巷道支护的自稳平衡圈理论

基于软岩巷道围岩变形破坏的自稳平衡现象，通过数值模拟揭示了巷道顶板、两帮和底板之间的相互影响关系，得出了巷道围岩不稳定区是以巷道为中心的椭圆形。基于普氏理论，考虑“底板-两帮-顶板”相互影响，提出了巷道围岩自稳平衡圈理论，给出了自稳平衡圈的椭圆曲线方程，明确了巷道支护对象为自稳平衡圈内的岩体，支护的目的是控制自稳平衡圈岩体的稳定性。研究表明，“底板-两帮-顶板”共同构成巷道稳定性的整体系统，巷道顶板自稳平衡拱的大小随着两帮塑性区的增大而增大，两帮塑性区随底板变形而增大。加强底板和两帮的支护，将大大缩小顶板自稳平衡拱的高度。提出了“治顶先治帮，治帮先治底”的巷道支护理念，得到多年实践验证，为软岩巷道支护控制提供了新的依据。

Theory of self-stable ring in roadway support

Based on the self-stable phenomena of surrounding rock deformation and failure in the soft rock roadway, the numerical simulation method is adopted to reveal the relationships among the roof, two ribs and floor of the roadway. It is found that the unstable zone of roadway surrounding rock is ellipse around roadway. According to the Protodyakonov’s theory and the interactions among the roof, two ribs and floor, a new theory of self-stable ring is put forward and its elliptic curve equation is given. This research clearly confirms that the rock mass within the ring is the supporting subject and the main purpose of support is to control the stability of rock mass within the ring. This research shows that the “floor - two ribs – roof” constitute the overall system of roadway stability system. The size of self-stable arch in the roadway roof increases with the increase of the plastic zone of ribs, while the plastic zone of ribs increases with the deformation of floor. Hence, the height of ring in the roof will be greatly reduced by strengthening the floor and two ribs. Therefore, the roadway control principle is put forward which can be described as “control roof must control ribs first, and control ribs must control floor first”, and it has been verified in practice by years. This theory provides a new basis for soft rock roadway control.