Study On Treatment Measures And Formation Mechanism Of The Collapse Disaster In Mayakou Tunnel

Tunnel collapse is one of the frequently oceurring disasters in construction of the tunnel, and it leads to great damages, such as the delay in the carrying out the projects, and the loss of life and property, and also poses great latent threat to the safety of the tunnels. Therefore, theresearch, centering on the failure mechanism and the treatment methods of the collapses of tunnels, is of great hep and necessity for design and construction of the tunnel in the future.In this paper, the subject investigated is the collapse in the construction of Mayakou tunnel, which is one of highway tunnels between Fengjie and Wushan in Chongqing. The highway is one paters of state's key highway from Lanzhou to Hangzhou. Research the reason and mechanism of the tunnel collapse came into being from many factors such as engineering geological, hydrological factors and construction, and give the analysis and evaluation for the corresponding treatment measures. Besides introduction and conclusion, this thesis consists of four chapters:â‘ Examines many instances of the collapse of highway tunnels by means of extensive reading of files, classifies these collapses into several types, and analyzes the maininfluencing factors attributing to the collapse and the preventive measures.â‘¡In this specific cases of collapse in MaYakou tunnel, by analyzing the measured data received by on-site monitoring, to analyse the distributing law of primary support stress, surrounding displacement and inner surrounding rock displacement, collate information at the scene, to describe the detailed process of the collapse and determine the reasons for the collapse according to the specific circumstances of the scene.â‘¢By using numerical simulationc software FLAC and UDEC which simulates the whole poeess of the collapse, comprehensive analysis the results of numerical simulation, did research and analysis focuiing on the factors such as engineering geology, support conditions, groundwater, construction and joint of rock mass., which is important influencing factors for the tunnel collapse., so that it can give a comprehensive explanation to the reason of the collapse.â‘£According to the specific circumstances of this collapse and influencing factors, this paper determined corresponding treatment methods. Through analyzing the measuring result, the paper also appraise the effect of the dealing method. The researching work strive to the future collapse precautions and dealing specially the huge colapse dealing in highway tunnel.