套护筒间碎石填充对桩基荷载传递的FLAC-PFC耦合数值模拟

FLAC-PFC Coupling Numerical Simulation of Load Transfer of Pile Foundation by Casing Gravel Filling

以贵南高铁某桥梁桩基套护筒间填充碎石保持长桩垂直度为工程背景,研究碎石对桩基荷载传递的影响,通过碎石孔隙率模拟填充松紧,建立了碎石不同填充松紧程度下的FLAC-PFC桩基荷载传递耦合数值模型。数值分析结果表明,竖向荷载主要依靠桩端阻力承担,桩周碎石竖向位移较大,随孔隙率增加而增大,水平位移较小,与孔隙率关系不大。

Taking as the project background of the gravel filling between pile casings of a bridge in Guinan High-Speed Railway to maintain the perpendicularity of long piles,a research has been conducted on the impact of gravel filling on the load transfer of pile foundation.Based on a simulation test of the filling tightness of gravel porosity,an FLAC-PFC pile foundation load transfer coupling numerical model is established under different levels of filling tightness.The numerical analysis results show that the vertical load is mainly borne by the pile end resistance with a large vertical displacement of the gravel around the pile,which is proportional to the increase of the porosity;meanwhile,the horizontal displacement tends to be small,which has little relationship with the porosity.