原状黄土土-水特征曲线与湿陷性的相关性  

Correlation between soil-water characteristic curve and collapsibility in undisturbed loess

作　　者：陈家乐 倪万魁[1] 王海曼 荣誉 CHEN Jiale;NI Wankui;WANG Haiman;RONG Yu(College of Geological Engineering and Surveying,Chang’an University,Xi’an,Shaanxi 710054,China)

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《中国地质灾害与防治学报》2024年第2期107-114,共8页The Chinese Journal of Geological Hazard and Control

摘　　要：为了研究原状黄土土-水特征曲线与黄土湿陷性之间的联系,在陕西西安长安区取地表以下30 m范围内的原状黄土土样,进行基本物理指标试验和湿陷性试验。对不同典型地层的黄土-古土壤试样进行土水特征曲线试验,通过电镜扫描从微观角度分析。研究结果表明:大孔隙的数量与饱和体积含水率呈正相关;中孔隙的数目与过渡区斜率的大小呈正相关,孔隙数目越多土体失水速度越快;微小孔隙的数目和土的塑性指数影响残余含水率的大小。对于不同深度土层,饱和体积含水率和过渡区斜率与土层的湿陷系数呈正相关;塑性指数接近土层的湿陷系数对残余体积含水率的影响不明显;古土壤层的SWCC与湿陷系数之间存在与黄土层相同的正相关性。文章从非饱和土力学的方向去研究黄土的湿陷性,为湿陷性的研究提供一种新的研究角度。This study investigates the correlation between the soil-water characteristic curve(SWCC)of undisturbed loess and its collapsibility.Undisturbed loess soil samples,obtained from depths up to 30 meters below the surface in Chang’an District,Xi’an City,Shaanxi Province,were taken for basic physical index tests and collapsibility assessments.SWCC analyses of loesspaleosol samples from different typical strata were conducted and analyzed using scanning electron microscope.The findings reveal a positive correlation between the number of macropores and saturated volumetric water content.Additionaly,the number of pores is positively correlated with the slope of the transition zone,indicating that a higher pore count accelerates the soil's water loss rate.The number of tiny voids and the plasticity index of soil affect the residual moisture content.For different soil layers,saturated volumetric water content and slope of transition zone exhibit a positive correlation with collapsible coefficient.The influence of collapsible coefficient of plastic index close to soil layer on residual volumetric water content is not obvious.The study also indicates a positive correlation between SWCC and the collapsibility coefficient of the loess layer.By approaching loess collapsibility from the direction of unsaturated soil mechanics,this paper introduces a novel research angle for the study of collapsibility.

关 键 词：原状黄土 双线法 土水特征曲线 电镜扫描 微观结构 

分 类 号：P694[天文地球—地质学]