Samenvatting
The measurement of surface and sub-surface settlements and surface horizontal movements caused by the construction of a 3m internal diameter tunnel in loose fill material comprising mainly ash and domestic rubbish is described. The maximum ground surface settlement was 81mm recorded over the centre-line of the tunnel and the cross-sectional area of the settlement trough represented 16 per cent of the area of the tunnel face. Sub-surface settlement measurements show that compaction within the fill caused three-quarters of the total surface settlement. Maximum horizontal movements recorded were about 20mm. (Author/publisher)