# Development and Application of Digital Twin-BIM Technology for Bridge Management
## 1 Introduction  
A digital twin (DT) refers to a virtual replication of a physical object, system, or process, serving as a valuable tool across diverse industries for several purposes, such as product development, manufacturing and operations, asset management, smart cities and infrastructures, healthcare, and energy and utilities. Digital twin technology has been a trending technology in recent years in all industries. The importance of the revolutionary technologies called Construction 4.0 is extremely increasing in the industry [1, 2].  
A specific form of the digital twin concept widely adopted in the architecture, engineering, and construction (AEC) industry is building information Modeling (BIM), which facilitates the creation of virtual representations of structures such as buildings, bridges, roads, and other infrastructure components. The employment of BIM models offers numerous advantages and benefits various stakeholders involved in the construction and building life cycle. By simulating and analyzing multiple design alternatives, quantities, and construction sequences, BIM empowers the resource allocation optimization, the identification of potential cost-saving measures, and the enhancement of project scheduling. These capabilities translate into reduced material waste, improved construction sequencing, and an enhanced overall project efficiency, leading to significant time and cost savings [3, 4, 5, 6].  
Bridges play a critical role in modern transportation infrastructure, facilitating the movement of people, goods, and services. Ensuring their safety, reliability, and durability are of paramount importance to the communities they serve. However, bridge management is a complex and challenging task, requiring careful planning, structural health monitoring (SHM), and maintenance [7, 8]. Additionally, one of the most interesting advantages of digital twin is that it can monitor, visualize, and evaluate the time-variable performance of the targeted structures by way of integrating ICT, IoT, and various information technologies.  
From the above backgrounds, many studies have been conducted on the development of structural health monitoring systems based on digital twins and their implementation for the maintenance and management of infrastructure facilities [9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20].  
Our research group conducted research on structural performance evaluation and anomaly detection based on monitoring long-span bridges using GNSS satellites and other technologies. Through this research, it was found that the structural analysis utilizing digital twin-BIM technology is extremely essential for verifying the structural performance of existing bridge structures based on GNSS monitoring and sensors [21; 22]. In addition, a research project on maintenance strategies based on the GNSS structural health monitoring for the targeted bridge in this study (Comoro Bridge) is planned to start in Timor Leste. Therefore, in this study, we explore the application of digital twin-BIM technology for bridge management and investigate the fundamental characteristics of structural performance based on an FE analysis using digital twin-BIM technology.