This thesis entitled “Compaction of Silty Sands through Biogenic Gas Desaturation Pretreatment” investigates a method to improve compactibility of an initially fully saturated soil body bringing it to a saturation corresponding to the optimum water content of the targeted soil layer. The process comprises
two stages: a reaction phase to desaturate the soil body, and compaction phase where the necessary loading is applied to the system. The substrate solution with predetermined concentration, combined with a bacterial inoculum to convert the substrate into nitrogen gas, is injected into the soil and left to react.
Gas is produced in-situ as a result of the stimulation of the bacteria which creates a local overpressure and expels water from the system. The desaturated soil body is subsequently compacted. The aim is to achieve a higher degree of compaction with the same energy, or the same degree of compaction with
less energy input in the desaturated soil as opposed to the fully saturated case where energy is wasted on expelling water.