岩石试件在不同圆柱荷载作用下的破坏特征

BROKEN CHARACTERS OF ROCK UNDER DIFFERENT CYLINDRICAL LOADS

在岩体切割、钻孔或破碎时,明确圆柱荷载周边产生的破坏机制,是提高切割效率的重要课题。通过对岩石试件不同直径的圆柱荷载对径受压试验,分析不同直径圆形荷载作用下岩石的破碎过程。随着荷载的增大,截头侵入岩石的深度也在增加,但当荷载突然急剧下降时,截头侵入岩石的深度却突然增加。通过对试验数据的处理发现,岩石的跃进荷载和圆柱截头面积呈线性关系,且随着截头直径的减小,岩石跃进破碎特性越来越不明显,不会出现二次裂隙的形成过程,且最终破坏荷载逐渐减小,破坏后块数较均匀,完整性好。同时,通过对压入模型应力分布规律的讨论,得出在离加载点较远的地方,应力状态趋于一致的结论,这和试验结果是完全一致的。

When cutting, drilling and fragmenting rock, failure mechanism around cylindrical load is an important research subject to improve cutting efficiency. Through diametrical compressive test on rock samples under cylindrical loads with different diameters, the broken process of rock is analyzed. With the load increment, the invading depth of head also increases. When the load decreases abruptly, however, the invading depth increases suddenly. Experimental data reveal a linear relation between leaping load and cylindrical cutting area. With the cutting diameter reducing, the leaping broken character of rock becomes more and more obscure; and the second formation process of fracture will not appear. At the same time, the final broken load reduces gradually; and the block after fragment is homogeneous and complete. Meanwhile, the stress distribution of press model is discussed. Analytical result indicates that the stresses at the place far from the loaded point approach consistent, which is complete in accordance .with the experimental result.