轻型桥台自身平面内的弯曲分析与参数的合理取值

轻型桥台自身平面内的弯曲问题通常采用Winkler地基上Bernoulli-Euler梁理论来进行分析,以对称中心的弯矩和基底应力作为最大值进行验算。考虑轻型桥台的剪切变形影响,采用Winkler地基上Timoshenko梁理论进行分析,得到了最大弯矩偏离对称中心,且比对称中心弯矩大得多;以对称中心弯矩作为最大值进行设计不安全;目前桥梁工程文献所推荐的设计验算方法值得探讨等结论。分析了最大弯矩随剪切刚度和基床系数、最大弯矩位置随襟边宽度的变化规律,探讨了以桥台基础不隆起为条件的襟边宽度合理取值问题。

Flexure Analysis and Parameter Optimization of Light Type Abutment in Self-plane

The theory of Bernoulli-Euler beam on Winkler elastic foundation was adopted to analyze light type abutment flexure in self-plane. The moment and foundation stress of symmetrical center were assumed as the maxima for checking computations.  Considering the shear deformation influence, the theory of Timoshenko beam on Winkler elastic foundation was used to analyze the flexure. It is concluded that (1) the maximal moment deviates from the symmetrical center, and  it is greater than the moment at the symmetrical center; (2) It is unsafe to take the moment at symmetrical center as the maximal design moment, and the current method and the design process recommended by bridge engineering literatures are unsafe and deserved to discuss. Maximal moment changing with shear stiffness and foundation modulus as well as position of maximal moment changing with width of footing tread were analyzed. Based on the condition of upheaval, rational width of footing tread is studied.