With the development of economy, people pursue a more harmonious and livable living environment, and the wide application of intelligent technology is increasingly expanding people's understanding of the future city and underground space. The construction and utilization of underground space are developing rapidly and playing an increasingly important role in urban large-scale infrastructure construction. The rational utilization of underground space is of great help to reduce urban traffic congestion, improve resource utilization efficiency, save energy and reduce greenhouse gas emissions. However, underground space planning, construction, operation and management are also accompanied by significant risks, which may lead to extremely huge economic and personnel losses, and seriously disrupt the normal operation of the city.

With the digital revolution, new concepts such as smart grid, smart building and smart city are gradually improving the efficiency and security of urban management. The conference will be around the many challenges of underground space, adopt intelligent technology to deal with them actively, learn and share experience and achievements from global cities government agencies, underground space construction and operation enterprises, network and intelligent technology provider, innovative laboratory , explore the applications of intelligent underground space in security, efficiency, risk management, sustainability and accessibility , through the innovation to improve our underground space full life cycle of management and intelligent technology application level.

With the successful opening of the foreword International Symposium of Smart Underground Space and Infrastructures Conference, we are pleased to invite you to participate in the fourth International Symposium of Smart Underground Space and Infrastructures Conference. Look forward to your views which will help us to create a more harmonious underground space in the future, welcome your arrival!

Professor：Xiongyao Xie （Tongji University）	Professor：ISAM Shahrour （（University of Lille,France– Tongji University） ）	Deputy Chief Engineer：Qianqian Ji （Shanghai Chengtou Group Corporation）