汽车荷载作用下空心板桥空间动力冲击效应

根据空心板桥结构特点,运用梁壳组合模型和铰接梁模型模拟空心板桥,考虑桥面不平顺影响,建立三维车桥耦合振动模型分析空心板桥动力特性,研究不同车速、行车道位置及路面状况对空心板桥冲击系数的影响,并将理论值与实测值进行对比.研究结果表明：空心板桥动力特性梁壳组合模型与实测值更接近;车速在12～16 m/s时,空心板桥位移冲击系数随速度有明显共振节拍,随着路面不平顺恶化,速度节拍影响不明显;位移冲击系数与应变冲击系数并不完全一致,跨中位移冲击系数略大于应变冲击系数,1/4位置应变冲击系数略大于位移冲击系数;实测与数值模拟的空心板桥冲击系数均满足现行规范要求.

Spatial dynamic impact effects of hollow slab bridge subjected to moving vehicle

According to the characteristics of hollow slab bridge,the bridge was simplified as shell and beam composite model and hinged girder model.A model of vehicle-bridge coupling vibration was proposed for resolution of dynamic interaction problem when the bridge with rough deck subjected to a vehicle running at a prescribed speed.Compared the theoretical value to the analysis value,the dynamic characteristics of the hollow slab bridge,vehicle speed,lane position,pavement behavior,the factors which affected the impact coefficient was researched.The results show that slab beam composite model was closer to the measured values in the dynamic characteristics.The hollow slab bridge displacement impact coefficient had obvious resonance beat as speed in 12 m/s ～ 16 m/s.As the deterioration of deck roughness,the resonance beat of speed weakened gradually.Displacement impact coefficient wasn＇t consistent with strain impact coefficient completely.Displacement impact coefficient was slightly larger than the strain impact coefficient in the cross,1/4 position impact coefficient caused by strain slightly larger than the displacement impact coefficient.The impact coefficients of the hollow slab bridge obtained through measuring and numerical simulating met the current criterion.