Development of Cable-Lok Anchor and its Application in Pre-stressed Cable Bolting in Mines

Brian Lamothe,
Abstract Pre-stressed cable bolting provides active rock reinforcement, which effectively increases the shear strength of rock joints and is greatly beneficial for ground stabilization. Pre-stressed cable bolting has been widely used in civil engineering to overcome the weakness of joints in concrete structure or rock mass, but rarely used in mining engineering mainly for the lack of technical reliable and cost-effective anchor product. This paper introduces the development of a new cable anchor - Cable-Lok and its application in pre-stressed cable bolting in mines.

Cable-Lok is spring-loaded cable anchor suitable for the drill hole diameter of 50 and 65 mm (2" and 2.5") in medium soft rock to hard rocks. The cable anchor is automatically set on installation, which enables the cable to be tensioned immediately and to provide immediate active support throughout its length. The anchoring capacity of the cable anchor exceeds the ultimate tensile strength of the cable. Installation of the cable assembled with Cable-Lok anchor is as easy as that with conventional rock bolts. Grouting can be independently conducted shortly before or after tensioning the cable. In comparison with the conventional cable bolting, Cable-Lok anchor greatly speed-up the cable bolting circle and decreases the cost in cable bolting.

Cabl-Lok anchor has wide application in cable bolting in mines. Pre-stressed and grouted cable bolting can be used in large span drifts, chambers and intersection areas for permanent rock support, or in hanging walls for temporary support. Cable-Lok anchor with no grouting can be used for cable lace anchoring or temporary support in stopes.

This paper introduces the principle of pre-stressed cable bolting, the specification of Cable-Lok anchor and the testing results in laboratory and in site, the application cases of Cable-Lok anchor in mines, and the cost comparison study on cable bolting.

Keywords: pre-/post-grouting, Cable anchor, Cable tensioning, Cable Lacing, pre-stressed cable bolting
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