摘要
对深部围岩分层断裂破坏机制模型试验进行再分析,研究模型介质断裂形态,指出模型裂缝存在剪切和拉伸2种形式。采用锯齿形岩石模型和极限应变破坏准则,推导洞室围岩的应力场,定量分析试验结果。通过与试验对比,证明解析方法的正确性。研究结果表明,在很大的轴向水平压力作用下,介质会产生间隔的拉伸裂缝,形成分层断裂现象。拉伸裂缝的几何形状逐渐趋于圆形,每形成一道拉伸断裂,模型等效于形成一个受支护作用的洞室,随着等效洞室半径的增大,其受到的支护力迅速增大,使得分层断裂现象局限在一定范围内。该解析方法可为研究不同条件下深部洞室围岩破坏规律奠定理论基础。
The model test on mechanism of layered failure within rock mass around deep-buried tunnel is re-analysed. At first, the fracture shape of surrounding rock mass is studied. The failure of the model medium has two patterns： tensile and shear. Stress field of surrounding rock mass is deduced using jagged rock mass model and ultimate strain failure criteria. By comparing with test results, the solution is proved to be correct. It is shown that the interval tension fracture would occur repeatedly under large axial compression stress, which forms the layered failure. The geometry of tension fracture tends to be round gradually. When a new tension fracture takes place, the model is equivalent to a tunnel with support. With the increment of tunnel radial, the supporting force increases rapidly, which makes the layered failure limited to a certain rangeal. The analytical method provides theoretical basis for studying rules of layered failure of rock mass around deep-buried tunnel under different conditions.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2009年第A01期2680-2686,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(50490270)
关键词
岩石力学
深部巷道围岩
分层断裂
破坏机制
rock mechanics
surrounding rock mass around deep-buried tunnel
multi-layered failure
mechanism of failure
