Secondary compression of sabkha “saline” soils: Fid-Bau Portal

Secondary compression of sabkha “saline” soils

Dhowian, Abdulmohsin W.

Abstract Sabkha soils are coastal and inland saline deposits of arid climates consisting mainly of loosely cemented sandy silt to silty clay particles. Invariably the soils contain an appreciable amount of organic material and therefore are characterized by being highly compressible. A significant part of the soil settlement takes place as secondary compression. Prediction of field settlement is very important since one of the most feasible methods of soil improvement is the preloading technique. In this study settlements were predicted using the conventional theory of consolidation and the Lo rheological model utilizing long-term consolidation test parameters. The prediction was compared with the field settlement of the compressible sabkha layer loaded by an instrumented test embankment. It was found that the model provides a better approximation with regard to the rate of settlement, which was underestimated by Terzaghi's theory. The magnitudes of primary and secondary consolidation settlement were adequately estimated by the model. Furthermore, almost identical values of the measured and predicted combined settlements were obtained at the end of the nine week period of observation.