This paper presents an equivalent pier method, in which three kinds of spring (kb at the pier base, ks along the pier shaft and kc of the pile compressibility) are used, for quickly and easily calculating the vertical spring of pile groups subjected to vertical load. Parametric studies of pile groups varying parameters, such as pile spacing, pile length, Young’s modulus of soil and number of piles, were performed. The validity of the vertical spring of pile groups using the equivalent pier method was examined by comparing with the results of hybrid analysis of pile groups.
