Acceleration of embankment construction on soft soils of Salamanga using wick drains and counterweight fills
Acceleration of embankment construction on soft soils of Salamanga using wick drains and counterweight fills
The construction of embankments on soft soils is an inevitable solution in the case of roads crossing thick clayey alluvial deposits. In such cases, consolidation acceleration techniques can be adopted, in order to prevent excessive settlements to occur as a result of the stress increase induced by the embankment or causing it to fail due to insufficient shear strength of the foundation. This paper evaluates technical solutions for accelerating the construction of embankments on soft soils using wick drains and counterweight fills. This solution was implemented on the construction of a 9.6 m high embankment between the years 2016 and 2017, along the Maputo River floodplain, in Salamanga District. The construction was preceded by an extensive geotechnical investigation, including in situ and laboratory tests, which identified the existence of a 39 m thick deposit of soils that were not only highly compressible and of low permeability, but also had a low shear strength, reason why counterweight fills were adopted to prevent failure of the embankment during the staged construction. Because of the uncertainties involved in the characterization of soft soils, related to the sedimentation process, and spatial variation of their properties, and in predicting their behavior when loaded, an instrumentation and monitoring plan of the construction was implemented, whose results were used to calibrate the geotechnical model. From the collected data, it was concluded that the designed solution performed satisfactorily and the project assumptions regarding the allowable residual settlements and stability of the embankment were met before laying the pavement.
Hans Dete; Carlos Quadros
18th European Conference on Soil Mechanics and Geotechnical Engineering (ECSMGE2024)
D - Current and new construction methods
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