Study On Security Risk Assessment And Control Technology About Xiangjiang Tunnel Under Water On Yingpan Road In Changsha

Xiangjiang tunnel on Yingpan road in Changsha is the first tunnel across the Xiangjiang, with two-way four lanes as the main line for the tunnel, and one-way single lane for ramp tunnel. The tunnel, located in the prosperous areas of Changsha, undertakes heavy traffic, and is surrounded by many high-rise buildings. With he interchange of the tunnel and great span of the progressive folded segment gradient, it becomes a great difficulty to design and construct the tunnel. And the requirements of the technology and experience on design, construction are high. As a large-scale tunnel project, it can cause great economic losses and very negative social impact once an accident happen. Under the requirements of2010No.175document "Notice on the implementation of the highway bridge and tunnel engineering safety risk assessment system in preliminary design phase", risk assessment should be carried out to this project. Thus, combined with Changsha science and technology project (K0902027-1), this paper will carry out the risk assessment on the safety of Xiangjiang underwater tunnel on Yingpan road in Changsha and study the control techniques, in order to provide a foundation for tunnel’s construction safety. The paper is mainly about the following aspects:1) Adopting expert survey method to survey the main risks and the source of risk events in the tunnel of this project, and calculate the corresponding level of risk event probability and loss. Based on this, the risk level is evaluated for the main risk events. There are4risk events of level111,4events of level Ⅱ identified in this project.2) For different risk events, the probability levels of the risk events in the tunnel are estimated section by section by specific comprehensive evaluation method. Meanwhile, the identification is done to the source of the tunnel risk events, combined with expert survey method. Hierarchical analysis method is used to sort the importance of risk source.3) Based on the risk evaluation and combined with the control measure of risk in original primary design, this paper proposes specific suggestion on control measure, especially promotes the control measure on the level Ⅲ risk events.