南水北调中线工程膨胀土渠段改性土施工中存在的困难及对策研究

膨胀土水泥改性后换填是“十一五”期间提出的针对膨胀变形引起的渠坡破坏模式的处理方案之一。由于改性土施工技术难度大,施工工艺较复杂,国内施工队伍缺少现场改性土施工的实践经验,且在大规模膨胀土输水渠道中应用尚属首次,因此,该技术在实际施工中存在一定的困难和问题,为此,国家“十二五”科技支撑项目设置“膨胀土水泥改性处理施工技术”研究课题对其开展专门研究。以南水北调中线工程鲁山—郑州段膨胀土渠段的现场科研和施工工作为基础,分析膨胀土渠段改性土填筑施工中存在的料源、施工工艺、检测方法及检测标准等普遍存在的问题,通过开展现场试验和室内研究,提出了相应的解决方案和建议,研究成果可直接应用于南水北调中线总干渠膨胀土渠段的大规模施工。

Construction Difficulties and Countermeasures of Cement Modified Expansive Soil in Mid-route of South-to-North Water Transfer

The replacement by cement modified expansive soil is one of the measures to cope with the slope failure caused by expansive deformation. Since the construction technology of cement modified expansive soil is complex, and the construction team lacks on-site experience, there are some difficulties and problems in the construction. Therefore, it was researched by the Chinese national “Twelfth Five-Year Plan” Science and Technology Support Program Construction Technology of Cement Modified Expansive Soil. According to the site investigation and construction of the expansive soil canal of Lushan-Zhengzhou segment of the middle route of South-to-North Water Transfer Project, the main difficulties in the construction, such as material source, construction technique, inspection method, and inspection criterion, are analyzed. Through field test and laboratory research, countermeasures and suggestions are put forward. The research results can be directly applied to the large-scale construction of expansive soil segment of the middle route of South-to-North Water Transfer Project.