【摘要】 为研究预应力损失对预制PC箱梁力学性能的影响，文中建立30mPC箱梁实体有限元模型，分析预应力钢绞线整体损失、单侧损失，以及增大预应力钢绞线力学性能条件下PC箱梁荷载-位移曲线及开裂荷载、极限荷载变化。结果表明，预应力损失不会对PC箱梁弹性阶段时截面抗弯刚度产生明显影响，但结构开裂荷载会随着预应力损失的增大而明显下降；在较大预应力损失率下，单侧与整体预应力损失对结构开裂荷载的影响基本接近；更高强度等级的钢绞线可明显提高预制PC箱梁的开裂荷载、极限荷载，但存在明显边界效应。更多还原

【Abstract】 To study the impact of prestress loss on the mechanical performance of precast PC box girders,a 30 meter PC box girder solid finite element model is established to analyze the changes in loaddisplacement curves,cracking load,and ultimate load of PC box girders under conditions of overall prestressed steel strand loss,unilateral loss,and enhanced mechanical performance of prestressed steel strands.The results indicate that prestress loss does not have a significant impact on the flexural stiffness of the PC box girder section during the elastic stage,but the cracking load of the structure decreases significantly as the prestress loss increases.At higher prestress loss rates,the impact of unilateral and overall prestress loss on the structural cracking load is basically similar.Higher-strength steel strands can significantly increase the cracking load and ultimate load of precast PC box girders,yet with noticeable boundary effect.更多还原