and expansion project was constructed, and the overall assessment results were calculated by the cloud digital characteristics of each risk index. Finally, an example analysis was conducted based on a highway reconstruction and expansion project under construction in Anhui Province. The results show that the traffic conditions have the highest influence on the construction safety risk, followed by the construction traffic organization, engineering characteristics, construction technology, and natural environment conditions. The overall risk value for the construction safety of the expressway renovation and expansion project is 33.044, with a low risk level of I, which is in line with the actual evaluation results.