Recent development of multi-purpose utility tunnels in China

Repeated excavations of buried utilities cause road congestion and maintenance conflicts. Besides, the interference of buried utilities in limited underground spaces does not meet the requirement of sustainable urban underground development. Multi-purpose utility tunnels (MUTs) integrate all utilities together in one tunnel and can be accessed by humans. MUTs reduce the excavation needs and costs and avoid the traffic congestion caused by excavations. MUTs also provide easy access for inspection and maintenance of all types of utilities inside the tunnel. There are many MUTs in use in Europe and Japan, but the development of new tunnels in recent years is limited and lacks long-term planning. On the contrary, China is making a big progress in MUT planning and construction in recent years because the Chinese government is taking MUT construction as an important urban infrastructure development. The experience of MUT planning, construction and management in China can be very useful for other countries to examine the potential of MUTs as a sustainable option for future municipal asset rehabilitation projects. This paper first reviews the new development of MUTs including MUT history in China and the total planned and constructed lengths. Furthermore, several projects in major Chinese cities are reviewed including basic data on the length, cross-section, utilities housed, and cost analysis. It is concluded that although the initial cost of MUTs is high, they are sustainable and cost-effective infrastructures for underground utilities in the long term. It is hoped that this paper will encourage further research about the usage of MUTs.