GROUND MOVEMENT OVER THREE YEARS AT THE HEATHROW EXPRESS RAIL TUNNEL

Measurements of ground deformation in London clay around the Heathrow Express Trial Tunnel, United Kingdom, were taken over three years since excavation, during which time only temporary support was installed. The observations show significant additional movements to have occurred after completion of construction, however by the third year the rate of movement was greatly reduced. Analysis of these data suggests an empirical basis for the prediction of long-term movements over other similar excavations and allows consideration of the effects of longer term tunnelling induced ground movements on overlying structures. For the covering abstract see ITRD E116463.