基于FENAP平台的RC高桥墩破坏过程模拟及分析

Simulation and analysis of damage process of RC high bridge piers based on FENAP platform

为精细模拟钢筋混凝土高桥墩在静力推覆荷载作用下的破坏过程,本文基于钢筋混凝土精细化纤维梁柱单元模型分析平台FENAP,对一实际的西部山区空心截面高桥墩进行了Pushover分析,通过对构件、截面和纤维层次的力-位移关系曲线分析,模拟了桥墩从墩底混凝土开裂、纵筋屈服到受压区混凝土压碎的完整破坏过程。并将FENAP平台与OpenSees计算结果进行对比,结果表明,FE-NAP平台可有效地模拟高墩在静力推覆荷载下的破坏过程和软化行为,具有较高的求解精度。进一步比较了不同轴压比、是否考虑约束混凝土效应及纵筋屈曲效应等因素对分析结果的影响,得出结论,轴压比和约束混凝土效应对高桥墩的破坏过程发展有较大影响,而纵筋屈曲效应影响较小,可忽略不计。

In order to simulate the damage process of RC high bridge piers under static pushover loading,on the basis of the simulation analysis platform FENAP of RC fiber beam-column element,a practical high pier of mountain hollow bridge has been modeled and analyzed by using pushover analysis procedure.The complete damage process from concrete crack at the bottom of the pier to buckling of reinforcement to concrete crush at the compression zone is simulated according to the analysis of the force-displacement curve at structural member level,section level and fiber level.And the comparison results of OpenSees and FENAP show that FENAP could simulate the damage process and softening behavior of the high bridge piers effectively,and has a good precision.Furthermore,the influence of axial force ratio,concrete confinement effect and longitudinal reinforcement buckling effect are compared.The results show that the axial force ratio and confinement effect would significantly affect the damage process of high bridge pier,however,the effect of longitudinal reinforcement is small enough to be neglected.