The Risk Assessment Of Tunnel Construction Based On AHP And Grey Theory

Tunnel Engineering has complex and changeable geological conditions and more unforeseen factors. The structure has its unique particularity and more differences with the structural construction of ground. Because of the various impacts of geological conditions, modern technology and management level in the tunnel construction, the surrounding structure destroyed and major loss of life and property damage accidents occur in the domestic and foreign tunnel construction. In order to ensure the reduction of engineering accidents with the achievement of objectives in the tunnel engineering construction, and the evaluation of risks at the tunnel project of planned and under construction, subsequently risk control is necessary.The risk control of tunnel construction as an example, the characteristics of the tunnel from human factors, physical factors, environmental factors, management factors determine the risk evaluation index of the tunnel construction. On this basis, the evaluation of the weight of each index is using the AHP. Then using gray system theory constructs comprehensive evaluation model, and taking the Xiao Ming mountain tunnel of the Lai Ma highway as an example makes a risk assessment by using the evaluation model. Based on the results of evaluation, the appropriate risk response measures have been proposed.Based on tunnel construction involves many factors, there are many uncertainties and other characteristics, after comparing several methods chosen AHP risk assessment, AHP calculation results due to relatively rough, but comprehensive evaluation model combines gray theory to establish the evaluation method can obtain better results.By identifying the risk factors of tunnel construction and based on the principles of construct evaluation index, so, established tunnel construction risk evaluation index system. Index system including the target layer, criteria layer and the index layer, using AHP to determine the weight of each factor’s weight, the weight of the human element of rule layer is the large; individual ability, on-site organizational capacity and management systems as well as the construction site of the natural environment of index layer accounted for the larger weights.For Xiao Ming Mountain Tunnel actual situation, use comprehensive evaluation model of AHP combined gray theory conduct a risk assessment, Obtain a comprehensive evaluation value 3.527, the results ranged between general risk and high risk, and tend to higher risk, so, Xiao Ming Mountain Tunnel total risk evaluation results are reasonable.According to the rule layer four factors in the overall risk of tunnel construction contribution degree, can seen the human factor dominates. Therefore, the measures should be focused on the effects of human factors considered. At the same time, the other three factors affect also nots allow to ignore; on the tunnel construction risk management should be in "prevention first, actively avoiding, reasonable transfer" as the guiding ideology.