Abstract:

In the paper, the methods and results of the in-situ monitoring of the ground pressures acting on a shield-driven tunnel are presented, including selection and layout of the monitoring elements, monitoring methods, monitoring results and relevant analysis. By means of analysis on the monitoring data, the law of the time-dependent variations of the ground pressures acting on the shield-driven tunnel is concluded. Furthermore, in the paper comparisons are made between the measured values of the ground pressures and the theoretical values of the ground pressures. T he study results indicate that the ground pressure calculation model of the traditional design method that are often used in the present designs are reasonable and that the calculated ground pressures are almost in agreement with the measured ones. The simultaneous grouting pressures, which are larger than the measured ground pressures, are the largest external loads acting on the outer surface of the segments during construction, therefore the simultaneous grouting pressures should be considered in determination of the values of the external loads.

Key words: shield machine  , tunnel  , ground pressure  , monitoring experiment