Study On Water Barrier Area Stability Based On Micro-seismic Monitoring Technique

Zhang Matun iron deposit is located in the contact belt among diorite in Yanshanian epoch, crystalline limestone and marble in Ordovician with extremely complex hydro-geological condition and tremendous water inflow as one of the famous metal mines in China. The exploitation can run safely after the curtain grouting is used to block water inrush. After the curtain is formed, a great hydraulic gradient exists inside and outside of the curtain area, as well as mining activities have been running at all time in the area. Along with the increase in the depth of mining, ore deposit is coming nearer the curtain. High water pressure and mining activities will inevitably cause damage to the stability of the curtain area.The thesis breaks through the traditional way of the information monitoring of macro-water inrush to predict water outburst disaster on mines. Beginning from the essence of the micro fracture induced by the mining stress, resulting in water inrush disaster on mines, taking the method of microseismic monitoring, taking the theoretical analysis of micro fracture evolution rule as the foundation, taking exploring the internal agent and the omen rule of gestating the water inrush disaster as the core, taking the microseism real-time monitoring, the water inrush disaster real-time forecast as the goal. Therefore, a multi-channel digital micro-seismic monitoring system has been installed to conduct continuous monitoring on the stability of the water barrier, analyze and forecast the micro-seismic activities in the water barrier area, and implement the early alarm on the area where the potential water rushing may be generated. By the discussion to the algorithms, analysis on the errors of the monitoring data which has been recorded, and the characters of different types signals, researching on the expandation rule of seismic events to draw the following conclusions:(1) The microseismic sensor's layout should combined with the location algorithm. Corresponding to the different algorithm, the sensor's layout is different. The mining geology, the ore deposit condition should be considered while arraying sensors, carries on the optimization to the sensor scheme of array, which is related to the entire monitor effect.(2) In the rock mass, there exist latent fault planes, water-bearing stratum, filling materials, the empty zones after exploitation and so on, and the rock character is various, the elastic wave will have the wave scattering, refraction, energy decay in the spreading process in the rock mass. In addition, the location algorithm also causes seismic events' inaccurate location.(3) Seismic events'waveform is obviously different from other interferential waveform by the analysis of events'waveform. As such, this is helpful to identify desired signal manually, and filter the noise signal.(4) Through researching on the expanding process and the distribution rule of monitoring data, according to the exploitation activities on the Jinan mine and the hydrogeological conditions of the water barrier, a early warning mechanism to water outburst around the water barrier has been proposed. At the same time, the microseism monitoring system still is real-timely running, as a new reference to guide the mine production safety.