Anomalous dynamic response and micro-zonation of saline sabkha soils of eastern Saudi Arabia using 3D seismic behavior modelling

Abstract

Abstract The available seismic response parameters do not accurately represent the unusual behavior of sabkha soils; the weak soils with high salt content. This study aimed at developing seismic response parameters for sabkha soils in Ras Al-Khair Industrial City, Saudi Arabia. These sabkhas revealed an anomalous response to geophysical and dynamic tests. The methodology involved analysis of extensive available data to come up with micro-zonation based on subsurface strata. Field and laboratory explorations were conducted, and 3-D seismic response was numerical simulated. This study identified an anomalous dynamic response of sabkha soil, as it has higher shear modulus. The spectral accelerations values, for both short-period and long-period, have been found to differ from the values specified in local codes. Scientific contributions include the localized liquefaction potential along the boundary of the contrasting strata. The site-specific seismic response is found to be not only dependent on the structure and fabric of the soil, but also highly affected by the pore fluid. Originality appears in utilizing 3-D modelling/ simulations to produce liquefaction hazard maps. It is concluded that 3-D modelling/simulations lead to a more realistic representation of ground conditions. The seismic parameters are recommended to be revised based on 3-D modelling that considers the type of pore fluids.