新建预应力混凝土梁上拱度研究

对新建预应力混凝土梁徐变对上拱度进行了研究。通过研究可知,存梁控制前3个月徐变引起的上拱度变化值相对比较重要;为降低拼接时新旧桥的位移差,在不采取其他措施的情况下,建议存梁40 d（最多不能超过3个月）,以减小混凝土收缩徐变对起拱的影响;分批张拉预应力筋及预压主梁对控制拼接时对新桥的总上拱度有一定效果,预压主梁的效果较为明显,拼接后的徐变位移差都很小,影响也很小;采用存梁40 d的方法,可轻松地满足施工工期安排的时间,不需采取分批张拉预应力筋及预压主梁的措施,也可达到控制结构上拱度的目标。

Research on the Arch of Prestressed Concrete Beam

In this paper,it research on the new prestressed concrete beam Creep to camber.Through the study shows that the control beam with 3 months before creep of the change of the arch caused the value is relative important;In order to reduce the joining together of the old bridge of displacement,in no other measures,it suggest that storage beam 40 days（up to no more than 3 months）,reduce shrinkage of concrete creep to the influence of the arch;Partial tension prestressed girder and preloading can control joining together of the new bridge of total arch,and preloading the effect of main girder is obvious,and joining together the creep of displacement is very small;Using the method of 40 days with beam,can be easily arrange to meet the construction period of the time,it do not need to take partial tension prestressed girder and preloading measures,also can achieve control structure on the goal of arch degrees.