双向大倾角煤层综放开采矿压显现规律研究

发布时间：2018-05-09 06:45

本文选题：双向大倾角厚煤层 + 综放开采　；参考：《河北工程大学》2015年硕士论文

【摘要】：随着我国煤炭资源开采强度的不断扩大,尤其前些年疯狂的开采,赋存条件良好的矿藏资源越来越少,部分地区甚至面临枯竭,大倾角复杂地质条件下的煤层开采技术有了很大的发展空间。本论文综合应用理论分析、关键层理论分析、FLAC3D数值模拟计算等方法,针对大社矿92716双向大倾角伪倾斜开采工作面实际地质条件,对工作面覆岩结构、覆岩运动规律、顶板控制技术等进行了分析和探讨,研究成果对于双向大倾角煤层安全开采提供理论和现实依据。本次研究得出如下结论:(1)根据92716工作面的上覆岩层具体情况,运用关键层理论,判别出厚度为12.2m的老顶为关键层,垮落带高度为10-14m之间,裂隙带高度为38-49m之间,弯曲下沉带达到344m;工作面上部冒落带和裂隙带发育高度较下部大。(2)通过模拟92716工作面开采过程中覆岩破坏场演化过程,开始至结束的整个开采过程中,覆岩与底板随着工作面的开采,发生的塑性破坏均较规律,大煤破坏区大部分分布在大煤覆岩层,大煤底板只有局部发生了破坏,开采380m前,大煤直接顶上方高度为6.2m厚的中粒砂岩一直未受到剪切和拉伸破坏,开采至380m时才与附近剪切塑性破坏区相连,此后直至开采结束大煤覆岩破坏区进入较稳定扩展状态。由覆岩破坏的演化过程得出,在大煤工作面开采至40m处时,关键层发生剪切破断,其是老顶的第一次周期来压,与前面第一章通过材料力学的方法得到上覆岩层中砂岩的初次垮落步距32.2m基本吻合;当大煤工作面采至40m~80m时,随着工作面不断推进,剪切破断的区域不断增大,可以看到开采至80m时,关键层上方岩层发生过往的剪切破坏,;覆岩破坏区不断扩大,大煤开采170m时,覆岩破坏区延伸到大煤覆岩顶部较厚的第二层粉砂岩关键层,大煤破坏场随着工作面的推进沿着走向不断扩展,直到结束开采。(3)92716工作面的周期来压步距比较稳定,在开采过程中来压步距在13.9m-16m之间,来压步距的平均值为14.2m,初次来压距开切眼平均距离36.3m,双向大倾角工作面周期来压强度不明显,动载系数的平均值为1.12,表明在使用放顶煤综采开采大倾角煤层的过程中,采高的增大不会使支架所承担的载荷也增大。通过实测发现工作面倾斜方向来压步距不同,首先来压在工作面上部,后逐渐向工作面下方转移,最后到达工作面下部,与理论分析基本一致。(4)经理论计算确定采面正常使用支架、端头过渡液压支架、下巷防滑支架型号为ZF3200/16/24B、ZFG3000/16/24、ZT12000/16/24液压支架;选择MG170/410-WD无链牵引采煤机;前后选择SGZ-630/264型可弯曲刮板输送机。支架载荷分布不均匀。在支架载荷观测的过程中,发现支架前柱的工作阻力大部分工作面小于后柱工作阻力,经过实测和理论分析,造成支架载荷前后支柱不一样的主要原因有:该工作面俯斜开采,采空区后方冒落矸石均向工作面方向施加水平推力,造成支架后柱承载了略大于前柱的压力,根据来压步距的大小和规律,提高支架的初撑力,以求改变近煤壁处围岩的应力状态,减小端面顶板下沉量,减轻片帮程度,加强围岩控制,保证来压期间工作面安全问题。
[Abstract]:With the continuous expansion of the mining intensity of coal resources in China, especially in the past years of crazy mining, the mineral resources with good conditions are less and less, and some areas are even exhausted. The coal mining technology under the complex geological conditions has a great development space. The theoretical analysis of the comprehensive application of this paper, the theoretical analysis of key layers, FLAC 3D numerical simulation calculation and other methods are used to analyze and discuss the overlying rock structure of the working face, the law of overlying rock movement, the roof control technology and so on in view of the actual geological conditions of the 92716 two-way big dip angle pseudo tilt mining face of the Da she coal mine. The research results provide the theoretical and practical basis for the safe mining of the two-way large inclined coal seam. The following conclusions are as follows: (1) according to the specific situation of overlying strata in the 92716 working face, using the key layer theory, the old roof of 12.2m thickness is identified as the key layer, the height of the caving zone is between 10-14m, the height of the fracture zone is 38-49m, the bend subsidence belt reaches 344M; the upper caving zone and fracture zone in the upper part of the working face are higher than the lower part. (2) through simulation 92716. During the whole mining process of overlying rock failure during the working face mining process, the plastic failure of overlying rock and floor with the mining of the working face is more regular, most of the large coal destruction area is distributed in the large coal cladding strata, and the large coal floor is only partially destroyed. Before mining 380m, the height of the direct top of the large coal is above the height. The 6.2m thick medium grain sandstone has not been damaged by shear and tensile. When mining to 380m, it is connected with the nearby shear plastic damage zone, and then until the end of the mining, the failure area of large coal overlying rock enters a stable expansion state. The first periodic pressure of the top is in accordance with the first chapter of the first chapter through the method of material mechanics to get the primary caving distance of the sandstone in the overlying rock. When the large coal face is picked up to 40m~80m, with the continuous advance of the working face, the area of the shear breaking is increasing continuously. It can be seen that the rock stratum above the key layer occurs when the mining to 80m is over. The failure area of the overlying rock enlarges continuously. When the large coal is mined for 170m, the overburden rock failure area extends to the second layer siltstone key layer on the top of the big coal overburden, and the large coal destruction field expands along with the working face along the direction until the end of the mining. (3) the period of the 92716 working surface is more stable and in the process of mining. The average value of the pressure step distance between the step distance and the pressure step distance is 14.2m, the average distance of the opening cutting eye of the initial pressure distance is 36.3m, the cycle pressure strength of the double direction large angle working face is not obvious, the average value of the dynamic load coefficient is 1.12, which indicates that the increase of the height of the mining height will not make the load undertaken by the support in the pass process of the large inclined coal seam with the fully mechanized coal caving mining with the top coal caving mining. It is found that the pressure step is different by measuring the inclination direction of the working face by measuring the working face. First, it is pressed on the top of the working face, and then gradually transferred to the bottom of the working face. Finally, it reaches the lower part of the working face, which is basically consistent with the theoretical analysis. (4) through theoretical calculation, the normal use support of the mining face, the end head transition hydraulic support, and the model of the anti slip support of the lower lane are ZF3200/16 /24B, ZFG3000/16/24, ZT12000/16/24 hydraulic support; select the MG170/410-WD non chain traction shearer; select the SGZ-630/264 type flexural scraper conveyor. The load distribution of the bracket is not uniform. During the load observation of the bracket, it is found that the working resistance of the front column of the bracket is smaller than the rear column. The main reasons for the difference between the supporting pillars before and after the support load are: the inclined mining of the working face and the horizontal thrust of the gangue behind the goaf to the direction of the working face, which causes the rear pillar to carry the pressure slightly larger than the front column, and to improve the initial bracing force according to the size and law of the step distance to change the surrounding rock near the coal wall. The stress state reduces the settlement of the roof face, reduces the extent of the rib, strengthens the surrounding rock control, and ensures the safety of the working face during the pressure.

【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD323;TD355

【参考文献】