干旱区地理2024，Vol.47Issue(12)：2041-2050,10.DOI:10.12118/j.issn.1000-6060.2024.152
盐风化作用下黄土结构的破坏特征与机理
Damage characteristics and mechanisms of soil structures under salt weathering
摘要
Abstract
This study investigates the damage characteristics of loess structures and the deterioration of loess strength under the influence of salt weathering,with a focus on unidirectional dehumidification conditions.The findings provide valuable references for soil and water conservation,as well as disaster prevention strategies in the Loess Plateau.Q2 loess from Fugu County,Shaanxi Province,China was selected for macro-and micro-scale ob-servations and shear strength tests under varying sodium sulfate contents.The results indicate the following:(1)Mac-roscopic effects:An increase in salt content significantly impacts the apparent damage degree and expansion dis-placement of the samples.Samples with salt contents ranging from 1.0% to 2.5% exhibited contour scaling dam-age characteristics,transitioning from uneven surface crusts to extensive salt spots and expansion cracks.In con-trast,samples with a lower salt content of 0.5% did not show salt swelling,salt spots,or crust formation.The salt weathering process progresses through three stages:germination,growth,and stability.(2)Microscopic effects:Salt weathering leads to the formation of agglomerates and expansive pores within loess.Sodium sulfate decahy-drate crystals were observed as a direct result of the salt weathering process.(3)Shear characteristics:The shear behavior of the samples transitioned from strain softening to strain hardening after salt weathering,with signifi-cant degradation in peak strength and reduced cohesion.As sodium sulfate content increased,salt weathering in-tensified the effects of"salt crystallization-induced expansion"and"soil drying-induced coagulation"in loess.This process generated numerous expansion cracks and pores both on the surface and within the loess,ultimately causing severe structural and strength deterioration.关键词
黄土/硫酸钠/盐风化/抗剪强度/损伤Key words
loess/sodium sulfate/salt weathering/shear strength/damage引用本文复制引用
段钊,李瑞怡,宋昆,闫旭升,郑立才,贺子光..盐风化作用下黄土结构的破坏特征与机理[J].干旱区地理,2024,47(12):2041-2050,10.基金项目
国家自然科学基金(42177155,41702298) （42177155,41702298）
河南省科技攻关计划项目(232102321016) （232102321016）
河南省教育厅高校重点科研项目(23A410003)资助 （23A410003）
