不同高径比石膏试样强度与尺寸效应的试验研究
发布时间：2019-03-06 20:37
【摘要】：确定合理的矿柱尺寸及其强度是保障石膏矿安全生产与长期稳定的关键因素。采用RMT-150B岩石力学试验机,对不同高径比石膏试样进行了单轴压缩试验。利用力学试验结果,建立了石膏试样强度与尺寸效应的理论模型及其表达式,采用FLAC~(3D)模拟了不同高跨比石膏矿柱的承载能力。研究结果表明:石膏试样的峰值应力、残余强度、弹性模量随高径比的减小而增大;初始应力和峰值应力所对应的轴向应变和横向应变随高径比的减小而减小;峰值应力后的轴向应变随高径比的减小而急剧减小,而横向应变则与之相反,且高径比越小横向应变越容易产生扩容破坏,呈现出软岩特性;变形模量与高径比之间的关系不明显,不能用其表征石膏试样的变形特性;当矿柱跨度超过4 m时,矿柱能充分发挥其支承能力,有效地支承上覆岩层的围岩压力。
[Abstract]:The determination of reasonable pillar size and strength is the key factor to ensure the safe production and long-term stability of gypsum ore. Uniaxial compression tests of gypsum samples with different ratio of height and diameter were carried out by using RMT-150B rock mechanics testing machine. Based on the mechanical test results, the theoretical model and expression of the strength and size effect of gypsum samples are established. The bearing capacity of gypsum pillars with different ratio of height to span is simulated by FLAC~ (3D). The results show that the peak stress, residual strength and elastic modulus of gypsum increase with the decrease of height-diameter ratio, the axial strain and transverse strain corresponding to initial stress and peak stress decrease with the decrease of height-diameter ratio. The axial strain after peak stress decreases sharply with the decrease of height-diameter ratio, but the transverse strain is opposite, and the smaller the height-diameter ratio is, the more easily the capacity expansion failure occurs, showing the characteristics of soft rock. The relationship between the deformation modulus and the ratio of height to diameter is not obvious and can not be used to characterize the deformation characteristics of gypsum samples, and when the span of the pillar exceeds 4 m, the pillar can give full play to its supporting capacity and effectively support the surrounding rock pressure of the overlying strata.
【作者单位】： 南华大学核资源工程学院;
【基金】：国家自然科学基金(51374129) 南华大学校级创新团队计划项目
【分类号】：TD315
本文编号：2435879
[Abstract]:The determination of reasonable pillar size and strength is the key factor to ensure the safe production and long-term stability of gypsum ore. Uniaxial compression tests of gypsum samples with different ratio of height and diameter were carried out by using RMT-150B rock mechanics testing machine. Based on the mechanical test results, the theoretical model and expression of the strength and size effect of gypsum samples are established. The bearing capacity of gypsum pillars with different ratio of height to span is simulated by FLAC~ (3D). The results show that the peak stress, residual strength and elastic modulus of gypsum increase with the decrease of height-diameter ratio, the axial strain and transverse strain corresponding to initial stress and peak stress decrease with the decrease of height-diameter ratio. The axial strain after peak stress decreases sharply with the decrease of height-diameter ratio, but the transverse strain is opposite, and the smaller the height-diameter ratio is, the more easily the capacity expansion failure occurs, showing the characteristics of soft rock. The relationship between the deformation modulus and the ratio of height to diameter is not obvious and can not be used to characterize the deformation characteristics of gypsum samples, and when the span of the pillar exceeds 4 m, the pillar can give full play to its supporting capacity and effectively support the surrounding rock pressure of the overlying strata.
【作者单位】： 南华大学核资源工程学院;
【基金】：国家自然科学基金(51374129) 南华大学校级创新团队计划项目
【分类号】：TD315
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