考虑承插深度变化的预制拼装桥墩抗震性能试验研究

Experimental investigations on the seismic performance of prefabricated assembled piers considering the variation of socket depth

为研究承插深度对承插结构抗震性能的影响,设计制作了现浇桥墩以及考虑承插深度变化的装配桥墩,其中承插桥墩的承插深度分别为1.0 d(d为方墩边长)、0.8d以及0.6d。通过拟静力试验研究分析桥墩的破坏现象、滞回性能以及耗能能力等,讨论承插深度对桥墩的影响。试验结果表明:4组试件的峰值承载力相近;1.0 d承插桥墩具有与现浇桥墩类似的破坏现象与滞回曲线,抗震性能等同现浇桥墩;0.8 d承插桥墩、0.6d承插桥墩由于承台的损伤,延性弱于现浇桥墩。通过对比破坏现象,分析了现有配筋情况下,承台侧壁抗剪承载力与墩柱极限抗剪承载力之间的相对关系。当墩柱和承台配筋率不变的情况下,墩柱承插深度越小,侧壁抗剪承载能力越低,承台插槽的侧壁越容易发生因抗剪承载力降低而导致的损伤。因此,设计中承插深度的选择需要考虑墩柱与承台插槽侧壁承载能力相对大小关系,以避免损伤发生于承台位置。

To investigate the impact of socket depth on the seismic performance of socket structures,a group of a cast-in-place pier and precast piers considering the variation of socket depth were designed and fabricated,of which the socket depths of the socket piers were 1.0 d(where d represents the side length of the square pier),0.8 d,and 0.6 d,respectively.Pseudo-static tests were conducted to analyze the damage patterns,hysteresis performance,and energy dissipation capacity of the piers,allowing for an examination of the influence of socket depth on their behavior.The test results demonstrate that the bearing capacity of the four groups of specimens is similar.The socketed piers with a socket depth of 1.0 d exhibit damage patterns and hysteresis curves that are comparable to those of cast-in-place piers,indicating equivalent seismic performance.However,the ductility of the socket piers with embedment depths of 0.8 d and 0.6 d is weaker than that of the cast-in-place piers due to damage to the footing.By comparing the damage phenomenon,the relative relationship between the shear bearing capacity of the footing sidewall and the ultimate bearing capacity of the column is analyzed under the existing reinforcement ratio.As the socket depth of the pier decreases,the shear capacity of the groove sidewall decreases.This increases the probability of damage to the groove sidewall due to the reduced shear bearing capacity.Therefore,it is crucial to consider the relative relationship of the bearing capacity between the footing and the column when selecting the socket depth in the design to prevent damage in the footing position.