COMPARISON OF UAVS PERFORMANCE FOR A ROMAN AMPHITHEATRE SURVEY: THE CASE OF AVELLA (ITALY)

Abstract. In the field of archaeological surveying, remote sensors and especially photogrammetric and laser scanner systems are widely used to create 3D models. The use of photogrammetric surveying with UAVs (Unmanned Aerial Vehicles), combined with Computer Vision algorithms, allows the building of three-dimensional models, characterized by photo-realistic textures. The choice of which method to use mainly depends on the complexity of the investigated site, the accuracy requirements and the available budget and time. The different components of the UAV system determine its characteristics in terms of performance and accuracy, therefore define its quality and the cost too. This study presents an assessment of the accuracy of point clouds derived by two UAV systems, a commercial quadcopter (DJI Phantom 3 Professional), a professional assembled hexacopter, and by a TLS (Terrestrial Laser Scanner) in order to compare photogrammetric and laser scanner data for archaeological applications. In this paper, we present a case study to compare and analyse the metric accuracy of the point clouds and the distribution of the GCPs (Ground Control Points). This accuracy assessment will serve to quantify the uncertainty in the absolute position of the GCPs, identified on the panoramic images in the absence of artificial targets. Executed experiments showed that in tested UAVs, the choice of the GCPs has significant impact on point cloud accuracy. Estimated absolute accuracy of point clouds collected during both test flights was better than 5&amp;thinsp;cm.</p

Development of a pavement life cycle assessment tool for airfield rehabilitation strategies

The demand to provide more sustainable facilities and infrastructure has increased over the past ten years. The ability to measure and quantify the environmental impacts of infrastructure projects like life cycle costs is in higher demand. Life cycle assessment (LCA) studies/tools are developed for highway infrastructure and pavements with a limited number of studies developed for airports and even fewer for the airport pavement infrastructure. A pavement LCA tool called LCA-AIR 1.0 is introduced to fill the necessary gap in quantifying sustainability strategies for airfield pavements. LCA-AIR incorporates the material production, construction/maintenance and rehabilitation, and use phases in the analysis. Standard indicators from TRACI are used to quantify these impacts based on two functional units (square yard and pounds-mile traveled). To assess and evaluate the viable rehabilitation strategies, comprehensive and accurate field data must be collected. A summary of LIDAR and laser scanning technology and projects for highway and airport infrastructure is presented. An LCA case study was performed for three candidate rehabilitation strategies on Taxiway A and B at O’Hare International Airport in Chicago, IL: rubblization with mill/asphalt inlay, precast concrete panel replacement, and full depth reconstruction of existing concrete pavement structure. An extensive literature review and investigation into the use of precast concrete pavement on airports in the US and abroad is documented for application to rapid rehabilitation. LCA-AIR showed that each phase contributed at different magnitudes to the environmental impact with the use phase producing the greatest LCA impact factors. The LCA analysis focused on the construction/maintenance and rehabilitation (CMR) phase, as the material production (MP) phase for initial construction and use (U) phase were the same for all cases. The GWP potential for PCP was 2,395 kg CO2/yd2 (4.700x10-10 kg CO2/lb-mile), for rubblization was 2,395 kg CO2/yd2 (4.310x10-10 kg CO2/lb-mile), and for reconstruction was 2,395 kg CO2/yd2 (4.701x10-10 kg CO2/lb-mile). The energy consumed for rubblization was 0.18612 TJ/ yd2 (3.576x10-8 TJ/lb-mile), for PCP was 0.18617 TJ/ yd2 (3.654x10-8 TJ/lb-mile) and for reconstruction was 0.18628 TJ/ yd2 (3.656x10-8 TJ/lb-mile)

Bridge monitoring and assessment by high-resolution satellite remote sensing technologies

Satellite Remote-Sensing has been successfully applied for detection of natural-hazards, (e.g. seismic events, landslides and subsidence) and transport infrastructure monitoring over the last few years. Persistent Scatterer SAR Interferometry (PSI), is a satellite remote sensing technique able to measure ground displacements over the time. More specifically, the PSI technique is an evolution of the DInSAR technique and it is based on a statistical multi-temporal differential interferogram analysis. This allows to determine coherent stable-pixels over a data-stack of SAR images, in order to identify potential ground displacements. This study aims at demonstrating the potential of the PSI technique as an innovative health-monitoring methodology for the structural integrity of bridges. For this purpose, X‐Band COSMO‐SkyMed images provided by the Italian Space Agency (ASI) were acquired and processed in order to detect structural displacements of the Rochester Bridge in Rochester, UK. Outcomes of this investigation outlined the presence of various PSs over the inspected bridge, which were proven useful to achieve a more comprehensive monitoring methodology and to assess the structural integrity of the bridge. This research paves the way for the development of a novel interpretation approach relying on the integration between remote-sensing technologies and on-site surveys to improve upon current maintenance strategies for bridges and transport assets

Eleventh International Conference on the Bearing Capacity of Roads, Railways and Airfields

Innovations in Road, Railway and Airfield Bearing Capacity – Volume 2 comprises the second part of contributions to the 11th International Conference on Bearing Capacity of Roads, Railways and Airfields (2022). In anticipation of the event, it unveils state-of-the-art information and research on the latest policies, traffic loading measurements, in-situ measurements and condition surveys, functional testing, deflection measurement evaluation, structural performance prediction for pavements and tracks, new construction and rehabilitation design systems, frost affected areas, drainage and environmental effects, reinforcement, traditional and recycled materials, full scale testing and on case histories of road, railways and airfields. This edited work is intended for a global audience of road, railway and airfield engineers, researchers and consultants, as well as building and maintenance companies looking to further upgrade their practices in the field