首页|击实和三轴压缩条件下炭质泥岩的颗粒破碎及力学响应研究

击实和三轴压缩条件下炭质泥岩的颗粒破碎及力学响应研究

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为充分认识炭质泥岩的颗粒破碎行为及力学特性,对不同粗粒质量分数的炭质泥岩在最佳击实状态下的破碎程度进行三轴剪切试验,分析粗粒质量分数对炭质泥岩粒径级配及力学性能的影响规律,明确炭质泥岩颗粒破碎与围压、粗粒质量分数间的关系.研究结果表明:在压实过程中,炭质泥岩存在明显的颗粒破碎现象,且粗粒质量分数越高,其颗粒破碎越明显;炭质泥岩的水敏性远大于硬质岩的土石混合体的水敏性,击实曲线更陡峭,且在粗粒质量分数为60%时具有最佳的击实状态;随着粗粒质量分数增大,炭质泥岩的抗剪强度呈现出先增长后减小的趋势,且在粗粒质量分数为60%时黏聚力达到最大,内摩擦角与粗粒质量分数呈负相关;当粗粒质量分数较小时,炭质泥岩抗剪强度主要由细粒间的黏聚力及粗粒与细粒间的咬合力提供,粗粒破碎较少;随着粗粒质量分数增大,试样中颗粒破碎现象更明显,颗粒间重新分布和咬合使其内摩擦力逐渐增大,抗剪强度由粗粒破碎及粗粒与细粒间的咬合力提供,细粒间的黏聚力较小;炭质泥岩的颗粒相对破碎率随围压、粗粒质量分数的增大而增大,且相对破碎率与粗粒质量分数和围压之间存在非线性关系.
Investigation of particle fragmentation and mechanical response of carbonaceous mudstone under percussive and triaxial compression conditions
To investigate the particle crushing behaviour and mechanical properties of carbonaceous mudstone,the triaxial shear tests on teh fragmentation degree of carbonaceous mudstone with different coarse grain mass fractions were carried out under the best compaction condition,the influence of stone mass fraction on the particle size gradation and mechanical properties of carbonaceous mudstone were analyzed,and the relationship between the particle crushing of carbonaceous mudstone and the surrounding pressure and coarse grain mass fraction was clarified.The results show that the water sensitivity of carbonaceous mudstone is much greater than that of the soil-stone mixture of hard rock,the compaction curve is steeper,and compaction state is the best when the coarse grain mass fraction is 60%.With the increase of coarse grain mass fraction,the shear strength of carbonaceous mudstone shows a trend of first increasing and then decreasing.When the coarse grain mass fraction is 60%,the cohesive force reaches the maximum,and the internal friction is negatively related to the coarse grain mass fraction.When the coarse grain mass fraction is low,the shear strength of the carbonaceous mudstone is mainly provided by the cohesive force of the fine grains and the occlusal force of the coarse and fine grains,and the coarse grains are less broken.With the increase of the coarse grain mass fraction,the broken grains in the specimen are more obvious,and the internal friction is increased by the redistribution and occlusion of the grains.The shear strength is provided by the coarse grain fragmentation and the coarse grain-fine grain occlusion,and the cohesive force of the fine grains is smaller.The relative fragmentation rate of carbonaceous mudstone increases with the increase of surrounding pressure and coarse grain mass fraction,and there is a non-linear relationship between the relative fragmentation rate and coarse grain mass fraction and surrounding pressure.

embankment engineeringcarbonaceous mudstoneparticle fragmentationmechanical propertiesrelative fragmentation rate

刘琼、曾铃、查焕奕、陈佳艳、卞汉兵

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长沙理工大学土木工程学院,湖南长沙,410114

长沙理工大学交通运输工程学院,湖南长沙,410114

法国里尔大学土木工程与岩土环境工程实验室,法国里尔,59000

路堤工程 炭质泥岩 颗粒破碎 力学特性 相对破碎率

国家自然科学基金国家自然科学基金湖湘青年科技创新人才项目湖南省自然科学基金杰出青年基金长沙市杰出创新青年培养计划长沙理工大学"双一流"科学研究国际合作拓展项目桥梁工程安全控制教育部重点实验室开放基金

52078067520780662020RC3062023JJ10045kq22060302019IC0415KB01

2024

10.11817/j.issn.1672-7207.2024.03.024

中南大学学报(自然科学版)
中南大学

中南大学学报(自然科学版)

CSTPCD北大核心
影响因子：0.938
ISSN：1672-7207
年,卷(期)：2024.55(3)
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