大跨度桥梁GPS施工加密网测量方法研究

Surveying method of GPS densified control network for long-span bridge construction

为了提高大跨度桥梁GPS施工加密控制网的测量精度,针对控制网边长短、精度要求高和现场条件复杂的特点,分析短边GPS控制网测量的主要误差来源,提出消除或削弱测量误差影响的措施;设计了大跨度桥梁GPS施工加密网测量的技术方法,并通过港珠澳大桥工程的实测数据验证了该方法的可行性。结果证明GPS施工加密点的坐标精度优于±2mm,边长精度优于±3mm,能够满足海中斜拉桥索导管高精度定位的需要。

In order to improve the surveying accuracy of GPS densified construction control network for long-span bridge, aiming at the characteristics of short vectors, requirement of high precision, and complicated site condition, the paper ana- lyzed the major error sources of GPS control network with short vectors, and put forward the technical measures to eliminate or weaken the influence of the errors. Moreover, the technological method of GPS densified control network surveying for long- span bridge construction was designed, and the feasibility of the proposed method was verified by the measured data of Hong Kong-Zhuhai-Macao Bridge engineering project. Result showed that the coordinate accuracy of the GPS densified control points would excel ± 2 mm and the side length accuracy would excel ±3 mm, which could meet the accurate positioning requirement of cable ducts of the cable-stayed bridge in the sea.