上拔荷载作用下挤扩支盘桩颗粒流数值模拟

摘要

基于颗粒流理论,采用PFC2D程序,研究粘土地基中挤扩支盘桩受上拔荷载时,荷载-桩体位移关系、土体变形破坏情况及地基位移场分布.结果表明:荷载与桩体位移变化曲线分为初始弹性阶段、中间塑性阶段和破坏阶段;土体破坏产生的滑裂面主要从下部支盘的端部沿斜上方向地表发展;土体颗粒受影响区域为倒钟形.%Based on particle flow theory, load-pile displacement relationship, soil deformation and distribution of foundation displacement field when squeezed branch pile under uplift loading in clay foundation are sludied using PFC2D program. The resulls show [hat load-pile displacement curve is classified into initial elastic stage, intermediate plastic stage and failure stage. Sliding face caused by soil failure is mainly from the tip of lower branch into ground surface along oblique direction. Soil particles are affected within inverted bell-shaped area.