多跨预应力混凝土连续梁桥合龙顺序研究

Study on Closure Sequence of Multi-span Prestressed Concrete Continuous Girder Bridge

多跨预应力混凝土连续梁桥属于多次超静定结构,受力状况复杂,选择最优的合龙顺序对桥梁建设至关重要。以宁夏一座8跨公路连续梁桥工程为背景,为得到该桥合理的合龙方案,采用有限元法计算4种不同合龙顺序下全桥的竖向位移、支座纵向位移以及箱梁截面底板下缘、顶板上缘的应力。通过分析这4种合龙方案的优缺点,确定了该桥最理想的合龙顺序为边跨→中跨→次中跨→次边跨,讨论了施工控制中相关注意事项。

Multi-span prestressed concrete continuous girder bridge belongs to the statically indeterminate structure,the force condition is complex,the choice of the optimal closure sequence is very important to the bridge construction. T aking the eight-span highway continuous girder bridge project in Ningxia as the engineering background, in order to obtain the rational closure sequence of the bridge,the finite element method was used to calculate the vertical displacement of the whole bridge,the longitudinal displacement of the bearing and the stress in both the upper and lower edges of the box girder section.T he optimal closure sequence with side span,middle span,secondary middle span and subside span of the bridge was determined by comparing and analyzing the four kinds of closure schemes.T he related matters of attention in the construction control were discussed.