On the Equivalent Pier Approximation for Pile Groups and Piled Rafts

This paper summarises the equivalent pier method for estimating the settlement of a pile group or a piled raft. Such an approach is very useful for preliminary estimates of settlement, and also for checking on the results of more refined analysis methods. Some suggestions for assessing the properties of the equivalent pier and the supporting soil are provided. A series of finite element analyses are presented in chart form for the settlement of a pier within a two-layer soil system. The accuracy of these analyses has been checked via comparison with some published closed form solutions for a uniform soil mass. Examples of the application of the equivalent pier method are presented for some published case histories to demonstrate that the method is capable of providing adequate preliminary settlement estimates.