ABSTRACT
ABSTRACT Structural defects are main factors affecting the safety and durability of metro tunnel. How to effectively obtain and correctly detect the tunnel defect has become a fundamental work of tunnel maintenance. It is also an essential precondition linking the evaluation of the service state. Leakages and cross-section deformations are two pathogenic defects in the service life of metro tunnels. With the expansion of city metro, traditional manual inspection approaches cannot meet the increasing demand of inspection work on account of their low efficiency, long feedback cycle and human judgment error etc. Thus, it is urgent to develop rapid detection equipment to meet current needs. Using CCD camera as basic element for information acquisition, the development of a rapid detecting equipment for metro tunnels is illustrated in this paper. The equipment is able to acquire the service condition information of tunnel structure at a speed of 10km/h. And the features of tunnel defect are extracted rapidly and intelligently by image processing software specialized developed for metro tunnel. The analysis result can be used for giving scientific judgment on the service state of metro tunnel structure through the setting criteria. The proposed equipment has been applied in metro tunnels of Shanghai, Beijing, Guangzhou and Shenzhen, the testing results show that its technical performance fully meet the requirement of rapid detection.
