不同影响因素下非饱和红土土-水特征曲线的试验研究

Experimental study of the soil-water characteristic curve of unsaturated laterite under different affecting factors

以江西典型的红土为研究对象,利用GEO-Experts压力板仪进行不同影响因素下红土的土-水特征曲线试验研究。研究内容包括不同粒径、不同干密度、不同含水率、不同预固结压力、脱湿和吸湿循环以及反复脱湿和吸湿循环对土-水特征曲线的影响;通过三种常用的SWCC模型(Brooks和Corey模型、van Genuchten模型及Fredlund和Xing模型)对试验数据进行拟合和分析,找出适合江西典型红土的土-水特征曲线方程,并提出了模型中参数的取值范围;本文还提出了土-水特征曲线的双曲线模型,该模型对计算残余含水率非常方便,参数变化范围小,容易选取。

The soil-water characteristic curve of the typical laterite in Jiaugxi is tested with the GEO-Experts pressure plate apparatus under different affecting factors. The influence of different particle sizes, dry densities, water contents, pre-consolidation pressures, moisture and moisture absorption cycle, repeated moisture and moisture absorption cycle on soil-water characteristic curve is examined. The suitable soil-water characteristic curve equation for the Jiangxi typic laterite can be obtained with the experimental data fitted by three kinds of commonly used SWCC model （Brooks and Corey model, van Genuchten model and Fredlund and Xing model）. The scope of model parameters of soil-water characteristic curve is put forward. Finally, this paper puts forward a hyperbolic curve model of SWCC. It is very convenient to calculate the residual moisture content, and the parameter variation range for this model is small and easy to select. The results are used as reference for engineering practice.