【摘要】 某客运专线某标段采用CFG桩加固技术。对CFG桩进行了低应变动测、单桩承载力试验、复合地基承载力试验及理论计算。结果表明:一类桩占93.9%,二类桩占6.1%;单桩承载力及复合地基承载力特征值均大于设计值。建立了三维有限元模型,模拟分析了CFG桩顶及桩间土应力随加载水平的变化关系以及CFG桩及桩间土应力分担比。模拟结果表明:1)随着荷载的增加,CFG桩顶应力及桩间土应力也随之增大,但CFG桩顶应力的增长速率大于桩间土;2)加载初期,CFG桩与桩间土应力分担比逐渐增大,且增长速度较快;随着荷载的增加,桩土应力分担逐渐趋于稳定。更多还原

【Abstract】 The CFG pile is used to consolidate the foundation in one passenger dedicated line.The field experiments including low strain dynamic testing,bearing capability of single pile and the composite foundation are done,and the bearing capability of composite foundation is calculated,too.The results show that the first and second class piles account for 93.9% and 6.1% respectively,and the bearing capability eigenvalues of single pile and composite foundation are larger than the designed values.The 3D FEM model is established to simulate the stresses of CFG pile top and inter-pile soil changing with load level,and the stress ratio between CFG pile and inter-pile soil is analyzed,too.The following results are got from the calculation results of FEM: 1) the stresses of CFG pile top and inter-pile soil increase with load level,but the increasing rate of the former is larger than the latter;2) the stress ratio between CFG pile and inter-pile soil increases quickly when the load level is low,and it tends to convergent gradually with load increasing.更多还原