Calculation Method Of CFRP Strengthened Highway Tunnel Lining Based On Reliability Theories

CFRP, which has such incomparable advantages as high tensile strength, ease of installation, light weight, resistance to corrosion, high durability and no increase of structural dimension, would be an effective method worthy applying in the rehabilitation of tunnels. For far-ranging application, Professional research are necessary, which are about the calculation method and the construction technique of CFRP strengthened tunnel lining. Criterion of design, construction, and test are also needed. Substantive research had been done on the Stripping failure, section bearing capacity, crack and deformation of RC eccentrically-loaded member. Based on these, research on the reliability of CFRP strengthened tunnel lining are inherit and development of previously production. Contacting the resistance and the load by degree of reliability, the design method of CFRP would be change from method of safety factor to method base on probability. The contents are mainly summarized as follow:1. Statistical rule and probability-distributing style are proposed, which are about load and resistance of tunnel lining. Influencing factors are also been proposed.2. Failure mode and limit state equation of single section strengthened by CFRP are proposed. Internal forces of lining are calculated by response surface method. Reliability calculation method of single section are proposed, and validated by examples. Result show that reliability index of large eccentrically-loaded section strengthened by CFRP are enhance greatly, the increase range have positive relations with the eccentricity of strengthened section.3. Failure mode of tunnel lining before and after strengthened by CFRP are proposed byβbinding limits method , the result show that the failure mode would be change after strengthened by CFRP. Performance function of all failure modes are given by virtual work principle, and also the calculation method of Correlation coefficient are given. Finally, based on these result, System Reliability are calculated by PNET method and Conditional probability estimation method, the result show that the reliability index of system are enhanced obvious.4. Confirming method of target reliability are proposed, and also the verification method, Finally, the preliminary design method based on reliability theories are given, which are used in high way tunnel lining strengthened by CFRP, Besides, the application condition for CFRP strengthened highway tunnel is given.