【摘要】 以重庆某高速公路跨沟大桥实际工程为研究对象,通过有限元分析方法,对连续刚构桥悬臂施工期预应力损失进行了研究。结果表明:随着混凝土加载龄期的增长,预应力钢筋各项预应力损失值逐渐减少,在实际施工过程中,加载龄期不可能无限延长,在进行大跨度预应力混凝土连续刚构桥的预应力筋损失值的控制时,需要确定合理加载龄期。通过施工期的有限元分析,加载龄期为7 d时较合适。在预应力损失所有项目中,占比重最大时摩擦损失,管道以及钢绞线成形质量间的摩擦是摩擦损失的主要起因。为了使施工的摩擦降到最低,就得控制管道成形质量以及合理的优化钢绞线穿束质量;预应力的损失可以通过合理的计算引申量来减少;另外为了减少预应力的损失还可以加强预张拉和持荷时间等。更多还原

【Abstract】 In this paper,the actual project of a highway bridge across Chongqing as the research object,through the finite element analysis method,the continuous rigid frame bridge cantilever construction of prestressed loss.The results show that with the concrete loading age,prestress loss of prestressed reinforced the value gradually decreased,in the actual construction process,loading age cannot be extended indefinitely,control in prestressed loss of long-span prestressed concrete continuous rigid frame bridge values,we need to determine reasonable loading age.Through the finite element analysis of the construction period,the loading age is 7 d.The prestress loss in all projects,the largest proportion of friction loss,friction loss caused by main factor of construction is steel wire and pipe friction between the forming quality.Optimization of steel strands and quality control of pipe forming quality can reduce the friction loss of construction;reasonable calculation drawing amount can reduce the loss of prestress;strengthen the loading time,pre tension tension technology can also reduce the loss of prestress.更多还原