西安地铁四号线南段大厚度湿陷性黄土浸水试验研究  

Xi'an metro line four South Thick Collapsible Loess of water immersion tests

作　　者：李开超[1] 高虎艳 郑建国[1] 王庆满[1] 姜梦林 LI kai - chao GAO hu -yan ZHENG jian - guo WANG qing - man JIANG meng - lin(China JK Institute of Engineering Investigation And Design Co, Xi＇an 710043, China Xi＇an Metro Ltd. , Xi＇an 710018, China)

机构地区：[1]机械工业勘察设计研究院有限公司,陕西西安710043 [2]西安市地下铁道有限责任公司,陕西西安710018

出　　处：《地下水》2017年第2期133-137,共5页Ground water

摘　　要：结合西安地铁工程国家重点建设项目,在西安地铁四号线南段塬区进行了试坑浸水试验,揭示出该区域大厚度自重湿陷性黄土具有独特特点,室内试验上部Q3黄土不具自重湿陷性,而下部Q2黄土自重湿陷性较为强烈,现场试坑浸水试验结果各沉降标点均未发生明显沉降变形,反而略有抬升;根据TDR土壤水分计监测结果发现古土壤层具有明显的隔水作用,水分入渗至该层有径向扩大的趋势,浸水影响范围是以试坑直径为圆台顶面,浸水影响范围形状类似一个倒置的漏斗;当水体自上而下入渗时,垂直向渗透较快,但随深度及土层性质的变化,渗透速率随即减缓;土体中由于基质吸力存在,开始孔隙水压力为负值,随着注水量增加孔隙水压力也随之变化,孔隙水压力变化与坑内水头变化一致。combined with the Xi＇an metro project of national key construction projects in Xi＇an, metro line four South table- land of test pit soaking test reveals that the region with large thickness self weight collapsible loess has unique characteristics, laboratory tests of Q3 loess with upper collapsible loess, and the lower Q2 collapsible more strongly the site, test pit water test results of each settlement punctuation were no obvious settlement, but a slight uplift; according to the TDR soil moisture meter monitoring results showed that the paleosol layer has obvious effect of water, water infiltration to the layer with the big trend of radial expansion, effect of flooding is a test pit diameter round table top effect of flooding range, funnel shaped like an invert- ed; when the water infiltration from top to bottom, the vertical penetration faster, but changes with depth and soil properties, and reduced infiltration rate In the soil, due to the presence of matrix suction, the pore water pressure is negative, the pore water pressure changes with the increase of water injection quantity, the change of pore water pressure is consistent with the change of the water head in the pit.

关 键 词：大厚度自重湿陷性黄土 湿陷变形特征 浸润线 渗透系数 孔隙水压力 

分 类 号：S152.7[农业科学—土壤学]