经纬仪投设建筑物轴线交点的精度分析

Analysis of the Precision for Locating Theodolite on the Axis Node of the Building

由于现代城市建设的需要，大量高层建筑物林立，这就给测量放样带来两方面困难：（１）施工场地狭窄没有足够的测量距离；（２）楼顶标高大多在１００ｍ以上，使经纬仪投点仰角过大无法观测。作者提出用经纬仪直接置于轴线交点上，利用弯管目镜垂直投点到各层轴线交点上。这样既解决了放样的难题又达到了如期的精度要求，是一种切实可行的测量放样方法。

As a result of the construction of modern cities, a large number of tall buildings stand like a forest. It brings trouble to surveying and locating in two aspects: (Ⅰ) The limited construction sites lack of enough distance for surveying. (Ⅱ) Most surveying and drawing elevation of the building are over 100 metres, which makes the casting point elevationangle of the theodolite too large to survey. A new kind of method to put the theodolite on the crossing point of axes directly and use diagonal ocular to cast vertically on the crossingpoint of axis of each layor is introduced in this paper. Thus, we not only solve the problem of locating, but also achieve the expected precision. Its really a practical and effective method of surveying and locating.