粉煤灰和聚丙烯酰胺固沙效果的风洞试验

寻找经济高效的固沙措施对于防治风沙危害具有重要意义。该文采用室内风洞试验,研究了不同粉煤灰施用率(10%,20%和30%)的固沙效果及在粉煤灰最佳施用率的基础上不同聚丙烯酰胺(PAM)施用率(0.05%和0.1%)对其的强化作用。试验研究结果表明,沙土施加粉煤灰后起动风速显著提高,施加PAM进一步小幅提高其起动风速;粉煤灰施用率为20%的沙土可以最有效地抵御8m/s净风和风沙流历时10min的吹蚀;施加粉煤灰的沙土在14m/s净风和风沙流历时10min的吹蚀条件下发生中度风蚀,其风蚀率随着粉煤灰施用率的增大而呈逐步降低的趋势;施加粉煤灰和PAM的沙土可以有效地抵御14m/s风沙流历时30min的吹蚀;从经济意义上考虑,推荐粉煤灰施用率为20%和PAM施用率为0.05%的用量水平处理用于风蚀防治。

Wind tunnel experimental study on sand-fixing effect of fly ash and polyacrylamide

Searching for an effective and economical sand fixation measure has important significance in wind erosion control. Wind tunnel experiments were conducted to study the sand-fixing effect of fly ash at three different application rates (10%, 20% and 30%) and the intensifying action of polyacrylamide (PAM) at two different application rates (0.05% and 0.1%) on it on the basis of the optimum fly ash application rate. The results indicated that fly ash increased the threshold wind speed of the treated soil significantly, which was further increased by PAM slightly. The soil treated with 20% fly ash could most effectively withstand pure wind and sand-carrying wind with a wind speed of 8 m/s for 10 min respectively. Moderate wind erosion occurred after exposure to pure wind and sand-carrying wind with a wind speed of 14 m/s for 10 min respectively, and there was a decline in the wind erosion rate with the increase of fly ash application rate. The soil treated with 20% fly ash and PAM could effectively withstand sand-carrying wind with a wind speed of 14 m/s for 30 min. 20% fly ash application rate and 0.05% PAM application rate were recommended to realize effective and economical wind erosion protection.