Measurement of shear movements in the overburden strata ahead of longwall mining

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• 作者：K.W. Mills ; ^{kmills@sct.gs" class="auth_mail" title="E-mail the corresponding author} ; O. Garratt ; B.G. Blacka ; L.C. Daigle ; A.C. Rippon ; R.J. Walker
• 关键词：Horizontal shear ; Longwall ; Overburden ; Inclinometer monitoring
• 刊名：International Journal of Mining Science and Technology
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：26
• 期：1
• 页码：97-102
• 全文大小：1184 K

文摘

An underground coal mine located in New South Wales has a target coal seam located 160–180 m deep directly below a 16–20 m thick conglomerate unit that has been associated with significant periodic weighting events on the longwall face. As part of the investigations to better understand the causes of periodic weighting at the mine, inclinometers capable of measuring horizontal shear movements through the full section of the overburden strata were installed ahead of mining at two locations approximately 1 km apart above the centre of two longwall panels. These inclinometers were monitored as the longwall approached each site. This paper presents the details of the installation, the results of the inclinometer monitoring at both sites, and the insights that these measurements provide for overburden behaviour about longwall panels. Horizontal shear movements were observed to develop on shear horizons that correlate closely across the two sites suggesting a mechanism that is consistent across a large area of the mine. Shear movements were observed to develop on a single horizon near the top of the conglomerate strata that was mobilised almost immediately after initial formation of the longwall goaf at a distance of 425 m ahead of the longwall face.