'Precasting of the Pier Structure' and 'soil Improvement at Reclamation Area' in Mombasa Port Development Project Phase 2
WODCON XXIII - Dredging is changing - The Practice. The Science. The Business.
J. Takeda, S. Tokiwa, D. Niina
"This project was started in 2018 to build a new container terminal on the west side of Phase 1, which was constructed by Toyo Construction Co., Ltd. and completed in 2016, in order to improve container handling capacity and operational efficiency at the Port of Mombasa, located in Mombasa City, the second largest city in the Republic of Kenya. In order to shorten the construction period based on the requirement of the owner, precasting of the pier superstructure was adopted. In the precasting of the structural members, it was necessary to design the structure considering the stress of each precast members at the construction stage. By manufacturing the precast concrete on land, we were able to simplify the construction method and shorten the construction period. In addition, the reclamation area, which is to be used as container yard, was found to have poor subsoil, and soil improvement was carried out using PVD (Prefabricated Vertical Drain) in order to expedite consolidation settlement and surcharging embankment to reduce residual settlement after the operation of the container terminal. This soft clay layer varied greatly in depth from about 10 to 30 meters and was undulating. Since the thickness of the clay layer has a significant impact on the calculation of consolidation settlement, it was necessary to accurately determine the thickness of the layer. In addition, due to the limited construction period, the consolidation period was only seven months, so it was necessary to study the amount of consolidation settlement at the time of removal of the surcharging material and the amount of removal of the surcharging material to minimize the residual settlement after the container terminal was put into service. As a result of these studies, we are now in the process of constructing the container terminal with the aim of completing it within the construction period with high quality."
Keywords: Precast concrete, Stress on member, Soil improvement, Thickness of Clay layer, Residual settlement