南水北调中线工程膨胀土边坡处理效果及评价

为研究膨胀土边坡在膨胀作用下的破坏形式及边坡处理方案,针对不同工况进行了现场模拟试验与监测。系统总结了膨胀土边坡处理的施工技术;从边坡变形、含水率变化2个方面,全面分析了水泥土改性、土工格栅加筋、土工膜封闭、土工袋填筑4个工况的边坡处理效果。结果表明:水泥改性土(换填非膨胀黏性土)处理效果最好;土工格栅加筋主要存在施工工艺较为复杂的问题;土工袋填筑存在压实度难以控制的问题;土工膜封闭主要由于没有压重处理,效果最差。最后总结并提出了膨胀土边坡处理原则。

Effectiveness of Treatment Measures for Expansive Soil Slope in the Middle Route of the South-to-North Water Transfer Project

According to the failure mode of expansive soil slope induced by expansion effect and the monitoring result of on-site simulation test, we summarize the techniques of expansive soil slope treatment. Furthermore, we compare and analyse the effectiveness of four treatment measures (cement soil modification, geogrid reinforcement, geomembrane, and geotextile bags filling) by evaluating the slope deformation and the variation of moisture content. Results reveal that cement soil (replacement of non-expansive clayey soil) has the best performance, whereas geogrid reinforcement is featured with complex techniques, and the compaction degree of geotextile bags filling is hard to control. Finally, we put forward the principles of expansive soil slope treatment.