Effect of soil layering on the ground response parameters: a parametric study

Soil layering has a pivotal role on the behavior and propagation of seismic waves, hence the ground response during seismic loading. Parametric study to estimate the effect of soil layering on ground response parameters is of prime importance considering the engineering significance of structure founded in seismic zone; nonetheless, it is yet to be well understood. The objective of this study was to investigate the effect of soil layering and soil properties on the ground response parameters. One-dimensional linear ground response analysis was conducted with variation in soil layer parameters including impedance ratio ( α z ), layer thickness ( d r ), and damping ratio ( D ). The acceleration time history of the Bhuj Earthquake ( M w = 7.7), India, was used in the analysis. The results obtained from the analysis were presented as variation of ground response parameters such as spectral acceleration (SA), amplification ratio ( M ) with the soil layer parameters. Results showed higher values of SA at lower D and then decreased with increase in D , that in fact depict the resistance offered to the particle oscillation at comparatively higher values of D . Similarly, variation in SA and M was very less or negligible when the α z was varied from 1 to 3 and the d r equal to 0.2, while for d r greater than 0.2 the variation increased with α z and d r . The outcome from the parametric study presented in this paper clearly demonstrates the significance of α z , D , and d r of the soil layers on the ground response parameters.