失水过程中的土壤孔隙比―含水量―吸力关系  

The Unique Suction―Water Content―Void Ratio Relation during A Drying Process of Soil

作　　者：李旭[1,2] 林森[2] 

机构地区：[1]水资源与水电工程科学国家重点实验室(武汉大学),湖北武汉430072 [2]北京交通大学,北京100044

出　　处：《西北地震学报》2011年第B08期52-57,共6页Northwestern Seismological Journal

基　　金：水资源与水电工程科学国家重点实验室开放基金(2010B075);中央高校基本科研业务费专项资金(2009JBM065)

摘　　要：当土体总应力状态保持不变时,基质吸力的提高是导致孔隙水排水、土样体积收缩、孔隙结构改变的根本原因,通过吸力可以将土壤收缩曲线和土水特征曲线联系起来进行比对研究。采用广义有效应力原理分析超固结土样和正常土样的失水过程,结果表明:超固结土样中存在着相应的先期固结压力的吸力值,称之为先期固结吸力ψc。当土样吸力小于ψc时,超固结土样和正常固结土样的收缩曲线、土水特征曲线不同:超固结土孔隙比随吸力提高而减小的坡度较缓,约等于土样的回弹再压缩指数,土样处于结构性收缩阶段;先期固结压力越大,土水特征曲线的进气值越高。当土样吸力高于ψc时,超固结土样和正常固结土样的收缩曲线、土水特征曲线重合。During the drying process for soil under constant total stress,the increase of soil suction will induce the drainage of pore-water,the shrinkage of soil and the change of pore-structure.Through the soil suction,the comparison research on soil shrinkage curve with soil-water characteristic curve,can be done.The principle of extended effective stress is used to analyze the drying processes for normal consolidated soil and over-consolidated soil,the result demonstrates that there is a pre-consolidated suction value ψc according to the pre-consolidation pressure in the over-consolidated soil.If the soil suction is lower than the value the slope of a void ratio vs.suction curve is lower for the over-consolidated soil comparing to the normal consolidated soil,and is equal to the soil swelling index;a higher pre-consolidation pressure for the over-consolidated soil will induce a higher air entry value on the soil water characteristic curve（SWCC）.After the soil suction increases over the ψc value,the void ratio vs.suction curves of the over-consolidated soil and normal consolidated soil merge as well the SWCC.

关 键 词：土水特征曲线 土址收缩曲线 吸力 广义有效应力 干燥过程 

分 类 号：TU441.8[建筑科学—岩土工程]