Laboratory Tests on Model Piled Raft Foundations

Laboratory tests were performed on four model piled raft foundations in a pot filled with over-consolidated clay. In these experiments a concentrated load or pattern of loads was applied to a foundation, and settlements and strains were measured for 60 min before adding more load. The experimental load-settlement and load-moment curves were compared with the results of theoretical calculations using values of Young's modulus for the clay back-figured from results for similar tests on single piles and small rigid circular rafts. The method of analysis for piled raft foundations which was used to obtain the theoretical results is described. In this method the raft is represented as a thin plate on piles and an elastic continuum. Nonlinear effects such as pile or soil bearing failure and uplift of the raft can be treated by this method of analysis.