Application of TLS Method in Digitization of Bridge Infrastructures: A Path to BrIM Development

Abstract

Over the past years, bridge inspection practices and condition assessments were predicated upon long-established manual and paper-based data collection methods which were generally unsafe, time-consuming, imprecise, and labor-intensive, influenced by the experience of the trained inspectors involved. In recent years, the ability to turn an actual civil infrastructure asset into a detailed and precise digital model using state-of-the-art emerging technologies such as laser scanners has become in demand among structural engineers and managers, especially bridge asset managers. Although advanced remote technologies such as Terrestrial Laser Scanning (TLS) are recently established to overcome these challenges, the research on this subject is still lacking a comprehensive methodology for a reliable TLS-based bridge inspection and a well-detailed Bridge Information Model (BrIM) development. In this regard, the application of BrIM as a shared platform including a geometrical 3D CAD model connected to non-geometrical data can benefit asset managers, and significantly improve bridge management systems. Therefore, this research aims not only to provide a practical methodology for TLS-derived BrIM but also to serve a novel sliced-based approach for bridge geometric Computer-Aided Design (CAD) model extraction. This methodology was further verified and demonstrated via a case study on a cable-stayed bridge called Werrington Bridge, located in New South Wales (NSW), Australia. In this case, the process of extracting a precise 3D CAD model from TLS data using the sliced-based method and a workflow to connect non-geometrical information and develop a BrIM are elaborated. The findings of this research confirm the reliability of using TLS and the sliced-based method, as approaches with millimeter-level geometric accuracy, for bridge inspection subjected to precise 3D model extraction, as well as bridge asset management and BrIM development.

A Robust and Effective Identification Method for Point-Distributed Coded Targets in Digital Close-Range Photogrammetry

“…Artificial targets include two types: common targets and coded targets [8]. In terrestrial laser scanning or unmanned aerial vehicle (UAV) applications, common targets can be used for the registration of a multi-station scanning point cloud or as control points [9].…”

“…Artificial targets include two types: common targets and coded targets [8]. In terrestrial laser scanning or unmanned aerial vehicle (UAV) applications, common targets can be used for the registration of a multi-station scanning point cloud or as control points [9]. For example, Mohammadi et al [10,11] adopted technology combining terrestrial laser scanning and UAV photogrammetry for the application of bridge monitoring.…”

Digitalization of bridge inventory via automated analysis of point clouds for generation of BIM models

“…3D Surveying -The process of capturing 3D point clouds using surveying techniques, e.g., laser scanning (LiDAR) or photogrammetry (based on geo-referenced images). Most relevant works in the field of Scan2BIM process, applied on bridge point clouds, are showing continuous efforts to obtain semantically meaningful bridge information models in an automated way [29], [30], [31], [32], [33], [34]. The authors propose methods for automatic identification of bridge elements, where they usually recursively decompose the bridge into parallel equidistant slices and describe the bridge elements by analyzing their 2D crosssection projection parameters.…”

Mixed Reality procedures for the maintenance of existing bridges and retaining walls

“…As a result of this technological progress, even the infrastructures inspection phase has been changing profoundly in recent years, thanks also to the development of many platforms and tools that favor multi-data management in a single environment, making alphanumeric data, images, audio and three-dimensional models available at the same time. By means of codified processes for laser and photogrammetric restitution and thanks to the presence on the market of well-performed and accessible instruments in economic terms, it is possible to obtain point cloud models that reproduce the reality of the artefacts with precision and accuracy in a short time and safety [28], [29].…”