| 摘要: |
| 为系统研究块石颗粒形状、含石量及岩性等多因素对土石混合体力学特性的影响规律，本研究利用GDS三轴测试系统开展了土石混合体固结排水剪切试验，分析不同因素对抗剪强度、变形特性及颗粒破碎行为的作用。结果表明:（1）块石球形度显著影响土石混合体的抗剪强度和剪胀效应，球形度增加会导致峰值强度下降及骨架结构稳定性降低；（2）随着含石量增加，抗剪强度呈先上升后下降的趋势，内摩擦角与黏聚力呈负相关；（3）在无土—岩胶结作用下，母岩单轴抗压强度对土石混合体力学特性的影响有限，其粗糙程度及破碎特性等参数影响更显著；（4）颗粒破碎率随围压增加而升高，在含石量为40%时达到最大。软岩颗粒强度低、刚度小，主要表现为劈裂破坏和边角断裂；硬岩颗粒强度高、刚度大，加载时棱角易产生应力集中，破碎以棱角破碎为主，而颗粒整体保持完整。 |
| 关键词: 土石混合体 球形度 含石量 岩性 颗粒破碎 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（No.52568046,41962017）;广西自然科学基金资助项目（No.023GXNSFAA026185） |
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| Influence of sphericity, stone content and parent rock type on mechanical properties of soil-rock mixture |
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LIU Bao-chen, GUO Jing-yu, LIN Zhi-nan, WANG Jia-quan, ZHANG Hui, QI Xin-yu
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College of Civil and Architectural Engineering,Guangxi University of Science and Technology,Liuzhou
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| Abstract: |
| In order to systematically study the influence of stone particle shape, stone content and lithology on the mechanical properties of soil-rock mixture, this study used the GDS triaxial test system to carry out the consolidated drained shear test of soil-rock mixture, and analyzed the effects of different factors on shear strength, deformation characteristics and particle crushing behavior. The results show that:(1) The sphericity of block stone significantly affects the shear strength and dilatancy effect of soil-rock mixture. The increase of sphericity will lead to the decrease of peak strength and the stability of skeleton structure. (2) With the increase of stone content, the shear strength increases first and then decreases, and the internal friction angle is negatively correlated with the cohesion. (3) In the absence of soil-rock cementation, the influence of uniaxial compressive strength of parent rock on the mechanical properties of soil-rock mixture is limited, and the influence of parameters such as roughness and crushing characteristics is more significant. (4) The particle breakage rate increases with the increase of confining pressure, and reaches the maximum when the stone content is 40 %. Soft rock particles have low strength and small stiffness, which are mainly characterized by splitting failure and corner fracture. Hard rock particles have high strength and stiffness, and the edges and corners are easy to produce stress concentration during loading. The crushing is mainly angular crushing, while the particles remain intact as a whole. |
| Key words: soil-rock mixture particle shape rock content parent rock type particle breakage |
