On the recovery coefficient and parameter selection for a new type of diskspring pile cap

The use of the disk spring pile cap, consisting of a contained group of sev eral stacked disks, because of its high spring constant and high recovery c oefficient, can raise pile driving construction efficiency. In order to rea ch the optimum effect, however, the proper spring arrangement in the stack. the proper composite spring stiffness, and the proper spring recovery coef ficient must be selected. The authors have carried out an optimization anal ysis of these disk spring parameters in order to find the most appropriate set for effective pile driving under given conditions.