大型储油罐碎石桩地基差异沉降有限元数值分析

为减少大型储油罐碎石桩地基差异沉降，采用轴对称有限元方法进行数值模拟和计算，研究了桩长、置换率、褥垫长度等参数对差异沉降的影响，及负向侧向位移与差异沉降的关系。结果表明，3个不等桩长的分布范围在某一定值时，差异沉降最小；油罐中心范围内复合地基，通过固定桩径不变，增加桩间距来增大置换率，可使复合地基在相对较小的置换率条件下获得更小的差异沉降；保持置换率不变，桩径越大（即桩间距越疏），复合地基差异沉降越小；调整桩长、置换率对差异沉降的改变较为明显，而改变褥垫长度对其影响不大；油罐地基负向侧向位移的出现是差异沉降调整的一个重要特征。

FEM Analysis of Differential Settlement of Gravel Pile Foundation Under Large scale Oil Tank

In order to reduce the differential settlement of gravel pile foundation under large-scale oil tank, axisymmetric numerical simulation method and finite element method was employed to study the pile length, the exchange rate of length, the length of the cushion course to the influence of differential settlement and the relationship of negative lateral displacement and the settlement. It is found that： differential settlement has a minimum range of pile length. For the oil tank foundation center, by keeping the pile diameter, increasing pile spacing can increase the rate of exchange and obtain smaller differential settlement in relatively smaller displacement rate conditions. And by keeping replacement rate unchanged, the larger the pile diameter（namely the looser pile spacing） is, the smaller the differences settlement of the gravel pile foundation is. Moreover, pile length adjustment and the exchange rate have obvious effects on different subsidence and not obvious effects on the length of the cushion course. The appearance of oil tank foundation negative lateral displacement is one of the most important features of differential settlement adjustment.