【作者】 王本强；

【导师】 蒋金泉； 代进；

【作者基本信息】 山东科技大学 ， 采矿工程， 2008， 硕士

【摘要】 厚煤层综放沿空大跨度开切眼具有沿空侧煤柱因采动影响而严重损伤、跨度大、围岩主要为煤层、支护难度大的特点。目前沿空大跨度开切眼还没有形成完整的支护体系,亟待研究科学合理的支护方式,确保其支护安全可靠。本文以鲍店煤矿为原型,采用离散元数值模拟、物理模拟、理论分析、现场试验研究等方法,对厚煤层综放沿空大跨度开切眼围岩稳定性、合理煤柱尺寸、顶板结构、支护原理、合理支护方式及参数进行了综合研究。对厚煤层综放沿空大跨度开切眼围岩稳定性进行离散元数值模拟分析知:煤柱尺寸、支护方式及支护参数对开切眼围岩稳定性有较大影响。随煤柱尺寸的增加,开切眼所处的应力环境逐渐由应力降低区向应力峰值区再向原岩应力区转变;随支护方式改变,围岩整体受力结构将发生变化,当采用锚网桁架锚索支护方式后,顶板形成“挤压加固梁”,提高了围岩承载能力;随顶板锚杆支护间距的加大,围岩稳定性减弱,“挤压加固梁”的承载能力降低。通过对开切眼覆岩结构的物理模拟可以看出:随采场工作面推进,采动覆岩中下位岩层形成了许多以“空间小结构”为主的块体,上位岩层则形成了许多以“空间大结构”为主的块体:“大顶”来压时,老顶破断形成阶梯状岩层结构,来压强度大,影响范围广;应用锚网桁架锚索支护后,开切眼围岩整体稳定。对开切眼合理位置和支护技术进行理论分析认为:开切眼掘进后,支承压力呈“驼峰”状分布,而开切眼掘进前后支承压力峰值出现的位置和数值变化甚小;锚网支护使开切眼顶板较松散煤岩层和弱面形成“承载梁”,在此基础上加打桁架锚索,增加了梁的厚度和承载能力,而且将下位“挤压梁”固定到深部稳定岩层中,从而有效控制了围岩变形。经过现场试验研究表明,开切眼顶板煤岩层力学平衡拱结构的稳定性对于开切眼的稳定具有很大的影响,采用锚网桁架锚索支护后,顶板形成了一个弯曲厚板,由压缩层、中性层和拉伸层组成,限制了水平裂纹的贯通与层错发生,锚网桁架锚索支护取得了显著的技术经济效果。更多还原

【Abstract】 The full-mechanical caving along gob large span length open-off cut in thick seam has own characteristic: the coal pillar along gob has been damages seriously, the span of open-off cut is large, the roof of open-off cut is the coal seam, difficult to support. It has not form the complete supports and protections system at present, and it urgently awaits to research science reasonable supports and protections way to guarantee that its supports and protections is safe and reliable.This dissertation set Baodian colliery as the prototype. Using numerical simulation analysis, similar material simulation experiment, theoretical analysis and scene experience, we do research to rock stability, reasonable coal pillar, roof structure, supporting principle, supporting way and parameters.Discrete element numerical simulation analysis on the rock movement of open-off cut is being done, and we obtain the following conclusion: the size of pillar, supporting way and parameters has great effects on surrounding rock stability. With the pillar size be larger, the stress area that the roadway be located change from low stress area to peak stress area and final be in original rock stress area; with the supporting way be change, the surrounding rock structure is change, when using cable truss, the roof form "pressing reinforced beam"; cable span more bigger, and surrounding rock stability more weaker.It can get some conclusions from the similar material simulation experiment of open-off cut. With working face advancing, the inferior rock of moving rock is forming "space small structure", and superior rock is forming "space large structure"; when "large roof is coming, the basic roof turn into step structure, the pressure and the influence scope is large. When using cable truss, the surrounding rock is steady.Theoretical analysis is being done on reasonable position and supporting way of open-off cut. Supporting pressure is assume "the camelback" distribution, the position and the value of the biggest supporting pressure does not have the sweeping change; after using the cable supporting way, and the loosening rock layer and weakness plane form "carrier beam"; and then hits the anchor cable, thickened bar’s thickness correspondingly, moreover it make "extrusion beam" fix to the stable rock layer, it is more effective to control the rock distortion.Thanks to the scene study, we can see that the stability of surrounding rock balance structure has great influence to open-off cut, when using cable truss, the roof forms bend thick plank, and limiting horizontal crack cut through, cable truss supporting way has obtain great technology and economic result.更多还原