轮廓爆破下柱状节理岩体开裂过程的数值模拟

以白鹤滩水电站柱状节理玄武岩为研究对象，根据现场的柱状节理分布统计资料生成数值模型，模拟边坡开挖轮廓爆破下柱状节理岩体的开裂过程。结果表明：轮廓爆破时，柱状节理面对岩体裂纹的发展起着导向和控制作用；爆炸荷载作用下炮孔周围的节理面首先张开，然后裂缝沿着炮孔连心线附近的节理面扩展，最后形成贯通的由大量柱状节理面连接而成的裂缝；预裂爆破条件下，预裂缝宽度先增大后减少，最后达到稳定的开度，而且预裂爆破在柱状节理岩体中产生的裂纹范围比光面爆破产生的大。

Numerical simulation on the cracking process of columnar jointed rock masses in contour blasting

With Baihetan columnar joints basalt as the research object, numerical model is generated according to the local distribution statistics. Based on numerical analysis, the cracking process of columnar jointed rock masses with the slope excavated by contour blasting is simulated. The results show that the columnar joints control and lead the generation of cracking in contour blasting. The joints around the hole are firstly opened by the explosion load. Then they extend along the joints near the defiled line of holes. Finally the cracks formed by a large number of columnar joints are connected. The process of the width of pre-splitting crack is that it reduces to stabile opening after increases under the condition of pre-splitting blasting. And the range of cracks in pre-splitting blasting is larger than these in smooth blasting.