Geometric Analysis of a Space Grid Structure by an Integrated 3d Survey Approach

Abstract

Abstract. The survey and modeling of spatial grid structures is often a challenging task to solve, due to the many bottlenecks present in the reverse modelling process. Geometrical and material complexity, scale variation, shadows effects, low accessibility, mismatch between similar elements, metrical validation, data management are all critical passages. They must be solved to obtain a reliable data able to solve the system maintenance and intervention requirements. In these cases, in particular, when the structure is difficult to be accessed, it is essential to plan an integrated survey approach. This paper shows how the survey and modelling of an impressive structure was carried out using both TLS and RPAS photogrammetry. After being validated, the data is integrated into a single point cloud that completely describes the structure, eliminating shadow areas and hidden parts. In the modeling process, particular attention was paid to verifying the correspondence between as-built and project. Finally, an element of particular interest is represented by the attempt to recognize the individual construction components belonging to specified geometric and dimensional classes, with the advantage of obtaining a complete model that is as faithful as possible to the real situation of the structure.

Analysis on Using 3D Scanning and BIM to Reduce the Physical and Non-Physical Construction Waste for Sustainable Fireproofing of Steel Trusses

“…However, laser scanning also presents some challenges in terms of data acquisition due to the complex configuration of the steel truss, which results in shadowed areas where the laser beam cannot reach [20]. This problem can be overcome by using multiple terrestrial stations or positioning them according to this limitation by using UAVs (Unmanned Aerial Vehicles) equipped with scanning instruments to complement the data acquired by terrestrial scanning [21], or by collecting data using conventional techniques (manual surveying and photographs) when possible.…”

Machine Learning and Deep Learning for the Built Heritage Analysis: Laser Scanning and UAV-Based Surveying Applications on a Complex Spatial Grid Structure

“…Beyond the acquisition phase, many problems have been raised in terms of processing the survey data (e.g., automating the identification and mapping) within raw point clouds or meshes of the characteristics of buildings [14,15], structures [16,17], and infrastructure [3,18] such as the shape, size, and location. In this context, artificial intelligence (AI)-derived techniques might become effective tools to assist in the detection of collapse mechanisms [19] or anomalies in the data [20], the diagnosis of problems and failures [21,22], and maintenance and recovery activities.…”