摘要
针对西北地区非饱和黄土存在的增湿湿陷问题,利用非饱和固结仪对石灰改良黄土进行无应力测吸力和控制基质吸力的压缩试验,研究了不同石灰含量及不同干密度石灰改良黄土土水特征、压缩特性,以及增湿变形和湿陷变形特性。研究结果表明:石灰含量对非饱和黄土的土水特征曲线影响不大,但干密度对石灰改良黄土的土水特征曲线影响较大;压缩指数和屈服应力都随着吸力的增大而增大,回弹指数随吸力的变化几乎不变;同一竖向压力下,初始吸力越大,湿陷系数越大,湿陷起始压力都随着初始吸力的增大而减小,而最大湿陷系数和最大湿陷压力却都在增大;当石灰含量超过3%时,ds(p=200 kPa)小于0.015,说明石灰改良黄土已基本消除湿陷性,具有工程应用意义。
Aimed at the collapsibility of unsaturated loess in Northwest China,an unsaturated consolidation instrument is used to test matric suction and to conduct compression test of lime loess.Different contents of lime are added with different dry densities of the loess;various characteristics of the improved soil,including soil-water characteristic,compression property,moistening and collapse deformation,are measured and examined.Results show that lime content has little effect on the soil-water characteristic curve of lime-improved loess,while dry density produces a great influence.Compression index and yield stress increase with the increase in matric suction,while the expansion index is nearly independent of it.Under the same vertical pressure,the collapsibility coefficient increases with initial suction.As initial matric suction increases,initial collapse pressure decreases,while both the maximum collapsibility coefficient and highest collapse pressure increase.When lime content exceeds 3%,the collapsibility coefficient ds(p=200 kPa)will be less than 0.015,indicating that the collapsibility of lime-improved loess is nearly eliminated,which can be useful in engineering application.
作者
梁志超
胡再强
郭婧
王凯
冯哲
折海成
LIANG Zhichao;HU Zaiqiang;GUO Jing;WANG Kai;FENG Zhe;SHE Haicheng(Institute of Geotechnical Engineering,Xi'an University of Technology,Xi'an 710048;Key Laboratory of Destruction Mechanism and Control Technology of Earth and Rock Dam of Ministry of Water Resources,Nanjing 210024)
出处
《水力发电学报》
EI
CSCD
北大核心
2020年第3期66-75,共10页
Journal of Hydroelectric Engineering
基金
水利部土石坝破坏机理与防控技术重点实验室开放基金(YK916006).
关键词
非饱和
石灰改良黄土
土水特征曲线
增湿变形系数
湿陷系数
unsaturation
lime-improved loess
soil-water characteristic curve
Humidification deformation coefficient
collapsibility coefficient
作者简介
梁志超(1993—),男,硕士生.E-mail:2170720016@stu.xaut.edu.cn;通信作者:胡再强(1964—),男,教授.E-mail:huzq@xaut.edu.cn
