Abstract:

 Based on analysis of grouted tubular rock bolts used in improving the mechanical property of fractured and weak surrounding rock and enhancing the anchoring force of rock bolts, the mechanical model of tunnel with shotcrete and tubular rock bolt support is created. The comparative analysis between plastic zone formed by tubular rock bolt support and that formed by common rock bolt support demonstrates the mechanism of improving supporting effect of tubular rock bolt in fractured and weak surrounding rock. The theory analysis and construction practice show that tubular rock bolt is an efficient method for tunnel support in fractured and weak surrounding rock. Tubular rock bolt can improve the supporting effect and can control the surrounding rock deformation in these geologic conditions. Moreover, the characteristics and key points in construction of tubular rock bolt are presented in this paper.

Key words:  , tubular rock boltweak surrounding rockanchoring forcemechanismconstruction