软土的含水率与界限含水量意义的讨论  

Discussion on Significances of Natural Moisture Content and Limit Moisture Contents of Soft Clays

作　　者：郭进京[1] 王芳[1] 赵光鹏[1] 

机构地区：[1]天津城市建设学院土木工程系,天津300384

出　　处：《岩土工程技术》2009年第1期26-29,共4页Geotechnical Engineering Technique

基　　金：天津市应用基础研究计划项目(07JCYJC13000)

摘　　要：鉴于软土的含水率、塑限、液限等工程性质指标的理论定义和试验测试结果不完全吻合,同时考虑到软土中不同形式的水对软土工程性质的不同影响和实际工程中应用习惯,建议废弃软土含水率的理论定义,而将软土含水率定义为软土中除强结合水外其它水的质量与土的固体颗粒质量之比,这里软土固体颗粒中粘粒定义为粘土矿物聚集体与其表层强结合水的组合体,这样使软土含水率理论定义与试验测试的结果相统一。软土的塑限(w_p)、液限(w_L)以及由此而派生的塑性指数(I_p)和液性指数(I_L)都是通过重塑土的测试获得的,未考虑软土天然结构对这些指标数值的影响,建议通过对软土结构研究,能提出一个结构影响系数,进而修正试验获得的数据,使这些指标更接近天然软土的实际。同时根据粘粒与水相互作用的特点和软土中各种形态水对软土状态和变形机制的影响,把塑限和液限的含义予以修正,塑限是软土中弱结合水的最小含量,而液限是弱结合水最大含量并有一定数量自由水。Based on the analysis for the differences between the theoretical definitions of w,wP and wL of soft clays and usually used their test values, in consideration of different water forms and their functions in soft clay, it is suggested that w should be redefined as the ratio of total water mass except for strong combined water and soil grain mass, where soft grain means the integrated particles of real soil grains and strong combined water. This definition can avoid the confusion between theoretical definition and test results. The limit moisture contents （wL ,wp） and deduced plastic and liquid indexes（ IL, Ip ）from limit moisture contents （wL, wP） are all obtained from remold soft soil test without considering the effect of the natural structure of soft soils for them. Therefore, it is proposed that introducing a structure coefficient which can get from structural study for soft soil, emends the wL, we, IL and Ip. Emended wL, wP, IL and IP will be conformed to natural soft soil engineering practice. Meanwhile, on the interaction between clayey particles and different form water in soft soils and different function of different form water for the soft soil deformation mechanism, implication of wL. and wp should be revised, that is, wp represents minimum weak combined water contents and wL represents maximum weak combined water contents with little free water.

关 键 词：软土 含水率 塑限 液限 水-土作用 

分 类 号：TU447[建筑科学—岩土工程]