Discussion of 'Tunnel-Pile Interaction Analysis Using Cavity Expansion Methods' by Alec M. Marshall

摘要

The author has presented a very interesting and useful approach for analyzing the effect of tunneling on the end-bearing capacity of piles using the cavity contraction method. The method determines the reduction in the pile-base capacity through evaluation of the changes in mean effective stress according to the cavity contraction model. One of the characteristics of the cavity expansion and contraction solutions is that outside the plastic region, in the elastic region, the mean effective stress remains constant. This characteristic may be used to directly evaluate the critical tunnel pressure and volume loss at which the pile end-bearing capacity begins to degrade according to the method.