短壁联采密实充填安全高效开采关键技术及实践

Key technology and practice of safe and efficient mining with short wall combined mining and dense back filling

为安全高效回收"三下"压覆资源,孙村煤矿在借鉴旺格维力采煤技术的基础上,针对"三下"压煤和遗留煤柱开采、回收困难问题,采用现场调研、文献检索、室内试验、理论分析、数值模拟、现场探测等综合手段,提出了短壁连采密实充填开采技术,建立了短壁连采无充填和密实充填时顶板及关键层破断力学模型,获得了工作面开采上覆岩层运动特征及地表移动沉降规律,为短壁连采密实充填开采技术应用提供理论指导。在分析不同开采阶段覆岩对煤柱和充填体加载作用基础上,建立短壁连采密实充填相邻工作面围岩失稳力学模型,结合数值模拟研究,得到了短壁连采密实充填工作面围岩变形及应力迁移规律。提出了支巷及联络巷宽度、支巷支护参数、充填体强度等关键参数设计方法,设计了具有"采充平行-分步置换"特点的短壁连采密实充填系统,研发了以水泥、粉煤灰和矸石颗粒为主料的高强快凝环保充填材料,提出了节能高效的巷道式自流漫灌充填技术及工艺,为实施短壁连采密实充填开采技术提供了保障。以孙村煤矿地质条件为背景,对短壁连采密实充填技术进行工业性试验,提出相应的综合支护技术和管理措施,并对煤体-充填体应力、锚杆索受力、顶板离层量及巷道移近量进行在线监测。巷道服务期间围岩稳定性好,地表沉降量小,经济和社会效益均十分显著,实现对"三下"压煤和遗留煤柱的安全高效回收。

In order to safely and efficiently recover the under buildings,water bodies and railway overburden resources,Suncun Coal mine,on the basis of Wangge Weili coal mining technology,and aiming at the difficult problems of mining and recovery of under buildings,water bodies and railway compressed coal and remaining coal pillars,adopted comprehensive means such as field investigation,literature search,laboratory experiment,theoretical analysis,numerical simulation and field detection,put forward the short-wall continuous compaction back filling mining technology,established the mechanical model of roof and key layer breaking when short-wall continuous mining without back filling and compaction back filling,obtained the movement characteristics of overlying strata and the law of surface movement and settlement,and provided theoretical guidance for the application and design of short-wall continuous mining compaction back filling mining technology.Based on the analysis of the loading effect of overburden on coal pillar and backfill in different mining stages,a mechanical model of surrounding rock instability of adjacent working face was established for Short-wall continuous compaction back filling.Combined with numerical simulation study,the deformation and stress migration rules of surrounding rock of short-wall continuous mining compaction back filling working face were obtained.The design method of key parameters such as the width of branch roadway and coal pillar roadway,supporting parameters of branch roadway and strength of backfill was put forward.The short-wall continuous dense back filling system with the characteristics of"parallel mining and back filling-step displacement"was designed.The high-strength and fast-setting environmental protection back filling materials with cement,fly ash and gangue granules as the main materials were developed.In this paper,the energy-saving and efficient roadway type self-flow back filling technology and process are put forward,which provides a guarantee for the implementation of short-wall continuous compaction back filling mining technology.Based on the geological conditions of Suncun Coal mine,the industrial test of short-wall continuous compaction back filling technology is carried out,the corresponding comprehensive support technology and management measures are put forward,and the online monitoring of coal-backfill stress,anchor cable stress,roof separation amount and roadway proximity amount is carried out.During the service period of roadway,the surrounding rock has good stability and small surface settlement,and the economic and social benefits are very significant,realizing the safe and efficient recovery of under buildings,water bodies and railway compressed coal and remaining coal pillars.