Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

Recently, as tunnel structures are getting older and decrepit, many tunnel inspections are carried out for evaluating the tunnel state and safety. But, because there is no exact tandard for tunnel state and safety, depending on subjective decision, the new standard to assess the tunnel state is required. The existing standard including mainly the assessment of the state of tunnel lining is not considered the characteristics of tunnel as underground structures. Also, the item of assessment and process of grading and classifying the state of tunnel is not objective and systemetic. In this study, new standard for assessment of tunnel state is presented for improving the problems in evaluating the tunnel state and safety. In the new standard, the new items of assessment including geotechnical condition were selected and graded, the process in classifying the tunnel state is quantitative for objective assessment for tunnel state. This new standard and method is practically used in effective safety inspection and diagnosis and tunnel maintenance.