A Numerical Investigation of the Bearing Capacity of Shallow Foundations on Salt-Encrusted Flat Sabkha

Abstract

Salt-encrusted flats, or Sabkha, are common in arid and semi-arid regions worldwide, including coastal and inland areas. Due to their low shear strength and high compressibility, these soils are often unsuitable for supporting infrastructure or structures. The unique salt content of sabkha formations sets them apart from other soil types. This study aims to evaluate the geotechnical properties of sabkha soils using numerical modeling. Specifically, the study focuses on the bearing capacity of shallow foundations underlain with sabkha soils. A numerical model of a sabkha soil deposit is developed to simulate soil behavior under various soil layering conditions. The present study has produced several significant outcomes. Initially, a thorough database of sabkha soil properties was developed by conducting a comprehensive review of the existing literature. This database was subsequently classified according to the location of the soil. Using this database, a finite element method analysis of the load-displacement response of shallow foundations was undertaken. The results revealed that the bearing capacity of Sabkha soil was generally low, ranging from 70 to 110 kPa, depending on the salt content of the soil and its geotechnical properties. Notably, the coastal sabkha exhibited a lower bearing capacity compared to inland sabkha, which is contrary to some previously reported findings. Additionally, our investigation demonstrated that the stress state of the soil was affected by the level of dryness, wetness, and cementation. However, these changes did not result in a significant increase in bearing capacity, with the increment being limited to 10 to 30%. Also, ensuring the serviceability of structures erected on Sabkha soil presents a challenge due to its heightened strain, which in turn complicates the acceptance of its corresponding increased bearing capacity. Overall, further testing and evaluation of this soil is necessary to compare its properties with those reported from other locations. Although current reports are limited, it is imperative to conduct additional research due to the increasing development demands in these areas.