Risk Analysis On Large Diameter Pipe Jacking Project Under Hun River In Shenyang

With the rapid development of tunnel and underground engineering, risk accidents are occurred frequently at the same time. How to do precautions well to reduce or prevent accidents in the construction is an urgent problem. As a consequence, it has important theoretical significance and engineering application value to carry out the research of risk identification and assessment on large diameter pipe jacking project under Hun River in Shenyang.For the engineering background of large diameter pipe jacking project under Hun River in this study, firstly, in terms of the character of tunnel construction, basic theory of risk management is stated systematically. By analyzing the risk characteristic and key and difficulty in the construction, shallow overburden which will cause collapse or water bursting、face instability and other risks are identified with the method of Expert Investigation and Preliminary Hazard Analysis.Secondly, risk assessment system of large diameter pipe jacking project under Hun River is established. It presents that the main factors in the construction consist of Man-Machine-Environmental factor, construction equipment factor, operator factor and so on. However, each level factor contains a number of secondary factors.Then risk assessment of the construction is completed by means of Fuzzy Comprehensive Evaluation and Preliminary Hazard Analysis. It concludes that the risk on the stage of through the Hun River and tunneling in the first level factor in the pipe jacking project increases. In the secondary level, shallow overburden which will cause collapse and water blasting、face instability、tunnel floating and axis deviation which is too large, etc, plays a great role in the construction. It should be noticed on these risks and should be taken proper precautions to improve the construction safety. According to the risk caused by shallow overburden, theoretical analysis and numerical simulation is achieved and corresponding measures are presented simultaneously.Finally, emergency plan is proposed on large diameter pipe jacking under the Hun River. So we can take action at the first time of the accident to decrease the loss to the minimum. Pipe jacking construction safety risk management system is created and the project is achieved in the system. It concludes that encountering the impassable barrier belongs to the extremely high risk which needs great attention and avoidance. The risk of management is the range of high risk, needing taking measures and monitoring. The working well which is collapsed belongs to moderate risk and we should take measures to prevent them.