考虑施工误差的弯坡跨线桥转体施工线形调整

针对既有施工误差影响下弯坡跨线桥转体施工的平顺拼接问题,提出了一种基于最小二乘法原理的线形调整方法,即首先实测两侧梁体中心点和球铰不动点的三维坐标,利用最小二乘法原理拟合得到平、纵曲线的理想线形;再以理想线形为目标,利用最小二乘法原理确定实际转体角度、转体到位标识及转体微调值等参数。通过在滨德高速公路上跨京沪铁路立交桥转体施工中的实际应用,结果表明,该方法计算精确,操作简便,能考虑既有误差的影响,实现线形的最优调整。

Alignment adjustment of curve and slope flyover bridges by considering construction error

In view of the smooth joining between the rotating bridge and the bridges on the sides during the rotation construction of a curve and slope flyover bridge with the existing error,an alignment adjustment method based on least squares method was put forward.Firstly,the three-dimensional coordinates of the central points of the bridges on the sides and fixed point of ball-hinge were surveyed and the ideal alignments were fitted using the least squares method.And then aimed at the fitted ideal alignments,such parameters as actual required rotation angle,the mark of bridge rotated in its place and its fine adjustment value were determined using the least squares method.By its application in the rotation construction project of Bin-De expressway flyover bridge across Beijing-Shanghai railway,the results indicate that this method with high accuracy and easy operation,can eliminate the influence of existing errors and realize the optimal alignment adjustment.