Study On The Bearing Performance And Evaluation Method Of Tunnel Split-damage Lining Structure

The domestic highway tunnel has been built already appeared a variety of diseases,these diseases seriously affecting the safe operation of the tunnel,which,cracking of tunnel lining in the most common and serious,and the current "standard of highway tunnel maintenance technology" is only technical condition evaluation method based on structure state,not based on the analysis of bearing capacity of lining structure safety evaluation method,so the crack influence on the bearing performance of the lining structure and its safety evaluation method is particularly important and necessary.In this paper,the influence of longitudinal crack on the load-bearing performance of the lining structure is studied,and the different parts and depth of the cracks are combined,and 1656 working conditions are analyzed in total.Lining bearing performance attenuation rate is established and the structure safety attenuation rate of two concepts,and through the calculation of 1656 kinds of working condition based on bearing capacity analysis of tunnel lining structure fracture safety evaluation standard,to the safety evaluation of 318 kinds of working condition.The main results of this paper are:1?To analyze the cause of the lining cracking defect and its type,choose one of the biggest risk longitudinal cracks and depth of research,site selection of the cracks vaults?hance?sidewall;2?After analysis of the basic principle of the theory of fracture mechanics,choose the maximum circumferential tensile stress failure criterion as the crack criterion of the model,the extended finite element method is adopted lining cracking numerical calculation model is set up;3 ? Defines the attenuation rate of performance,in view of the highway tunnel longitudinal cracks,when the crack appears in different depth in any single place,and when the crack with different depth and the parts are combined in different situations are simulated.In this paper,the attenuation rate database of lining bearing capacity is established,and the evolution law of the attenuation rate of lining bearing capacity is obtained;4?Defines the safety coefficient of attenuation,the establishment of lining structure safety evaluation method,the fracture of each security level shows that the handling measures to construct the lining safety evaluation standard;5?The safety factor attenuation rate of each working condition under single crack is calculated,and the corresponding safety grade,category and treatment measures are given according to the established safety evaluation criteria.The corresponding safety grade,classification and treatment measures are summarized for the combination crack,the safety grade of the lining of single crack and the related engineering data and engineering experience;6?Using VB language development the crack damage of tunnel lining structure bearing performance and safety assessment management system ",the system can be carried out on the combination of tunnel lining crack based on the bearing capacity of structural safety evaluation;Established in this paper,based on the bearing capacity of the tunnel lining structure safety evaluation standard,to make up for the evaluation of the tunnel structure at present evaluation method based on the mechanics analysis of blank,the structure of the industry based on strict mechanical analysis for tunnel safety evaluation method has made the beneficial exploration and try.