Risk Assessment of a Tunnel Collapse in a Mountain Tunnel Based on the Attribute Synthetic Evaluation System

Collapse is one of the common disaster in tunnel construction. In order to ensure the construction safety of mountain tunnels, the attribute recognition model of risk assessment for tunnel collapse is established based on attribute mathematics theory. By the comprehensive analysis for influencing factors of the tunnel collapse, the surrounding rock grade, tunnel depth, angle of unsymmetrical pressure, rock mass integrity, earthquake, and the excavation span are selected as the indexes of the risk assessment attribute measurement functions were rigorously constructed to compute attribute measurement of single index and synthetic attribute measurement. The identification and classification of risk assessment of mountain tunnel samples were recognized by the confidence criterion. An exemplification study of a tunnel showed that the assessment results, obtained through attribute measurement analysis and the date of geological forecast agreed well, with the tunnel construction. This risk assessment methodology provides a powerful tool for systematically assessing the risk of tunnel collapse.