ABSTRACT
Fully grouted steel strands have been substituted for steel cables in cable bolting at Outokumpu Oy mines. Steel strands have high strength properties and can be installed easily into holes. A mechanized cable-bolting jumbo has been developed for bolting : drilling, pushing and cutting of strands, and grouting. The water-cement ratio used in grouting is about 0.30.
The application of the unique mechanized installation technique eliminates the need for grout plugs and strand anchors, even in long vertical upholes. Normal roof bolting can be performed by the cable bolting jumbo. Because the strands are not precut, any bolt length between 1.0 m and 40 m can be chosen as required.
Presented in this paper are examples from Outokumpu Oy mines of how long and short cable bolting has been applied in sublevel and cut and fill stoping and also the strengthening effects, which were observed in practice.
