Haein Jeon

Numerous studies have developed extensions to the IFC schema to meet the needs of specialized domains or represent nascent technologies, and in turn have expanded the scope of interoperability for BIM data exchanges. However, these studies used varying approaches for IFC extensions and validation, making it difficult to identify research gaps and agree on legitimate extension protocols. This study collected 64 studies of IFC schema extensions spanning over two decades, from 2001 to 2022. The analysis first focused on categorizing these cases with respect to their target domains and sectors, their purpose and extension approaches, as well as their methods for implementation and validation. Timeline analyses were also conducted to track the temporal trends over the specified period. The results revealed that architectural cases have recently shifted from process to product representations due to new technology adoptions, while infrastructure cases, initially centered on major sector elements, have transitioned towards operation and maintenance processes. The findings also showed the need for a more holistic and organized approach for extensions, as current ad hoc developments were limited to products and processes only applicable for specific sectors.

The utilization of Building Information Modeling (BIM) on-site has been limited due to the lack of an appropriate medium for visualizing and accessing models and project data intuitively in the field. AROS, an Augmented Reality-based site management system, was developed to allow the visual projection of BIM models and relevant data directly to field personnel. Detailed field experiments with inspection experts revealed specific issues with the stability and accurate placement of model projections in AROS. Projection stability was improved by reducing the number of triangle meshes of the model to relieve the need for processing power. Investigations revealed that simplification rates of 40% and 20% were optimal for rectilinear and curvilinear components, respectively. Projection placement was improved by implementing a hybrid of target anchoring methods. Specifically, ARWorldMap was used to add additional anchor points, which were identified from the topologies of the structure and surrounding planes. Post-evaluations demonstrated increased stability and reductions in displacement errors. The formalizations provide measures for using AR and BIM models when applying these technologies to large-scale civil infrastructure projects.