An interpretation of jet grouting effects on the retaining structures of a deep excavation and on adjacent buildings

This paper deals with the effect that an extensive jet grouting treatment produced on preexisting structures. For the excavation of the new underground station of Conca d'Oro in Rome, adjacent jet grouted columns were created, that connected the two opposite diaphragm walls to provide horizontal contrast, and to reduce the hydraulic flow into the excavation. The jet grouting operations induced significant movements of the diaphragm walls and of the adjacent buildings, that were monitored carefully during the entire construction process. The monitored quantities allowed to establish relationship between the induced structure deformations and some jet grouting parameters, such as the daily production rate and the cumulative number of the jet grouted columns. On the basis of the monitoring results, it was also possible to devise an interpretation of the mechanisms that regulate the jet grouting-induced soil displacements. © 2012 Taylor & Francis Group.