Embankment responses to shield tunnelling considering soil-structure interaction: case studies in Hangzhou soft ground

As more and more under-river tunnels are constructed in urban areas, the deformations and potential damage of existing embankments due to tunnelling have become a major concern. This problem is complex because not only does tunnelling affect the existing embankments, but their presence also alters tunnelling-induced ground movements. An analytical method, which takes account of the effects of the embankment's self-weight, the property of the soil-embankment interface, and the embankment's bending and axial stiffness, is put forward to estimate the embankment's deflections and horizontal strains due to tunnelling. Subsequently, a procedure is proposed to identify the embankment's damage level based on its calculated maximum tensile strain. In the end, case studies of three embankments in Hangzhou soft ground are conducted to examine and validate the analytical method and the damage identification procedure. Further parametric studies show that the embankment's bending stiffness has a significant effect on its deflections and damage level, while the influence of self-weight is mild.