共查询到20条相似文献,搜索用时 9 毫秒
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通过相似材料模拟实验,研究了全部开采和部分开采条件下的采空区在地表新增荷载后,地表附加沉降和采空区上覆岩层内应力的变化规律.研究表明,地表加载点与采空区的相对位置不同时加载后地表附加沉降量具有明显差异,越靠近采空区,中央沉降量越大,实测到的开采前上覆岩层内应力基本上随深度增加线性增大,开采后上覆岩层内应力发生重分布,加载后的附加应力分布随深度增加逐渐减小. 相似文献
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S. L. Freidman 《Journal of Mining Science》1984,20(3):223-229
Conclusions In all the investigated ventilation layouts, large segments have been recorded in the worked-out space, where volume concentration
of methane is consistent with Coward’s explosion triangle.
The volume of the explosion-prone zone is somewhat lower with a ventilation layout reverse with respect to the rock mass.
This is determined by a greater reduction of the rate of outflow, beginning with distance from the cutting stretch, typical
of the given section.
The comparatively short distance of the explosion-prone zones from the mined section with an outflow indicates feasibility
of engineering installations securing mine safety through pumping in of neutral gases.
Maintaining a ventilating shaft behind the cutting stretch in a ventilation layout reverse with respect to the rock mass substantially
removes the zone of higher methane concentration (at the established level of ventilation) from the working side.
Four characteristic variants of changes in methane concentration deeper into the worked-out space are theoretically possible
depending on the character of inflow and filtration properties of rocks. In ventilation layouts considerably bending the outflow
channels, and also in the presence of disturbing factors during unloading the coal measures, changes in methane concentration
may be polyextreme.
Donets Coal Institute. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 78–85, May–June,
1984. 相似文献
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V. V. Borovikov A. S. Ivanov S. D. Lyubarskii V. A. Sklyar 《Journal of Mining Science》1994,29(6):522-526
A. F. Mozhaiskii Military Space Engineering Institute, St. Petersburg. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 51–55, November–December, 1993. 相似文献
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在选煤厂的设计中,采暖设计不仅直接关系到正常的生产秩序,而且对改善人们的工作环境也起着重要的作用。作者从四个方面论述了需要改进的问题,指出选煤厂的采暖设计应不断适应采暖技术的新潮流,使用新技术、新产品,以达到提高设计水平,降低能耗,扩大采暖面积,提高采暖效率,更好地为生产服务。 相似文献
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离柳矿区5号煤层以其镜质体、矿物和灰分含量高为特点明显区别于4号煤层,8号煤层以其惰质体和半镜质体含量较高为特征有别于9号煤层。 相似文献