Study On Symbol System Of Structure Safety And Health Status Of Highway Tunnels

Highway tunnel project are key projects in highway, and its structure safety and health status during service have a significant impact on the smoothly operation of road transport. Currently the studies on the safety state of tunnel also more concentrated in the damaged tunnel, the monitoring data of health status of tunnel is not sufficient, the safety evaluation methods are not unified. Therefore, all kinds of complicated geological and environmental condition of the highway tunnel to carry out long-term monitoring, prediction, diagnosis of tunnel structure safety and health status, has the vital significance.Taking a large number of tunnels in Chongqing under construction as the background, by applying combination of on-site investigation, theoretical analysis, numerical simulation, model tests and field tests, the tunnel long-term health monitoring and diagnostic sysmbol system is established, The system can provides an objective basis for the tunnels health assessment in the same period and similar regions.The main results are as follows:1 Mechanical characteristics of tunnel body and subsidiary structures in early and operation period is studied systematically, effectively guide the symbol system in the selection of typical sections and provide the basis and foundation data for tunnel safety evaluation classification; the damage recognition method is studied on the tunnel structure there are different positions and degree damage.2 The structural safety of the tunnel status evaluation has been built. The Evaluation factors including structure force, RQD, groundwater occurrence situation, etc. have been considered. The AHP is used to determine the weight of evaluation factors and establish a tunnel structure safety evaluation and early warning system.The evaluation of the structural safety and the health status are classed as four grades. Furthermore, the usage of fuzzy comprehensive evaluation, gray theory and other intelligent evaluation methods is introducedto evaluate the safety status of the tunnel.3 Considering the characteristics of the highway tunnel structure and different means of monitoring structures, network monitoring system for the long-term health status of the highway tunnel has been established, the smart tunnel structure safety evaluation and early warning software is developmented, and realize the monitoring data remote automatic acquisition, transmission, reception and evaluation.4 On the basis of the investigation and analysis on highway tunnels of Chongqing, the site geology and environment condition and the design & construction conditions are obtained, this study extracts common region characteristics of the highway tunnel in the field.According to the above, Motianling tunnel is selected to be the identity Project in the structural safety and health status identification system of the highway tunnel in the field. These systems can provide the scale of reference data for highway tunnel in this region, and realize the prediction and diagnosis the health status of tunnel.