Ground movements resulting from urban tunnelling: predictions and effects

The paper provides practical guidance for estimating the effects of ‘soft ground’ tunnelling in urban areas upon existing structures and services. Various empirical approaches to the definition of the surface settlement zone are summarized and the assessment of the magnitude and distribution of surface movements is compared with case history data. A tentative risk classification related to settlement and maximum slope criteria is proposed, which will allow rapid optimization of route adjustments and thereby identification of those buildings particularly at risk and requiring a more detailed assessment.