摘要
为研究预崩解炭质泥岩持水特性在长期大气环境影响下的演变规律,通过扫描电镜和压汞试验研究干湿循环作用下预崩解炭质泥岩的微观结构及孔隙分布特征,并开展预崩解炭质泥岩土水特征曲线试验和渗透试验。基于Van Genuchten模型建立考虑干湿循环作用的预崩解炭质泥岩土水特征曲线修正模型,并预测预崩解炭质泥岩非饱和渗透系数。研究结果表明:干湿循环可促进预崩解炭质泥岩继续崩解,导致大孔隙体积及孔隙率增加,土体结构变得松散,但在干湿循环作用6次后孔隙率趋于稳定;干湿循环对预崩解炭质泥岩的持水特性影响显著,土水特征曲线随干湿循环次数增加整体向左偏移,土体进气值减小;在高基质吸力阶段,不同干湿循环作用下Van Genuchten修正模型预测得到的预崩解炭质泥岩的土体非饱和渗透系数曲线基本重合,说明干湿循环作用对其渗透性影响较小。
The microstructure and pore size distribution characteristics of pre-disintegrated carbonaceous mudstone in different numbers of dry and wet cycles were studied by scanning electron microscopy and mercurypressure test, and soil-water characteristic curve test and permeability test of pre-disintegrated carbonaceous mudstone were carried out to study the evolution of water-holding characteristics of pre-disintegrated carbonaceous mudstone under long-term atmospheric influence. The unsaturated permeability coefficient of predisintegrated carbonaceous mudstone was estimated using a modified model of soil-water characteristic curve of pre-disintegrated carbonaceous mudstone based on the Van Genuchten model that took account of the effect of dry and wet cycles. The results show that the dry and wet cycles can promote the continued disintegration of predisintegrated carbonaceous mudstone, resulting in the increase of large pore volume and porosity, and the soil structure becomes loose, but porosity stabilizes after six dry and wet cycles. The dry and wet cycles have significant effects on the water-holdingcharacteristics of pre-disintegrated carbonaceous mudstone, and the soilwater characteristic curve shifts to the left with the increase of the number of dry and wet cycles, and the value of soil air intake decreases. In the high matric suction stage, the predicted unsaturated permeability coefficient of the pre-disintegrated carbonaceous mudstone remains essentially the same after multiple wet and dry cycles,indicating that the pre-disintegrated carbonaceous mudstone is unaffected by changes in permeability.
作者
付业扬
刘朝晖
高乾丰
曾铃
余慧聪
FU Yeyang;LIU Zhaohui;GAO Qianfeng;ZENG Ling;YU Huicong(School of Traffic&Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China;School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第1期292-304,共13页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51838001,51878070,52078066,52078067)
湖湘青年科技创新人才项目(2020RC306)
湖南省研究生科研创新项目(CX20210746)
长沙市杰出创新青年培养计划项目(kq1905043)
长沙市自然科学基金资助项目(kq2014110)。
关键词
干湿循环
微观结构
土水特征曲线
预崩解炭质泥岩
非饱和渗透系数
wetting-drying cycles
microstructure
soil-water characteristic curve
pre-disintegrated carbonaceous mudstone
unsaturated permeability coefficient
