Diaphragm wall as a mitigation technique to reduce ground settlements induced by tunnelling

The adoption of mitigation techniques in addition to the accurate control of excavation stages is often required to contain soil movements caused by the construction of new underground railway lines, thus preventing damage or loss of functionality to existing buildings and structures. The mitigation technique studied in this paper consists of an embedded diaphragm wall pre-installed between the tunnel and an existing building. Two- and three-dimensional analyses were performed to define the most convenient dimensions of the diaphragm wall, related to tunnel diameter and cover. 3D analyses are fundamental to consider the influence of the planar extension of the diaphragm, useful for verifying its compatibility with the built environment.