Research On ZhongTiaoShan Tunnel Preliminary Design Risk Assessment

Compared with other projects, tunnel engineering is latent, complicated and uncertain, such prominent characteristics makes the design, construction and operation process are influenced by many factors, such as the project schedule, cost, environment and safety, the investment risk is larger, if decisions are thoughtless, it may cause serious economic damage and bring undesirable social influence. So it is necessary to carry out strict control to reduce tunnel project risk, especially design stage, because of limitation of geological data, there is greater risk, once risk events occur, consequence will be unimaginable.As ZhongTiaoShan tunnel preliminary design for engineering background, according to its own characteristics, through the field investigation, the theoretical analysis methods, the paper apply the methods suitable for assessment large tunnel project preliminary design risk, it provides the reference. The main contents include the following aspects:1,The paper expound the concepts of definition of risk, risk identification and risk evaluation, risk assessment methods, risk analysis steps and risk assessment process are introduced, then, the risk control measures are introduced.2,Apply to established evaluation model of ZhongTiaoShan tunnel preliminary design risk evaluation, according to the geological conditions, using the method of load structure V surrounding the worst level 20 meters buried deep structure calculation, simulation calculation analysis shows that in shallow tunnel, tunnel deformation seriously influence construction, especially late stage, we should strengthen the displacement support parameters, timely closed early arch supine to avoid deformation. The second lining structure according to limit state law force concrete size eccentric loading strength calculation, each component section safety coefficient were greater than lining unit specification requirements, the second lining the safety of the structure. It can be see that structure calculation and risk analysis of structure fits well.3,According to the brainstorming method, the project risk identification is done, it formed the basic risk structure, through the cause analysis, according to level analysis methods, the risk system is established, this tunnel preliminary design risk assessment conclusion is obtained, the risk control measures are given.Based on the actual projects and engineering survey, the paper established tunnel preliminary design risk evaluation model; assess preliminary risk level; developed a risk control measures. These will provide a reference for the smooth implementation of the ZhongTiaoShan tunnel.