双孔结构非饱和压实黏土的渗流-变形耦合微观机理

发布时间：2018-10-26 11:22

【摘要】：土体中的渗流-变形耦合问题是岩土工程中极为常见但却易被忽视的问题之一,尤其是对于拥有双孔结构的非饱和压实黏土,渗流-变形耦合过程较为复杂,从微观机理上对耦合全过程进行分析,有助于深入理解土体在渗流-变形耦合作用下的内在机制,为建立理论模型及开展进一步的试验研究奠定基础。基于已有的试验研究成果,并结合相关本构模型的建立及预测,以双孔结构土在常应力条件下的干燥过程为例,揭示了双孔结构非饱和压实黏土在不同阶段的渗流-变形耦合规律,以及耦合全过程的微观机理;对初始干密度对非饱和土渗流-变形耦合特性的影响进行对比分析。研究表明:渗流-变形耦合作用在大孔隙渗流阶段表现较为显著,而在小孔隙渗流阶段则不够明显;初始干密度对渗流-耦合作用的影响仅在大孔隙渗流阶段起作用。
[Abstract]:The coupling of seepage and deformation in soil is one of the most common but neglected problems in geotechnical engineering. Especially for unsaturated compacted clay with double pore structure, the coupling process of seepage and deformation is more complex. The analysis of the whole process of coupling from the microscopic mechanism is helpful to understand the internal mechanism of soil under the coupling of seepage and deformation and to lay a foundation for the establishment of theoretical model and the further experimental study. Based on the existing experimental results and combined with the establishment and prediction of the related constitutive model, the drying process of double-pore structure soil under constant stress is taken as an example. The coupling law of seepage and deformation of unsaturated compacted clay with double pore structure at different stages and the microscopic mechanism of the whole coupling process are revealed. The effect of initial dry density on the coupling characteristics of seepage and deformation of unsaturated soil is analyzed. The results show that the coupling effect of percolation and deformation is obvious in the percolation stage of macropore, but not obvious in the percolation stage of small pore, and the effect of initial dry density on the percolation and coupling is only in the percolation stage of macropore.
【作者单位】：北京交通大学土木建筑工程学院岩土工程系;城市地下工程教育部重点实验室;澳大利亚纽卡斯尔大学岩土科学与工程研究中心;中南大学高速铁路建造技术国家工程实验室;
【基金】：国家自然科学基金项目(51208031,51409292) 中央高校基本科研业务费专项资金资助(2015JBM068,2014JBZ013)
【分类号】：TU442

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