缓倾斜煤层构造顶(底)板石门揭煤过程中岩石薄板压曲破坏临界值分析

为了解决缓倾斜煤层揭煤耗时长,穿过石门和煤门距离长,过煤门时易发生突出的问题,推出了一种新工艺——构造顶(底)板石门揭煤。该工艺关键难题是,构造顶(底)板石门一般为岩石薄板,它容易发生压曲导致突出发生。为此,基于弹性理论建立了薄板力学模型,应用能量法推导出岩石薄板发生压曲破坏的临界载荷和板厚,并分析影响因素。结果表明,适当增大底板岩石的厚度,减小岩石的宽度能够有效提高临界载荷,保证安全揭煤。

Ⅱ级围岩薄板状水平岩层隧道施工技术研究及应用

文章针对某隧道施工过程中水平岩层段在隧道开挖过程中出现的平拱、顶板变形过大、易坍塌等现象,对产生这些危害的原因及机理进行了分析。根据分析结果,在施工过程中针对容易产生危害的区域,通过调整爆破参数和炮眼布置、加强初期支护措施等技术手段,确保隧道施工安全。对于水平岩层隧道,在控制顶板坍塌和变形方面,前期控制预防相对于后期被动控制效果要好。

Bearing mechanism and thickness optimization of ore roof in bauxite stope

Based on the elastic thin plate theory,the main law of the ore roof failure was analyzed and the formula of the ore roof thickness was deduced.The results show that the tensile stress in the roof center accounts for the roof failure.According to the limit failure conditions of the point,the formula of the ore roof thickness was derived.Taking No.10 stope of a bauxite mine as an engineering case,the optimal thickness of the ore roof was 0.36 m.The safety factor was taken as 1.3,therefore the design thickness was 0.5 m.In the whole industrial test process,the dynamic alarm devices did not start the alarm and the ore roof was not damaged.Compared with other stopes under similar conditions,its thickness was reduced by 0.1-0.3 m.The recovery rate of the ore roof was increased by 16.7%-37.5%.

挑顶法石门揭煤过程中顶板突变失稳分析

为了解决缓倾斜煤层揭煤耗时长,穿越石门、煤门距离长,而过煤门时更易突出的难题,采用了一种挑顶法石门揭煤新工艺;应用弹性力学薄板理论建立了顶板岩石薄板模型,基于突变理论得到了顶板岩石发生突变失稳临界应力值,并求解出当临界应力值达到岩石强度时的临界厚度解析解;通过实例分析了临界值的影响因素,结果得出,适当增大煤层顶板的岩石的厚度,减小的宽度能够有效提高其发生突变失稳的临界应力值.经过多次现场成功应用和验证,挑顶法石门揭煤工艺具有一定的推广价值和研究意义.