THE NEED FOR MULTI-LOD 4D SIMULATIONS IN CONSTRUCTION PROJECTS.

The increasing application of BIM processes and technologies has facilitated an increase in the use of 4D (3D+Time) simulations of construction projects. Previous research has acknowledged the benefit of 4D models in the project planning and construction phases enhancing communication between construction teams and avoiding unforeseen conflicts during the build process. The development of BIM has spurred a deeper understanding of the issues surrounding Level of Development, Level of Information (LOI) and Level of Detail (LOD) pertaining to the graphical detail and non-graphical information of the static geometric design model. However, to date there is limited research thoroughly investigating the issue of LOD within 4D applications. This work presents an ongoing study to derive a framework for the development of more dynamic 4D simulations incorporating discrete forms of LOD. Level of graphical detail (LODg) corresponds to the graphical detail of the model geometry and also the 'granularity' of the geometry required for dynamic 4D production, whilst the temporal level of detail (LODti) relates to time period required between state changes in the model during the simulation. In order to support the development of the framework, an industry-based survey was conducted to assess the application of 4D, subsequent issues and use cases around levels of graphical and temporal details to improve dynamic 4D simulations. The work concludes with the development of a framework and schematic to support the specification of the LOD of a 4D simulation (LOD4d) throughout the various phases of a construction project. [ABSTRACT FROM AUTHOR]