A NOVEL METHOD FOR DETERMINING SOIL DAMPING RATIO COMBINING DMA AND STRAIN ENERGY

Abstract

Despite extensive research efforts, no comprehensive method for measuring soil damping has been established at either the national or international levels. In this study, a novel approach is introduced, utilizing a box-soil structure combined with Dynamic Mechanical Analysis (DMA) to experimentally determine the damping loss factor for both the box-soil structure and an empty box. Simultaneously, finite element analysis was employed to calculate the strain energy of the soil and the box separately.  This process allowed for the derivation of the damping value in soil, presenting an innovative and accessible method for assessing soil damping. Additionally, this research offers a systematic approach to investigating soil damping patterns and compares the results with conventional triaxial dynamic testing. The comparison affirmed the viability of this new technique. The results show that the damping loss factor of soil increases and then decreases with the strain, with the maximum value. By calculation, the damping ratio of soil is between 0.08 and 0.3, and the damping ratio (λ) increases as dynamic shear strain(γ) increases and its range and change trend are consistent with the results obtained by conventional test methods.