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以往在新布罗肯希尔联合有限公司的矿山中使用的全长注浆的普通锚索的经验表明,这样的支护方法在高应力区加固顶柱并非完全有效,顶柱发生了破坏,留下很长一段锚索悬挂在顶板上,砂浆和岩石剥落下来,锚索没有充分发挥其具有的承载能力。在该公司采到12中段的三个深孔空场法采场,用普通锚索加固的顶柱中观察到了这种观象。为了支护以后的采场顶柱,提出了一种载荷从岩石到锚索传递机理得到改善和充分发挥锚索强度的支护系统. 对这些顶柱破坏起主要作用的因素是在该地段由于回采引起的较高的应力。加固顶柱以防止破坏是不现实的,所以,要求一种有效的破坏后支护的方法.在所观察的顶柱破坏中,是由于上下盘的闭合、顶柱的膨胀造成了岩石大面积的冒落.因此,这套支护系统要提供破坏后的支撑能力,而且容许顶柱在一定限度内变形,以使矿柱解除应力,而不完全破裂.所提出的这套系统是在预应力混凝土中广为使用的钢绳上间断增设锚头.载荷从岩体向钢绳的传递主要是通过锚头实现的. 在12中段的两个采场用这套支护系统加固了顶柱,采场成功地进行了回采.在采用改进型的锚索支护地段,发生了上下盘闭合,顶柱膨胀以及应力释放,而整个顶柱厚度也得到了维护.
The experience with conventional full-length grouted conventional cables used in the mines at New Brockenhill Joint Ltd. has shown that such support methods are not fully effective at top-column reinforcement in high stress areas and that the top column is damaged, Leaving a long period of cable hanging from the roof, mortar and rock peeled off, the anchor cable did not give full play to its carrying capacity. This observation was observed at the company using three deep-hole stopes staged in the middle of the 12th stanchion reinforced with normal anchor lines. In order to support the following stope roof pillar, a support system for improving the load transfer from rock to anchor cable and giving full play to the strength of the anchor cable is proposed. The main factor affecting the roof cap damage is that in this section, High stress caused by mining. It is unrealistic to reinforce the top column to prevent damage, so an effective method of destroying the back support is required.In the observed collapse of the top column, due to the closing of the upper and lower plates, the expansion of the top column causes the large area of the rock Therefore, this support system to provide the support capacity after destruction, but also allow the top column deformation within a certain limit, so that the mine stress relieved, but not completely rupture.The proposed system is in the pre An anchor head is intermittently added to widely used steel cables in stress concrete.The load is transferred from the rock mass to the steel wire mainly through the anchor head.The two stopes in the middle section of 12 reinforce the top column with this support system , The stope was successfully recovered.With the improved anchor support section, the upper and lower disk closure, the top pillar expansion and stress release, and the entire top pillar thickness has also been maintained.