兰花宝欣矿中厚煤层无巷旁充填沿空留巷技术与工程实践

发布时间：2019-02-15 16:18

【摘要】：山西古县兰花宝欣煤矿设计产量0.9Mt/a,目前主采3号煤层,平均煤厚1.77m,倾角为4~10°,埋深400m,位于山西组中部,K7粉细砂岩之上。存在工作面接续紧张、资源采出率低等问题,因此本文以兰花宝欣矿3号煤层为工程背景,研究攻关无巷旁充填沿空留巷技术,取得主要成果如下:(1)对无巷旁充填沿空留巷覆岩大结构的演化规律及稳定性进行了理论分析和研究。在工作面回采结束、接替工作面回采前,弧形三角块B受下部直接顶和矸石提供的支承力、相邻块体的夹持作用,大结构能够达到平衡稳定状态;二次采动影响期间,大结构承受的载荷虽然不断的增加,各块体之间的受力状态发生了变化,但是支承条件未改变,因此会保持随机的平衡状态,接替工作面推过后,大结构会彻底失稳。(2)分析了无巷旁充填沿空留巷围岩小结构的组成及力学特征,是指由巷道锚杆锚索组合支护、巷内辅助支撑和锚固作用范围的围岩构成的锚固承载体系。将无巷旁充填沿空留巷顶板的前期垮落简化为三边或四边支承的矩形叠加层板受弯折破坏的力学模型,给出了巷内辅助支撑载荷分别在顶板初次垮落、周期垮落以及后期破坏活动过程中的计算公式。(3)以兰花宝欣矿3号煤层地质条件为依据,采用3DEC离散元数值分析方法,模拟了3103工作面和3105工作面无巷旁充填沿空留巷开采过程,研究了无巷旁充填沿空留巷在两次采动过程中的围岩变形规律与应力变化特征。3103工作面回采时,在工作面后方10m~30m的范围内,巷道顶板下沉最为剧烈,下沉速度为12.2mm/d~18.1mm/d,最大下沉量达到122~175mm,为煤层采厚的6%~9%;3105工作面回采时,在超前工作面10m至工作面后方25m的范围内,巷道顶板急剧下沉,在巷道报废前,下沉速度达到35.5mm/d~41.1mm/d,顶板最大下沉量达到350~435mm,为煤层采厚的17%~22%。3105工作面回采过程中,靠近3103采空区部分的采场顶板首先形成弧三角形垮落,然后向O型垮落发展。因此,推断在当前的地质条件,无巷旁充填沿空留巷采场顶板在两边支承的情况下,采空侧会形成“X—O”型的垮落形态。(4)采用巷内强力支护方式和顶板自然垮落实现了兰花宝欣矿无巷旁充填沿空留巷技术,截至2017年1月,3103工作面已经顺利回采完毕,留巷长度达到660m,多回收煤炭约3.98万t,增加收入约1122.18万元,取得了阶段性成功。本论文研究成果解决了兰花宝欣矿矿井采掘接替紧张的难题,目前减少了3个掘进工作面,提高煤炭回采率10~20%,延长了矿井服务年限。
[Abstract]:The design output of Orchid Baoxin Coal Mine in Guxian County, Shanxi Province is 0.9 Mt / a. At present, the main coal seam No. 3 has an average coal thickness of 1.77 m, a dip angle of 4 掳10 掳and a buried depth of 400 m. It is located in the middle part of Shanxi formation and above the K7 fine sand rock. There are some problems such as tight working face and low recovery rate of resources. Therefore, taking No. 3 coal seam of Orchid Baoxin Coal Mine as the engineering background, this paper studies the technology of keeping roadway along goaf by filling side roadway without roadway. The main achievements are as follows: (1) the evolution law and stability of overburden rock structure with no roadway side filling along gob are analyzed and studied theoretically. At the end of the mining face, before replacing the mining face, the arc triangle block B is supported by the direct roof of the lower part and the gangue, and the clamping action of the adjacent block can achieve the equilibrium and stability of the large structure. During the influence of secondary mining, although the load borne by the large structure increases continuously, the stress state among the blocks changes, but the supporting conditions remain unchanged, so the random equilibrium state will be maintained to replace the work face after pushing. Large structure will be completely unstable. (2) analyzing the composition and mechanical characteristics of surrounding rock structure without roadway side filling along goaf retaining roadway, which means the combined support of roadway bolt and anchor cable, Roadway supporting and anchoring range of surrounding rock composed of Anchorage bearing system. In this paper, the early collapse of the roof with no roadway side filling along the gob is simplified as the mechanical model of bending failure of rectangular superimposed laminates supported by three or four sides, and the auxiliary supporting load in the roadway collapses for the first time, respectively. Based on the geological conditions of No. 3 coal seam in Orchid Baoxin Coal Mine, the 3DEC discrete element numerical analysis method is used. This paper simulates the mining process of 3103 and 3105 working face without roadway side filling along goaf retaining roadway, studies the deformation law of surrounding rock and the variation characteristics of stress in the second mining process of roadway side filling and gob retaining roadway without roadway side filling. When 3103 face is mined, the deformation of surrounding rock and the variation of stress in the second mining process are studied. In the range of 10m~30m at the back of the face, the roof of the roadway is the most severe, with a subsidence velocity of 12.2mm / d ~ 18.1mm / d and a maximum subsidence of 122mm / 175mm. During the mining of 3105 face, within the range of 10 m ahead of the working face to 25 m behind the working face, the roof of the roadway sinks sharply. Before the roadway is scrapped, the subsidence speed reaches 35.5mm / dT 41.1 mm / d, and the maximum subsidence of the roof reaches 350mm / 435mm. In the mining process of 17 / 22 / 3105 working face for coal seam thickness, the roof of the stope near the 3103 goaf area first forms arc triangle caving, then develops to O type collapse. Therefore, it is inferred that under the present geological conditions, if the roof of the stope with no roadway side filling along the gob is supported on both sides, The caving side will form the "X-O" type collapse form. (4) by adopting the strong support in the roadway and the natural roof collapse, the technology of keeping the roadway along the gob without side filling in Orchid Baoxin Mine has been realized. As of January 2017, The 3103 face has been successfully mined, the length of the roadway is 660m, the coal recovery is about 39800 tons, and the income is about 11.2218 million yuan, and the stage success has been achieved. The research results of this paper have solved the difficult problem of mining replacement in Orchid Baoxin Mine. At present, it has reduced 3 working faces, increased the coal recovery rate by 10 ~ 20, and prolonged the service life of the mine.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD353

【参考文献】