有压圆形隧洞围岩径向裂纹应力强度因子研究

Study on Stress Intensity Factor of Rock Radial Crack behind Circular Tunnel under Inner Water-pressure

为研究隧洞围岩周边径向裂隙的水力劈裂问题,利用复势法分别给出了高水压和构造应力两种因素作用下围岩径向裂隙应力强度因子的解析公式。研究表明:在压应力构造应力场中,构造应力只主导裂隙的Ⅱ型扩展,围岩孔隙水压力只主导裂隙的Ⅰ型扩展;侧压力系数和构造主应力与裂隙夹角是影响裂隙Ⅱ型扩展的重要因素。研究结论对于进一步研究高水压和构造应力对径向裂隙的水力劈裂效应具有重要的参考价值。

In order to study hydraulic fracturing of circumference rock radial crack behind hydraulic tunnel,this paper brings forward stress intensity factor analytic expressions of rock radial crack under high water pressure and tectonic stress individually by use of complex potential method.The result shows： in tectonic compressive stress field the tectonic stress only leads to the extension of typeⅡ crack,the rock pore water-pressure only leads to the extension of typeⅠ crack;the lateral pressure coefficient and the angle between direction of tectonic primary stress with direction of the crack extension are the important factors which influence the extension of typeⅡ crack.The results will play an important reference role in the further study on the hydraulic fracturing effect of the rock radial crack under high water-pressure and tectonic stress.