南水北调中线工程改性土余料再利用研究

摘要

The useable soil sources for the most bidding sections of Middle Route Project of South to North Water Diversion are insufficient and using cement-mixed modified soil to replace the canal soil is a main measure for guaranteeing the canal slope stability. In the backfilling construction, large amount of surplus modified soil was produced after slope cutting and the indoor and field tests discovered that the surplus modified soil could be used as backfilling soil. In the test, the selection method of the maxi-mum dry density, construction technology and application scope of the modified soil were determined. The soil re-utilization has increased backfilling soil sources in weak expansive soil area, which could save farmland, resources and protect environment.%南水北调中线工程大部分标段可用土料源不足，采用弱膨胀土掺入水泥(简称水泥改性土，下同)后对膨胀土渠段进行换填施工，是确保膨胀土渠段边坡稳定的主要措施之一。在填筑施工中，按设计坡比削坡后产生大量的改性土削坡余料，通过室内试验及现场试验验证了改性土余料亦可用于工程回填。为此，确定了改性土余料最大干密度的选择方法、改性土余料的施工工艺及使用部位。对余料土的再利用，保证了弱膨胀土地区土方施工的回填料源，避免或减少了农田占压面积，取得了节约资源与保护环境的双重效果。