On the stress state in rock burst

Abstract

By means of the stress state analyses on the rockmass surrounding underground openings and truely triaxial compressive testing, the stress state of rock burst and the limiting depth of rock burst in rocks are studied. The research results show that the rock burst of flake-splitting pattern takes place around the opening's surface under the biaxial compressive stress state whereas that of shearing-dislocation pattern takes place inside the rockmass. There exists a rock burst zone with a limiting depth dependent upon the ratio of the vertical principal stress to the horizontal one of the geostress field.

通過地下洞室圍巖的應力狀態分析和真三軸壓縮試驗，研究了巖爆應力狀態及其在圍巖中的極限深度問題。研究結果表明，片狀劈裂巖爆是在雙軸壓縮應力狀態作用下在洞壁面上產生；剪切錯動型巖爆是在真三軸應力狀態下在圍巖內部產生；圍巖內部存在著產生巖爆的極限深度區，極限深度的深淺取決于地應力場中的垂直和水平主應力的比值大小。