The Research On Risk Management In Construction Of The Changhongling Tunnel

Changhongling tunnel is the second longest tunnel in Yuli railway, which is single hole with two lanes. The lithology of the tunnel is mainly mudstone sandstone, which properties are soft rock, easily weathered and gently dipping strata. The hazards include vaulted off the block and landslides are particularly vulnerable to occur in the excavation of the tunnel, especially the underpass in the Jiangchi town Fengdou county section, which buried depth was shallow and surface building intensive and more dangerous old, which leaded to great difficulties in construction. The tunnel is listed as one of the most difficult engineering in the whole railway. Therefore, it is important to research on risk management in the project.Geological conditions and engineering characteristics of Changhongling tunnel were firstly introduced in the paper, then significance of risk management and master goal in the project and the main research contents and steps were expounded. Combined with the characteristics of Changhongling tunnel, risk identification, risk assessment and risk response were deeply and comprehensively studied finally.Expert investigation method is mainly adopted in risk identification to find the main risk factors in Changhongling tunnel in the paper. Multilevel hierarchical structure model was structured through the analytic hierarchy process and risk factors discrimination matrix was set up by comparing factors one by one. Finally, the relative weight of each risk factor can be figured out. Probability of occurrence and loss estimation of risk factors had quantitatively analyzed through the fuzzy theory. Risk rank of risk factors in target of evaluation of the project was obtained which based on the fuzzy comprehensive evaluation method. Through the analysis and evaluation of Changhongling tunnel, master goal of geological risk was shallow buried section to prevent landslides, which was the main factors that lead to surface building third party loss in the underpass of Jiangchi town and belong to level4risk. At the same time, great importance should be attached at blasting vibration factor which is also belong to level4risk and have to do some prevention before the construction.In the paper, a variety of risk response method were put forward according to risk of metal shed landslide in flat rock arch department in Changhongling tunnel and characteristics shallow buried in the underpass of Jiangchi town. Special construction methods and shock blasting design were took especially for surface third party risk loss. Perfect professional mechanical equipment was equipped for risk prevention, combined with approaches that temporary resettlement plan for surface dilapidated building person and risk monitoring to reduce risk loss.