边梁负弯矩预应力筋受损对桥梁结构的影响

Influence of Damage of Prestressed Strand in Hogging Moment Zone of Outside Beam on PC Bridge Structure

研究目的:一座六跨一联单跨32 m的先简支后连续公路预应力混凝土T梁桥,因施工疏忽造成边梁负弯矩预应力钢绞线多处受损。该桥尚未交验通车,其损伤对桥梁结构的影响不明确,参建单位对该桥的质量和后期运营安全有担忧。研究结论:本文用ANSYS9.0有限元程序建模,施加公路一级车道荷载,划分了9个施工阶段进行计算分析,用跨中断面的挠度、跨中断面的上下缘应力及支座断面的上下缘应力的变化这三个指标评价边梁负弯矩预应力钢绞线受损对桥梁结构的影响。通过计算得知,边梁负弯矩区预应力钢绞线受损对桥梁结构的影响很小,只是支座位置的混凝土防撞墙可能会开裂。

Research purposes： The hogging moment prestressed steel strands in outside beams of a 32m 6 -span and 1 -connection simply supported -to -continuous T girder bridge were damaged in many places due to the construction negligence. As the bridge was not open to traffic at that time, the influence of the damage on the bridge structure was not clear and definite. Therefore, it was necessary to calculate the influence of the damage on the bridge structure for ensuring the bridge quality and the bridge safety in the later service period. Research conclusions： By using the ANSYS9.0 program for modeling, the I -level lane load was imposed and the calculation and analysis were made for the nine construction phases. By using the changes of the cross - section deflection, the upper and lower edge stress of the middle cross - section and the upper and lower edge stress of the bearing cross - section, the damage influence of the prestressed strand in hogging moment zone of outside beam on the bridge structure was evaluated. From the calculation it was known there was a little influence of such kind damage on the bridge structure and only some cracks would happen on the concrete protection wall in bearing place.