Abstract:

The mechanism of jointly deformation-failures between roadway surrounding rock and bolt-support system were studied and summarized. A new steelstrand bolt with high pretension stress was developed in this experiment. This kind of bolt can provide high pre-stress and effectively control the harmful deformation of surrounding rock. In addition, the synchronous deformation between the bolt and rock was achieved, and the self-support power of the bolt can be effectually exerted. At the same time, the prestressed steel-strand bolt is difficult to  be made flexible after being fixed, and is less influenced by shock wave. It was shown that this steel-strand bolt is technically feasible for supporting in roadway and can reduce the cost of support in the same strength condition. It also has the vale of having a wide spread in engineering application as a supporting-system to soft rock in deep mines.

Key words: prestress； steel-strand bolt； elongation； synchronous load bearing