Mechanical characteristics and stability analysis of surrounding rock reinforcement in rectangular roadway

Abstract

The stability of surrounding rock with bolt support depends on the stability within the reinforcement range. To understand the reinforcing mechanism of a rectangular roadway bolt fully and accurately, a quantitative method for evaluating the stability of the surrounding rock of a rectangular roadway must be developed. First, a roof beam model of a rectangular tunnel is established according to the deformation law of surrounding rock. Based on the elastic–plastic theory, the deflection calculation formula can be derived, and the ultimate load of the roof beam can be obtained under the plastic state without support. Second, based on the reinforcement effect of bolts, a model of a surrounding rock reinforcement body is established, the physical and mechanical properties of this body are deduced, and a method for evaluating the stability of surrounding rock is derived. Finally, by considering actual engineering cases, the theoretical calculation results of surrounding rock deformation are compared with the numerical simulation and field monitoring results. Moreover, the influence of different parameters of the bolt support on the mechanical characteristics and stability of reinforcement is investigated. The results show that the theoretical calculations approximate the numerical simulation and field monitoring values, thus verifying the rationality of the theory. The physical and mechanical properties and stability of the surrounding rock reinforcement body are considerably affected by changes in bolt length and spacing. The anchor design must apply the following principle: the bolt must either be long and sparsely spaced or short and densely spaced. The theory presented in this paper provides a relatively simple and fast quantitative calculation method for the study of the surrounding rock stability of bolt-supported rectangular roadways.

Study on the anchorage mechanism and roof stability control technology of bolts in fractured or weak surrounding rock

“…Many scholars have carried out fuzzy research on the 'reinforcement force' or 'anchorage stress' generated in the reinforcement of anchor bolts, but relatively few studies have evaluated the scope of bolt action [18][19][20] . Based on the roof failure of a soft rock roadway in the 150202 working face of the Youzhong Coal Mine as the research background, this paper analyses and summarizes the causes of failure.…”

The Retention and Control Technology for Rock Beams in the Roof of the Roadway: A Case Study

“…On-site monitoring demonstrated that the outcomes complied with engineering specifications and might serve as a guide for mines with comparable geology. In the numerical study of the reinforcement effect of rock bolts on enhancing the stability of the surrounding rock, Gu et al [22] concluded that rock bolts can effectively improve the stability of surrounding rock. At the Yuandian no.…”