深层搅拌桩复合地基的现场试验研究

结合雍六高速公路长江二桥江北接线工程 ,对填土荷载下复合地基的应力、变形特性进行了长期现场观测研究 .结果表明 :路基经深搅桩加固后 ,沉降变形得到有效控制 .加固区沉降量较小 ,下卧层沉降量较大 ,总沉降量满足设计及规范的要求 ;柔性路堤下桩与桩间土的沉降规律有差别 ,桩身上部桩周土沉降较大 ,随着深度增加 ,桩周土沉降逐渐小于桩的沉降 ,在这个过程中 ,桩与桩周土存在等沉面 ;在填土加荷过程中 ,桩与土各自分担的应力处在动态的变化之中 :加荷时 ,桩上应力相对集中 ;间歇期 ,桩土应力比减小 ;体现了荷载传递过程中桩与土是相互协调作用的

Field experimental study on composite foundation with deep mixing piles

A long term observation was performed for the north part connection of the Second Yangtze River Bridge Project at the Yongliu Highway to disclose the stress and deformation of the composite foundation under fill loading. The results show that the settlement induced deformation of the subgrade was effectively controlled after consolidation with deep mixing piles, that the settlement of the consolidated region was small, the settlement of the substratum was large, and the total settlement satisfied the requirement of the design criterion, that the settlement of the soil between the piles decreased with increasing depth and gradually became smaller than that of piles, and a settlement contour of piles and the soil around piles existed in this process, and that the stresses of piles and soil changed dynamically: in the loading process, stresses of piles were relatively concentrated, and during the interval, the pile soil stress ratio reduced, reflecting the coordinated action between piles and soil in the process of loading transfer.