Study on the anisotropic mechanical properties of bedding sandstone under acid corrosion
刘奇许家杭李青海陈淼
LIU Qi;XU Jiahang;LI Qinghai;CHEN Miao
山东科技大学 能源与矿业工程学院山东科技大学 矿山灾害预防控制重点实验室
为了揭示酸腐蚀对不同层理倾角砂岩力学特性的影响, 开展了不同酸性环境、不同层理倾角下层状砂岩的单轴压缩试验, 结合声发射监测, 对比分析了砂岩试样强度、变形、脆性与破坏模式等各向异性特征, 建立了不同酸性环境、不同层理倾角下砂岩单轴抗压强度模型。研究结果表明: ①随着层理倾角的增加, 砂岩峰值强度呈先下降后上升趋势, 砂岩弹性模量总体呈上升趋势, 泊松比呈先上升后下降再上升的趋势。②随着浸泡溶液酸性增加, 砂岩的峰值强度、弹性模量呈下降趋势, 泊松比呈上升趋势, 砂岩强度和变形各向异性特征增强。③提出了不同酸性环境下完整岩块单轴抗压强度的计算模型, 建立了不同酸性环境、不同层理倾角下的砂岩单轴抗压强度模型。④随层理倾角的增加, 砂岩的破坏模式改变明显, 层理倾角为30°, 45°和60°时, 试样脆性较低, 更易发生剪切破坏; 随着浸泡溶液酸性增强, 岩石脆性降低, 实时声发射计数由“低频高峰”转变为“高频低峰”, 破坏模式由拉伸劈裂破坏居多转变为剪切破坏居多。研究成果可为酸性矿井水影响区岩石工程稳定变形分析提供参考。
To investigate the effects of acid corrosion on the mechanical properties of sandstone with varying bedding angles, uniaxial compression tests were conducted under different acidic environments and bedding angles, combined with acoustic emission (AE) monitoring. The anisotropic characteristics of sandstone, including strength, deformation, brittleness, and failure modes, were analyzed, and a uniaxial compressive strength model for sandstone under varying acidic conditions and bedding angles was established. The results indicate that: (1) as the bedding angle increases, the peak strength of sandstone initially decreases and then increases, while the elastic modulus generally increases, and Poisson's ratio exhibits a trend of first increasing, then decreasing, and finally increasing. (2) With increasing acidity of the soaking solution, both the peak strength and elastic modulus decrease, while Poisson's ratio increases, indicating enhanced anisotropic characteristics in the strength and deformation of sandstone. (3) A predictive model for the uniaxial compressive strength of intact rock under different acidic environments was proposed, alongside a uniaxial compressive strength model for sandstone incorporating both acidity and bedding angle effects. (4) The failure modes of sandstone vary significantly with bedding angle. At bedding angles of 30°, 45°, and 60°, sandstone exhibits lower brittleness and is more susceptible to shear failure. Additionally, increased acidity reduces the brittleness of the samples, with AE counts transitioning from "low-frequency high peaks" to "high-frequency low peaks". The dominant failure mode shifts from splitting failure to shear failure as acidity intensifies. These findings provide a reference for analyzing the stability and deformation behavior of rock engineering in regions affected by acidic mine drainage.
岩石力学酸腐蚀砂岩各向异性声发射
rock mechanics;acid corrosion;sandstone;anisotropy;acoustic emission
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会