The main topic of this graduation thesis is a design for construction of pier III at the Port of Koper. More precisely, my attention has been focused on the southern part of the pier which it only is to be designed for the purposes of the port. The first part of the thesis presents a theoretical basis for designing the construction of the future pier. The specific purposes of a particular part of the pier, their geometrical assumptions and other requirements related to the installation into the surroundings, are determined by the National Spatial Plan. Geomechanical characteristics of the seabed composition and cross section of the port taken from existing geomechanical measurements are to be used to make a computer seabed model in Plaxis program. The selection of the pier type construction is based on these results. Two types of pier structure have been selected as suitable: one type is a relieving platform whose basic concept is transferring a
horizontal back pressure through deep foundations, e.g. piles and the other is an open berth. The design consists of a concrete platform and deep foundations on piles. Both types have also been compared interms of implementation costs per metre. The cost of Pier III construction works for both types has also been estimated.