Utilization of Tunnelling and Underground Structures for Sustainable Development

Even though tunnels for highways and railways have been dominant for the last several decades, the tendency of underground space utilization is more diverse nowadays; for example, the underground structures for public use, caverns for oil and gas storage or for nuclear waste depository. Nowadays, the usage of underground space for sustainable development is also more common. As a Keynote speech, challenges on utilization of tunnelling and underground structures for sustainable development will be presented. On the other hand, one of the major issues in urban tunnelling is the construction of new structures adjacent to existing above and/or below ground structures. When excavating ground near to existing structures, the ground-structure interaction effect has to be considered in the stability analysis as well as in the structural and/or ground behavior. Five case studies are presented in this paper to provide an overview of urban tunnelling with the presence of above/below ground structures. The first example is a case of a cut-and-cover tunnel above existing cable tunnels. The following 3 case studies involve the construction of subway tunnels underneath existing structures: underneath an existing subway station; underneath an existing building; and underneath an existing bridge. The last example is a case where cut-and-cover excavation has to be carried out near to an existing bridge foundation.

Keywords:

Arching , Urban tunnelling , Caverns , Undersea tunnels , Sustainable development , Nearby existing structures