The role of digital monitoring technologies in the development of comprehensive tunnel maintenance strategies

Abstract

Owners and operators of infrastructure such as railways, roads, subway systems and water supply systems are obliged to provide state-of-the-art, safe, dependable and economical services to their customers in an ever increasingly complex environment. One key aspect is the maintenance of tunnel infrastructure. The economic effectiveness of maintaining tunnel infrastructure can be increased through implementation of comprehensive maintenance strategies which utilize modern digital monitoring technologies. Digital technologies are finding increasing application for a variety of monitoring, planning, engineering, and maintenance tasks such as periodic tunnel inspections and state assessments, operational and financial planning as well as tunnel rehabilitation or renewal design. A wide range of digital monitoring technologies are currently available, two of which include tunnel mapping and tunnel scanning. Both of these technologies can be systematically applied within the framework of comprehensive long-term maintenance planning. Tunnel mapping is a methodology used to chart and provide an overview of the condition of the tunnel surface. The data are recorded on-site by an inspection engineer into a ''tunnel map'' which has been prepared in the office. Tunnel maps enable fast and accurate input of structural data including the type and location of damage, installations, construction materials and other relevant information with the desired degree of detail. Digital equipment and software has been developed to rationalize data input and help manage information in the tunnel maps. Digital tunnel maps replace the recording of observations by hand on to paper, thus simplifying all aspects of the mapping process. The development of laser scanning systems enables continuous, rapid and objective digital data collection in tunnels. These systems scan the entire tunnel surface to provide full-coverage digitized visual images and profile measurements. Scanning results are typically delivered with special software that allows viewing of visual images and profile data. Both tunnel mapping and tunnel scanning technologies provide efficient methods of collecting and viewing data concerning a tunnel structure over the entire tunnel surface. One important application is the assessment and interpretation of the collected digital data by qualified specialists, thus providing an accurate determination of the structural state. The collected data may often be further applied in the development of optimal maintenance solutions with respect to the given technological, operational and financial boundary conditions. This presentation introduces tunnel mapping and tunnel scanning technology and provides insight into how these and other digital monitoring technologies may be successfully integrated into the development of comprehensive tunnel maintenance strategies. (A). Reprinted with permission from Elsevier. For the covering abstract see ITRD E124500.