匝道桥的计算方法及设计要点

Calculation Methods and Design Key Points for Ramp Bridges

高等级公路互通立交中的匝道桥由于受线形及纵坡限制具有斜、弯、坡、异形等特点。故相比于直梁桥的"弯、剪"作用,匝道桥处于"弯、剪、扭"的复合受力状态。在结构计算时应考虑复合受力状态;设计的上、下部结构也应采取有利于"弯、剪、扭"的措施。文章结合具体工程实际,介绍此类桥梁的结构计算方法及主要设计要点,以供设计人员参考。

Owing to restriction from geometry and longitudinal slope, ramp bridges of high grade highway interchange projects are featuring inclination, bending, slope and abnormality.In contrast with bending-shear action to straight girder bridges, ramp bridges are subjected to combined action of bending-shear-torsion, which will be taken into account during performing structural calculations.Moreover, superstructure and substructure shall be designed in such a way that it is in favor of resisting combined action of bending-shear-torsion. This paper gives a brief description of structural calculation methods and key design points for ramp bridge combined with experience in design of ramp bridges and practice in handling some technical issues.