By R A Nicholls, Halcrow, A J Barry, Peter Fraenkel & Partners and R Shoji, Rinkai Construction
This paper was first published in GE’s May 1984 issue
Construction work for an additional five ocean-going berths at the Port of Belawan in Sumatra, Indonesia, started in April 1980 and the first contract, for reclamation and ground treatment, has now been completed.
The reclamation area is some 900m by 250m in extent and is underlain by compressible marine clay. Along the line of the future quay the soft clay was removed by dredger and replaced by sand dumped from bottom discharging barges. Above the level at which the barges could operate the sand was placed hydraulically to the required profile.
The additional loading of the clay by the reclamation fill was expected to result in significant vertical and lateral deformations. In order to reduce the long-term movements to within acceptable levels the use of vertical drains was adopted.