直排式与抽水式固结在地基加固中的联合应用

Application of Combination Wick-Drain Direct Connection and Vacuum Pre-Loading Methods in Soil Improvement of Dredger Fill

针对新近吹填土＂三高一低＂的特性,无法直接铺设砂垫层、施打排水板进行真空预压地基处理的问题,结合浙江苍南围垦区吹填与地基处理工程实例,提出了浅层直排式与深层抽水固结联合使用的真空预压处理方法。该方法采用排水板直接连接真空滤管的直排式对浅层浮泥进行处理形成表面硬壳层,再在硬壳层上进行深层抽水固结预压处理。通过理论计算与现场监测数据分析,处理效果显著,达到了处理的目的。通过初步经济效益分析,认为该处理方案有助缩短工期、节省材料、降低造价,特别是在砂源紧缺、新近吹填土上施工困难等方面优势显著。

The new dredged fill has the characteristics of high thickness,highly compressible,high water content and low permeability.The conventional sand blanket could not be placed for the drainage and as the construction access for the wick drain installation and other activities.This paper presents a case study of Reclamation and Soil Improvement of Dredged Fills of Cangnan,Zhejiang.The combination of wick-drain direct connection and vacuum pre-loading consolidation methods are introduced.This innovative approach is to install the wick drain and connects the wick drain directly to the vacuum pumps.A relatively hard crust at the surface could be formed due to the dewater effect.The vacuum pre-loading method was followed on top of the crust.The prediction results were compared with the construction monitoring results.It is concluded this method achieved satisfactory results.The advantages are：shorter construction periods,cost effective,and material savings,especially,in areas that sand supplies need to be imported.