# Data-Driven Modeling Algorithms for Cable-Stayed Bridges Considering Mechanical Behavior
## 1 Introduction  
In the construction industry, BIM (building information modeling) has been implemented in numerous major construction projects for an improved collaborative working environment. Many countries are mandating the implementation of BIM in construction projects. Recognizing the advantages of BIM, generally, BIM tools are widely used today for document creation. However, today, construction companies and engineers need to recognize the real value of BIM as a database and modify its use accordingly. The next phase in BIM adoption should be focused on data generation and its uses [1]. In a traditional construction project, a bridge is modeled, and the information for design and construction is obtained separately. Fragmented information delivery is commonly considered as the primary cause of low productivity. Efforts to adopt the latest manufacturing industry-related technology, such as robotics, are actively progressing [2]. To communicate with machines and for data analytics, the current BIM practices should be further aligned towards data-driven engineering. Through the creation of a suite of standardized objects using algorithms and databases, valuable data can be generated in the construction industry. In the design of a cable-supported bridge, the mechanical behavior depends on the geometry of the cables. Geometry modeling and information architecture have been widely introduced for the different BIM use-cases in bridge engineering [3, 4, 5, 6, 7]. Parametric modeling and alignment-based object-oriented modeling is essential for authoring a digital model. Byapplying a set of parameter databases and appropriate algorithms, the entire bridge model can be realized without any discontinuity through the construction project stages [8]. When there is an agreement to share the digital models and their data architecture, collaborative work among various stakeholders must be realized across different stages of the project, even during the operation and maintenance stage. The Industry Foundation Classes (IFC) represents a standardized open data model that meets the information requirements of the construction projects and is adopted in many BIM solutions. ISO 19650 is the international standard for managing information delivery across the entire life cycle of a construction project using BIM. It contains all the principles and high-level requirements for organization and digitization [9; 10]. The IFC-Alignment and the IFC-Infra Overall Architecture projects provide good foundations for the modeling of the linear civil engineering structures. The IFC-Bridge project was officially started by buildingSMART International [11]. The three-dimensional (3D) alignment-based bridge modeling was proposed by many researchers [8; 12; 13]. Current BIM projects in bridge construction encounter difficulties in the sharing and delivery of information models between the BIM solutions due to the lack of interoperability. For automatic or machine-based fabrication needs, improved and more generalized data-driven information delivery is necessary. For example, DfMA (design for manufacturing and assembly) requires data interfaces between the digital models and robotic operation data [2]. Tension structures are designed mainly in three steps: form finding, load analysis, and pattern layout [14]. Once the initial equilibrium shape or target configuration is decided, the behavior of the cable structure under various load combinations must be checked to ensure all necessary limit states. A cable structure has no unique undeformed configuration corresponding to the equilibrium configuration under dead loads because the lateral stiffness of a cable is defined based on the applied tension [15]. The initial equilibrium configuration under a dead load can be determined by the target configuration under dead load (TCUD). The initial tension forces and unstrained lengths of cables can be determined by TCUD analysis. The geometric constraint method and the initial member force method have been adopted for the TCUD analysis.