基于板理论的公路混凝土槽形梁内力计算方法

为了研究适用于公路混凝土槽形梁行车道板内力的计算方法,将公路混凝土槽形梁比拟成带有边梁的弹性矩形薄板,考虑边梁的挠曲和扭转,运用功的互等定理,推导出槽形梁的挠曲面方程,求得行车道板弯矩及挠度的计算公式,提出了边梁抗弯刚度及抗扭刚度的合理计算方法。采用该方法对一足尺模型试验梁进行了计算,并分别采用有限条法、比拟板理论、梁理论对不同边梁高度的槽形梁模型在轮载作用下行车道板的内力进行了计算分析。研究结果表明：运用比拟板理论计算行车道板中部在轮载作用下的弯矩及挠度具有较高精度;相较于梁理论,比拟板理论可进一步反映截面尺寸变化对槽形梁内力的影响及其整体受力特点。

Calculation Method of Internal Force of Concrete U-shaped Girder Based on the Theory of Plate

In order to investigate the calculation method of internal force suitable for highway concrete U-shaped girder,with the concrete U-shaped girder being considered as an elastic rectangular thin plate with edge beams,considering the flexure and torsion of edge beams,using the reciprocal theory of works,the equation of deflectional surface was derived,and then the expressions of moment and deflection of deck were derived,and the appropriate calculation method of flexural rigidity and torsional rigidity was also put forward.A full scale model beam for test was calculated with this method,and the bending moments of deck with different beam height under wheel load were calculated and analyzed with finite strip method,the theory of plate and the beam theory.The results show that the theory of plate can be used to calculate the bending moment and deflection under wheel load accurately and can better reflect the influence on internal force induced by cross section differences,and the loading features of the whole structure,compared with the beam theory.