基于数字水准仪的桥上精密水准测量方法

Method of Precise Levelling on the Bridge Based on Digital Level

以港珠澳大桥首级控制网的复测工作为例,分析数字水准仪测量的主要误差来源及消除或削弱误差的技术措施,针对桥上的测量特点和环境条件,提出基于数字水准仪的桥上精密水准测量方法,制定了水准路线布设、数字水准仪检校、外业观测及限差验算等方面的技术要点和技术措施。在港珠澳大桥首级控制网第八次复测中,使用数字水准仪完成了单线总长28. 2 km的二等水准测量,线路起终点水准测量高差与原跨海水准测量传递高差的较差仅2. 1 mm,远小于二等水准测量限差(21. 5mm),局部水准高差闭合环检验(环线长度11. 53 km)、4测段跨海水准测量高差对比检验及高差闭合差均满足二等限差要求。

Taking the repetition survey of the first order control network of Hong Kong-Zhuhai-Macao Bridge as an example,the main error sources of digital levelling and the technical measures to eliminate or weaken the errors are analyzed.Aiming at the characteristics and environmental conditions of levelling on the bridge,a precise leveling method based on digital level is put forward.The technical essentials and measures of leveling route setting,digital level calibration,field surveying and limited error checking are formulated.In the eighth repetition survey of the first order control network of Hong Kong-Zhuhai-Macao Bridge,the second leveling surveying of a route with a total single length of 28.2 km was completed using the digital level.The error between the levelling elevation difference from the starting point to the ending point of the levelling route and the the original sea-crossing leveling height difference was only 2.1 mm,which is far less than the limited error of 21.5 mm.And the closure errors of height difference of a local closed loop with 11.53 km length,4 sea-crossing leveling checking errors and height closed error all entirely meet the requirements of the limited errors of the second levelling.