Solutions on Establishing and Utilizing BIM for General Contractors in Key Scenarios of Digital Construction

Nowadays, digital construction has become popular when bringing convenience and efficiency to the traditional building construction industry. The primary tool of digital construction is the building information model (BIM). However, from the perspective of general contractors, unresolved puzzles still hinder obtaining the benefits of digital construction. When establishing a unified BIM from submodels provided by subcontractors, there will possibly be incomplete or inconsistent data during model merging. But extracting submodels from unified BIM often includes redundant data, thus making models less usable for subcontractors. It is also difficult for general contractors to effectively and accurately utilize resource information and submodel changes. This paper proposed solutions that depend on the widely adopted industry foundation classes standard to ensure the universality of our methods. First, a model merging algorithm is proposed to support the continuous merge of submodels created by different subcontractors. Second, an instance-level model extraction method based on strongly related entities is proposed, which extracts model instances to the minimum submodel and meets the subcontractor requirements at the same time. Third, the new model storage and indexing method are designed to reduce the complexity of model data and support rapid data retrieval, and a new BIM change detection method based on object metadata is provided. The proposed methods were applied by the general contractor of a large airport project during the construction stage. The application results proved that the proposed methods could ensure the quality of established deepening design models and extracted submodels and significantly reduce human labor by improving efficiency when utilizing BIM, which in turn supported key scenarios throughout the digital construction workflow.