复杂应力状态下土料三轴渗透试验

发布时间：2018-05-15 02:16

本文选题：复杂应力状态 + 三轴渗透试验　；参考：《河海大学学报(自然科学版)》2017年05期

【摘要】：为研究高土石坝坝体内土体单元在复杂应力状态下的渗透性能,在中型三轴仪上对同一土料场3种不同级配土料进行三轴渗透试验。试验围压分为5级(100 k Pa、400 k Pa、800 k Pa、1 200k Pa和2 000 k Pa),每级围压下分4种应力水平(0、0.2、0.4和0.8),当试样在初始应力状态下变形基本稳定后,采用常水头法测试试样的渗透系数。试验结果表明:级配是影响渗透系数的重要因素,相同应力条件下土料粉粒和黏粒含量越高,渗透系数越小;随围压和应力水平的提高,土料的渗透系数逐渐降低;粉粒和黏粒含量越低、大颗粒含量越高,围压对土料渗透系数的影响越显著;对于不同级配相同密实度试样,应力水平对渗透系数的影响程度基本一致。在分析渗透系数随围压和应力水平变化规律的基础上,建立了能描述复杂应力状态条件下土体渗透系数的经验公式。
[Abstract]:In order to study the permeability of soil element in high earth rockfill dam under complex stress condition, triaxial permeation tests were carried out on three different gradation soil materials in the same soil material field on a medium triaxial meter. The confining pressure of the test is divided into five grades (100k Pa100k Pa-400k Pa-800 KPA 1 200kPa and 2 000 KPA). Under each stage of confining pressure, there are 4 kinds of stress levels: 0 / 0. 2 / 0. 4 and 0. 8 ~ 0. 4 respectively. When the specimen is deformed under the initial stress state, the permeability coefficient of the specimen is measured by using the constant head method after the deformation of the specimen is basically stable under the initial stress state. The results show that the gradation is an important factor affecting the permeability coefficient, the higher the content of silt and clay is, the smaller the permeability coefficient is under the same stress condition, and the lower the permeability coefficient is with the increase of confining pressure and stress level. The lower the content of silt and clay, the higher the content of large particles, the more significant the influence of confining pressure on the permeability coefficient of soil, and the same degree of influence of stress level on permeability coefficient for the samples with the same compactness of different grades. Based on the analysis of the variation of permeability coefficient with confining pressure and stress level, an empirical formula is established to describe the permeability coefficient of soil under complex stress state.
【作者单位】：南京水利科学研究院水文水资源与水利工程科学国家重点实验室;水利部土石坝破坏机理与防控技术重点实验室;中国电建集团贵阳勘测设计研究院有限公司;
【基金】：国家自然科学基金(51679149)
【分类号】：TV41

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