采空巷道上方桥梁群桩基础受力特性数值分析

Numerical Analysis on Force Characteristics of Pile Group Foundation for Bridge over Laneway along Goaf

以合肥至福州高速铁路采空巷道上方官山底特大桥群桩基础为对象,采用FLAC3D软件分析采空巷道上方桥梁群桩基础在荷载作用下的受力特性,得出不同工况下群桩的桩轴力、桩侧摩阻力、桩间土应力、桩顶应力和桩荷载分担比等受力规律。研究结果表明:在承台刚度较大,桩身较长的情况下,采空区对桥梁群桩基础受力影响不大,群桩基础能很好地对采空区进行处理。

Taking the Grand Guanshandi Bridge over the laneway along the goaf under the high-speed railway from Hefei to Fuzhou as the object, analyzed the force characteristics of pile group foundation for such bridge under load with FLAC3D software, and then concluded the force rules under different conditions, including axial force, side friction, pile-soil stress, top stress and load sharing ratio of the piles. The study results show that in case of large cap rigidity and long pile length, the mined-out area has minor effect on force of the pile group foundation for bridge, and the pile group foundation may tackle the mined-out area well.