干湿循环条件下压实黄土变形特性试验研究

发布时间：2018-04-14 14:14

本文选题：压实黄土 + 干湿循环　；参考：《岩土力学》2016年08期

【摘要】：由于降雨及蒸发的周期性变化等原因,压实地基土经常处于干湿交替状态,这种干湿循环作用会影响路基及地基的长期稳定性。通过气压式固结仪测试压实黄土试样经过不同次数干湿循环作用后的侧限压缩应变与垂直压力(ε_(si)-p_i)曲线,研究干湿循环作用对压实黄土变形特性的影响,同时利用已有模型对实测曲线进行拟合,并基于割线模量法分析了割线模量与初始压实度及干湿循环次数的关系。结果表明:初始压实度对黄土的压缩变形有显著影响,不同初始压实度的试样其各级压力下的侧限压缩应变均随着干湿循环次数的增大逐渐增加,之后趋于稳定;初始压实度越高,干湿循环作用影响效应越显著;干湿循环作用并不改变土体ε_(si)-p_i曲线的形式;割线模量与干湿循环次数及初始压实度的关系均呈指数关系。
[Abstract]:Due to the periodic changes of rainfall and evaporation, the compacted foundation soil is often in a dry and wet alternate state, which will affect the long-term stability of subgrade and foundation.The lateral compression strain and vertical pressure curves of compacted loess specimens after different times of dry and wet cycles were measured by a pneumatic consolidation apparatus. The effects of dry and wet cycles on the deformation characteristics of compacted loess were studied.At the same time, the existing models are used to fit the measured curves, and based on the Secant modulus method, the relationship between the Secant modulus and the initial compaction degree and the number of dry and wet cycles is analyzed.The results show that the initial compaction degree has a significant effect on the compression deformation of loess, and the lateral compression strain of the samples with different initial compaction degree increases gradually with the increase of the times of dry and wet cycles, and then tends to be stable.The higher the initial compaction degree, the more significant the effect of dry and wet cycle is, the effect of dry and wet circulation does not change the form of 蔚 _ S _ I -pi curve of soil, and the relationship between Secant modulus and the number of dry and wet cycles and the initial compaction degree is exponentially related.
【作者单位】：中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室;中国科学院大学;南京工业大学交通学院;
【基金】：甘肃省科技重大专项计划项目(No.143GKDA007) 中国科学院西部之光重点项目中科研寒旱所STS项目(No.HHS-TSS-STS-1502) 冻土工程国家重点实验室开放基金(SKLFSE201302)~~
【分类号】：TU444

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