Three-dimensional (3D) modelling of the pedestrian bridge over the river Neris

Abstract

With the rapid development of new technologies, there is a growing necessity to optimize and to digitize as much as it is possible in all areas of work, including the designs of new facilities. Pre-formation of location's 3D model (by scanning) allows us to evaluate how the newly constructed object will integrate into the territory. The object of research is the pedestrian bridge over the river of Neris in Vilnius city (Lithuania). The aim of the research is to create a 3D model of the embankments of river Neris which will be required for the integration of the future bridge model. Equipment used for scanning of the embankments: Scanner Trimble X7, tablet T10 with new software Trimble Perspective and device Survey Mobile Point. Measurement results were processed using the program Trimble Real Works. Scanning points, geodetic data and other available data were integrated into the program. Scanning results (generated 3D models) and the project of river embankments were combined into a general model. The model was coordinated and data "garbage"was removed. Cloud-to-Cloud errors, point's coincident percent and results confidence have been identified during the modelling - joint between the scanning stations. The Cloud-to-Cloud errors of the connection between two embankments ranged from 1 mm to 28 mm. Points coincident percent varies from 25 to 62 %. The largest errors and the smallest coincident percent occurs by combining two sides of the embankments together into one model. The smallest errors and the largest coincident percent were between the one-side scanning stations point clouds. In the general project of embankments and the bridge project, some discrepancies were identified due to possible project coordination or modelling errors.