棱镜常数测定新方法

New Method for the Determination of the Prism Constant

在地铁精密导线测量中,准确测定棱镜常数,对隧道精准贯通具有重要意义。常见的棱镜常数测定方法对场地条件要求较高,数据处理复杂。本文提出基于正弦定理的三角形测定法,可结合地铁联系测量测设井上近井点的原始数据,构建三角形,利用附有参数的条件平差原理,直接计算棱镜常数,无须采用传统方法额外测定。本方法无须专业设备和场地,能做到边施工边测定,避免了时间和数据浪费。

In the subway precision wire measurement, the accurate determination of the prism constant is of great significance to the accurate completion of the tunnel.Common prism constant determination methods require high site conditions and complex data processing.In this paper, the triangle measurement method is proposed based on the cosine theorem, which can use the original data of the near well point on the subway connection survey well to construct the triangle shape, and calculate the prism constant directly without the traditional method. This method does not need professional equipment and site, and can be determined while construction, avoiding time and data waste.