Numerical investigation into time-dependent effects on short-term tunnelling-induced ground response in London Clay

The application of the finite element method to tunnelling problems in London Clay has received significant attention over decades of research, but has proved to be a challenging problem. Numerical predictions usually produce a surface settlement trough wider and shallower than field observations. Given the low permeability of the London Clay strata, previous studies assumed undrained conditions to assess the short-term ground response. This paper explores the time-dependent effects on the short-term ground response to tunnelling in a series of hydro-mechanically coupled plane-strain finite element analyses. The influence of adopting different values of soil permeability as well as different ratios of horizontal and vertical permeability on the surface settlement trough was assessed by comparison with the undrained condition case and the Gaussian distribution.