Study On Safety Evaluation Method Of Operating Tunnel Lining

In the past 20 years,China's tunnel industry has entered a period of great construction.However,the operating tunnels have serious diseases in the years after completion.In the civil engineering industry,the management system of the operation tunnel has been formed by detection,maintenance and operations management.At present,China's highway tunnel inspection is divided into routine inspection,regular inspection,special inspection and emergency inspection at different stages.During the special inspection,the site is usually calibrated for the tunnel mileage pile,but there is a certain accumulated error between the fixed pile number and the actual pile number,which leads to the miscalculation of the detection result.At the same time,there are some problems in the practical evaluation of lining safety,which mainly include:(1)the randomness and fuzziness of the evaluation process are not fully taken into account in the safety evaluation;(2)the selection of index membership functions is usually based on experience;(3)the status of qualitative indicators is usually described in a single value method.According to the above problem,the safety evaluation of tunnel lining in the secondary fuzzy comprehensive evaluation method has been established;the evaluation model of index layer based on special inspection content and testing technology has been defined and the reasonable segmentation way has been chosen which based on construction joints and the basis of several simple ring lining of evaluation objects to solve the error between the operation mileage pile number and the site calibration pile number.The rating standard of each index has been clarified with numerical simulation and literature research.In this paper,a "normal cloud model" is introduced,and the calculation method of index membership is established based on the degree of certainty and similarity.The weights of the indexes have been determined by the entropy weight method and the analytic hierarchy process.According to the actual evaluation habit,this method is converted into a percentage evaluation method and the evaluation standard is put forward.Finally,the applicability of the evaluation method is proved by engineering case.