基于土体固结流变的桩基长期沉降数值模拟

通过考虑上海饱和土体的固结流变特性以及桩端压缩层为砂土的三层土层剖面,运用有限元分析程序ABAQUS,对钻孔桩基和打入桩基的沉降特性进行了模拟分析,并对浅层砂土的存在对两种桩基的影响进行分析。通过引入小孔扩张理论模拟打桩引起的超静孔隙水压力,模拟验证施工效应对桩基沉降的影响,并基于打桩施工对浅层砂层的挤土效应,模拟分析了浅层砂土对减少打入桩基沉降的作用。

NUMERICAL SIMULATION OF LONG-TERM SETTLEMENT OF PILE FOUNDATION CONSIDERING CONSOLIDATION AND RHEOLOGICAL PROPERTIES OF SOILS

By considering consolidation and rheological characteristics of Shanghai saturated soils and three soil layers calculated model in which the compressible strata of pile toe is sand,the numerical simulation of settlement characteristics of bored pile and driven pile foundation is carried out by FEM software package(ABAQUS) and the effects of sand layer surrounding the pile in shallow depth on both kinds of pile foundations are analyzed.The effects of piling effect on pile foundation settlement are effectively verified in accordance with the usage of cylinder expansion theory to simulate the excess pore water pressure induced by pile driving.Finally,based on the displaced soil effect in shallow sand layer surrounding the pile induced by pile driving,numerical simulation of positive action of shallow sand strata surrounding the pile to reduce the driven pile foundation settlement is also presented.