梁侧横向挡块间隙设置对桥梁结构抗震响应分析

Analysis on Seismic Response of Bridge Structure by Space Setting of Transverse Retaining Block on Beam Side

根据单墩横向简化力学模型,分析了桥梁横向各构件间的刚度关系;以一座装配式预应力混凝土T梁为分析对象,利用空间有限元分析软件Midas Civil建立4×50 m一联的三维模型,输入安评报告提供的3条地震波,研究其在不同挡块初始间隙下的地震响应。通过分析桥墩、桩基、挡块碰撞及支座剪切变形随初始间隙的变化规律,得出随着间隙的增大桥墩及桩基内力整体上均呈减小趋势,在强震下适当增大挡块初始间隙有利于桥梁抗震。但挡块的碰撞力与间隙的变化不是十分规律,因此随意选取间隙是不合理的,在特殊情况下可能是不安全的。

According to the transverse simplified mechanical model of the single pier, the rigidity relationship among the transverse components of the bridge was analyzed. Taking an assembling prestressed concrete T-beam as the analysis objective, Midas Civil 2019, a spatial finite element analysis software, was used to establish a 4×50 m 3 D model. Three seismic waves provided by the safety evaluation report were input to study their seismic response under different initial block spaces. Through the analysis of the change rules of pier, pile foundation,retaining block and bearing shear deformation with the initial space, it was concluded that the internal forces of the pier and pile foundation decreased as a whole with the increase of the space, and under strong earthquake,increasing the initial space of the retaining block was beneficial to the seismic resistance of the bridge. However,the collision force of the block and the change of the space were not regular, so it was unreasonable to choose the space randomly and might be unsafe under special circumstances.