A Study of the Anchorage Body Fracture Evolution and the Energy Dissipation Rule: Comparison between Tensioned Rock Bolts and Torqued Rock Bolts

Abstract

Rock bolt support is an effective technique for controlling surrounding rock of deep roadway. The stability of the anchorage body composed of rock bolts and surrounding rock mass is the core in keeping the stability of roadways. In this paper, the UDEC Trigon model was used in simulating uniaxial compressive test on the anchorage body under different pretension loads. The energy equilibrium criterion of the anchorage body under the uniaxial compressive state was proposed. Furthermore, the fracture evolution and the energy dissipation during the failure process of the anchorage body were analyzed. Results showed that before the peak strength, the external work was stored in the anchorage body in the form of the elastic strain energy (Ue). After the peak, energy dissipated through three ways, including the fracture developing friction (Wf), plastic deformation (Wp), and acoustic emission (Ur). Based on the simulation results, the high pretensioned rock bolts can eliminate the continuous tensile fractures in the anchorage body, decreasing the damaging extent of the anchorage body and the energy that was consumed by the following two main approaches: fracture developing friction (Wf) and plastic deformation (Wp). Moreover, the surplus of the elastic strain energy (Ue) and the strength of the anchorage body can be improved. The pretension load had a positive relationship with elastic strain energy and a negative relationship with the anchorage body damage degree. Based on the above research, the transport roadway of the working face 6208 in the Wangzhuang Coal Mine selected tensile rock bolts to establish the high-performance anchorage body. The monitoring data showed that this reinforcement method effectively managed the serious deformation issue of the roadway surrounding the rock masses.

A Dynamic Numerical Simulation on the Grouting Timing in Retained Rib of Pillarless Mining

“…Timely grouting in the surrounding rock can repair the damaged bolt structure in time. The roadway support structure and the surrounding rock can be effectively coupled and become an effective bearing structure again [45,46].…”

An Insight from Rock Bolts and Potential Factors Influencing Their Durability and the Long-Term Stability of Deep Rock Tunnels

“…Wu et al [22] Defined rock bolts as essential techniques used for dealing with the stability of surrounding rocks in deep roadways, and their anchorage pattern is crucial for that. Kang et al [3] Defined rock bolts as kind of key support handling deformations and stability in mining operations.…”

“…Wu et al [22] Defined rock bolts as essential techniques used for dealing with the stability of surrounding rocks in deep roadways, and their anchorage pattern is crucial for that.…”

The Influences of Bladder Properties on the Working Performance of the Multibladder‐Type Inflatable Anchor

“…Anchorage technology can enhance the strength and selfstability of rock and soil mass, so as to achieve the construction purpose and safety requirements [1][2][3][4]. It has been recognized internationally since 1872 when the rebar was firstly applied to reinforce the rock slope of the open shale mine in North Wales of England and produced expectant results [5] and was first proposed in the patent application in 1913 [6].…”