非饱和原状土与重塑土土-水特征曲线对比研究  

COMPARATIVE STUDY OF SOIL-WATER CHARACTERISTIC CURVE FOR UNSATURATED UNDISTURBED SOIL AND REMOLDED SOIL

作　　者：刘熙媛[1,2] 刘永前[1] 周建彪[1] 梁金国[2] 窦远明[1] 

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]河北建设勘察研究院有限公司,石家庄050031

出　　处：《工业建筑》2017年第7期109-113,共5页Industrial Construction

基　　金：河北省建设科学技术研究计划项目(2015-24)

摘　　要：土-水特征曲线(SWCC)是反映非饱和土工程特性的重要表现形式。由于原状土的取土及试验过程较为繁琐,所以现有非饱和土分析大多用重塑土,而重塑土的土-水特征曲线与原状土的特征曲线的对比研究还不充分。通过对石家庄地区非饱和原状土与同条件下的重塑土土-水特征曲线的测定,分析抽气饱和过程对SWCC的影响,对比原状土与重塑土的进气值、排水速率、排水量大小、残余饱和度对应的基质吸力、固结时间的量化差异。研究结果表明:抽气饱和对SWCC影响不大;原状非饱和土的进气值要低于重塑土的进气值;试验中由于原状土中有历史形成的大孔隙,土-水特征曲线的斜率比重塑土大,排水速率在试验前期大于重塑土;但原状土的排水量没有因这些大孔隙而比重塑土大;原状土达到残余饱和状态时的基质吸力比重塑土小;原状土比重塑土达到残余状态早、达到残余饱和度所需时间短。在此基础上,得到了更适合于石家庄地区区域性非饱和土土-水特征曲线的三参数拟合方程。Soil-water characteristic curve（ SWCC） is the improtant form to reflect the mechanical characteristic of unsaturated soil. Because the sampling and testing process both are complex for undisturbed unsaturated soil,the studies used to adopt remolded soil. However,the comparative analysis of the soil-water characteristic curve between the undisturbed and the remolded was not enough. Therefore,the SWCC of unsaturated undisturbed soil and remolded soil in Shijiazhuang area were mensurated under the same condition. The influence of the saturation process by pumping gas on SWCC was analyzed. The differences were compared from air-entry value,drainage rate,water discharge volume,the matric suction for the residual saturation,and consolidation time between the undisturbed and the remolded. The results showed that the saturation process had little influence on SWCC. The air-entry value of the undisturbed was lower than that of the remolded. In existence of the historical formed large pores in the undisturbed,the gradient of SWCC and the water discharge rate for it were larger than that of the remolded in the early stage of experiment. But the water discharge volume of the undisturbed was not larger than that of the remolded. When the residual saturation state was reached,the matric suction of the undisturbed was smaller than the remolded. The time to the residual state for the undisturbed was less than that of the remolded. Based on the research results,the three parameters fitting equation was obtained,which was more suitable for the SWCC of the unsaturated in Shijiazhuang area.

关 键 词：非饱和土 土-水特征曲线 原状土 重塑土 

分 类 号：TU43[建筑科学—岩土工程]