Identification of soil damping for stiff piles based on experiments: Soil damping curves from physical model tests
Sachin Jindal, Ulvi Rahmanli, Muhammad Aleem, Liang Cui, Subhamoy Bhattacharya
Abstract
Addressing a significant research gap concerning soil material (hysteresis) damping in monopile structures, this study, conducted at the SAGE laboratory at the University of Surrey, investigates the damping behaviour of stiff piles in sandy soil. It examines three monopile sizes with slenderness ratios ranging from 3.75 to 7.5, subjecting them to forcing frequencies between 0.1 and 5 Hz for up to 50,000 loading cycles. The paper presents a thorough examination of bending moments, shear forces, pile displacements, and soil resistance for each test pile, showcasing consistency across test piles. This research critically analyses the effects of embedment length, slenderness ratio, cyclic load amplitude, forcing frequency, and cycle count on soil hysteresis damping. The findings facilitated the introduction of novel soil damping curves along the length of piles. For practical engineering applications, the study introduces a novel framework – Zonal Soil Damping Curves – offering a structured approach to applying soil damping curves.