工程地质学报2025，Vol.33Issue(6)：2063-2073,11.DOI:10.13544/j.cnki.jeg.2025-0373
干湿-冻融循环条件下黄土状盐渍土的力学特性及土-水特征曲线试验研究
EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES AND SOIL-WA-TER CHARACTERISTIC CURVE OF SALINIZED LOESS UNDER WET-DRY AND FREEZE-THAW CYCLES
摘要
Abstract
Through multi-cycle environmental simulation tests(0-8 drying-wetting cycles and 0-50 freeze-thaw cycles),this study investigated the coupled effects of drying-wetting and freeze-thaw cycles on salinized loess.Triaxial shear tests,filter paper method measurements,scanning electron microscopy(SEM),and PCAS-based quantitative microstructural analysis were employed to elucidate the mechanisms by which cyclic environmental conditions influence mechanical strength and water-retention behavior.The results indicate that:(1)Mechanical strength exhibits a three-stage evolution:initial enhancement due to salt crystallization filling the soil skeleton;subsequent rapid degradation caused by water-salt phase changes damaging the structural framework;and eventual stabilization after reaching critical cycle thresholds,where the soil develops a more compact structure.(2)As the number of cycles increases,the soil-water characteristic curve(SWCC)shifts toward lower suction and lower water content.Van Genuchten model fitting indicates reductions in both saturated and residual water content,reflecting a deterioration in water-retention capacity.(3)Microscopic analyses reveal that coupled cycles transform interparticle contacts from surface-to-surface to point-to-surface types,promote crack development,and lead to structural loosening.These microstructural changes result in the coupled degradation of mechanical and hydraulic properties.关键词
黄土状盐渍土/干湿-冻融循环/力学特性/土-水特征曲线/微观结构Key words
Salinized loess/Coupled drying-wetting-freeze-thaw cycles/Mechanical properties/Soil-water characteristic curve/Quantified microstructure分类
天文与地球科学引用本文复制引用
张传鑫,常立君..干湿-冻融循环条件下黄土状盐渍土的力学特性及土-水特征曲线试验研究[J].工程地质学报,2025,33(6):2063-2073,11.基金项目
青海省高等学校省级骨干教师培育计划 （）
青海省自然科学基金项目(资助号:2017-ZJ-791),岩土力学与堤坝工程教育部重点实验室开放基金项目(资助号:2019005).This research is supported by the Qinghai Provincial-Level Backbone Faculty Cultivation Program for Higher Education Institutions,Natural Science Foundation of Qinghai Province(Grant No.2017-ZJ-791)and Open Research Fund of MOE Key Laboratory of Geomechanics and Embankment Engineering(Grant No.2019005). （资助号:2017-ZJ-791）
