基于非饱和渗流理论的土石坝渗流分析

针对考虑土壤非饱和区且设有排渗系统对水库渗流影响研究不足的问题,结合工程实际,采用非饱和渗流分析方法,对设有集水廊道的土石坝渗流进行研究。结果表明:土壤非饱和区的存在导致大坝单宽流量增大,浸润线抬升;考虑非饱和渗流的影响研究渗流问题更符合工程实际情况,弥补了饱和渗流研究存在的不足,丰富了已有的渗流研究成果;此外,采用设置集水廊道的排水措施能够有效地降低坝内和下游河床浸润线,减少下游浸没区范围,有利于大坝整体抗滑稳定和后期安全运行。

Numerical Simulation of Earth-rock Fill Dams Seepage Field Considering the Effect of Unsaturated Soils

At pres-ent, the effect of drainage system on saturated-unsaturated seepage is little investigated under the condition of unsaturated soil in a dam. In present study, the aim is to investigate the change of seepage field in earth-rock fill dam with the collec- tion gallery on the basis of saturate-unsaturated theory. The results showed that the discharge of seepage per unit width and phreatic line increased owing to the effect of unsaturated soil. The saturate-unsaturated theory which was used to analyze seepage field in earth-rock fill dam was more reasonable than that of saturated theory. It made up even for the harshness of saturated seepage theory and enriched its achievements. Moreover, the results indicated that the collection gallery increased seepage gradient and could lead to seepage failure in some local region. However, the application of collection gallery reduced phreatic line in a dam and downstream riverbed of the dam. It decreased submerge areas in the downstream of the dam and could help to improve the anti-slide stability and safe operation of the dam.