粉煤灰含量对砂土中毛细水上升规律的影响

Effect of fly ash content on capillary water rise law in sandy soil

毛细水对土壤中水分运移和盐分变化有重要的影响作用。通过对5种不同粉煤灰含量的砂土进行室内竖管法毛细水上升高度试验,得到掺加粉煤灰的砂土中毛细水上升高度与时间关系曲线。结果表明,掺加粉煤灰砂土中毛细水的上升过程可以分为快速上升期、缓慢上升期和稳定期3个阶段;粉煤灰含量越大,毛细水上升前两个阶段持续的时间越长,持续时间与粉煤灰含量之间可用二次多项式进行拟合。采用幂函数对试样中毛细水上升高度随时间变化关系进行拟合,获得了毛细水上升高度计算式。试验范围内毛细水最大上升高度随着粉煤灰含量的增加而线性增大,建立了2者之间的回归方程式。

Capillary water has a significant influence on moisture migration and salt dynamics. The relationship between the rising height of capillary water and time was obtained from the comprehensive tests on the rising height of capillary water in sandy soil with five kinds of different fly ash contents using the method of standpipe. The results show that capillary water rise process can be divided into three stages including fast rise,slow rise and plateau stage. The corresponding times of the first two stages increase with the increase of fly ash content,and the relationship between rise time and fly ash content can be fitted as quadratic polynomial. The relationship between rising height of capillary water and time can be better fitted by the power function,and thus the calculation equations are obtained. The largest rising height of capillary water linearly increases with the increase of fly ash content.