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为研究大跨度斜拉桥倒Y型混凝土主塔横向破坏机理和弹塑性性能,选取典型大跨度倒Y型混凝土主塔斜拉桥,基于OpenSees非线性有限元平台,建立了考虑主塔弹塑性的非线性全桥有限元模型;以3组实测地震记录为地震动输入,采用动力增量分析方法(IDA)进行研究分析。研究结果表明:在不同实测地震动输入下,斜拉桥混凝土主塔横向屈服在横梁上侧截面,并由核心混凝土外侧钢筋拉应变控制,而破坏则在塔底或横梁上侧截面,并由核心混凝土外侧混凝土压应变控制;倒Y型混凝土主塔横向在地震中可形成3段塑性区域;斜拉桥混凝土主塔截面应考虑箍筋约束效应影响,该效应能明显增强混凝土主塔横向塑性性能,提高主塔横向抗震性能。
In order to study the transverse failure mechanism and elastoplastic performance of inverted Y-shaped concrete pylon of long-span cable-stayed bridge, a typical long-span inverted Y-type concrete pylon cable-stayed bridge is selected. Based on OpenSees nonlinear finite element platform, The nonlinear full-bridge finite element model is established. Three sets of measured seismic records are input to ground motion, and the dynamic incremental analysis method (IDA) is used to study and analyze. The results show that under different measured ground motions, the main tower of cable-stayed bridge is yielding transversely to the upper cross-section of the cross-member and controlled by the tensile strain of the steel outer reinforcement of the core concrete, while the failure is at the upper cross-section of the tower bottom or cross member. The lateral concrete of inverted Y-shaped concrete tower can form three plastic zones in the lateral direction of the earthquakes; the section of concrete tower of cable-stayed bridge should consider the confinement effect of stirrup, which can obviously enhance the transverse plasticity Performance, improve the tower lateral seismic performance.