华北平原卸荷深层土体变形特性  

Characteristcs of Unloading Deep Soil Deformation in North China Plain

作　　者：孙琳[1] 王秀艳[1] 王志良[1] 孙珊[2] 

机构地区：[1]中国地质科学院水文地质环境地质研究所,石家庄050061 [2]中国地质大学(武汉),武汉430074

出　　处：《南水北调与水利科技》2012年第6期79-82,共4页South-to-North Water Transfers and Water Science & Technology

基　　金：中国地质科学院水文地质环境地质研究所基本科研业务费项目"开采地下水应力条件下华北土体微结构变化特征研究"(SK201010);国家自然科学基金项目"华北平原深层地下水超采引起的黏性土再固结效应研究"(40472139)

摘　　要：利用压缩试验,对在华北平原地区199～479m深处所取的深层砂土、粉土、黏土土样进行取样后卸荷的变形特性进行了研究。结果表明,荷载1 200kPa和3 200kPa,199～439m土样变形量分别在0.43～1.386mm和0.725～1.896mm间;不同岩性土变形量砂土>黏土>粉土,黏土回弹最强。变形过程分析发现,砂土变形压缩初期主要为孔隙压缩,后期主要为颗粒磨损;黏土变形为颗粒相对移动和破损交互作用结果;粉土变形主要为孔隙压缩。A compression test was carried out using deep soil （199~479 m） of North China Plain, whose unloading effects were caused by sampling from the deep ground, and the deformations of sandy soil, silty soil and clay soil were studied. The result showed that the deformations of soils taking from 199-439 m depth were 0. 43-1. 386 mm and 0. 725-1. 896 mm respectively under 1 200 kPa and 3 200 kPa loading. Comparison of the different soil samples resulted that deformation value of sandy soil was greater than that of clay soil, and that of silty soil was minimum. The analysis on deformation process revealed that deform- ation of sandy soil was mainly caused by compression of porosities at the beginning and caused by wear behavior of particle at the end, but it was caused by interaction effect of particle movement and breakage for clay soil, and by porosities compressed for slity soil.

关 键 词：压缩试验 土体变形 荷重 孔隙比 卸荷 疏干 

分 类 号：P641[天文地球—地质矿产勘探] TU43[天文地球—地质学]