双向冻结-单向融化土压缩性及水分迁移试验研究

发布时间：2018-03-01 09:15

本文关键词： 冻融循环双向冻结-单向融化压缩变形水分迁移融土相对压缩系数　出处：《岩土力学》2015年04期 　论文类型：期刊论文

【摘要】：通过室内冻融试验,研究双向冻结-单向融化作用下不同冻前含水率和干密度对青藏粉黏土压缩特性的影响及水分迁移的变化规律。试验结果表明:(1)大梯度冻融作用使低密度土压缩性减小,使高密度土压缩性增大;而小梯度冻融作用使低、高密度土的压缩性均减小;(2)随着冻前含水率的增加,大梯度冻融作用使土体压缩性增大,但变化幅度逐渐减小,小梯度冻融作用的土体压缩性变化并不明显;(3)随着冻结梯度的增加,不同干密度融土相对压缩系数均呈现先减小后增加的变化趋势,不同冻前含水率融土相对压缩系数总体呈增大趋势;(4)温度梯度冻结后,试样含水率分布从上冷端到下冷端呈增大-减小-增大的变化规律,随着冻结温度梯度的减小,试样中部含水率先增大后减小。
[Abstract]:Through indoor freeze-thaw tests, The effects of moisture content and dry density on the compression characteristics of Qinghai-Xizang silt and its water migration under bidirectional freezing and unidirectional melting were studied. The experimental results showed that the compression of low-density soil was reduced by the freezing and thawing with large gradient freezing and thawing. The compressibility of high-density soil increased with the increase of moisture content before freezing, but decreased gradually with the increase of moisture content before freezing, but the range of variation decreased gradually with the increase of moisture content before freezing, while the compressibility of high-density soil increased by low-gradient freezing and thawing, while the compressibility of high-density soil decreased with the increase of moisture content before freezing. With the increase of freezing gradient, the relative compressibility coefficient of different dry density thawed soils decreased first and then increased. After freezing, the moisture content distribution of the sample increased from the upper cold end to the lower cold end with the change of increasing, decreasing and increasing, and with the decrease of the freezing temperature gradient, the relative compression coefficient of the melt soil with different moisture content showed an increasing trend after freezing, and the distribution of water content of the sample increased from the upper cold end to the lower cold end. The moisture content in the middle of the sample first increased and then decreased.
【作者单位】：中国矿业大学深部岩土力学与地下工程国家重点实验室;中国矿业大学力学与建筑工程学院;
【基金】：国家重点基础研究发展计划(973计划)项目(No.2012CB026103) 国家自然科学基金(No.41271096) 博士后特别资助(No.2014T70555)
【分类号】：TU445;TU411

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