Simulating the consolidation of TBM grout at Noordplaspolder

This paper analyses grout pressures measured in two instrumented sections of the Groene Hart Tunnel (GHT) located 20 km South-west of Amsterdam. The consolidation of grout under these field conditions, as well as the formation of a grout cake, is analysed using a consolidation model that applies to both boring and standstill conditions of the tunnel boring machine (TBM). It is shown that consolidation of tail void grout is governed by physical properties that can be quantified in the laboratory. As well as the physical properties of the grout, the properties of the surrounding soil and the bentonite-slurry at the face of the TBM are also important.