不完整岩石样品的断裂与摩擦滑动

在单轴压力下对具有锯口面的岩石样品的破裂和摩擦滑动进行了实验室试验。当锯口面与轴应力方向垂直时（拼合样品）,研究了岩石的强度,破裂形态和前兆。对于锯口面与加载轴成65°和75°的样品,发现在宏观断裂发生之前有粘滑现象发生。粘滞时的应力降和轴向位移的变化比断裂时要小得多。实验发现,在锯口样品中的断裂往往从锯口一侧发生,穿过间断面而向另一侧发展。本文还简要地讨论了这些结果的意义。

FRACTURE AND FRICTIONAL SLIDING OF ROCK SAMPLES WITH SAW CUT

Uniaxial tests were performed on cylindrical samples of gabbro, granite and marble containing pre-fabricated surfaces （simple saw cut, polished saw cut surfaces） oriented at various angles with respect to the load axis. The major object of the tests was to investigate both the fracture and the frictional sliding of the samples. When the polished saw-cut surface was perpendicular to the load-axis （combined sample）, the strength, fracture pattern and the precursors were investigated. For those samples with simple saw cut surfaces oriented at 65° or 75° to the load axis, there existed some stick slips along the saw cut before the macrofracture occurred; the stress drop and axial displacement in stick slip were much less than that in the eventual fracture. It is found that the fracture usually occurred on one side of the saw cut at first, then developed through the saw cut surface to another side of the samples. The implication of the experimental results to earthquake prediction was briefly discussed.