Geological risk of TBM construction in urban hydraulic tunnel and comprehensive advanced geological prediction technology

Abstract

In order to reduce or avoid the risk of TBM construction in urban hydraulic tunnels, it is necessary to construct a set of comprehensive advanced geological prediction technology for the high-risk characteristics of TBM construction in urban hydraulic tunnels. Under the condition of fully analyzing the characteristics of urban hydraulic tunnels and the risks of TBM construction, the geological analysis method is used to preliminarily determine the main unfavorable geological bodies and geological defect parts(sections) as the key points of prediction, so as to determine the targeted geophysical exploration and drilling detection method and implementation parts(sections). Then, the obtained data and information are comprehensively interpreted in geology, and finally the surrounding rock types and main unfavorable geological bodies in front of the tunnel face are predicted. The possible geological disasters such as surrounding rock collapse, water and mud inrush and soft rock deformation are analyzed, and then the possibility and harm degree of accidents such as TBM equipment jamming, submergence and ground collapse are predicted, and targeted measures and suggestions were put forward. The prediction technology has been applied to several major urban hydraulic tunnel projects. According to the analysis of the applied engineering effect, the accuracy of the prediction of the surrounding rock type and the bad geological body is 93% and 94% respectively, The accuracy of advanced geological prediction of TBM construction tunnel has been effectively improved, and good result have been achieved. The result show that in view of the high risk characteristics of TBM construction in urban hydraulic tunnels, the use of targeted comprehensive advanced geological prediction technology can effectively improve the accuracy of prediction, provide technical support for optimization design and emergency treatment measures, thus reducing construction risks and avoiding disaster accidents. It is worthy of wide application and promotion in related projects. This technology can provide reference for the design, construction and researchers of urban hydraulic tunnels.

Keywords

urban hydraulic tunnel / TBM tunneling / geological prediction