公路混凝土弯箱梁桥的动反应

分析了公路混凝土连续弯箱梁桥在车辆动荷载通过粗糙桥面时的动反应.分别应用拉格朗日方程和模态叠加法推导车辆和桥梁的振动方程,二者在接触点处满足接触力和位移的协调条件.分析采用一个三维三轴汽车,模拟为具有11个自由度的非线性模型,车辆结构包括车体、悬挂体系和轮胎.假定桥面等级为好,并采用功率谱密度函数进行随机过程模拟.研究四种不同曲率半径的弯箱梁桥的不同位置在三种不同行车路线、六种不同行车速度下的动反应.结果表明:弯桥的动反应与直桥是不一样的;尽管随着曲率半径的增大,弯箱梁桥的竖向弯曲基频也随之增大,但冲击系数并不完全遵循该规律.

Dynamic response of highway concrete curved box girder bridges

Dynamic response of highway concrete continuous curved box girder bridges due to vehicles moving across rough bridge decks is analyzed.Dynamic equations of vehicle and bridge have been developed by meant of Lagrange Formulation and mode superposition theory,which satisfy the geometrical compatibility conditions and equilibrium conditions of the interaction forces at contact points.A 3D nonlinear three-axle vehicle model is developed which consists of 11 independent degrees of freedom.Vehicle parameters include the body,suspensions,and tires.The bridge deck is assumed to be good and the road surface is generated from power spectral density function.Dynamic response of different locations of curved box girder bridges with four types of radius were investigated subjected to three different traffic conditions and six different traffic speeds.Results show that dynamic behavior of curved box girder bridges is different from that of straight bridge.Results also show that the natural frequencies of curved box girder bridges increase with the increase of radius,but the impact factors do not follow this rule fully.