IMPLEMENTATION OF SOIL IMPROVEMENT WORKS AS PART OF RECLAMATION ENGINEERING IN BELAWAN PORT PROJECT

摘要

Soil improvement as steps to be taken in reclamation works where the condition of soil under seabed is very bad based on soil investigaton. It is engineering requirement to do so in order to be able to get the stable soil surface where people can built port facilities on top of it. Pumping or deformation have to be hindered and for this purpose many method can be used in port project. Port facility is a heavy duty construction due to it works for loaded cargoes and heavy equipment as well. It's bearing capacity have to be strong enough to support it. In case of Belawan port development project there are two (2) difference project side by side for the same purpose namely the extention of the existing Belawan International Container Terminal. The Phase I finance by Islamic Development Bank (IDB) and Phase II finance by joint venture parties consist of PT Pelindo I, as majority share holder 70%, PT Hutama Karya and PT Wijaya Karya 15% respectively. Soil improvement works used in both project. In order to make stabilize soil and reduce time settlement both project installed Prefabricated Vertical Drained known as PVD. The original design required that for soil stabilization the project have to install PVD for -40 M depth below seabed and use the triangular pattern. If the phase II project used PVD for 26,5 M depth below seabed and have already installed but the phase I project which don't start the works yet will install the PVD for - 44 M from final surface. Settlement for -40 M in phase I around 4.654 M and in phase II at around 7.039 M. For the same purpose namely construction of container yard but apply different method. Both project have the same soil characterisic under the seabed. The impact of it probably vertical and lateral deformation under seabed will occur from phase II into phase I. In this case the soil improvement works will not obtained the engineering requirement. The research finding that there is no lateral deformation from phase II into phase I but vertical deformation will happen within 99 days.