虎门大桥高程控制网的设计与施测

Design and Measurement of Vertical Control Network for Humen Bridge

本文介绍了虎门大桥高程控制网的布设与施测方法,其中包括用光学测微法成功地完成了珠江口1.1～1.4km四段宽水域的跨河水准测量。为了克服跨河水准遇到的困难,以及施工现场仪器设备条件的限制,自制了特殊觇牌,用一台N_3水准仪,采取“Z”字型布置进行观测,结果达到予期要求。平差后的成果完全满足工程测量二等水准各项精度指标的要求。

A method for establishing and measuring vertical control network for Humen bridge is introduced. The work includes four parts of the broad estuary river crossing leveling by the optical micrometry with sight lines from 1.1km to 1.4km in length. In order to overcome the difficulties encountered in river crossing leveling and coincide with the practical conditions of instrument, the authors made a special signal and observed with the mode of 'Z' by the only one Ns level. The results of height measurement reached the expected level. The accuracy of final adjusted results satisfies the requiremebts of 2nd- order leveling of engineering survey.