The role of building dimensions and position on the response of buildings to tunnelling subsidence: centrifuge modelling

In urban tunnelling it is essential to predict the performance of surface structures to tunnelling-induced ground movements. Existing methods to assess potential building damage assume that a building located within the hogging and sagging region of the settlement trough can be subdivided into its sagging and hogging parts, which are then analysed separately. Netzel (2009) importantly identified that this splitting of a building can underestimate the structural damage. This paper examines the effects that both the building length perpendicular to the tunnel axis and the building location relative to the tunnel have on the building response to tunnelling in dry sand. A series of centrifuge model tests, performed on 3D printed surface structures with different building stiffness, are discussed. The findings confirm that potential structural damage caused by tunnelling-induced ground movements significantly depends on the building length and the location of the building within the settlement trough. Importantly, structures that span the sagging/hogging transition zone were found to be more vulnerable to building damage (in the form of cracking) than equal length structures wholly located in either the hogging or sagging region. Longer structures that span the sagging/hogging transition zone were found to be even more vulnerable. As a consequence, experimental results indicated that partitioning a structure into its sagging and hogging parts can lead to underestimation of building damage