Mohamed Khaled, Rashed Gamal, Radakovic-Guzina Zorica
Centers for Disease Control, National Institute for Occupational Safety and Health, Pittsburgh, PA 15236, USA.
ITASCA Consulting Group, Minneapolis, MN 55401, USA.
Int J Min Sci Technol. 2020;30(1):17-24.
Underground coal mines use mechanical bolts in addition to other types of bolts to control the rib deformation and to stabilize the yielded coal ribs. Limited research has been conducted to understand the performance of the mechanical bolts in coal ribs. Researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted this work to understand the loading characteristics of mechanical bolts (stiffness and capacity) installed in coal ribs at five underground coal mines. Standard pull-out tests were performed in this study to define the loading characteristics of mechanical rib bolts. Different installation torques were applied to the tested bolts based on the strength of the coal seam. A typical tri-linear load-deformation response for mechanical bolts was obtained from these tests. It was found that the anchorage capacity depended mainly on the coal strength. Guidelines for modeling mechanical bolts have been developed using the tri-linear load-deformation response. The outcome of this research provides essential data for rib support design.
地下煤矿除使用其他类型的锚杆外，还使用机械锚杆来控制煤壁变形并稳定已屈服的煤壁。关于机械锚杆在煤壁中的性能，人们开展的研究有限。美国国家职业安全与健康研究所（NIOSH）的研究人员开展此项工作，旨在了解在五个地下煤矿的煤壁中安装的机械锚杆的加载特性（刚度和承载能力）。本研究进行了标准拉拔试验，以确定机械煤壁锚杆的加载特性。根据煤层强度，对测试锚杆施加不同的安装扭矩。通过这些试验，得出了机械锚杆典型的三线型荷载-变形响应。研究发现，锚固能力主要取决于煤体强度。利用三线型荷载-变形响应制定了机械锚杆建模指南。该研究成果为煤壁支护设计提供了重要数据。
