赤石特大桥主梁顶推合龙调整成桥塔偏研究

Research on adjustment bridge tower deviation of main girder segmentally launching closure of Chishi super-large bridge

针对赤石特大桥恒载稳定状态下的塔偏大且叠加车辆荷载作用后将使主塔偏心受力过大的问题,提出了在主梁合龙时进行顶推来调整成桥塔偏的解决方案。采用BDCMS软件和有限元方法,对赤石特大桥施工全过程进行了计算分析。计算结果表明:顶推方案对成桥塔偏改善明显,在一定程度上,抵消了后期收缩徐变的影响,能降低主梁水平累积位移,给塔与梁之间支座的安装带来便利;顶推方案对主梁应力有一定影响,但影响较小,可通过后期预应力束进行调整,对成桥索力没有影响。该顶推调整塔偏方案可用于各种类型的两塔或多塔斜拉桥,具有调整直接、操作便利的优点,具有一定的推广应用价值。

The solution of segmentally launching tower on adjustment deviation is presented under conditions of main girder closure directed against the tower deviation which is too large under dead load steady state,and the superposition of vehicle load will make the main tower of eccentric force too large to Chishi super-large bridge.Finite element method is used to calculate the whole construction process by BDCMS software.The analysis shows that tower deviation can be effectively improved under the dead load state by segmentally launching tower top solution,the influence of shrinkage and creep is partly counteracted,which can reduce the horizontal displacement of the main beam and bring convenience to bearings installation between tower and beam.The solution has some influence on the stress of the main beam,but it's small and it can be adjusted by the late prestressing beam,which has little effect on the cable force of the bridge.The solution can be used in two-tower or multi-tower cable-stayed bridges of various types,which can be adjusted directly and is convenient.It has certain application value.