Compensation grouting is increasingly employed as a mitigation technique of settlements induced by tunnelling and its effectiveness both in clayey and sandy soils is reported in a wide number of case histories. However, the results are highly dependent on grout properties, injection characteristics and soil properties. An experimental study was conducted to investigate the parameters that control grout injections in silty soils. The results from one injection test in a large sample of silty soil show that the compensation efficiency, defined as the ratio of the volume of heave obtained at ground surface and the injected grout volume, is much lower than one and tends to decrease with time, while the initial volume of grout lost due to pressure filtration is small. Finally, results from finite elements back analyses of the laboratory test show that a good agreement with the experimental data can be obtained if the development of large strains is taken into account.
Experimental and numerical study of grout injections in silty soils / Masini, Luca; Rampello, Sebastiano; G. M. B., Viggiani; K., Soga. - STAMPA. - 1:(2012), pp. 495-503. (Intervento presentato al convegno 7th International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground tenutosi a Roma nel MAY 17-19, 2011) [10.1201/b12748-65].
Experimental and numerical study of grout injections in silty soils
MASINI, LUCA;RAMPELLO, SEBASTIANO;
2012
Abstract
Compensation grouting is increasingly employed as a mitigation technique of settlements induced by tunnelling and its effectiveness both in clayey and sandy soils is reported in a wide number of case histories. However, the results are highly dependent on grout properties, injection characteristics and soil properties. An experimental study was conducted to investigate the parameters that control grout injections in silty soils. The results from one injection test in a large sample of silty soil show that the compensation efficiency, defined as the ratio of the volume of heave obtained at ground surface and the injected grout volume, is much lower than one and tends to decrease with time, while the initial volume of grout lost due to pressure filtration is small. Finally, results from finite elements back analyses of the laboratory test show that a good agreement with the experimental data can be obtained if the development of large strains is taken into account.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
