复杂群桩基础冲刷计算方法研究

为研究公路桥梁群桩基础的冲刷计算,根据我国现有公路桥梁群桩基础的现状,详细分析、研究各类群桩布设情况下的河流的阻力特性、流态、流速分布以及泥沙运动性态。研究结果表明,在复杂布设群桩条件时,存在四种冲刷机理:纵向掩蔽作用、纵向冲刷联动作用、横向阻力增大作用和横向冲刷联动作用。并根据该研究结果,修订完善目前我国行业标准《公路工程水文勘测设计规范》中,桥墩非黏性土的局部冲刷计算公式中边界条件不合理部分,在原公式中仅考虑群桩横向排列影响系数的基础上,进一步提出同时考虑群桩横向和纵向排列的综合影响系数。并用实桥数据进行验证后,提出了复杂群桩基础冲刷计算的推荐公式。这一结论使原有冲刷计算公式更加趋于合理,从而能运用于复杂群桩基础的冲刷计算。为非黏性土群桩基础的局部冲刷计算提供有价值的参考依据。

A Study on Erosion Calculation Method of Complex Pile Group Foundation

In order to study erosion calculation of pile group foundations,the resistance characteristics,flow state,flow velocity distribution and sediment movement form under different pile group placement which based on the current situation are analyzed.The results show that: there are four erosion mechanisms when layout complex pile group: longitudinal masking effect,longitudinal erosion linkage effect,transverse increasing resistance effect and transverse erosion linkage effect.Based on this result,the unseasonal parts of boundary conditions for local erosion calculation formula of non-viscous soil of the standard "Hydrological Specification for Survey and Design of Highway Engineering" are revised.Besides,considering simultaneously transverse and longitudinal arrangement influence coefficient is advised.After verifying by real bridge data,the recommendation formula for erosion calculation of complex pile foundation which makes the primary formula more reasonable are proposed.So the reference for the calculation of non-viscous soil pile group is offered.