Abstract: The authors conduct a systematic study on the development status of digital twin technology in China′s tunnel engineering in recent years. First, the concept, elements, and advantages of digital twin technology are systematically expounded. Then, the development and research status of digital twin technology in China′s tunnel engineering is analyzed. The key technologies of digital twin in tunnel engineering, data acquisition and processing, digital twin modeling, and connection and interaction technologies, are elaborated in detail. Some application scenarios of digital twin technology in the three stages of tunnel engineering design, construction operation, and maintenance are summarized, and based on the cases of some smart tunnel engineering applications of digital twin technology in recent years, such as the Shenzhen-Zhongshan tunnel, the Taihu tunnel in Jiangsu, and the Daloushan tunnel in Guizhou, are generalized. Furthermore, some insights are proposed on the data characteristics of the digital twin model throughout the life cycle of tunnels and the standards of the digital twin model. Currently, the research on digital twins in the tunnel industry is still in its infancy. Although the key technology system for digital twins in tunnel engineering is becoming more and more mature, and the application scope throughout the life cycle is continuously expanding, it still faces challenges such as the difficulty of data acquisition and integration, the complexity of model construction and evolution, the need to improve simulation analysis and decision support capabilities, and the lack of unified application standards. In response to these challenges, the integration of emerging sensing and computing technologies, as well as intelligent technologies, will be the direction for future in-depth research.

Key words: digital twin, tunnel engineering, full life cycle, data fusion