DOI: 10.15986j.1006-7930.2019.03.009
非饱和土中孔隙水在不同含水量条件下的赋存状态各异,孔隙水的赋存状态随着土体含水量的增加可分为结合水状态、毛细角边水状态和毛细水连通状态.由不同类型的孔隙水所引起吸力的机理各不相同,对应于孔隙水的3种赋存状态,吸力可分为吸附作用力、吸附—毛细作用力和毛细作用力.吸附作用力可通过等温吸附试验确定,其试验原理和试验结果均较为明确.毛细作用力的计算原理虽较为明确,由于参数取值的困难致使难以通过理论计算获得准确的结果,但可通过高进气值材料测量.分析认为高进气材料较为适合量测毛细作用力,对高进气值材料不恰当的使用是造成土水特征曲线在低含水量段迅速上扬的主要原因.吸附—毛细作用力尚难以通过理论计算或试验获得准确的结果,该吸力在数值上介于吸附作用力和毛细作用力之间.
The occurrences of pore water in unsaturated soil are different with water content conditions, they were divided into bound water state, capillary edge water state and capillary water connected state with the increase of water content. The mechanisms of the different suction caused by different types of pore water were different. Corresponding to the three kinds of pore water occurrence, suction in unsaturated soil was divided into adsorption force, adsorption-capillary force and capillary force. The adsorption force can be determined by isothermal adsorption test, and the test principle and results are all clear. The calculation formula of the capillary force is explicit; however, it is difficult to obtain the accurate result by theoretical calculation due to the difficulties to obtain the parameter value. Nevertheless, the capillary force can be measured by high entry material. The results of analysis indicate that the high entry material is suitable for measuring the capillary force, and the improper use of the high entry material is the main reason for the rapid increase of the soil water characteristic curve in the low water content section. It is difficult to obtain accurate results of adsorption capillary force by theoretical calculation or experiment. The value of adsorption capillary force is between the adsorption force and the capillary force.
