山区桩柱式桥梁基桩破坏模式和受力分析

The force analysis and failure mode of bridge pile-columns in mountain area

在西部山区修建公路或铁路时,桩柱式桥梁基桩应用非常广泛.受山区水文地质环境的影响,基桩的破坏模式和受力状况尚存在着一定的差异.首先,根据山区桩柱式桥梁基桩的承载状况,分析了基桩在水平推力作用下的破坏模式.其次,根据桥梁基桩的受力特性,建立了基桩受力分析的简化计算模型,导得了基桩内力与位移计算的挠曲变形微分方程及其幂级数解答.最后,通过对大坝二号桥中1#～6#墩中的基桩进行计算分析发现,本研究计算结果与现行规范法计算结果差别较小,它们的最大误差不足10%,验证了该计算方法的可靠性.此外,利用本研究方法设计的桥梁基桩,其内力与变形均能满足上部结构对基础的要求.

Pile-column-supported bridge foundation is widely adopted in projects of building roads and railways in western mountainous regions. Due to the influence of geo- logical environment of mountainous area. Firstly, the concise calculation mode of pile force is established based on its bearing characteristics. Secondly, the deflection differen- tial equations and its power series solution are deduced. Lastly, through the calculation and analysis of 1~ ~6~ abutments of Daba bridge 2 ~ , the calculation results using this method show small difference between the calculation results using present code meth- od,with a margin less than 10%,by which the reliability method is testified. Besides, bridge pile foundations designed by this method meet both the force and deformation re- quirements which the superstructure had on the foundation.