近断层地震动作用下钢筋混凝土桥墩的抗震性能

Performance of reinforced concrete bridge pierssubjected to near-fault ground notions

通过对满足规范延性要求的12根典型钢筋混凝土桥墩试件的线性和非线性地震反应分析,指出在近断层地震动作用下满足延性需求与延性能力比小于1 0的桥墩仍可能发生严重破坏和倒塌,若考虑桥墩的地震损伤性能,允许的延性需求与延性能力比不宜超过0 6～0 8。讨论了桥墩延性抗震设计中强度折减系数Rμ和设计基底剪力系数BSC取值问题。

Ductile behavior and damage performance of RC bridge piers designed by using Chinese Highway Engineering Seismic Design Code (JTJ004-89)are evaluated by elastic/inelastic time history analysis when they are subjected to near-fault ground motions.The ductility capacities of 12 piers included in the study all were test by quasi-static cyclic loading previously.It is found that piers with ductility demand/ capacity ratio less than 1.0 may sustain heavy damage and even collapse.If damage performance is considered,the ductility demand/capacity ratio should not exceed the range in value from 0.6 to 0.8.The reduced coefficient and the design shear coefficient for ductile seismic design of RC bridge piers subjected to near-fault ground motions are also discussed.