深水基础超长钢板桩围堰施工仿真及监测研究

Research on Construction Simulation and Monitoring of Super-long Steel Sheet Pile Cofferdam in Deep Water Foundation

五峰山过江通道芒稻河特大桥33#主墩位于芒稻河主航道中,基础采用36 m超长钢板桩围堰施工,其施工技术难度远超普通钢板桩围堰,施工期间围堰内外水头差高达19 m。为保证该深水基础超长钢板桩围堰的结构安全,建立了结构整体有限元模型,对施工过程进行仿真模拟计算。选取变形和应力较大的结构部位进行现场监测,并将各施工阶段的监测值与计算值进行对比分析,研究超长钢板桩围堰施工全过程结构内力和变形的变化规律。结果表明:超长钢板桩围堰各施工阶段的变形、应力均在允许范围内,计算值与实测值的变化趋势总体吻合较好。研究成果可为类似桥梁施工提供参考。

The 33#main pier of the Mangdaohe Bridge in Wufengshan Expressway crossing Yangzi River is located in the waterway of the Mandaohe River.The foundation is constructed with 36m super-long steel sheet pile cofferdam,which is much more difficult than the ordinary steel sheet pile cofferdam.The water head difference between inside and outside the cofferdam is as high as 19m during the construction.In order to ensure the safety of the super-long steel sheet pile cofferdam in deep water foundation,the finite element model of the whole structure is established and the simulation calculation is carried out during the construction.The structural elements with larger deformation and stress are selected for on-site monitoring,and the measured value and the calculated one in each construction stage are compared to study the change rule of the internal force and deformation of the structure during the whole construction process of the super-long steel sheet pile cofferdam.The results show that the deformation and stress of the super-long steel sheet pile cofferdam in each construction stage are within the allowable range,and the variation tendency of the calculated value and the measured value are generally in good agreement.The findings in this paper can provide additional input for the construction of the similar bridge.