中文摘要：

给出了火灾下预应力混凝土多肋T型梁桥的火灾模型和有限元建模计算方法,分析了火灾下预应力混凝土多肋T型梁桥延火变形,揭示了其桥面平整度的变化规律。结果表明,整个延火过程中,受火梁体均由反拱状态逐渐下挠,对称边肋受火,桥面呈倒＂U＂型,对称中肋受火,桥面呈＂V＂型,4片梁肋均匀受火,桥面变形基本同步;所有梁肋受火,桥面平整度不受影响;中肋受火,桥面平整度随延火时间直线变化;余肋受火,桥面平整度大多呈曲线变化。

英文摘要：

The fire model and calculation method of FEM for pre-stressed concrete multi-beam T-shaped girder bridge exposed to fire were proposed,the time-dependent deformation was analyzed,and the roughness of deck was disclosed.The experimental results indicate that during the fire-extending process,the beam body exposed to fire has a transformation procedure from reverse arch to dawn warping,deck presents an against U type under condition of symmetric edge rib subjected to fire,deck presents V type under condition of symmetric middle rib subjected to fire;the roughness of deck is not affected by all ribs＇ fire,the roughness of deck presents a linear variation under condition of mid-ribs＇ fire,the roughness of deck presents a curve variation under condition of other ribs＇ fire.