振冲碎石桩与CFG桩组合桩型复合地基试验研究

摘要

The vibro-replacement stone columns are mainly used to treat the shallow-layer soil and generate one kind of composite foundation in order to reinforce the bearing capacity of the foundation,decrease the settlement and eliminate the sand liquefaction.The CFG pile is settled at the centroid of four gravel columns and the tip of the CFG pile is deep in the hard layer,which plays an important role in controlling the bearing capacity and the displacement of the composite foundation.This paper researches the composite foundation consisting of the vibro-replacement stone columns and the CFG piles before and after the treatment by the static sounding test,the dynamic sounding test and the static load test.The results indicate that the vibro-replacement stone column in the combinedpile composite foundation largely increases the bearing capacity of the single CFG pile and the soil layer,and the smaller the distance between piles,the greater the strengthening effects will be.%振冲碎石桩主要加固浅层地基,与桩间土构成复合地基,使地基承载力提高、变形减少,并可消除砂土层的液化;CFG桩布置在4根碎石桩的形心,桩端置于相对硬层,对复合地基的承载力和变形起控制作用.对某工程试验区振冲碎石桩与CFG桩组合桩型复合地基加固前后静力触探、动力触探和静载荷试验等进行研究,结果表明组合桩型复合地基中的碎石桩较大程度地提高了CFG桩的单桩承载力和地基承载力,桩距越小,加固效果越好.