轨道交通高架桥独柱墩足尺模型偏载试验及破坏形态判定方法

郭建强1陈浩1刘钊2王序2陈轶鹏3

Eccentric Loading Test and Failure Pattern Identification Method on a Full-scale Hammerhead Pier Model in Rail Transit Viaduct

GUO JianqiangCHEN HaoLIU ZhaoWANG XuCHEN Yipeng
摘要:
以宁句城际轨道交通(南京—句容)项目为背景,开展了预制盖梁独柱墩的足尺模型偏载试验。研究表明,预制盖梁接缝面在设计偏载下始终受压,在极限荷载下表现为受拉侧墩柱弯曲破坏。提出了判断独柱墩偏载破坏形态的方法。该方法基于正常使用条件下的应力约束不等式,以及承载力极限状态下的弯矩轴力包络,根据加载路径与公式对应的曲线交点顺序获得偏压墩柱的破坏形态,其所预测的偏载失效顺序与试验结果一致。此外,在给定偏载控制工况下,可运用该方法确定墩柱截面设计参数,使之符合预期的失效破坏模式或增强墩柱承载力。
Abstracts:
Taking the project of Nanjing-Jurong intercity rail transit as background, the eccentric loading test of a full-scale model of hammerhead pier with precast cap beam is carried out. Research results show that the joint interface of precast cap beam remains compressed under the designed eccentric load, and bending failure occurs on tension side pier shaft under ultimate load. A method for judging the failure pattern of hammerhead pier is proposed. This method is based on the stress constraint inequation at standard service, and moment-axial force envelope at ultimate stress condition. According to the intersection sequence between the loading path and the aforementioned inequation, the failure pattern of hammerhead pier under eccentric load can be clearly identified. The failure sequence predicted by this method is consistent with the test results. In addition, this method can be used to finalize the pier section design parameters under given eccentric load conditions, so that the failure pattern is within expectation and the pier bearing capacity is enhanced.
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