Abstract: In response to the serious problem of over- and under-excavation in the drilling and blasting excavation of jointed rock masses, the HJC(Holmquist-Johnson-Cook)model combined with compressive-shear and tensile-shear failure criteria was employed to analyze stress field distributions near profile blast holes and crack evolution paths under different joint characteristics. The results indicated that crack propagation was significantly affected by the dip angle, thickness, and strength of the joints.The most severe over- and under-excavation occurred when the angle between the joint and blast hole axis was 45°, forming a distinct “Z”-shaped profile. The weaker the joint strength was, the stronger the barrier effect on the explosion stress wave and the tensile failure effects would be. The same principle applies to the width of joints. Integrating the influence mechanism and practical effects of joint characteristics on contour formation, this study proposed a “blank hole induction” layout scheme for smooth blasting holes and optimized detonation sequencing measures. The research enriched the theory of directional fracture and contour forming in smooth blasting.
马晨阳, 胡英国, 刘美山, 徐辰宇, 黄月君. 节理岩体隧洞光面爆破轮廓成型的影响机制[J]. 隧道与地下工程灾害防治, .
MA Chenyang, HU Yingguo, LIU Meishan, XU Chenyu, HUANG Yuejun. The influence mechanism of smooth blasting forming of jointed rock mass tunnel. Hazard Control in Tunnelling and Underground Engineering, 0, (): 1-15.