止水帷幕侧向约束条件下黄土地基非饱和入渗

Infiltration in unsaturated loess foundation under the condition of lateral constraint of waterproof

以青海东部黄土区新建川大公路为依托,通过在坡脚处增设3排水泥土挤密桩来形成止水帷幕,并在坡脚处开挖浸水坑,以此来研究当坡脚积水时止水帷幕对黄土地基中水分场变化的影响。研究结果表明:止水帷幕未穿透湿陷性黄土下限深度时,由于侧向约束作用,水分在止水帷幕处理深度范围内只能沿竖向入渗,浸水9 d后绕过止水帷幕下端侵入内侧地基,坡脚、坡中处地基分别有约2 m和1 m厚的湿陷性黄土层被浸润,路肩处地基湿陷性土层未受影响;止水帷幕穿透湿陷性黄土下限深度时,水分被阻止未侵入止水帷幕内侧地基,止水帷幕具有良好的防排水效果。研究成果可为黄土地区地基处理提供参考。

Based on the newly founded road in the loess area of eastern Qinghai province, the effect of waterproof on the moisture changes of loess foundation was studied when waterlog at slope foot, by adding 3 rows Cement soil compaction pile as waterproof and evacuating soaking pit to simulate waterlog at slope foot. The results show that： when waterproof does not penetrate the lower limit depth of collapsible loess, moisture can only infiltrate vertically within the range of treatment of waterproof because of its constraint. After 9 days immersion, the moisture bypasses the waterproof and infiltrates to the foundation inside the waterproof. About 2 m thick of collapsible loess in the foundation of slope foot and 1 m thick in the foundation of middle slope are affected. While the collapsible loess in the foundation of the road shoulder isn’t affected. When waterproof penetrates the lower limit depth of collapsible loess, moisture is blocked and does not infiltrate to the foundation inside thewaterproof. Waterproof has satisfactory drainage effect. The study result can be referred by the foundation treatment in loess area.