单箱多室波形钢腹板组合梁斜拉桥抗弯特性研究

Flexural Behavior of Cable-stay Bridge withMulti-cell Boxed Girders

本文结合某单箱多室波形钢腹板组合梁斜拉桥的实桥施工,通过塔柱主梁施工过程精细模型的有限元计算,结合实桥施工检测数据,研究施工过程中组合箱梁的抗弯特性。研究结果表明:组合梁斜拉桥施工过程中波形钢腹板纵向应力很小,可不计波形钢腹板的抗弯承载力;施工过程中组合梁顶、底板纵向正应力会出现明显的横桥向不均匀分布现象,顶板尤为严重;施工过程中出现的剪力滞效应,随着施工节段加长趋于平缓。

Based on practical construction of a cable-stay bridge of multi-cell composite boxed girder with corrugated steel web,a FE model of the bridge is proposed,and numerical simulations of construction process of the main tower and main girders are conducted.The onsite monitoring data are used to validate the analytic model,and flexural behavior of composite girders during the construction process is investigated.It is illustrated that the induced longitudinal stresses of the corrugated steel web during each construction stage of the cable-stay bridge are very small,and have negligible effect on the flexural bearing capacity of the steel web.During the construction process of the bridge,longitudinal normal stresses in the top and bottom concrete flanges have apparent non uniform distributed pattern,especially in the top flange.This shear lag phenomenon in distribution of normal stress,however becomes gentle as advance of the construction stages.