关键词: 隧道, 层状岩石, 岩爆, 高预应力长锚索, 能量场

Abstract: To address the challenge of controlling rockburst in tunnels under extremely high stress in deep geological conditions, a mechanical model of layered rock under stress is constructed based on the principle of composite beams. This model is used to deeply analyze the stress mode of layered rock and the mechanical mechanism of the cooperative effect between anchor cable support and layered rock. Meanwhile, a numerical model is established based on the discrete element method to systematically examine the evolution patterns of the energy field of the tunnel surrounding rock, and to reveal the influence mechanism of different support methods on the energy field of the surrounding rock. The research results indicate the following: (1) Under the same geological stress conditions, the amount of elastic strain energy accumulated by layered rocks is closely related to the rock mechanical properties and the inter-layer spacing. Among them, thin hard rocks are more prone to rockburst phenomena. (2) By installing anchor cables to connect the weak layered rocks into a whole, the rock fractures on both sides are closely adhered. Compared with the force state where the rock can freely slide along the fracture surface without support, the elastic strain energy accumulated by the rock under external force is significantly reduced, thereby significantly reducing the risk of rockburst. (3) High pre-stressed long anchor cables can effectively reshape the stress state of the surrounding rock, promote the transfer of energy from the surrounding area of tunnel excavation to the deep surrounding rock, weaken the energy concentration degree of the surrounding rock around the tunnel, and further reduce the risk of rockburst. In contrast, passive support structures cannot actively regulate the stress of the surrounding rock, disabling effective intervention in the energy field.

Key words: tunnel, layered rock, rockburst, high prestressed long anchor cable, energy field