New Design Method and New Test Technology

   doi:10.3850/978-981-07-0188-8_P140

ABSTRACT

Crack detection and measurement are crucial for safety and maintenance of tunnel lining structures. Currently, crack measurement is mainly done manually. However, manual measurement is slow and usually yields subjective results. In this paper, an integrated approach for automated crack detection and measurement is presented. In the algorithm, non-uniformity of brightness is firstly removed from original images by shading correction with subtraction operation. Subsequently, the Otsu thresholding technique is used for binarization. In the binarized images, local image processing in local window is applied to eliminate isolated pixels. Based on geometric shape analysis, cracks are detected and distinguished from other meaningless objects. Finally, width measurement along the crack from start point to end point is achieved using the improved route-finder algorithm. Experimental results show that the proposed method is effective for crack detection and measurement in tunnel lining structures.

© 2012 by Geotechnical Society of Singapore (GeoSS)