Lateral Dynamic Response of Constrained‐Head Piles

Abstract

This paper utilizes an efficient finite‐element formulation to study the dynamic response characteristics of single constrained‐head piles embed ded in a soil stratum whose modulus is proportional to depth from the surface. The excitation consists of a harmonic horizontal force or moment applied at the pile head, and the soil is modeled as a linear hysteretic medium. The results of a comprehensive parametric study are presented in the form of non‐dimensional graphs from which one can readily estimate static and dynamic stiff nesses and effective damping ratios of piles in many practical situations. For flexible piles, in particular, simple, yet sufficiently accurate, algebraic formulas are derived, valid for a wide range of problem parameters. Finally, the concept of an effective soil modulus is introduced to elucidate the importance of soil nonhomogeneity and to gain valuable insight to the mechanics of the problem.