Hydro – TBM
The use of TBMs having the more and more complex characteristics is diffusing in deep tunnels excavation. In this context knowledge of rock mass hydrogeological behaviour became in time an issue of growing interest. In particular, the use of TBMs with face counterpressure under high hydraulic groundwater heads may require a complex management of the excavation process to have a prior drawdown of groundwater pressures and to keep them under control.
In order to support at best its clients in the design and construction phase, GDP-GEOMIN has activated a research project on forward pressures drawdown effects by means of different techniques. The project rests on hydrogeological numerical modelling aiming at reproducing effects induced by applied measures. Several case histories are defined, allowing rapid pre-evaluations on pressures drawdown techniques according to several different geological and constructive contexts.
The project is under development and validation by means of case histories from construction sites where GDP-GEOMIN is involved; more details can be found in Baietto & Perello (2020) .