Risk Assessment Of Construction Safety For Highway Deep Cutting Slope

With the rapid development of our county,more and more expressways are layout in mountainous area,the construction of mountainous expressway will inevitably lead to a large number of deep cutting slopes being constructed.The geological conditions of the deep cut slope are complex and changeable,the precision of survey is not enough,and there are many factors affecting the construction safety.How to ensure the safety and stability of a large number of deep cutting slopes in the construction stage and operation stage is an urgent problem to be solved.This article mainly studies the construction safety risks assessment of expressway deep cutting slope.By using AHP and fuzzy comprehensive evaluation method to establish the construction safety risk estimation model of deep cutting slope,using the risk matrix method for risk assessment.According to the result of risk assessment,classification of risk control measures will be taken to reduce the slope instability accident loss.First of all,according to the scope of deformation,the deformation instability mode of cutting slope is classified.The influence factors of construction safety risk are analyzed,and the influence mechanism of different factors on the stability of cutting slope is analyzed.Then,using AHP to identify risk factors of the construction safety of deep cutting slope,establishes the analysis model of safety risk factors of construction safety of deep cutting slope.The judgment matrix through the importance of structural risk factors was used,to make calculation the weight of various risk factors impact on slope stability.Secondly,the indexes of the possibility of instability of the slope are classified,and the possibility of cutting slope instability is estimated by using the fuzzy comprehensive evaluation method.This paper discusses the method for estimating the severity of the slope failure according to the environmental characteristics and the personnel density in the influence of cutting slope collapse.By using the risk matrix method,the possibility of slope instability and the severity of the slope are combined to get the construction safety risk of cutting slope.The rationality and effectiveness of the risk assessment model is verified by an engineering example.Finally,the paper discusses the safety risk acceptance criteria and risk control measures of the construction of deep cutting slope of expressway.This paper summarizes three kinds of construction safety risk control measures of cutting slope,and discusses the selection principles and applicable conditions of these three kinds of risk control measures.Take the K443 deep cutting slope in Renhua to Boluo expressway as an example.Deformation monitoring information is used to verify the accuracy of the possibility instability estimate model;Strength reduction finite element method is used to verify the necessity and the effectiveness of the risk control measures.The results show that the use of the construction safety risk assessment model can accurately assess the construction risk of a large number of deep cutting slopes.According to the result of risk assessment,can effectively control the slope construction safety risk.