船撞作用下苏通大桥群桩基础水平承载力分析

Analysis on Horizontal Bearing Capacity of Main Pylon Pile Group Foundation of Su-tong Bridge under Vessel Impact

针对船撞桥问题,以苏通大桥北塔群桩基础为研究对象,建立了船撞桥破坏准则,运用m法及FLAC3D有限差分软件,对不同工况下群桩基础的水平承载力进行了分析,并得到了桩顶剪力的分布规律。结果显示,数值模拟计算结果更加符合实际情况;海水冲刷深度对基础水平承载力影响很大,而不同的碰撞方向对基础水平承载力影响较小;在船撞力作用下,桩顶剪力分布不均,但不同工况下分布规律一致,在角点处桩顶剪力达到极大值。

The main pylon pile group foundation of Su -tong bridge was taken as a reasearch object, aiming at the vessel - bridge collision problem, the failure criterion of bridge was established. Analysis on horizontal bearing capacity of pile group under different conditions was performed, using ＂m＂ method and FLAC3D program. The shear force distribution on the top of piles was studied. The results show that the numerical calculation tallies with the actual situation compared with ＂m＂ method. The scour depth has great influence on horizontal bearing capacity of the pile group, but the impact direction has little influence. The shear force on top of piles is uneven distributed under the vessel impact, but the distribution keeps consistent under different conditions. The shear force on the top of comer piles reachs the maximum.