BIM Enabled Optimisation Framework for Environmentally Responsible and Structurally Efficient Design Systems

The present research investigates the potential to reduce the environmental impacts of structural systems though a more efficient use of materials. The main objective of this study is to explore and to develop an automated and integrated methodology that utilises Building Information Modelling's (BIM) capabilities combined with structural analysis and Life Cycle Assessment (LCA) as well as with a two-staged structural optimisation solver that achieves efficient and environmentally responsible steel design solutions. The implemented workflow utilises Autodesk Revit - BIM, Tally - LCA and Autodesk Robot - Structural Analysis. RobOpt is the plug-in that has been established using the Application Programming Interface (API) of Robot and the .NET framework of C?, and it inherits several structural functionalities based on Robot Finite Element Method (FEM) engine. The proposed RobOpt application can be accessed via a graphic user interface (GUI) within the Robot software. The operations that can be executed are: geometric definition, support assignment, load cases classification, standard and custom steel sections' selection, structural analysis, Eurocode verification/optimisation and constraint genetic algorithm optimisation. A novel characteristic of the application is the development of an integrated visualisation tool, which allows the user to graphically summarise the results from the obtained structural analysis.

The developed BIM optimisation methodology could be utilised as a design tool to inform early stage structural design solutions. A case study that focuses on a prototypical steel framed structural system under certain loads has been explored. Four input parameters of the I-section have been investigated: web thickness, flange thickness, section's width and depth. For the verified design configuration and by customising the steel I-beams, the developed optimal solution is one that minimises the total weight of the structure without compromising its structural performance by maximising the efficiency of the tested structural system. The resulting bespoke I-section from the genetic algorithm optimisation demonstrates that significant savings - up to 21% - can be achieved in the tested structure's overall weight and in all tested TRACI environmental indicators - Global Warming Potential (GWP), Ozone Depletion Potential (ODP), Acidification Potential (AP) and Eutrophication Potential (EP) - compared to the standard catalogue of steel sections. Further studies of various structural models would enable designers to develop their understanding on minimising the overall environmental impacts of their design decisions. All considered, the proposed framework constitutes a useful and an intuitive workflow, which aims to quantify the environmental savings of structural systems by utilising advanced computational analysis and common construction techniques.