底板采动破坏带分段观测系统与应用

Section observation system on floor mining damage zone and its application

针对工作面开采后底板采动破坏带探测难题,为掌握开采引起的底板岩层破坏规律,确保承压水上安全开采,自主研发底板采动破坏带分段观测系统。该系统主要包括测漏-封堵一体化子系统、供给-测定子系统和推进子系统等,采用的测试探头最大外径为78 mm,每次推进最大有效测量长度为4 500 mm,设计封堵工作压力为2.5~2.6 MPa,测漏工作压力为0.1 MPa。该系统具有如下特点:1)测漏系统和封堵系统融合,可利用同一外界水源进行封堵和观测工作,实现封堵测漏一体化,减少钻孔内管道数量为1根,解决了钻杆绕线问题;2)设计压力转换端子,实现封堵高压水源向观测低压水源转换,保证封堵过程和观测过程在各自压力下工作;3)采用多探测单元观测,实现一次封堵多段测量,与双端封堵测漏装置相比,可减少2/3工作量。用华丰煤矿41501工作面底板采动破坏带现场实测对该系统的准确性和可靠性进行验证,并与理论预计和数值模拟结果相对比。研究结果表明:理论预计值为16.89~20.65 m,数值模拟结果为15 m,而现场实测深度为15.49 m,系统测量结果是准确的,且测试过程未发生钻杆绕线现象。底板采动破坏带分段观测系统的研制和应用,丰富了底板岩层采动破坏范围现场观测手段,对于承压水上安全开采,预防底板突水具有重要的实用价值。

On the issue of the floor failure depth detection after working face mining,a section observation system on floor mining damage zone was developed to master the law of the floor rock failure caused by mining and to ensure safety of mining above the confined water.The structure,function and operation steps of the section observation system were introduced.This system mainly includes the leak-seal integration section,the supply and measurement section and the propulsion section.The maximum outer diameter of the test probe used is78mm,and its maximum effective measurement length for each propulsion is4500mm.The sealing pressure and leak pressure designed in working condition are respectively2.5~2.6MPa and0.1MPa.This system has the following characteristics:1)The fusion of the system in leak section and plugging section can use the same external water source to make the sealing and observation work being completed,to achieve the integration of the function in sealing and leak detection,to reduce the number of pipes in the borehole to one and to solve the problem of winding the drill pipe;2)The pressure converting terminal designed can realize the conversion of the blocking high pressure water source to the observation low pressure water source,which ensures that the plugging process and the observation process operate under respective pressures;3)Compared with the double side seal-leak device of drilling,multiple observation units are adopted to realize multi section measurement with single plugging and can reduce the workload by2/3.The accuracy and reliability of the system were verified by field measurement of the detection of the floor failure depth in the41501working face of Huafeng coal mine.By comparing the theoretical prediction and numerical simulation results,the results show that the theoretical predicted depth is16.89?20.65m,and the numerical simulated result is15m,and the measured depth in the section observation system is15.49m.The measurement results of the system are accurate.In the test process,there is no drill pipe winding phenomenon.The development and application of the section observation system on floor mining damage zone could enrich the field observation methods of the floor failure depth detection.For safe mining on confined water,it is of important practical value to prevent water inrush from floor.