Open-face tunnelling effects on non-displacement piles in clay ii) Tunnelling beneath loaded piles and analytical modelling

Abstract

Results from centrifuge modelling of tunnelling beneath loaded non-displacement piles in clay are presented in this paper; the principal variables were soil strength, pile loading and pile position relative to the tunnel. The details of the experimental set-up and the importance of understanding the loading history of the soil and the piles are presented in a companion paper. The subsurface pile–soil interaction was captured through particle image velocimetry; the effects of pile loading and pile position were found to have a significant impact on pile settlements. Analysis of tunnel–pile interaction through t–z load-transfer modelling of the pile–soil interface is presented using the approach described in the companion paper. The mechanisms observed in the centrifuge tests are predicted reasonably well. A significant improvement in the prediction of the induced pile loading and settlements was achieved with the inclusion of plasticity and simple power-law non-linearity for the soil.