Investigation of impact dynamics of roof bolting with passive friction control

• Published in: International journal of rock mechanics and mining sciences (Oxford, England : 1997) Vol. 70; pp. 559 - 568
• Main Authors: Chen, Liangbiao, Sheng, Gang, Chen, Gang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.2014; Elsevier
• Subjects: Applied sciences; Bolts; Building structure; Buildings. Public works; Construction (buildings and works); Dynamic load; Dynamic tests; Dynamical systems; Dynamics; Exact sciences and technology; Frictional energy absorber; Geotechnics; Loads (forces); Rock; Rock bolt; Rock bolts; Sliding; Stabilization. Consolidation; Stresses. Safety; Structural analysis. Stresses; Underground openings; Underground structure; Underground openings; Frictional energy absorber; Rock bolt; Dynamic load; Nonlinear analysis; Impact study; Passive system; Modeling; Numerical analysis; Friction; Underground construction; Blast wave; Energy absorption; Rock bolting; Seismic load
• ISSN: 1365-1609; 1873-4545
• DOI: 10.1016/j.ijrmms.2014.06.003

In this paper, the impact dynamics of rock bolt with passive friction control is modeled. Numerical investigations are performed for the bolts with frictional energy absorber under various dynamic loads. The results are compared with those from fully grouted rigid bolts. The studies indicate that without the frictional energy absorber, the bolts are highly susceptible to failure under dynamic impact loads, while the bolts with the fictional energy absorber significantly reduce this risk. The studies also reveal that the bolt sliding may occur at the combined effect of vibration frequency and velocity magnitude. Sliding will only initiate above certain threshold value defined by vibration frequency and velocity magnitude. Furthermore, the simulation results show that under certain impact forces when rock mass subject to only elastic deformation, bolt sliding may occur causing the detachment of bolt head and rock face, which may incapacitate the rock bolt in supporting the rock excavation. The investigation signifies that further development and appropriate design of the rock bolt system with a frictional energy absorber are critical in maintaining stability under dynamic loading. •Developed a non-linear model for modeling yieldable rock bolt (Roofex).•Established a conceptual mechanism of bolt yielding and validated it by laboratory data.•Investigated the effects of ground vibrating frequency and velocity on bolt behavior.•Identified a potential problem due to a gap between the rock surface and bolt plate.