高水平压力作用下洞室围岩变形与破坏

为揭示高轴向水平压力作用下洞室围岩变形与破坏规律,研究了模型介质断裂形态,指出模型裂缝存在剪切和拉伸两种形式;采用锯齿形岩石模型和极限应变破坏准则,推导了洞室围岩的应力场,定量分析了试验结果;通过与试验对比,证明了解析的正确性。研究表明,在高轴向水平压力作用下,洞周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。可为深部防护工程设计提供参考。

Deformation and failure of rock mass around tunnel under high horizon pressure

Under hig h axial direct ion horizon pressure, the medium of tunnel model presents mult i-layered failure. The f racture shape of enclosing rock mass w er e studied and the failur e of the model medium w as pr oved to be in the pat terns of tension and shear. By the hackly ro ck mass model and the ult imate st rain failure criteria, the st ress field o f the enclosing ro ck mass w as deduced. Co nt rasted w ith the test result , the so lut ion w as pro ved to be correct . T he analyt ical r esult show s that the tensio n fracture w ill repeatedly occur under high axial compression stress, causing layer ed failure, that the geomet ry of tension fracture go es to roundness gradually , that w hen a new tension f racture is taking shape, the model is equal to a new tunnel w ith support ing, and that w ith the increment of the tunnel radial, the suppor ting force grow s rapidly, w hich makes the layered failure localized in a certain range. T he analy t ic metho d can of fer valuable reference to pro tect ive engineering design in deep