高精度微震监测技术在煤矿突水监测中的应用

APPLICATION OF HIGH-PRECISION MICROSEISMIC MONITORING TECHNIQUE TO WATER INRUSH MONITORING IN COAL MINE

为了监测导水通道(断层、陷落柱等)在采动影响下的动力学活动和失稳过程,以及对其造成的突水危险性进行实时预测预报,利用高精度微震监测技术进行煤矿突水危险监测的工程实践。采用全局寻优定位技术,充分考虑内、外场震源定位的不同影响因素,结合速度结构、检波器一致性等校正技术,实现微震震源的高稳定、高精度定位;优化布置微震监测台网,对大断层、陷落柱等隐伏构造进行实时监测,通过对定位结果的三维展示和分析,得到地质构造的活化规律、底板破裂深度、顶板破裂高度、合理煤柱尺寸等实测参数,实现对突水危险性的预测预报。工程实践证明,微震监测能够准确诊断出断层和陷落柱等构造活化的强度、烈度以及相关的时空参数,是实现突水预警预报的强有力的地球物理监测手段。建立基于定位结果的岩体空间破裂场的定量描述模型、实现定位结果的多角度、多层次的展示技术,从防治水、矿山压力等多学科角度出发实现突水监测的超前预警预报,是突水监测预警的重要的发展方向。

For the progressive failure of geological structures（faults, karst collapse columns） to be investigated and their microseismic activities associated with water inrush to be predicted, microseismic monitoring is firstly undertaken in a deep coal mine where the water inrush is a significant issue. The development of a technique for the event location and the analysis ofmicroseismic events are concerned. A new optimum method is provided; the preferred measurement of focal time is the basic calculation process, and also several concepts of event location types are defined according to the actual location, e.g. within the receiver array or outside it, nearby the receiver array or far away from it. The localizing method and judgment of location type, together with the correction of velocity and the monitoring system using artificial blasting sources make the improvement of the event location accuracy be significantly possible. With the results of microseismic events and 3D illustration technique, the activities of geological structure, fracture-depth of roof and floor, and the parameters of boundary pillar are obtained. These studies indicate that it is considerably possible to predict the water inrush using microseismic monitoring with its inherent ability to remotely monitor the progressive failure caused by mining. The approach used to integrate microseismic data should be comprehensive with different interpretations from different subject views, such as geology, mining engineering and geophysics. How to make a 3D quantitative mechanical model to describe the failure region from the energy view, instead of qualitative analysis, is put forward. Apparently, it will be an important research direction with its further application associated with gas and coal projects, rock burst and so on.