【摘要】 为准确计算钢筋混凝土桥墩位移延性,计入P-Δ效应,对传统的塑性铰模型进行修正。基于MATLAB程序,编制了计算钢筋混凝土桥墩截面弯矩~曲率曲线和水平荷载~位移曲线的程序;利用自编程序,计算了考虑和未考虑P-Δ效应的钢筋混凝土桥墩的位移延性系数,并与基于塑性铰模型计算得到的位移延性系数进行比较;通过定义一个反映P-Δ效应对位移延性系数影响的修正系数,分析了轴压比、剪跨比和曲率延性系数3个参数对该修正系数的影响,得到了相应的回归公式,并将回归公式计算的结果与已有试验数据进行比较。结果表明:编制的MATLAB程序计算结果可信;P-Δ效应对钢筋混凝土桥墩位移延性有较大影响,而塑性铰模型本身不能很好地反映P-Δ效应,需要修正;修正系数随3个参数变化有明显规律性;对于具有良好延性的桥墩,回归公式具有较好的计算精度。更多还原

【Abstract】 To exactly calculate the displacement ductility of reinforced concrete bridge piers,the P-Δ effect is taken into account in the modification of plastic hinge model.Based on the MATLAB program,the programs for calculating the bending moment-curvature curve and the horizontal load-displacement curve of the sections of reinforced concrete bridge piers are compiled,to calculate the displacement ductility factors for the reinforced concrete bridge piers with the consideration and without the consideration of P-Δ effect.The results of the calculation were compared with those calculated from the plastic hinge model.The influences of the three parameters of axial press ratio,shear-span lengh ratio and the curvature ductility coefficient were analyzed,by defining a modification coefficient that can reflect the influence of P-Δ effect on displacement ductility coefficient.The related recursion formula was acquired,and the results calculated by the regression formula were compared with the existing testing data.The results of the comparison indicate that the data gained from the compiled MATLAB program are reliable,P-Δ effect has great influence on the displacement ductility of reinforced concrete bridge piers,but the plastic hinge model itself can not reflect the P-Δeffect well,necessitating modification.The modification coefficient shows distinct regularity following the variation of the three parameters.For the bridge piers with good ductility,the regression formula exhibits sound calculating precision.更多还原