坝陵河大桥钢桁加劲梁合龙关键技术

为保证坝陵河大桥钢桁加劲梁架设的顺利进行,针对合龙过程中可能出现的竖向、横向、扭转偏差及跨中合龙段合龙口长度偏小,上、下弦合龙口长度偏差不同等难点,对合龙口特征、参数敏感性、各种偏差调整措施及合龙方案进行了研究.研究结果表明,采用在两桥塔处对梁端进行牵引措施可较好解决合龙口纵向长度不配匹的难点,保证钢桁梁合龙杆件安装顺利实施；采用合龙段前端吊索暂不安装并辅以临时吊索的措施,可有效解决上、下弦合龙口偏差问题,同时也可作为钢桁梁横向、扭转偏差的调整措施.

Key Techniques for Closure of Stiffening Steel Truss Girder of Baling River Bridge

To ensure that the erection of the stiffening steel truss girder of Baling River Bridge could be carried out smoothly,the characteristics of the closure gaps of the girder,the related parameter sensitivity,various adjustment measures and closure schemes were studied in the light of the vertical,lateral and torsional deviations that would possibly occur in the process of the closure and also the problems that the length of the closure gap at the midspan was slightly short and the length deviations of the closure gaps at the upper and lower chords were different.The results of the study show that the measure of hauling the girder ends at the two towers can well resolve the problem that the longitudinal length of the closure gaps does not match and can guarantee the smooth installation of the closure members of the girder.The measure of temporarily not installing the permanent suspenders in the front ends of the closure sections and aiding the closure with the temporary suspenders can effectively resolve the problem of the deviations of the closure gaps at the upper and lower chords and at the same time,can serve for adjustment of the lateral and torsional deviations of the girder as well.