Abstract:

The running tunnel from Guloudajie Satation to China Art Gallery Station on Line 8 of Beijing Metro crosses underneath old residual building groups for long distance. There is great difficulty in the monitoring and control of the settlement induced by tunneling. The zone within the scope of 15 m on both sides of the center line of the running tunnel is determined, by means of engineering analogy and theoretical calculation, as the zone heavily influenced by tunneling. The buildings located in the mentioned zone are monitored on basis of their positions and types. Technologies, including insidetunnel radial grouting, ground surface Soletanche grouting and insidetunnel grouting assisted by ground surface Soletanche grouting, are adopted to cope with different conditions. Furthermore, ground conditioning and simultaneous grouting assisted by insidetunnel radial grouting are made in waterrich cobble strata. In the end, the ground surface settlement is brought under effective control and safe and successful shield boring is guaranteed. 

Key words: Beijing Metro, shield, longdistance boring underneath buildings, radial grouting, Soletanche grouting, ground conditioning, settlement control, monitoring