桥梁抗震挡块的研究进展探讨

Discussion on Research Progress on Bridge Seismic Shear Keys

桥梁挡块作为桥梁重要的横向限位装置,在地震作用下可以约束主梁位移,避免落梁震害发生,但现有抗震挡块设计规定存在一些不足,影响其理想作用的发挥。对常见的三种破坏形式的混凝土挡块和耗能型钢挡块进行破坏机理和力学性能模型分析后发现,挡块设计应有可靠的屈服强度和耗能机制,以减小主梁的横向位移和墩台的地震响应。相比传统的混凝土挡块,滑移剪切破坏形式的混凝土挡块以及耗能型钢挡块在抗震设计中的强度和耗能机制更可控,更适合在实际工程中推广应用。针对这些挡块的构造形式和承载能力,值得开展进一步深入研究。

As an important restrainer for bridges,bridge shear keys can restrain the lateral displacement of girders and avoid the damage from falling girders during earthquakes,but there are some deficiencies about the current shear keys design regulations,influencing their function.The results from analysis on the failure mechanism and mechanical performance model of concrete shear keys with three types of failure and energy-absorbing steel shear keys show that the shear key design should have reliable yield strength and energy dissipation mechanism to reduce the transverse displacement of the girders and the seismic response of the pier and abutment.Compared with the traditional concrete shear key,the concrete shear key in slip shear failure mode and the energy-dissipation steel shear key are more controllable in terms of strength and energy dissipation mechanism in seismic design,more suitable for popularization and application in practical engineering.Their structural form and bearing capacity are worthy of further research.