# Digital Twins' Application for Geotechnical Engineering:
###### Abstract
Because digital twins are based on the interaction between the virtual and the real and the digital-model-driven approach, they can break through many physical limitations and meet application service requirements such as simulation (reflecting the real with the virtual), control (controlling the real with the virtual), prediction (predicting the real with the virtual), and optimization (optimizing the real with the virtual), achieving immediate response to demands, continuous innovation of services, and upgrading and optimization of industries. Currently, more than 50 countries around the world, over 1000 research institutions, and tens of thousands of experts and scholars are conducting related research on digital twins [14]. In recent years, China has also developed rapidly in the field of digital twins. For example, in 2019, the Institute of Industry 4.0 of China initiated the world's first Digital Twin Consortium (DTC), while the OMG of the United States followed up and initiated a similar American Digital Twin Consortium in 2020 [15]. In March 2021, the national \"14 th Five-Year Plan\" outline clearly proposed to \"explore the construction of digital twin cities\", providing national strategic guidance for the construction of digital twin cities. Since then, the state has successively issued the \"14 th Five-Year Plan\" in different fields, making strategic deployments on how to use digital twin technology to promote high-quality economic and social development in fields such as overall planning, information technology, industrial production, construction engineering, water conservancy and emergency response, comprehensive transportation, standard construction, energy security, urban development, and so on [16]. According to data from the China Academy of Information and Communications Technology (CAICT), the digital twin market holds significant growth potential and vast development prospects. In 2022, China's digital twin market reached a scale of CNY 10.4 billion. As digital transformation accelerates across industries, the penetration rate of digital twin technology is expected to rise, driving domestic market growth. It is projected that the Chinese digital twin market will expand to CNY 37.5 billion by 2025 [17]. Digital twinning has become an essential driver for industrial advancement and economic development. With the proposal of new infrastructure construction, digital twinning has become an opportunity that cannot be let go in the new infrastructure construction. Geotechnical engineering is an indispensable part of new infrastructure construction. A large number of geotechnical engineering projects, such as underground pipe galleries, rail transit, high-speed railways, and highways, have the characteristics of large investment scale, long infrastructure period, complex construction environment, and high risk. There are prominent problems such as data and information islands, multimodality, and scattered applications. Traditional engineering management models and technologies struggle to meet the needs of the development of modern geotechnical engineering, and there is an urgent need to study and utilize new information technologies to promote intelligent construction and improve the management level. The digital twin technology is reshaping the paradigm of geotechnical engineering practice. By constructing a closed-loop system of \"perception-modeling-decision-making\", three breakthroughs have been achieved: First, the problem of underground space invisibility has been overcome. With the help of three-dimensional geological modeling and real-time monitoring data fusion, the hidden engineering state has become transparent and visible. Secondly, the uncertainty risk of geological conditions is significantly reduced, and the geotechnical parameters are continuously corrected by dynamic data assimilation technology. Finally, the whole-lifecycle management and control system is established, from traditional static design to dynamic predictive maintenance.