Dynamic Soil–Structure-Group Interaction Under Incident Antiplane Shear Waves: Analytical Solution and Parametric Analysis

Dynamic soil–structure-group interaction (SSGI) effect is of great significance for seismic analysis and design of structural portfolios in densely built areas. However, previous studies investigating the SSGI effect fail to rigorously disclose the fundamental physics and comprehensively assess the influences of various affecting parameters. Based on elastic wave diffraction theory, this study considers the single-degree-of-freedom (SDOF) structures with rigid circular-arc foundations buried in elastic semi-space and derives the analytical solution to quantify the SSGI under antiplane shear waves, and solves the solution by MATLAB software. The proposed solution can solve the dynamic interaction between soil and an arbitrary number of structures. Its accuracy is also examined against previous studies for simple structure group scenarios. Subsequently, a comprehensive set of parametric analyses is performed to quantify the influences on the structural response due to the presence of adjacent structures. This study indicates that the SSGI effect is highly dependent on the frequency and incident angle of the wave, the structural number, natural frequencies, and spacing, the soil shear wave velocity, and the depth and size of foundation. Greater structural damping generally reduces the SSGI effect, though the magnitude of this reduction is minimal. In addition, the SSGI effect does not always increase with a larger number of structures, it fluctuates and tends to decay with a larger structure spacing.