Observed and calculated pore pressures and deformations induced by an earth balance shield

The observed pore pressures and deformations induced by an earth balance shield used to construct the Furongjiang sewer tunnel in soft saturated ground in Shanghai, China, are briefly described. A numerical technique for predicting these pore pressures and deformations is outlined. This approach adopts a coupled viscoplastic-consolidation analysis to describe the time-dependent deformations and strain-hardening behaviour of the soil using parameters obtained from triaxial creep tests. A comparison is then made between numerical results and the results of field measurements, and it is shown that there is encouraging agreement between the calculated and observed response.