材料性能劣化对RC墩抗震性能的影响

Influence of Material Performance Deterioration on Seismic Performance of RC Piers

摘要:

为了探讨混凝土和钢筋材料长期性能劣化后，桥墩的变形能力、延性水平等变化规律，以不同直径、不同轴压比、不同纵筋率以及不同服役年限条件下的圆形RC墩截面为代表，采用Ucfyber记录不同条件下RC墩截面的初始、等效、极限弯矩、曲率；研究了随着服役年限的增加，桥墩的最大容许转角和最大容许位移的变化规律，并探讨了墩柱直径、轴压比、纵筋率对桥墩抗震性能的影响。结果表明：在采用合适的轴压比和纵筋率条件下，桥墩的变形能力和延性水平等在整个服役期内会有明显的下降趋势，最大降幅在10%左右，并未存在因脆性而发生的突变，能够较好地满足由于地震动作用产生的变形要求。

Abstract:

In order to explore the variation laws of the deformation capacity and ductility level of bridge piers after the long-term performance deterioration of concrete and steel bar materials, taking the sections of circular RC piers under different diameters, different axial compression ratios, different longitudinal reinforcement ratios and different service life conditions as the representatives, the Ucfyber is used to record the initial, equivalent, ultimate bending moments and curvatures of RC pier sections under different conditions. The variation laws of the maximum allowable rotation angle and the maximum allowable displacement of the bridge piers with the increase of service life are studied. The influence of pier diameter, axial compression ratio and longitudinal reinforcement ratio on seismic performance of pier is discussed. The results show that the deformation capacity and ductility level of the piers will decline dramatically in the whole service period under the condition of adopting appropriate axial compression ratio and longitudinal reinforcement ratio. The maximum decline is around 10%. There is no sudden change due to brittleness, which can well meet the deformation requirements caused by ground motion.