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Introduction
Published in Bujang B. K. Huat, Arun Prasad, Sina Kazemian, Vivi Anggraini, Ground Improvement Techniques, 2019
Bujang B. K. Huat, Arun Prasad, Sina Kazemian, Vivi Anggraini
Sabkha (or Sabkha soils) are soils with a high concentration of salts. These soils originate due to capillary suction and intense evaporation in the coastal and inland flat plains. Sometimes the salinity of the pore fluid reaches as high or higher than that of seawater. The high salt content has a great impact on the strength properties of soils and also on structures in contact with these soils. The collapse potential of saline soils is principally related to the dissolution of salts. These soils have very low strength, low bearing capacity and high compressibility. The expected settlement is always above the recommended tolerable limits. In addition, the salts are highly corrosive. Figure 1.10 shows a picture of Sabkha soils.
Special Fill Materials and Problematic Subsoils
Published in Jan van ‘t Hoff, Art Nooy van der Kolff, Hydraulic Fill Manual, 2012
Jan van ‘t Hoff, Art Nooy van der Kolff
There is no consensus on the precise definition of the term sabkha. The expression sabkha (spelled in some publications as sabkhah, subkha, sebkha, etc.) is originally an Arabic name that has been used to describe saline flats that are underlain by sand, silt or clay and often encrusted by salt. From a broader perspective, sabhka flats are distinguished as being large (in dimensions), flat (gentle slopes), salt-encrusted, evaporate terrains (the rate of evaporation is significantly higher than that of precipitation) situated either along the coast or further inland (Abduljauwad and Al-Amoudi, 1995). The vast bulk of the evaporites are sulphates (gypsum and anhydrite), chlorites (halite) and carbonates.
Hydrogeophysical characterization of the Southern Red Sea coastal aquifer, Saudi Arabia, using Time-Domain electromagnetic method
Published in Human and Ecological Risk Assessment: An International Journal, 2023
Salman S. Alharbi, Saleh I. Qaysi, Mahmoud M. Elwaheidi
The geological setting of the area is highly affected by the opening of the Red Sea tectonics that began in the late Oligocene and is still active today (Bosworth 2015). The Arabian Shield was a part of the Arabian-Nubian Shield before the divergence occurred between the Arabian Plate and the African plate forming the Red Sea rift. The evolution of the Red Sea basin has resulted in the accumulation of salts along the coastal area and formed sabkha areas that are dominated by the presence of halite and gypsum (Nehlig et al. 2002). The surface geology of south Jazan (Figure 1b) is mainly composed of the igneous and metamorphic rocks of the Proterozoic basement in the eastern part, which is separated from Quaternary sediments and Quaternary-Tertiary carbonates along the Red Sea coastal plain by an escarpment. The Quaternary sediments contain alternating layers of sand and gravel that originated by the erosion of basement rocks (Fairer 1983; Camp and Roobol 1989; Zaidi et al. 2017).
Optimised multivariate Gaussians for probabilistic subsurface characterisation
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2019
Mohammad B. Abdulla, Rita L. Sousa, Herbert Einstein, Sara Awadalla
Sabkha is a salt flat. John K. Warren (1989) defined it as marine and continental mudflats where displacive and replacive evaporite minerals are forming in the capillary zone above a saline water table. In general, the Sabkha results from the variation of the evaporation rates of salt water in the soil. The UAE climate is hot during the summer and relatively cool during the winter as it lies close to the Tropic of Cancer. The high temperature of the air and the water in the summer, the strong winds and the low rainfall cause significant evaporation which results in increasing the salinities. Zones with Sabkha are one of the main sources of the geological hazards because of the high concentration of evaporites, such as gypsum, halite and anhydrite, Sabkha layers are prone to heave and/or dissolve when in contact with water, negatively affecting structures on and below the surface.