欠压密饱和黄土基本物理力学性质研究  

Study on basic physical and mechanical properties of uncompacted saturated loess

作　　者：康佐 亢佳伟 邓国华[2,3] KANG Zuo;KANG Jia-wei;DENG Guo-hua(Xi’an Rail Transit Group Co.,Ltd.,Xi’an,Shaanxi 710018,China;Institute of Geotechnical Engineering,Xi’an University of Technology,Xi’an,Shaanxi 710048,China;Xi’an Loess Underground Engineering Technology Consulting Co.,Ltd.,Xi’an,Shaanxi 710000,China)

机构地区：[1]西安市轨道交通集团有限公司,陕西西安710018 [2]西安理工大学岩土工程研究所,陕西西安710048 [3]西安黄土地下工程技术咨询有限公司,陕西西安710000

出　　处：《岩土力学》2023年第11期3117-3127,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52178355)。

摘　　要：黄土浸水可形成两类工程性质差异较大的压密饱和黄土或欠压密饱和黄土。通过对西安地区22个黄土场地的试验和数据统计,分析了两类饱和黄土性质的差异,系统地研究了欠压密饱和黄土的基本物理力学性质,揭示了其具有饱水软弱性和失水大变形的根本原因,归纳得到了西安地区欠压密饱和黄土的物理力学特征指标,为科学研究和工程实践中严格区分两类饱和黄土、分类制定技术措施提供了依据。研究表明:欠压密饱和黄土是黄土浸水过程中未被充分压密、大孔隙结构仍然存在的土,在Q_(3)和Q_(2)上部地层中均有揭露,其具有大孔隙比、高含水率、中高灵敏度、中高压缩性、低承载力和强度等特征,一般处于软塑或流塑状态,其与湿陷性黄土、古土壤和压密饱和黄土邻近分布,形成了软硬不均的地层组合特征。Immersion of loess can form compacted saturated loess or uncompacted saturated loess,and their engineering properties are significantly different.Based on the tests and data statistics of 22 loess sites in the Xi’an area,this paper systematically studied the basic physical and mechanical properties of the uncompacted saturated loess for the first time,revealed the fundamental reasons for its water-saturated weak property and large deformation due to water loss,and summarized the physical and mechanical characteristics of the uncompacted saturated loess in Xi’an area.The above research results can provide a basis for scientific research and engineering practice to strictly distinguish two types of saturated loess and formulate technical measures by classification.It is concluded that:uncompacted saturated loess is a kind of soil in which collapsible loess is not fully compacted,and macropore structure still exists in the immersion process.It is exposed in Q_(3) loess or the upper part of Q_(2) loess.It has a large void ratio,high water content,medium and high sensitivity,medium and high compressibility,low bearing capacity and strength,and is generally in soft plastic or flow plastic state.It is distributed adjacent to the compacted saturated loess,collapsible loess,and paleosol,forming a combination of soft and hard strata.

关 键 词：饱和黄土 欠压密特性 物性状态 力学特性 

分 类 号：TU444[建筑科学—岩土工程]