## 1 Introduction  
Along with economic and social development, traditional construction production faces problems such as labor shortage, large resource consumption, and environmental pollution. Many countries have issued a series of policies to promote building construction industrialization to solve these problems. As one of the industrialized building systems, the steel structural system, whose members are generally processed and produced in factories, has the unique advantages of high industrialization because of its lightweight, high strength, and short construction cycle [1; 2]. Since many components are involved in steel structures, high installation quality is required, bringing difficulties in project management. Existing research has indicated that the use of information technology to process data during construction can significantly improve project management and the whole life cycle assessment level [3; 4; 5]. As an important information technology, building information modeling (BIM) has been widely used in project design, construction, and management [6; 7; 8]. [PERSON] et al. [9] pointed out that the application of neutral and open BIM standards can achieve the interoperability of BIM data among different types of software. For steel structures, BIM-based steel structural design software has been widely used in studies such as references [10; 11; 12; 13], but this software mainly focuses on structural design rather than the management of construction information. With the rapid development of the Internet, more and more Web-oriented BIM applications are emerging, aiming to solve the problem of information interaction in BIM models. Some Web-oriented open-source BIM systems are available, such as BIMServer [14]and xBIM [15]. The BIMserver system is developed as an open-source BIM server that supports storage, maintenance, and the query of industry foundation class (IFC). The xBIM plugin is a free software module with a specific set of functions, which can be invoked in application software to support geometric data calculation. However, without specific performance optimization for steel structural models, such systems are mainly used in concrete structural models rather than steel structural ones, and they have difficulty in handling large-scale steel structural models. Although some software providers have developed a Web version of the BIM system, the source code is not available, and secondary development is challenging to achieve. Furthermore, the internal structure of the IFC format is still imperfect, which is mainly caused by the following three drawbacks [16]. (1) IFC contains more than 900 predefined entities and native data types, and its internal logical structure is very complex and coupled. The reference in IFC files needs to follow strict hierarchical rules. In other words, the deeper a reference level is, the more complex its logic structure will be. (2) There is a large amount of information that is unnecessary in IFC files. Because of the intended generality of the IFC format, the parsed model data in real-life projects are usually much larger. Furthermore, according to the reference rules, many intermediate layers are always needed, causing a large quantity of redundant information in IFC files. (3) The IFC format has a loose scene organization. Therefore, current limitations of the Web-based system include the following: (1) the model file is too large, which requires too much time to transmit; (2) too much unnecessary information in IFC models causes some problems during data storage; and (3) too many components that are similar in terms of geometry overconsume the hardware resource, resulting in a time delay or system crash. Geometric redundancy removal in BIM presents significant challenges. In the IFC framework, multiple components sharing the same geometry can be recorded, but existing methods for removing redundancy rely heavily on data organization and export logic of the IFC files.