BIM to FEM Model Conversion of Low-Rise Residential Buildings for Debris Flow Damage Analysis

In Hong Kong, low-rise residential buildings, which are mostly built next to mountains and occupy half of the total residential area, are often seriously damaged by debris flow. The extent of damage to each building depends not only on the intensity of the debris flow but also on the interaction of the neighboring components of the building and their collective performance. With the application of BIM (Building Information Modeling) technology in structural analysis, data conversion and information transfer between the BIM model and the FEM (Finite Element Method) model have become the main factors limiting its efficiency and quality. Unlike the automatic conversion method for frame structure building models, the conversion method for such models is a semi-automated method that relies on manual labor at the cost of losing a large amount of BIM information due to the problems of non-standardization and confusing information. Therefore, this study proposes an automatic standardized conversion method based on OpenBIM data (IFC) for developing refined FEM models of low-rise residential buildings. It consists of three parts: 1) guaranteeing model refinement and spatial robustness through model geometry transformation and calibration; 2) standardized conversion during the conversion process through material information database establishment and matching; and 3) integration of the output information to achieve data interoperability and provide a reference for debris flow damage assessment. Conversion tests of this method and the traditional conversion method were conducted in the same BIM model, and the results show that the FEM model generated by this method is significantly better than the traditional conversion method in terms of spatial closure and mesh quality (i.e., spatial robustness and model refinement). Future research will continue refining spatial robustness detection, standardized conversion, and data interoperability.