Freetown, Sierra Leone, is home to the West African Coast’s largest natural harbour. Beckett Rankine has planned, designed, and managed the construction of a new berth to expand the port terminal.
In the latest phase of work, dredging and reclamation for the new berth has taken place using an innovative approach.
Learning from previous projects in the area, good quality hydraulic fill material was sourced from a nearby area of seabed.
A reasonably small dredger (with a hopper capacity of approximately 1000m3) was used to carefully place fill in the structure at a controlled rate. Both rainbowing and piped delivery techniques were used.
To ensure stability of the structure in the soft ground conditions, a sophisticated, automated observational method for the reclamation was used, consisting of multiple prisms, tiltmeters and settlement markers placed on the new steel walls and within the reclamation.
This resulted in a comprehensive monitoring system that was simple to use, yet highly effective in tracking displacements against the design modelling.
