不同预制梁台座对软基差异沉降的影响分析

Influence of Different Precast Beam Pedestal on Differential Settlement of Soft Ground

在软基路段上建造预制梁场,合理的布设预制梁台座能有效地减小软基差异沉降。采用有限元软件Midas/GTS建立三维计算模型,分析不同预制梁台座布设形式对软基差异沉降的影响。结果表明:当梁台座按横向排布时,梁场中部的梁台座总沉降量与每2m长度上的最大差异沉降量均比外侧要大,且每2m长度上最大差异沉降量较纵向排布大,建议优先纵向布设预制梁台座;当台座采用扩大基础时,台座总体沉降量比浅基础明显减小,最大沉降量由11.6mm降低至8.5mm,台座的2m长度上的不均匀沉降量由0.41mm降低至0.12mm,建议优先选用扩大基础台座。

A proper layout of precast beam pedestals can effectively reduce the soft ground differential settlement in construction of the precast beam pedestal field on the soft ground section.The finite element software Midas/GTS was adopted to create a three-dimension calculation model for analysis of the influence of the different precast beam pedestal on the soft ground differential settlement.Results show that when the beam pedestals are arranged in the lengthwise direction,the middle one’s total settlement and the maximum differential settlement over each 2 mlength is greater than the outside ones,with the maximum differential settlement over 2 mlength larger than that in the widthwise arrangement;thus it is recommended to employ the widthwise arrangement.When the spread foundation is adopted,the overall settlement of the pedestal is significantly reduced from that in the shallow foundation,with the maximum settlement reduced from 11.6 mm to 8.5 mm,and the differential settlement over each 2 mlength of the pedestal reduced from 0.41 mm to 0.12 mm.It is recommended to use the spread foundation in priority.