公路特大桥墩台施工定位精度估算

Accuracy Estimation on Layout of Piers and Abutments of Highway Extra-large Bridges

采用测量间接平差原理建立桥梁墩台定位精度分析模型,通过理论分析和模拟计算,探讨公路特大桥施工控制网的优化布设方案和墩台放样最有利的交会图形.结果表明,桥位两岸施工控制点应垂直对称布设在桥轴线左右两侧,其边长等于桥轴线长度的0.7倍时,有利于提高最弱点桥墩的放样精度;角度交会应采用归化法放样方案.

A precision analysis model for laying out of piers and abutments of a bridge was built by u-sing the principle of indirect adjustment. On the basis of theoretical analysis and simulation, the optimized layout scheme of construction control network is investigated for highway extra-large bridges and the most fa-vorable intersection figure for setting out of piers and abutments was discussed. The results show that the construction control points for a bridge site at the banks of a river should be placed symmetrically in perpen-dicular to the bridge axis, and it is beneficial to increase the accuracy of setting out a pier at the weakest point when the control side length equals to the 0.7 times of the bridge axis length. The intersecting angle should adopt a normalized layout scheme.