工作面顶板灾害类型、监测与防治技术体系

长期以来顶板灾害在我国煤矿灾害事故中发生起数和死亡人数始终占据首位,是困扰煤矿安全生产的主要难题。笔者开展了顶板岩性、矿压显现特征和顶板灾害案例统计分析,结果表明:我国回采工作面顶板灾害主要表现为片帮冒顶、顶板大面积突然垮落和大面积切顶压架3种类型。系统分析了各类型顶板灾害的发生特点及致灾原因:片帮冒顶多发生于松软煤岩体,采煤方法不合理及管理不当的工作面;顶板大面积突然垮落一般为坚硬顶板大面积悬顶、瞬时垮落所致;大面积切顶压架主要发生在薄基岩浅埋深工作面或顶板累积下沉量大引起顶板在煤壁处断裂的工作面。针对我国顶板灾害监测与防治,建立了工作面顶板灾害全景监测预警技术架构,即采用微震监测系统监测远场顶板活动,采用矿压监测系统监测近场顶板运动,采用三维激光扫描技术监测煤壁片帮时空演化,通过监测数据系统分析,动态掌握采场围岩的活动规律和支架工况,实现顶板灾害监测预警。提出了工作面开采全过程的顶板灾害综合防治技术体系,在工作面开采前确定合理采煤方法,合理工作面布置方式,科学开采参数及优化设备选型配套,这是防治顶板灾害的核心技术;在开采过程中保持支架良好的工况辅以顶板弱化技术,进而实现工作面顶板灾害防治。

Types,monitoring and prevention technology system of roof disasters in mining face

For a long time,roof disasters have been the major problem in coal mine safety production,and the number of death and occur?rence of roof accidents in coal mine always ranks No.1.In this paper,the properties of roof,characteristics of strata behavior and cases of roof disasters were investigated.The results show that there are three main types of roof disasters in mining working face:rib spalling and roof caving,roof collapse and roof cutting and supports crushing.The characteristics and causes of all kinds of roof disasters were system?atically researched:rib spalling and roof caving mostly occur in soft coal and rock mass,and unreasonable coal mining method and work?ing face management also cause the disasters.The sudden collapse of large area roof is usually caused by the instantaneous collapse of large area suspended roof in hard roof.The large area roof cutting and supports crushing mainly occurs in the working face with shallow embedment and thin bedrock or the roof ruptured at the coal wall due to the large cumulative subsidence.For monitoring,prevention and control of roof disasters in China,the technical framework of roof disasters panoramic monitoring and early warning is established.In the technical framework,the micro-seismic monitoring system is employed to monitor roof movement in the far field,the mine pressure moni?toring system is used to monitor the roof movement in the near field,and the 3D laser scanning technology is adopted to monitor coal wall space-time spalling.Through analysis of the monitoring data,the activity law of stope rock and support working situations are dynamically mastered.Then roof disasters monitoring and early warning are implemented.A comprehensive roof disaster prevention and control technol?ogy system for the whole working face mining is put forward.Before working face mining,the works such as reasonable coal mining meth?ods,reasonable working face arrangement,scientific mining design parameters and optimized equipment selection should be performed.Those are core technologies for roof disaster prevention and control.In the mining process,the support should work well and the weakening roof technology should be added to realize the roof disaster prevention in the working face.