Highway Tunnel Structure Of Disease Security Assessment And Comprehensive Treatment Technology Research

The subject of tunnel locating in circumstance of natural medium,is artificial underground structure,diseases such as water leakage,lining split and air pollution in tunnel appear inevitably during operation process because of the effect of construction quality and existing circumstance, thereinto the structural disease reduce the safety reliability of tunnel directly and endanger safety of traveling crane seariousely. Jiaoxiling tnnels on Changsha-Liuyang road were taken as an example,aiming at the body characteristic of structure disease in road tunnel,the detection method,disease cause,safety assessment and renovated measure were studied systermly and deeply by comprehensive analysis with many subjects such as mechanics,chemistry,soil mechanics and rock mechanics.The main research achievements are as following.(1)The main disease type and detection methods of structure disease in operation road tunnel were summarized sysytermly.The formation mechanism of disease in road tunnel was reaveled by comprehensive analysis with many subjects, and Jiaoxiling tunnels were taken as an engineering example.The cause of disease were analyzed deeply throngh ovaerall detection and investigation of test instu and design,construction datum,and assesst its disease grade toⅢ,which supply a direct base for maintain and reinforce work.(2)According to the concept of tunnel mechanic,three disease modes including deficiency of lining thickness,cavities behind the lining and deterioration of concrete model within load-structure model were established, and then a tipical computation model of Jiaoxilin tunnels was conputed based on the detection result. The conputed results indicated that the existence of diseases is changed the overall stinffness and force state of lining structure, more than 70% safety factor of Jiaoxiling tunnels sections are less than allowable value of codes,so the bearing capacity of this tunnel is deficiency and the tunnel need to maintain and reforcement right now.(3)Based on disease model of operation road tunnel within load-structure mode,the effect laws of safety of lining structure against to each type disease were studied concretely by setting different characteristic parameter,the results show:with the grade of deteriatation of material and deficiency of lining reducing, the most safty factor of lining structure is minishing as line;relative to the others,the disease cavities bhiande the lining is more searious, especially when the breath of cavity is more than 2.0 m, the lining structure will lose its bearing capacity.(4)According to the concrete characteristics of Jiaoxiling tunnels,a compare research was poformed from econom and technique, and the renovated measures and construction methods were advanced.The renovated work of Jiaoxiling tunnels was finished in 2007y, no engineering accident appeared during the construction process,and now the operation environment is good.So the renovated concept and construction method advanced in this thesis is effective,and can take as an conference for other similar engineering.