摘要
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.
引文
[1]Cofer W F,Zhang Y,McLean D I.A comparison of current computer analysis methods for seismic performance of reinforced concrete members[J].Finite Elements in Analysis and Design,2002,38(9):835-861.
[2]Taucer F F,Spacone E,Filippou F C.A fiber beam-column element for seismic response analysis of reinforced concrete structures[R].EERCReport 91/17,Earthquake Engineering Research Center,University of California,Bekerley,CA,1991.
[3]Powell G H,Chen P F.3D beam-column element with generalized plastic hinges[J].Journal of Mechanical Engineering,ASCE,1986,112(7):627-641.
[4]Sfakianakis M,Fardis MN.Bounding surface model for cyclic biaxial bending of RC sections[J].Journal of Mechanical Engineering,ASCE,1991,117(12):2748-2769.
[5]Roufaiel MS L,Meyer C.Analytical modeling of hysteretic behavior of R/C frames[J].Journal of Structural Engineering,ASCE,1987,113(3):429-444.
[6]Spacone E,Filippou F C,Taucer F F.Fibre beam-column model for non-linear analysis of R/C frames:Part I.Formulation[J].Earthquake En-gineering and Structural Dynamics,1996,25(7):711-725.
[7]Spacone E,Filippou F C,Taucer F F.Fibre beam-column model for non-linear analysis of R/C frames:Part II.Applications[J].EarthquakeEngineering and Structural Dynamics,1996,25(7):727-742.
[8]McKenna F,Fenves G L.The OpenSees command language manual.Pacific Earthquake Engineering.Research Center,University of California,Bekerley,CA,2001.
[9]Prakash V,Powell G H,Campbell SD.DRAIN-2DX:Static and Dynamic Analysis of Inelastic Plane Structures[R].NISEE,Earthquake Engi-neering Research Center,University.of California,Berkeley,CA,1993.
[10]禚一,李忠献.钢筋混凝土纤维梁柱单元实用模拟平台[J].工程力学,待发表.
[11]Mohd-Yassin MH.Nonlinear analysis of prestressed concrete structures under monotonic and cyclic loads[D].University of California,Berke-ley,1994.
[12]Scott B D,Park R,Priestley MJ N.Stress-strain behavior of concrete confined by overlapping hoops at lowand high strain rates[J].ACI Struc-tural Journal,1982,79:13-27.
[13]Kent D C,Park R.Flexural members with confined concrete[J].Journal of the Structural Division,ASCE,1971,97(7):1969-1990.
[14]Blakely R W G,Park R.Prestressed concrete sections with cyclic flexure[J].Journal of the Structural Division,ASCE,1973,99(8):1717-1742.
[15]司炳君,李宏男,王东升,等.基于位移设计的钢筋混凝土桥墩抗震性能试验研究(Ⅰ):拟静力试验[J].地震工程与工程振动,2008,28(1):123-129.
[16]Papanikolaou V K,Kappos A J.Numerical study of confinement effectiveness in solid and hollow reinforced concrete bridge piers:Methodology[J].Computers&Structures,2009,87(21-22):1427-1439.