Page 58 - 2022年第53卷第4期

［ 24 ］ XU JIAN， LI YANFENG，WANG SONGHE，et al . Shear strength and mesoscopic character of undisturbed
loess with sodium sulfate after dry-wet cycling［J］. Bulletin of Engineering Geology and the Environment： The
official journal of the IAEG，2020，79（3）：1523-1541 .
［ 25 ］ 骆亚生，谢定义，邵生俊，等 . 复杂应力状态下的土结构性参数［J］. 岩石力学与工程学报，2004（24）：
4248-4251 .
［ 26 ］ 邵生俊，郑文，王正泓，等 . 黄土的构度指标及其试验确定方法［J］. 岩土力学，2010，31（1）：15-19，38 .
［ 27 ］ 冯志焱 . 非饱和黄土的结构性定量化参数与结构性本构关系研究［D］. 西安：西安理工大学，2008 .
［ 28 ］ 邵 生 俊 ，龙 吉 勇 ，于 清 高 ，等 . 湿 陷 性 黄 土 的 结 构 性 参 数 本 构 模 型［J］. 水 利 学 报 ，2006，37（11）：
1315-1322 .
［ 29 ］ YE WANJUN，BAI YANG，CUI CHENYANG，et al . Deterioration of the Internal Structure of Loess under
Dry-Wet Cycles［J］. Advances in Civil Engineering，2020（2）：1-17 .
［ 30 ］ LI GUOYU，WANG FEI，MA WEI，et al . Variations in strength and deformation of compacted loess exposed to
wetting-drying and freeze-thaw cycles［J］. Cold Regions Science and Technology，2018，151：159-167 .

Study on macro-micro parameter relationship of undisturbed loess under dry-wet cycle

2
1
1
1
LIU Yuyang ，WANG Geng ，LAI Hongpeng ，XIE Mengdong ，AN Chi 1
（1. School of Civil Engineering，Chang’an University，Xi’an 710064，China；
2. School of Highway，Chang’an University，Xi’an 710064，China）
Abstract： In order to explore the effects of different drying-wetting cycles on the macroscopic mechanical
properties and microstructure of undisturbed Q 2 loess， and to clarify the quantitative relationship between
macroscopic mechanical parameters and microstructure parameters， drying-wetting cycle tests， triaxial com⁃
pression tests and scanning electron microscope tests were carried out. The change rules of macroscopic
strength and microstructure of undisturbed loess during the drying-wetting cycle were analyzed. Based on
the idea of comprehensive structural potential， the expression of variability parameters of undisturbed loess
was defined by using macroscopic mechanical parameters. The pore characteristic parameters used to de⁃
scribe the microscopic pore structure characteristics of loess were deduced，and the expression of macroscop⁃
ic and microscopic parameters of undisturbed loess was established. The results show that under the action
of dry-wet cycle， the void area ratio and fractal dimension of undisturbed loess show an increasing trend，
and the peak deviatoric stress and cohesion of loess decrease continuously. The larger the amplitude of
dry-wet cycle and the higher the lower limit moisture content，the faster the expansion of loess pore struc⁃
ture and the attenuation of macroscopic strength，but the internal friction angle changes little. The variabili⁃
ty of undisturbed loess can be characterized by the ratio of macroscopic peak deviatoric stress to soil cohe⁃
sion，that is，the variability parameters. With the increase of drying and wetting cycles，the variability pa⁃
rameters of undisturbed loess show a non-monotonic growth trend. The microscopic pore structure characteris⁃
tics of intact loess can be characterized by the product of pore area ratio and pore fractal dimension，name⁃
ly， the pore characteristic parameters， which are close to the variation relationship and trigonometric func⁃
tion of variability parameters. The ratio of peak deviatoric stress of intact loess to pore characteristic parame⁃
ters follows an exponential function with the variation of cohesion. It is proved that this function can reason⁃
ably describe the quantitative relationship between macro and micro parameters of intact loess.
Keywords：loess；wetting-drying cycle；structural property；SEM；triaxial test

（责任编辑：韩 昆）

— 432 —