This paper presents a case of closely spaced twin tunnels excavated beneath other closely
spaced existing twin tunnels in Beijing, China. The existing twin tunnels were previously
built by the shield method while the new twin tunnels were excavated by the shallow
tunnelling method. The settlements of the existing tunnels and the ground surfaces
associated with the new tunnels construction were systematically monitored. A superposition
method is adopted to describe the settlement profiles of both the existing tunnels and the …