初始含冰量对冻结粉质砂土变形与强度的影响

发布时间：2018-07-07 17:25

本文选题：高含冰冻土 + 变形特性　；参考：《岩土力学》2014年10期

【摘要】：基于一系列同一温度、不同初始含冰量和应变率条件下的高含冰冻结粉质砂土的单轴压缩试验,开展了高含冰量对冻结粉质砂土变形行为和强度特性的初步研究。结果表明:随着试样中初始含冰量的增加,冻结粉质砂土的塑性增强,当初始含冰量超过210.1%后,应力-应变曲线趋近于冰的特性,可用修正的Duncan-Chang双曲线模型较好地描述其单轴压缩应力-应变关系;当应变率为0.083×10-3 s-1和0.467×10-3 s-1时,其初始切线模量呈非线性增大,但当应变率为0.667×10-3 s-1时,初始切线模量增大到一最大值之后转而减小,并且影响程度与应变率大小有关;当初始含冰量从32.9%增加到304.0%,冻结粉质砂土强度也是先非线性增大,然后逐渐趋于稳定,两者可用对数函数关系很好地描述。其研究结果可为开展高含冰冻土区路基的稳定性评价提供基础。
[Abstract]:Based on a series of uniaxial compression tests of frozen silty sand with high ice content at the same temperature, different initial ice content and strain rate, a preliminary study on deformation behavior and strength characteristics of frozen silty sand with high ice content was carried out. The results show that the plasticity of frozen silty sand increases with the increase of initial ice content in the sample. When the initial ice content exceeds 210.1%, the stress-strain curve approaches the characteristics of Yu Bing. The modified Duncan-Chang hyperbolic model can better describe the uniaxial compression stress-strain relationship, when the strain rate is 0.083 脳 10 ~ (-3) s ~ (-1) and 0.467 脳 10 ~ (-3) s ~ (-1), the initial tangent modulus increases nonlinear, but when the strain rate is 0.667 脳 10 ~ (-3) s ~ (-1), The initial tangent modulus increases to a maximum and then decreases, and the influence degree is related to the strain rate. When the initial ice content increases from 32.9% to 304.0, the strength of the frozen silty sand increases nonlinear first and then tends to stabilize gradually. The logarithmic function relationship between the two can be well described. The results can be used to evaluate the stability of roadbed in high ice frozen soil region.
【作者单位】：中国科学院寒区旱区环境与工程研究所
【基金】：优秀国家重点实验室专项基金(No.41023003) 冻土工程国家重点实验室自主课题(No.SKLFSE-ZT-07,No.SKLFSE-ZY-02)
【分类号】：TU441

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