Abstract: At present, the quality inspection of the reinforcement skeleton of prefabricated components mainly relies on manual labor, which is time-consuming and error-prone. BIM (building information model), 3D reconstruction and other technologies provide the possibility of improving the quality inspection method of the reinforcement skeleton of the prefabricated components. When using these technologies, it is necessary to generate a point cloud that can distinguish each steel bar from the BIM model of the reinforcement skeleton. Therefore, the concept of the semantic as-designed point cloud was proposed, and a BIM-based algorithm for automatic generation of the semantic as-designed point cloud of reinforcement skeleton was built. First, the algorithm extracts each steel bar from a BIM model and stores them in separate files. Then, the format of these files is converted, and the semantic as-designed point cloud of each steel bar is generated. Finally, a semantic as-designed point cloud of the reinforcement skeleton is generated based on the semantic as-designed point cloud of each steel bar. The algorithm was experimentally verified with a simple reinforcement skeleton and a complex reinforcement skeleton respectively. The result shows that the algorithm can automatically and quickly generate an accurate sematic as-designed point cloud of a reinforcement skeleton. 

Key words:  , reinforcement skeleton, quality inspection, building information model, as-designed point cloud, semantic point cloud