Application of infrared photography and image processing in natm tunnel

Abstract

There is lots of dust in the constructing rock tunnel with New Austrian Tunneling Method. Since the length of visible light wave is shorter than dust, and the light is always not sufficient in the tunnel, it's hard to get clear pictures with classical photography technique. Using the infrared photography technology, it is possible to get vivid picture through dust and fog for the length of infrared wave is close to dust. This paper specifies the process of shooting tunnel face with infrared technology in the constructing rock tunnel. Based on sufficient experience of taking pictures of tunnel face with this method, regulation has been advanced which describes how to get clear pictures in the complex circumstance in constructing rock tunnel with the special equipments. Based on former researches of identifying the digital photographs of tunnel face with joints and cracks, this paper has attempted several ways of image processing and intelligent recognition on the tunnel face photographs. After the comparing and analyzing of the results, regulations of image processing and intelligent recognition which are fit for this kind of photographs was advanced. Infrared photography which is described in this paper is a useful innovation for getting clear tunnel face photograph in constructing rock tunnel with NATM. The image processing implements semi-automatic geological sketching. The intelligent recognition of tunnel face images provides some critical parameters for rock masses classification, and makes 3-D numeral reconstruction of the tunnel more precise and convenient. © 2008 Science Press Beijing and Springer-Verlag GmbH Berlin Heidelberg Geotechnical Engineering for Disaster Mitigation and Rehabilitation.