混凝土芯砂石桩的单桩承载力时间效应分析

在饱和软黏土地基沉桩过程中,挤土桩桩周土体将遭受相当大的挤压应力并引起很高的超静孔隙水压力，桩周土体超静孔隙水压力的消散，使桩周土体有效应力相应地增长，单桩承载力在间歇期内也会随着时间而逐渐增加。基于挤土桩沉桩过程所产生的挤土效应，运用圆孔扩张理论和固结理论分析了新型软基处理技术-混凝土芯砂石桩的挤土性状，并与软基处理中常用的CFG桩作了比较，从单桩侧摩阻力的时间效应方面分析了混凝土芯砂石桩的优越性。

Analysis of time effect of bearing capacity of concrete-cored sand-gravel piles

When driving piles in the saturated soft foundation, soil surrounding pile will bear high squeezing stress which will cause high excess pore pressure. When the excess pore pressure dissipates, the effective stress in soil surrounding pile will increase accordingly, and the bearing capacity of the pile will be heightened gradually in this period. Considering the squeezing effect in the progress of sinking pile, the squeezing behavior of the concrete-cored sand-gravel pile is analyzed by applying cavity expansion method and consolidation theory. The squeezing effect of the concrete-cored sand-gravel pile is strikingly weaker, and its superiority is also revealed by analyzing the time effect of single pile lateral frictional resistance.