强夯法在排水固结加固后地基工程中的应用

Application of Dynamic Compaction for Foundation AlreadyConsolidated by Drainage Compaction

通过对地面变形、孔隙水压力的监测,分析了强夯施工时地基的有效变形率随夯击次数的变化规律及夯点的分布情况,以及强夯作用下土体中孔隙水压力的增长和消散规律,从而进一步找到了孔压增量与夯点距离的关系、孔隙水压力与深度的关系,及孔隙水压力的消散过程。并通过试夯验证和确定设计技术参数,施工后检验结果表明采用该法处理排水固结后地基对消除粗粒料过大的孔隙比、提高地基承载力、减少残余沉降和差异沉降都有极大的作用。

Through monitoring of ground deformation and pore pressure, we analyzed the variation law of effective deformation rate of foundation with the changing of tamping times and distribution of tamping points during dynamic compaction construction, and increasing and disappearing law of pore pressure in soil under dynamic compaction, based on which, we found the relation between increment of pore pressure and space be tween tamping points, relation between pore pressure and the depth, as well as the disappearing process of pore pressure. Through trial tamping, we verify and determine the design parameters. The examination results after construction revealed that by adopting this method for treatment of foundation already consolidated by drainage consolidation is very effective for eliminating the pore ratio, improving foundation bearing capacity, reducing residual settlement and differential settlement.