恒昇和恒晋煤矿地质、水文地质条件相对比较简单,煤层赋存较稳定。2、 9-10号煤层为主采煤层,其中9-10号煤层直接顶板为K2石灰岩,厚12. 2米15.10米,平均厚13. 09米,分布稳定。通过对K2石灰岩顶板岩样的测定,分 析计算得出1#岩样的抗拉强度为6.8 Mpa,单轴压缩情况下的抗压强度为91.5 Mpa,三轴压缩情况下的抗压强度为175.6 Mpa,内摩擦角52°,凝聚力为 15. 744Mpa; 岩样的抗拉强度为6. 3 Mpa,单轴压缩情况下的抗压强度为114. 8 Mpa,三轴压缩情况下的抗压强度为211. 2 Mpa,摩擦角为54. 3°,凝聚力为18. 465 Mpa,老顶砂岩和泥岩强度也较高。具有强度高,抗变形能力强等显著特点。 依据岩样物理力学性能测试成果,对裸巷直接顶板进行力学理论分析,计算 得出按该矿现有设计恭道宽度(4. Om)和高度(2. 5m)计算,即使[h覆岩层的压力全 靠直接顶K2石灰岩来承担,按固支梁计算所需最大厚度为4.68m,按简支梁计 算得所需直接顶板最大厚度为5. 74m,而实际该矿直接顶板厚度均大于12m,故 无论按照何种载荷和何种约束,设计巷道直接顶板的厚度均大于理论分析计算所 需最大厚度,巷道采用裸体支护直接顶不会发生垮落性破坏。 在此基础上,应用FLAC3D程序对巷道围岩应力和塑性区的分布特征进行了 数值模拟,得出巷道顶底板均处于应力降低区,掘进形成支承压力位于巷道两帮 和掘进头一定范围内,最大支承压应力约为13.72MPa,最大水平拉应力约为 0. 73MPa,均未超过直接顶板石灰岩的抗压、抗拉强度,说明石灰岩直接顶岩层 不会发生压断和拉裂。塑性区主要位于巷道两帮且巷道主要为剪切破坏,剪切破 坏巷道两帮01. 8m的范围内。进一步对加锚杆支护后围岩应力和塑性区的分布 进行了模拟,通过两者比较得出加锚杆支护后垂直应力的数值和塑性区的范围变 化不大,因此顶板加支护意义不大。 鉴于恒昇煤矿9-10煤层直接顶板K2石灰岩厚度大、强度高,且埋深不大, 工作面和巷道的所承受地压较小,巷道掘进时对顶底板的影响范围小和破坏程度 弱等特征,且两帮煤壁强度较高,底板的泥岩强度也较大,故顶板釆用裸体巷道 而不进行支护是安全可靠的。裸巷支护方式不仅可以节约大笔支护费用,而且可 以降低工人劳动强度,加快巷道掘进速度,使施工效率得到很大的提高,并能使 现代化机掘效能得到充分的发挥,进而建设更高效的双高矿井。 由于周围煤矿都没有如此简单的支护形式,因此在恒昇、恒晋煤矿要加强收 敛变形的观测,即设立观测站进行观测。从观测站、点的统计资料可以看出,工 作面在回采状态时,各个观测站观测断面的顶板、底板移近量以及巷道两帮的收 敛变形量非常明显,而将这两者相比,巷道两帮的收敛变形会更大一点,所以巷 女徽让SiL「、丨k〒:院硤丨学位报告 逍支护吋应该点控制两帮,其次应加强顶板女护。 综上所述,忉昇煤矿的覆沿岩性、类项、工种地质特性均打利于劣现巷逍的 长期稳定和9-10煤层的安全绿色刀:釆,即实行顶板裸休支扩在技术k足呵行的, 经济t足合理的、安全可靠的。报告的研究成果在同类型地质采矿条件的矿并几 有推广应jfj价值。 图[66]表[n]参[73] 关键词:坚硬项板;闽沿稳定;锚杆支护;组合梁理论;丨词穴分类; 分类号:TD823 -II- 女徽迚筑r业学院硕1:7:位报告 Abstract The geology and hydrological geology of the Heng sheng, Heng-Jin Coal is simple relatively, coal seam hosting are more stable. The 2nd, 9-10 coal seam is primary mining coal seam,the immediate roof of 9-10 coal seam is the K2 limestone, and the depth of K2 limestone is 12.215.10 meters, average is 13.09 meters, distributing stability. By the determination on K2 limestone roof rock sample, analysis calculation 1# rock sample of tensile strength for 6.8 Mpa,single axis compression situation of compressive strength for 91.5 Mpa, three axis compression situation of compressive strength is 175.6 Mpa, friction angle is 52 degrees, cohesion is 15.744Mpa; 2# rock sample of tensile strength is 6.3 Mpa, single axis compression situation of compressive strength is 114.8 Mpa, three axis compression situation of compressive strength is 211.2 Mpa, angle of friction is 54.3 degrees, cohesion is 18.465 Mpa. It has a high strength、 resistance to deformation and a notable feature. Based on the physical and mechanical properties of rock specimen test results, mechanical analysis the nude lane directly by physical and mechanical properties of rock specimens on roof,according to the mine's existing bare lane calculated width (4.0M) and height (2.5M), even if directly depends on the pressure of overlying strata to take,Clamped beam needed by its maximum thickness of 4.68m,calculated on a simply supported beam roof thickness directly required for the 5.74m,and the actual roof thickness of 13.09m directly in the mine, regardless of the load,in accordance with the constraints directly in the mine roadway roof thickness is greater than the maximum thickness, immediate roof damage does not occur. On this basis, by application FLAC3D program on roadway surrounding rock stress and plastic area of distribution for has numerical simulation, the came roadway top floor is stress reduced area,driving into formed supports pressure is located in two roadways and driving into head must range within,maximum supports pressure stress about for 13.72MPa, maximum level pull stress about for 0.73MPa,is not over directly roof limestone of anti-pressure, and tensile strength, description limestone directly top rock does not occurs pressure broken and pull crack. Plastic zone mainly located in the roadway,and tunnel two main plastic zone for shear failure, shear failure of roadway within the two 01.8M. Further on the surrounding rock stress in the bolt support and the distribution of the plastic zone were simulated that the value of the vertical stress in the bolt support and the plastic zone changes little between the -in- 安徽迚筑T业7:院硕卜学位报告 two, therefore roof support has little significance. Given constant Heng Sheng coal mine 9-10 seam directly roof K2 limestone is largely thickness, and strength highly,and buried not deeply, roadway face and roadway of is pressure smaller, roadway driving into Shi on top floor of damage is small, analysis came constant Sheng coal mine roadway of support nurse way, and due to two help coal wall not is soft,floor of mudstone strength also larger, so used nude roadway and does not for support nurse is security reliably. Nude of mine roadway support method to save large sums of support costs, more meaningful is to thoroughly solve the contradiction of excavation support, effectively accelerating the driving speed, increase driving efficiencymodernization of to maximize driving efficiencely, promote the building of double high mine. Due to the coal mines around the support form is not so simple, so constant observation of deformation of Shanxi coal mine should be strengthen convergence to set up observatories for observation in Heng Sheng coal. From the observatory, statistical information can be seen, face in mining State, each section of roof,floor Observatory observations is close and the roadway deformation amount of convergence of the two groups are obviously, the two roadway deformations of convergence of the two groups could be a bit larger compared,so when roadway should focus on controlling two strengthen roof support compared. To sum up, the mine overburden of rock engineering geological characteristics, types of Heng Sheng coal are conducive to achieve long-termstability and 9-10 of coal seam roadway safety green mining, that practice nude roadway is safe、feasible and reliable in technically ; in addition, saving the mine roadway support costs and maintenance the costs, have reasonable economic benefits. Pigure[66] Table [11] Reference [73] Key words: Hard roof; Stability of surrounding rock; Bolt support; Composite beam theory; Rock classification Chinese books catalog: TD823 -IV- 女徽U丨筑:丨:业学院硕丨:学位论i: 目录 M W I Abstract Ill 目录 , V Contents VII 插图清单 IX 附表清单 XI 第一章 绪论 1 1.1 M题的提出 1 1.2 PU内外研究现状 1 1.3报告的土耍内容、研究方法和研究思路 6 1.3.1报告的主要内容 6 1.3.2研究方法 6 1.3.3研究思路 7 第二章恒昇煤业及巷道所在煤层概况 9 2.1恒昇煤业概况 9 2.1.1矿并地理位置及周边情况 9 2.1.2矿井开拓方式、水平及采区划分 10 2.1.3地质特征及可采煤层 10 2.1.4生产现状 10 2.2巷道所在煤层情况及其开采技术条件 11 2.2.1 船 11 2.2.2含煤地层 13 2.2.3煤层情况 14 2.2.4水文地质条件 15 2.2.5 瓦斯 16 2.2.6煤尘爆炸性 17 2.2.7煤的自燃性 17 2.2.8 地温 17 第三章井下巷道实际支护现状及围岩顶底板情况调研 19 3.1井F巷道实际支护现状 19 3.2裸巷所在围岩顶底板情况 23 3.3岩样岩W力学实验 23 3.4煤巷围岩稳定性分类 28 3.5裸巷直接顶板力学分析 30 第四章巷道围岩FLAC3D