Pretension effect on the performance of cable bolts in underground coal mines

Pretension plays a critical role in providing active support to control roof sagging and bedding plane slippage in underground coal mines. However, the optimal amount of pretension for cable bolts to achieve effective ground control remains unknown. Applying excessive pretension on cable bolts may cause cable bolt failure. On the other hand, insufficient pretension is ineffective in preventing large roadway deformation and roof fall incidents....