Research On Risk Assessment And Its Application In Mountain Highway Tunnel Construction

As we known, the project of mountain highway tunnel has many characteristics such as environmental impact, long construction period, unforeseen factors, a large amount of investment, construction and high degree of difficulty. So the project of mountain highway tunnel is a high risk of construction projects. With the development of mountain roads and the construction of a massive mountain highway tunnel, the risk of an accident resulting in tunnel construction increased year by year, the problem of risks in tunnel construction phase get more and more people's attention, so doing the job of tunnel construction safety risk assessment and research have become a necessity. In this paper, the following work has been done.(1)The improved Fuzzy AHP comprehensive evaluation is used to research holistic risk assessment of tunnel. In the specific research content, mountain tunnel construction safety risk assessment is divided into two factors, one is holistic risk assessment of tunnel, the other one is substantial risk sources. Aim to the feature of holistic risk assessment research, this article improved traditional Fuzzy AHP comprehensive evaluation. Using the Fuzzy AHP to calculate the index weight instead of the method of AHP, this improvement measure has the following advantages: ? Eliminating the AHP judgment matrix consistency test, so the computational difficulty and computational amount has been reduced; ? fuzzy judgment matrix in line with the way people think logical. Using the improved Fuzzy AHP comprehensive evaluation as the core to establish holistic risk assessment research model, it means that using the improved Fuzzy AHP comprehensive evaluation and accidental loss equivalent estimation to calculate the level of the holistic risk probability and accident losses rating, then through the method of R P C? ? to get the two approaches together, eventually give an overall risk assessment tunnel levels.(2)The introduction of efficacy coefficient method to tunnel risk assessment study, and focus on risk assessment applied to the tunnel among major risk sources. Efficacy coefficient method can solve the tunnel risk assessment different evaluation standards are not uniform, quantification difficult, tedious calculations and other problems. In this paper, using the advantages of efficacy coefficient method to establish a risk assessment model for the tunnel of significant risk sources and establish clearly principles and evaluation index system of the major idea. Based on the principle and meaning-based of efficacy coefficient method, the article established the procedures and principle of the major risk sources risk assessment, then derived the rating of risk probability. Finally superiority, operability and practicability on efficacy coefficient method is used to demonstrated the feasibility of tunnel risk assessment.(3)Using the results of this research and the highway projects of Dahua mountain tunnel to applied the research. In the overall risk assessment of Dahua mountain tunnel, the article established management systems, as many as 17 categories of recognition results. By the improved Fuzzy AHP comprehensive evaluation, the method give IV grade of the overall risk estimation of Dahua mountain tunnel; Based on equivalent estimation, the method give an overall risk rating for C-level consequences, and finally get Dahua mountain overall risk rating of four. In the risk assessment of major risk sources Dahua mountain tunnel, by piecewise assessment methodology, the paper established appropriate risk assessment system for landside risk and gushing water risk based on the efficiency coefficient method, and come to its corresponding risk rating of IV class and III class. Compared with the actual situation and traditional methods, the efficiency coefficient method is verified the validity of this method. Combining these studies, given the measures of Dahua mountain tunnel...