一、边桩断面仪的原理 71型边桩断面仪是根据相似三角形和交会法的原理来施测横断面;用透视跟踪交会的方法来确定边桩点的位置。如图1所示,△ABC为实地交会的三角形,△AB′C′为仪器所显示的三角形,△AB′C′≈△ABC,设其比例系数为K,因AB为实地基线,AB′为仪器基线, First, the principle of side pile section instrument 71 Side pile section instrument is based on the principle of similar triangles and intersection method to measure the cross-section; with the perspective of tracking intersection method to determine the location of side pile points. As shown in Fig. 1, △ ABC is the triangle of the field intersection, △ AB’C ’is the triangle displayed by the instrument, △ AB’C’≈ △ ABC, set its proportion coefficient as K, because AB is the real baseline, AB’ For the instrument baseline,