Method for quickly positioning and measuring dead load condition of in-service bridge structure

The invention discloses a method for quickly positioning and measuring the dead load condition of an in-service bridge structure. The method specifically comprises the following steps of: performing layout of measurement and control points and reference points on site according to the geometric morphology of the structure; constructing an absolute coordinate system based on a total station and collecting coordinate data of the reference points; constructing relative coordinates of measurement and control points; according to the absolute reference points P1-P3, obtaining a transmission relation between the absolute coordinate system and the internal and external measurement and control points; a three-dimensional laser scanner is placed on a measurement and control point, and segmented scanning and orientation are carried out on the measurement and control point; performing data processing on the three-dimensional laser point cloud according to point cloud cutting and noise data elimination; an ideal three-di