干湿循环下重塑黄土水分迁移试验

(1.西安科技大学 建筑与土木工程学院,陕西 西安 710054; 2.中国铁路设计集团有限公司 工程经济设计研究院,天津 300124)

干湿循环; 重塑黄土; 水分迁移; 高填方工程; 含水率; 湿润峰

Moisture transfer test of remolded loess under drying-wetting cycle
YE Wan-jun1,LIU Kuan1,DONG Xi-hao1,LI Qian2,WANG Yan1

(1.College of Civil and Architectural Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.China Railway Design Group Co.,Ltd.,Institute of Engineering Economic Design,Tianjin 300124,China)

drying-wetting cycles; remolding loess; moisture transfer; high filling engineering; moisture content; wet peak

DOI: 10.13800/j.cnki.xakjdxxb.2018.0609

备注

黄土地区高填方工程改变地下原有给排水体系,土体长期处于干湿循环状态引发系列工程病害。为了阐明不同干湿条件下重塑黄土水分迁移规律,在干湿环境下对初始干密度和含水率不同的土样进行了水分迁移试验,结果表明:土体在干湿环境下,水分迁移导致含水率变化呈径向分区分布,上部土体含水率略低于下部; 减湿过程,水分不断迁移,随迁移高度的增加,含水率分布逐渐稳定; 干湿次数增多,土体持水能力弱化,水分上移速度减慢,湿润峰爬升的最大高度降低; 土体初始干密度越小,湿润峰推进速度越快; 初始含水率越大,水分迁移速率越快,但稳定后,土体最终含水率差异不大,并且随着距底板高度的增加呈下降趋势; 干湿环境下水分迁移也受水分重分布及土颗粒结构重组等多方面的影响,初始含水率和干湿循环次数不同,主导因素也不同,土体水分迁移规律呈现出相应的多样化特征。

The high fill project in loess area changes the original underground water supply and drainage system,and a series of Engineering diseases are caused by the long-term drying-wetting cycle of soil.In order to clarify the law of water migration in remolded loess under different drying-wetting conditions,the soil samples with different initial dry density and moisture content were tested under drying-wetting conditions.During the process of moisture reduction,the water content migrates continuously,and the distribution of water content becomes stable gradually with the increase of the height of moisture migration; with the increase of the number of times of drying and wetting,the water holding capacity of the soil decreases,the velocity of water moving up slows down,and the maximum height of wetting peak climbing decreases; the smaller the initial dry density of the soil,the faster the advance speed of wetting peak; the larger the initial water content,the faster the water content.The faster the migration rate is,but after stabilization,the final water content of the soil is not very different,and it tends to decrease with the increase of the height from the floor.Water migration in drying-wetting environment is also affected by water redistribution and soil particle structure reorganization,the initial water content and the number of drying-wetting cycles are different,and the dominant factors are different.The law of water migration showed different characteristics.