Study On Water Inrush Mechanism And Real-time Monitoring Method Of Karst Cave In Tunnels

Based on the water filling cavity water inrush mechanism of the structure as the main research object. Discussion on the mechanism of water-inrush and real-time monitoring method of karst cave in deep tunnel, by means of theoretical analysis, model test, numerical simulation and field test. Water inrush mode analysis was carried out on the water inrush cases in the practical engineering, it proved the practicability of theory system in this paper, and some useful conclusions were obtained.(1) Filling karst cave occurrence regularity are summarized from soluble rock lithology, attitude of rock formation, topography and landforms, geological tectonic feature. According to the different conditions, put forward the exposed instant strong filling lag and weak intermittent type three subsquently filling patterns. From the three aspects of geological and geophysical field real-time monitoring analysis filling type subsquently precursory information of karst cave. In the selection of the 9 indicators, which are easy to obtain and analyze, the classification of the disaster of the filling type karst cave is carried out by means of investigation, prediction and monitoring, and the corresponding classification standards are put forward. According to the type of water resisting mud structure, the structure of water and rock mass was divided into three types of water inrush, the seepage instability of water inrush and the composite type.(2) A three-dimensional model test platform for positioning and identification of main supply channel was developed. Surface runoff source simulation system and supply pipeline pre burying method were developed. The simulation of supply channel under different water pressure and water flow was realized, which provides the technical support for the identification and positioning of the supply channel. Based on the analysis of the monitoring results, the feasibility of identifying and locating the supply channel of water inrush disaster was verified.(3) Relying on Baokang, Hubei Province Yichang expressway is home bay tunnel water inrush cases, establish expose calculation model of karst cave, cave simplified for the sphere, the model into FLAC3D for simulation of excavation and solve the equilibrium. The displacement field, stress field and seepage field evolution law of the surrounding rock of the tunnel and the surrounding rock are analyzed in a comprehensive analysis, disaster analysis of multivariate information by handling inadvance for the data, the matching mode of water inrush precursor information of water inrush model of water partition rock mass was put forward.(4) The microseismic monitoring into the tunnel water inrush monitoring, and microseismic monitoring as the main means of water inrush in tunnel monitoring. Developed a set of water resisting rock rupture water inrush special microseismic monitoring equipment proposed a water resisting rock mass structure damage process and real-time monitoring of water scheme. The global seismic monitoring, comprehensive monitoring, information fusion scheme of displacement, seepage and conventional monitoring information in vitro, realize the three functions of water inrush channel positioning, water inrush time warning, damage level prediction.