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本文著者提出的关于减小竖井锥形保安煤柱尺寸的几点建议能使原先作为呆滞煤量的部分储量得到开采。理论上的假定通过实践得到了证明,在捷克斯洛伐克几个煤矿中应用了这些理论来开采井筒保护煤柱,均末引起竖井结构的任何严重的损害。在好多国家中用极限影响角μ留设竖井煤柱以保护竖井免受开采的影响。这种竖井保护方法的必要性,从现阶段来看必须重新加以考虑,因为根据极限影响角作的四个倾斜平面构成的竖井保安煤柱压煤的面积很大,使矿井井田相当大的一部分煤炭储量留在煤柱中不能进行开采。在捷克斯洛伐克许多煤矿中,关于竖井保护煤柱的问题过去也是很需要加以解决的问题。例如在俄斯特拉发一卡尔维纳煤田竖井煤柱留至地表以下1000米的深度时,井筒煤柱压煤的面积占煤田净开采面积的30—35％。俄斯特拉发一卡尔维纳煤田最近五十年来采用逐步试验的方法解决减小竖井保安煤柱压煤面积的问题。这里没有任何理论根据,主要是井筒煤柱设计时煤柱倾斜平面的角度采用了比极限影响角还大的角度,例如达到70—80°。在个别情况下也有采用圆柱形竖井保安煤柱的。所有这些试验都证明了采用上述相似的留媒柱方法是可能的。因此,需要在理论上再加以阐述,证明此种留井筒煤柱方法可以应用,以便使矿业局同意在实践中使用。关于减小井筒煤柱尺寸方面的创议可以在许多作者的著作中见到,特别是在R·巴尔斯1943年和1956年的著作中。他认为沿井筒轴线方向的垂直变形是主要的,井筒水平变形是次要的。巴尔斯的观点是与捷克斯洛伐克的实践经验相符合的。这种情况使井壁具有比较好的工作特性。鉴于上述情况,我想就沿井筒轴线方向的垂直变形的问题,特别是垂直变形的过程和变形量加以详细探讨。在第二部分中,从大量井筒煤柱开采实践中举一个例子加以说明;该实例中井筒煤柱的开采工作一直进行到竖井附近。
The suggestions made by the author of this paper to reduce the size of the shaft pits of conical pits can make some of the reserves originally used as sluggish coal mines. Theoretical assumptions proved by practice that these theories were applied in several coal mines in Czechoslovakia to mine shaft protection pillars without causing any serious damage to the shaft structure. In many countries, vertical shaft pillars are set aside with the limiting influence angle μ to protect the shaft from the effects of mining. The need for this type of shaft protection has to be reconsidered from the present stage because the shaft security coal pillar consisting of four inclined planes made at the critical angle of influence has a large area of coal so that a substantial part of the mine shaft Coal reserves remain in the pillars can not be mined. Of the many coal mines in Czechoslovakia, the issue of shaft protection for pillars was also a problem that needed to be addressed. For example, when shaft pillars in a Calvary coalfield in Ostrava were left at a depth of 1,000 meters below the surface, the area occupied by the coal billets was 30-35% of the net coal mining area. In the last 50 years, the Ostrava-Kalvinna coalfield has adopted a step-by-step trial to solve the problem of reducing the area of coal bored by shaft security briquettes. There is no theoretical basis here, mainly because the angle of the inclined plane of the pillars in the design of the shaft of the shaft adopts an angle larger than the limit influence angle, for example, 70-80 °. In some cases there are also cylindrical shaft with security pillar. All of these experiments demonstrate that it is possible to use the similar method of leaving the cartridge as described above. Therefore, it needs to be further elaborated in theory to prove that this kind of method for retaining wellbore pillars can be applied so that the mining bureau can agree to be used in practice. The proposal to reduce the size of the wellbore pillars can be found in the writings of many authors, especially in R. Balls’ 1943 and 1956 writings. He believes vertical deformation along the axis of the wellbore is of primary importance, and horizontal deformation of the wellbore is of secondary importance. Bales’s point of view is consistent with the practical experience of Czechoslovakia. This situation makes the well wall has better operating characteristics. In view of the above, I would like to discuss in detail the vertical deformation along the axis of the wellbore, in particular, the vertical deformation process and deformation. In the second part, an example is given from the practice of a large number of wellbore coal pillars. In this example, the mining of the wellbore pillars has been conducted to the vicinity of the shaft.