岩土工程学报2025，Vol.47Issue(8)：1619-1628,10.DOI:10.11779/CJGE20240309
一维压缩条件下砂-黏土混合物热导率演化规律
Evolution of thermal conductivity of sand-clay mixtures under one-dimensional compression
摘要
Abstract
The aim of this study is to reveal the evolution law of natural sand-clay mixtures under varied stress conditions.A series of one-dimensional compression tests and dry density and thermal conductivity measurements are conducted on both dry and saturated samples to investigate the variations of dry density ρd as well as thermal conductivity k with the increasing stress level and clay content f,and the influences of pore fluid on packing behaviors and heat flow efficiency of the mixtures.Based on the binary packing theory,a new thermal conductivity model for sand-clay mixtures considering the effects of stress state and clay content is developed and verified.In addition,the microstructural characteristics and the thermal conduction mechanisms of the binary granular mixtures are discussed.The results indicate that the thermal conductivity k of sand-clay mixtures exhibits a trend of'increasing first and then decreasing'with an increase in the clay content f,and the pore fluid significantly reduces the thermal resistance among soil particles and increases the sensitivity of thermal conductivity to both the clay content f and stress level.The maximum k value is found around f of 40%.The dry density ρd presents a similar evolution with that of k,where the maximum ρd value is detected as the f is in the range of 30%to 40%.Increasing vertical stress is beneficial for improving the compaction behavior of the mixtures,while the presence of the pore fluid imposes a negligible effect on ρd.The critical clay content f* and the minimum void ratio emin are closely related to the state of stress,pore fluid and particle morphology.The proposed model for the thermal conductivity of the sand-clay mixtures comprehensively incorporates the hybrid effects of state of stress and fine content,which is also consistent with the binary packing theory and has good applicability.The particle deformation and breakage and the spatial structural evolution of the granular matter mixtures are recommended to further explore the thermal conduction mechanism.关键词
热传导/堆积特性/颗粒土/竖向应力/计算模型Key words
thermal conduction/packing characteristic/granular soil/vertical stress/computational model分类
建筑与水利引用本文复制引用
张涛,蔡国军,杨玉玲,张家铭,周逸文..一维压缩条件下砂-黏土混合物热导率演化规律[J].岩土工程学报,2025,47(8):1619-1628,10.基金项目
国家杰出青年科学基金项目(42225206) （42225206）
国家自然科学基金项目(41907248,41807260)This work was supported by the National Natural Science Foundation of China for Distinguished Young Scholars(Grant No.42225206)and the National Natural Science Foundation of China(Grant Nos.41907248,41807260). （41907248,41807260）
