A discretization-free method for horizontal dynamic impedance of pile groups in layered, generalized Gibson foundation

This paper presents a novel method for directly analyzing the horizontal dynamic impedance of pile groups in layered soils, characterized by a linearly varying modulus with depth, also known as a generalized Gibson foundation. By introducing the Adomian modified decomposition method, this method eliminates the need for soil discretization, a requirement of traditional approaches such as the integral transforms and transfer matrix methods. As a result, the continuous nature of the soil is better captured, leading to improved computational efficiency and convergence performance. The validity and efficacy of this method are confirmed by comparisons against existing approaches. A parametric study explores the influence of pile configurations and soil properties on the horizontal dynamic interaction factor and dynamic impedance of pile groups. The results highlight a complex nature of dynamic pile-soil interaction under varying non-homogeneous soil conditions and reveal a strong frequency-dependent effect of soil inhomogeneity on the horizontal dynamic impedance of the pile groups. • A novel solution for horizontal dynamic impedance of pile groups was proposed. • Discretization in Gibson soils, essential for traditional methods, is eliminated. • Soil inhomogeneity contributed to a frequency-dependent effect.