Pile tunnel interaction : Pile settlement vs ground settlements

The underground space of densely populated cities contains parts of buildings, utility installations, deep foundations, tunnels, and deep excavations. It is possible, and increasing more probable, that new underground constructions will be built within proximity of existing pile foundations. This paper analyses how a new a framework for pile analysis, a modified version of the load transfer method, can be used to predict the consequences of the tunnelling induced settlements on existing piles. The soil settlements are calculated with an analytical solution, and the pile settlements are calculated for different pile lengths, loading conditions, and distances between the pile and the tunnel centreline. The results indicate a wide range of possible pile settlements, in relation to the greenfield settlement trough. A simple interpretation scheme is used to understand the results, showing the importance of the profile of soil settlements along the pile.