桥梁抗震规范中关于防落梁搭接长度的研究

Study on Overlap Length of Anti-falling Beams in Seismic Code of Bridges

摘要:

对于梁式桥，设置足够的墩梁搭接长度是防止上部结构发生落梁破坏的较为有效措施。基于我国城市桥梁和公路桥梁抗震设计规范中关于防落梁搭接长度的相关规定，对不同规范中常规直线桥、斜交桥和曲线桥的墩梁搭接长度计算方法进行比较和作图分析，指出了计算流程和公式上的异同。对于公路桥梁，总结了斜交桥和曲线桥搭接长度的计算流程，根据回转可能条件是否满足的几何关系推导了判断公式。研究成果可为桥梁设计人员理解和应用抗震规范进行实际工程设计提供参考。

Abstract:

For beam bridges, it is an effective measure to set enough overlap length of pier beam to prevent the superstructure from falling beam damage. Based on the relevant provisions on the overlap length of anti-falling beams in the codes for seismic design of urban bridges and highway bridges in China, the calculation methods of the pier and beam overlap length of conventional straight bridge, skew bridge and curved bridge in different codes are compared and analyzed graphically, and the similarities and differences in calculation flow and formula are pointed out. For highway bridges, the calculation flows of the overlap length of skew bridge and curved bridge are summarized, and the judgment formulas are derived according to the geometric relationships of whether the possible conditions of rotation are satisfied. The research results can provide reference for bridge designers to understand and apply the seismic codes for practical engineering design.