大体型旋转移位工程桩基上轨道梁有限元分析

Finite Element Analysis of Track Beams above Piles in Rotation Transportation Project of Large Size Building

本文结合福建濠景大厦复杂旋转移位工程,简单介绍了濠景大厦旋转平移工程轨道梁设计方案,并对轨道梁进行了内力分析.轨道梁、管桩、地基分别采用梁单元、铰支座和弹簧单元模拟,采用SAP2000软件建立了有限元计算模型,讨论了地基基床系数、弹簧单元间距、沿弧向桩数、轨道半径和桩间距对轨道梁内力的影响.分析表明：桩间地基对桩基上轨道梁内力影响不大;为减少建模工作量,可以适当放大弹簧单元间距;轨道半径对轨道梁弯矩影响不大,但对扭矩影响显著,建模计算时建议取趋于稳定的12～16根桩作为弧形轨道梁的计算范围;随着桩间距的增大,轨道梁的内力值显著增长;轨道半径对弯矩随桩距变化的增长幅度影响不大.将弧形轨道梁简化为直线的内力分析结果表明,简化后内力值误差较大,算例内力最大误差达到28％,故不宜采用直线形简化方法.

Combined with complex rotation and moving project of Haojing Building,the design scheme of track beam is introduced and the internal force is analyzed.The finite element model is established by using SAP2000 software,the track beams,piles and foundation beam are respectively simulated with beam elements,the hinged bearing and spring unit,the effect on internal force of track beams by coefficient of subgrade reaction,spring unit spacing,number of piles along the arc,orbital radius and pile spacing is discussed.The results show that：Soil between piles have little effect on internal force of track beam upper piles;In order to reduce the modeling work,spring element spacing can be properly amplified;It＇s not obvious for the impact of orbit radius towards track beam bending moment,but a significant impact on torque,so it is suggested to take between 12 and 16 piles as a curved track beam calculation range; With the increase of pile spacing,internal force value of track beam has significant growth; The impact of orbit radius towards bending moment with pile distance increasing is not big.If the curved track beam is simplified as linear type,the internal force calculated would be significant difference from no simplified,the difference reaches 28％ in example.