Abstract: The traditional model of urban underground utility tunnels faces challenges such as insufficient coordination between municipal pipelines and underground space development, a low level of intelligent construction and management, poor integration of equipment systems within the Internet of Things (IoT), high energy consumption during operation and maintenance, and numerous quality issues. To address these challenges, a case study is conducted on an urban underground utility tunnel project in the Xiong′an new area, China. The primary technologies for utility tunnel construction are comprehensively summarized based on the systematic requirements of utility tunnels in terms of system networking, spatial flexibilization, and intelligent operation. In the design stage, a "five-in-one" utility tunnel planning and design method integrating rail transit, utility tunnels, municipal pipe networks, underground space, and intelligent facilities is established. An overlapped co-constructed structural design method integrating utility tunnels, logistics galleries, and underground roadways, together with a three-dimensional spatial design concept, is proposed to resolve challenges such as high resource consumption, increased risks, and high costs associated with phased construction of utility tunnels and other municipal infrastructure within limited space. In the construction stage, innovations related to the U-shield segment erector and prefabrication and assembly technologies for long and large segments are summarized. In addition, the development process and primary implementation steps of large-scale construction equipment, including gantry cranes, gallery transport vehicles, and prestressing tensioners, are presented. In the operation and maintenance stage, an intelligent operation and maintenance platform for utility tunnels is designed and implemented. The platform software is developed based on the IoT concept. Considering the complexity of utility tunnel structures, an industrial IoT node self-organizing network algorithm is independently developed, and a series of IoT edge-access hardware products, including gateways, repeaters, collectors, and controllers, are designed and developed. These technologies effectively address management and technical challenges related to high operating costs, slow information transmission, difficult emergency coordination, and complex equipment terminal management in large-scale, cross-regional, and diversified utility tunnel operation entities.

Key words: utility tunnel, intensive planning, prefabrication and assembly, U-shield segment erector, Internet of Things operation and maintenance