桥墩及桩基形式对墩底平转施工转盘设计的影响

以新建福厦(福州—厦门)高速铁路17500 t转体刚构为背景,采用实体有限元方法分析了不同桥墩类型及桩基布置对墩底平转转体中转盘受力的影响,并对桥墩及桩基进行了优化。结果表明:实体墩对上转盘受力最有利,其次是空心墩,最不利的是双薄壁墩;增加墩底实体段能够有效降低空心墩、双薄壁墩上转盘的主拉应力;随着墩底实体段高度的增加,主拉应力降低的幅度逐渐变小;球铰正下方有桩基时对下转盘底部受力更加有利;距离球铰中心越远,桩基受力越小,适当增加中桩桩径,可使各桩基应力状态更加均衡。

Influence of Pier and Pile Foundation Types on Turntable Design in Pier Bottom Horizontal Swivel

Based on the newly built 17500 t rotating rigid frame of Fuzhou-Xiamen high speed railway,the influence of different pier types and pile foundation layout on the stress of the middle turntable in pier bottom horizontal swivel was analyzed by using the solid finite element method,and the pier and pile foundation were optimized.The results show that the solid pier is the most favorable for the upper turntable,followed by the hollow pier,and the most unfavorable is the double thin-walled pier.The increase of the solid section at the pier bottom can effectively reduce the main tensile stress of the turntable on the hollow pier and the double thin-walled pier.With the increase of the height of the solid section at the pier bottom,the decrease of the main tensile stress gradually decreases.When there is pile foundation directly under the spherical hinge,it is more favorable to the lower turntable bottom.The farther away from the center of the spherical hinge,the smaller the force on the pile foundation,and the proper increase of the diameter of the middle pile can make the stress state of each pile foundation more balanced.