Risk Management In The Wuzhishan Mountain Tunnel Project

With the fast development of highway construction in our country, especially its constant extension to deep mountains in west area, the. percentage accounted by the tunnel works also increases obviously, and the length of the tunnel tends to be longer and longer. The complicated and various geologic conditions result in more construction difficulties of tunnel works, and bigger construction risk as well,thus geologic calamities and accidents happen from time to time. However, in terms of highway engineering project risk management, the existing highway construction management system and mechanism in our country emphasize particularly on some aspects such as the financial assessment and national economy evaluation during the project operation period at the project feasibility study stage, special design for some individual engineering case at design stage, and remedy and mitigation measures after the engineering risk happens. A perfect risk management system has not yet been formed. Therefore, based on the research on risk management in the Wuzhi Mountain Highway Tunnel Project, this paper strives to introduce the risk management idea into highway construction sector, so as to further promote application of risk management in highway construction, and also provide experiences and lessons to risk management of other similar tunnel works.This paper first works out risk management procedures in the Wuzhi Mountain Tunnel Works. Based on this, with combination of qualitative and quantitative analysis and combination of theoretical and practical approach, this paper systematically studies and analyzes risks in safety and environmental impact of the Wuzhi Mountain Tunnel at its construction stage. Aiming at the very complicated hydrological geology and engineering geologic conditions of the Wuzhi Mountain Tunnel, and the actual situation of serious water gushing and collapse accidents happened, this paper synthetically adopts several risk identification methods such as engineering geologic survey, experts investigation, initial bills of quantities and risk investigation, so as to focus on the re-identification of risks of the Wuzhi Mountain Tunnel works at its construction stage, and also identify some basic risk in six aspects. At the same time, using the Analytical Hierarchy Process, this paper confirms the comprehensive weight of each aspect of basic risk, forms a basic risk system diagram of the Wuzhi Mountain Tunnel works at construction stage, and also estimates each aspect of basic risk with the method of anticipant risk loss.At the risk evaluation stage, with the use of Pareto Diagrams, this paper identifies tunnel water gushing and collapse as the principal controlling risk of this project, while the environmental impact of water drainage from the tunnel as the minor one. Through the integral risk level analysis, it is found that the tunnel water gushing has coupling effect together with the other risks. Therefore, the tunnel water gushing becomes the most important among all the risks which should be controlled in this project.Adopting the loss control technology, this paper focuses on the study and formation of the Wuzhi Mountain Tunnel works risk control measures, and also evaluates the effect of the risk control measures.In the end, with combination of the risk mangement idea throughout the whole process and the experience got from the research of Wuzhi Mountain Tunnel works risk management, this paper summarizes an outline of highway tunnel informationized construction and dynamic design management, aiming to provide some guidance and reference to highway tunnel construction risk management in our province.