文档介绍:墩基本和柱刚度比 [双柱墩地震反映的轴力
摘 要:地震作用下钢筋混凝土双柱桥墩产生的动轴力不仅会变化桥墩的屈服强度,并且也会相应地变化桥墩的刚度,但目前广泛使用的集中塑性模型一般并未考虑这种轴力刚度的耦合伙用。以自动计入轴力强度墩基本和柱刚度比 [双柱墩地震反映的轴力
摘 要:地震作用下钢筋混凝土双柱桥墩产生的动轴力不仅会变化桥墩的屈服强度,并且也会相应地变化桥墩的刚度,但目前广泛使用的集中塑性模型一般并未考虑这种轴力刚度的耦合伙用。以自动计入轴力强度及轴力刚度耦合伙用的纤维模型分析成果为基准,研究了轴力刚度耦合伙用对钢筋混凝土双柱桥墩地震反映的影响。成果表白,轴力刚度耦合伙用对双柱墩弹性阶段的反映有较大影响,但不变化构造的极限承载力;由于拉压桥墩的刚度互为消长,等高双柱墩的地震位移响应在不计轴力刚度的耦合伙用时和实际状况只略有差别,但墩柱弹性内力响应则会被较大地低估;不等高双柱墩的刚度受较矮侧桥墩控制,因此轴力刚度的耦合伙用对构造的地震位移响应和弹性内力响应所有有明显影响,桥梁不规则性越大影响越明显,在进行构造分析时不能忽视这一因素的影响。
核心词:钢筋混凝土;双柱墩;地震反映;集中塑性模型;纤维模型;轴力刚度耦合伙用
中图分类号:TU 375
文献标志码:A
文章编号:1674-476404-0066-06
Axial Force-Stiffness Interaction in Seismic Analysis of RC Double-Column Bridges
WEI Bin1,2, LI Jianzhong1
Abstract:Earthquake induced dynamic axial force in reinforced concrete bridge bent columns will not only change the yield strength of the columns but also change their stiffness, which is seldom considered by the common lumped-plasticity line model. Based on the fiber element model results that taking into account the influence of dynamic axial force on strength and stiffness simultaneously, the axial force-stiffness interaction effect on the seismic responses of RC double-column bridges was analyzed. The results show that, axial force-stiffness interaction has a large effect on the seismic responses of the double-column bridge in the elastic range, and it does not alter the ultimat