Considering the problems of the difficult data collection, nonstandard models, and inaccurate data in the digitalization of existing buildings, the BIMbased digitalization method for existing rail transit projects was studied and proposed, according to the characteristics of rail transit projects. First, based on data requirements of the operation and maintenance management, an overall framework for BIM digitalization and scenario applications in existing rail transit projects was developed. Second, the technical guideline for BIM modeling and delivery was studied and established, and a BIM component standard library was developed to standardize the creation of BIM models of existing rail transit projects. Third, according to the onsite data collection situation, different methods were adopted to create BIM models of existing rail transit projects. When the drawings were complete, models could be created based on the drawings. When some drawings were missing, the BIM model creation method based on the on-site images and point cloud data was studied through component feature recognition and matching component units in the BIM component standard library. Finally, to ensure the quality of BIM models, a compliance checking tool with embedded BIM standard specifications was developed for automatic model verification. Additionally, on-site inspection was conducted for various professional BIM models. The BIM construction of existing operating lines in Shenzhen Metro is being carried out, accumulating BIM-based digital assets, which provides reference for the BIM construction of existing operating lines in other cities.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |