关键词: 深部开采；圆形巷道；数值模拟；能量耗散；主应力差值

Abstract:

It is the key important problems in the world for research on rockburst disaster mechanism and control countermeasure of the deep mining tunnel under high stress conditions. The principal stresses distribution and energy dissipation was analyzed according to the cases of  the excavated radius, the stress level, and the non-uniform stress field of the tunnel with the  UDEC technique.The growth curves of the energy dissipation quantity and the energy dissipation ratio were concave with stress level increasing and the non-uniform stress field aggravating. The growth curve of the energy dissipation quantity was  also concave, but the energy dissipation ratio with the excavated radius increasing was almost holding constant. The concentrating zones of  principal stress difference were extended and gradually migrated from the outside to the inside in the tunnel surroundings with the non-uniform stress field aggravating. When the horizontal stresses are greater than vertical stresses，the concentrating zones of  principal stress difference in the roof usually have more serious consequences than those in both sides of the tunnel.

Key words: deep mining; the circular tunnel; numerical simulation; energy dissipation; principal stress difference