水-岩作用对岩石抗压强度效应及形貌指标的实验研究

Experimental Study of Compression Strength and Micro-Topography Description Index for Groundwater Saturated Rock

通过测定金川岩样的含水率以及水对岩石抗压强度,采用精度高达0.5μm的Talysurf CLI2000三维表面激光形貌仪,对经过矿井深部地下水作用前后的四种不同岩性的岩石试件进行形貌扫描,结合八个形貌参数作出定量分析对比。实验表明:矿岩遇水软化,岩石抗压强度降低,破坏时不属于脆性破坏,其原因可能就在于由于其中的粘土矿物吸水,当受力压缩时,水受压排出产生压密现象。水-岩作用后岩石表面形貌高度的离散性、粗糙程度变大,高度的分布概率更为集中,由负偏态变为正偏态且高度分布的对称性好于作用前。峰点算术平均曲度Ssc都有规律地降至0.62附近,更具协调性。

Four kinds of groundwater saturated rock from deep mine well were topographically scanned by three-dimensional laser surface topography apparatus Talysurf CLI 2000, the precision of which is as high as 0.5μm. The rock water containment rate and the influence of water on the rock compressive strength were measured. Then quantitative comparison and analysis were carried out based on 8 topographical parameters. Results show that the rock is softened by water and its compression strength declines due to the water absorption of clay mineral grains. When rock is compressed by force, the water is expelled from rock resulting in compaction. The discreteness of rock’s surface height and the roughness are increased after water-rock interaction. The distribution probability of highness is more concentrated, which turns from negative skewness into positive skewness and distributed more symmetrically than before. The Arithmetic mean summit curvature of the surface （Ssc） drops regularly to about 0.62, while the highness difference of the rock surface decreses and becomes more coordinated.