内蒙古阿拉善地区红层砂岩力学试验特性研究*

针对阿拉善沙漠世界地质公园范围内的敖伦布拉格峡谷与额日布盖峡谷的红色砂岩进行了岩石单轴、三轴压缩变形试验和岩石抗拉试验。得到以下结论:红层峡谷不同位置抗压强度不同,与野外观察到的岩层凹凸变化趋势能够相吻合;同一样品不同段的测试结果中抗压能力是有差别的,这可能与胶结在砂砾岩中的砾石分布不均匀有关;阿拉善红层砂岩力学特性与强风化砂岩力学特性相近,砂岩的内摩擦角随着风化程度的加剧而增大,凝聚力则随着风化程度加剧而减小,这可能是风化造成砂岩力学特性发生变化的原因。此成果填补了阿拉善地区红砂岩的基本力学特征信息的空白,对于研究峡谷地貌形成中的水动力和风动力具有参考意义。

The mechanics test properties of red sandstone in Alxa area in Inner Mongolia

The sandstone mechanics uniaxial tests, triaxial tests and tensile tests of Aolunbulage Canyon and Eribugai Canyon from Alxa Global Geopark have been conducted, and some conclusions were studied as follows: sandstones at different location in red canyon were of different compressive strength, which was identical with the layer concave-convex changing condition that had been observed in field work; compressive strength of different sections of one rock sample was discriminating, that might be related to the unevenness distribution of gravel in the sandstone; the Alxa sandstone mechanics properties are similar with some intense weathering sandstone, about which the internal friction angle of sandstone increase and cohesion decrease as the weathering degree increases, that is considered as the reason of rock properties changes due to weathering. The results fill up sandstone mechanics properties information in Alxa, and contribute to water and weathering dynamics in canyon evolution study.