降低滑坡地下水位的充气截排水法最佳充气压力研究

 充气截排水技术拟在潜在滑坡后缘或长边坡坡体上进行充气，在后缘来水路径上形成非饱和区，截断后缘汇水或减少后缘水流向坡体内的入渗，从而降低坡体内的地下水位，提高边坡的稳定性。为了探讨充气气压对充气截排水效果的影响，通过二维数值模型对不同气压下坡体水位变化进行分析，并通过物理模型试验对数值模拟结果进行验证，得出如下结论：在坡体中充气能显著降低坡体地下水位，截流减渗效果明显；对于特定坡体，存在与之对应的截排水起始充气压力和最佳充气压力；只有当充气压力大于截排水起始充气压力时，充气截排水才有效果，坡体前缘水位才会下降；当充气压力介于起始充气压力和最佳充气压力之间时，随着气压的增大，坡体前缘水位不断降低，充气截排水效果随气压增大而增大；当充气压力大于最佳充气压力时，充气截排水效果随气压增大而减小。

Research on optimal air filling pressure for groundwater blocking and draining in slopes

he method of drainage cutoff by air filling is a new approach to improve the stability of slopes. Injecting the compressed air into the saturated soil slope forms an unsaturated zone which can prevent the water entering into the critical failure surface of the slope. In this study，laboratory experiment and numerical simulation were carried out to investigate the relationship between the air pressure and interception effect. Results show that the air filling has remarkable effect on water flow interception. For a given slope，there exist a start-up pressure and an optimal pressure of air filling. When the air pressure is greater than the start-up value，the water table can be lowered. When the pressure ranges between the start-up and optimal values，the water table decreases with the increase of air pressure. However，when the air pressure is higher than the optimal value，the water table increases with the increase of air pressure.