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为研究简支梁桥在地震荷载作用下的碰撞响应和各因素对碰撞响应的影响程度,以一座3跨简支梁桥为研究对象,对桥梁碰撞响应的影响因素进行了动力非线性时程反应分析,得到了以下分析结果:纵向地震下,碰撞不会显著增大简支梁桥墩底的剪力和弯矩,但巨大的撞击力会给桥梁结构带来诸多不利影响;接触单元模型中碰撞刚度的取值对撞击力的正确模拟至关重要,碰撞刚度取值不同基本上不会改变结构的地震响应;梁体间的撞击力对邻梁间隙反应敏感,随着邻梁间隙的增大,撞击力和撞击次数逐渐减小,墩底剪力和弯矩逐渐增大;随着墩高比的增大,墩底剪力和弯矩不断减小,墩顶位移呈增大趋势,撞击力变化较大,但当相邻跨墩高相差不大时,撞击力相对而言要小得多;将不同的地震动峰值加速度调整到相同时,简支梁桥的地震响应差异很大。
In order to study the impact response of simply supported girder bridge under the earthquake load and the impact of various factors on the impact response, a 3-span simply supported girder bridge is taken as the research object to study the influencing factors of the bridge’s impact response under dynamic nonlinear time-history The results of the analysis are as follows: Under longitudinal earthquake, the collision will not significantly increase the shear and moment of the pier bottom, but the huge impact force will bring a lot of adverse effects on the bridge structure. In the contact element model The correct value of the impact stiffness is very important to correct the impact force. The different values of the impact stiffness basically do not change the seismic response of the structure. The impact force between the beams is sensitive to the gap of the adjacent beam. The impact force and the number of impact decreases gradually, and the shear and bending moment at the pier bottom gradually increase. With the increase of pier height ratio, the shear and moment at the pier bottom decrease and the displacement at pier top increases. The impact force varies a lot, but the impact force is relatively smaller when the adjacent pier height difference is not big; when the different peak ground acceleration acceleration is adjusted to the same, the seismic response of simply supported girder bridge varies greatly .