Discussion on Redevelopment of the South Side of Victoria Street, London by F.T. Hodgson and A.W. Bryan
Professor N. Simons: Being a foundation engineer I obviously found a great deal of interest in the paper. but I would like to discuss one point in particular this evening and this is this philosophy of the design of a piled raft about which the authors have written. Considering raft foundations in the London clay, which are also piled, in many cases the piles are provided solely to reduce settlement. In other words, if there were no piles whatsoever, there would be a perfectly adequate factor of safety against failure. So when such piles are installed only to reduce settlement then obviously the design concept must be considered. The point I wish to make is; should the piles be designed to carry the total building weight, or is it necessary only to carry the net increase in loading on the piles?