Study On The Environmental Risk Assessment About The Construction Of The Urban Tunnel

The ground settlement caused by the construction of urban tunnel threatens the adjacent buildings or underground pipelines very seriously. In order to evaluate the risk degree about the surrounding buildings or underground pipelines when urban tunnel is under construction, make reasonable risk regulate measures according to the results, and reduce the risk of the buildings and underground utilities which are close to a constructing urban tunnel. This article is meant to study the buildings or underground utilities' risk which there is a constructing urban tunnel nearby, and the major research and achievements in this paper are as follows:①Compared with the mountain tunnel construction, this thesis obtains the characteristics of urban tunnel, and makes the definition of environment risk of urban tunnel's construction. And reaches a dynamic management flow about the environment risk on urban tunnel construction, and analyzes about the identification, estimate, assessment, control, track system of risk and so on.②The influence of urban tunnel construction to the surrounding environments, not only related to the tunnel construction, but also to the surrounding buildings and underground utilities'characteristic and the axis's position relationship between the surrounding buildings or the underground utilities and the tunnel. This thesis makes a study of the risk identification from the deformation mechanism of resistance of the tunnel construction and of the buildings or the underground utilities separately.③By evaluating some different assessment methods, we adopt fuzzy comprehensive evaluation method establish the tunnel environmental risk fuzzy comprehensive evaluation model, about which make a detailed study. First establish the construction environment risk assessment indicator system's of urban tunnel and determining the index weight by using the analytic hierarchy process, and then estimated the loss probability and consequences about adjacent buildings or underground pipelines through the fuzzy comprehensive evaluation method. Finally, estimate adjacent building or underground pipeline's risk levels by the result.④According to the influence of the environment risk of the urban tunnel construction, the thesis analyzesthe tunnel construction measure, the stratum reinforcement measure, the buildings or underground utilities' protective measures and proposes the corresponding risk regulate measures. ⑤The thesis uses the fuzzy-hierarchy integrate evaluation model of the risk assessment for the typical buildings and the underground utilities into the 8th sector of the first line of the city tunnel transportation in Chong-Qing, Evaluates the risk of the typical surrounding buildings and underground pipelines and obtains the measure results matching the actual project.