温度梯度冻土蠕变变形规律和非均质特征

发布时间：2018-03-12 10:49

本文选题：温度梯度　切入点：冻结饱和黏土　出处：《岩土工程学报》2014年02期 　论文类型：期刊论文

【摘要】：采用K0DCGF(K0固结—保持荷载冻结—形成温度梯度—再试验)方法,开展不同温度梯度冻结饱和黏土三轴蠕变试验,研究冻土蠕变变形规律和温度梯度诱导的冻土非均质特征。结果表明:K0DCGF模式中温度梯度冻结饱和黏土蠕变曲线由瞬时蠕变、衰减蠕变、稳定蠕变和加速蠕变4个阶段组成;温度梯度冻土径向蠕变速率小于轴向蠕变速率;温度梯度冻土最小轴向蠕变速率与蠕变应力之间满足指数函数关系,而长期强度极限与蠕变破坏时间之间则满足对数函数关系;梯度温度冻结过程中的水分场重分布和试验后冻土变形的非均匀分布是K0DCGF蠕变试验中"温度梯度诱导的冻土非均质性"的重要体现;蠕变试验后温度梯度冻土冷端含水量最高,密实度最大;蠕变试验后温度梯度冻土宏观径向变形/试样高度沿试样高度方向分布随蠕变应力增加由先增加后降低规律逐步演化为持续增加规律,这一现象与冻土初始瞬时蠕变速率密切相关。
[Abstract]:Using K0DCGF (K0 Consolidation - keep load of frozen formation temperature gradient - Test) method, carry out different freezing temperature gradient of saturated clay three triaxial creep test, creep deformation law and the research on frozen soil temperature gradient induced by frozen soil heterogeneity. The results show that the temperature gradient in the K0DCGF model of frozen saturated clay creep curve by instantaneous creep attenuation the 4 stage of creep, steady creep and accelerated creep; radial temperature gradient of permafrost creep rate is smaller than the axial creep rate; temperature gradient in minimum axial creep rate and creep should be full of exponential function relation between force, and meet the logarithmic relationship between long-term strength and creep failure time; temperature gradient in freezing process the moisture redistribution and deformation of frozen soils after the test of non uniform distribution of K0DCGF in creep test of temperature gradient induced soil heterogeneity "heavy To reflect the creep test; the temperature gradient of permafrost cold end of the highest water content density maximum creep test; the temperature gradient of permafrost macro radial deformation / sample height distribution along the height direction of the sample with the creep stress increased by increased first and then decreased gradually as the increasing rule of law, the phenomenon of permafrost and initial instantaneous creep rate closely related.

【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;
【基金】：973计划项目(2012CB026103) 国家自然科学基金项目(51304209) 中央高校基本科研业务费专项资金项目(2011QNA03) 中国博士后基金项目(20110491489)
【分类号】：TU445

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