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.