Transparent Soil Model Tests and FE Analyses on Tunneling Induced Ground Settlement

Ground movements due to tunneling are crucial in urban areas where damages to surface structures and utilities should be prevented. In this study, transparent soil models are used to investigate not only the surface settlement profile induced by shield tunneling, but also the distribution of soil deformation within the soil mass near the tunnel. A series of finite element analyses have also been carried out using PLAXIS 2D for the tests conditions. The observed and computed surface settlement profiles are consistent with the normal probability curve commonly used in practice for predicting settlement, with only the inflection points or trough width parameters form the transparent soil models being somewhat different. The measured data is consistent with field measurements in that the trough width parameter is independent of the volume loss and linearly proportional to the tunnel depth. Analysis of the displacement field inside the transparent soil models indicates that subsurface settlement trough at different depths can also be approximated by a normal probability curve.