In the Ljubljana city center the Ministry of Higher Education, Science and Technology has plans for a construction of a new National University Library by Jože Plečnik (NUK II). The structure is designed in such a way that a central part of the library a high shelving storage is located over four cellar floors. The structure arrangement affects the foundation soil up to a depth of 17.0m. Geologically the region of construction is one of the most demanding in Slovenia. The structure site is located on the passing through high compressible sediments of the Ljubljana Moors (in a thickness of up to 32m) at a southern part and somewhat better gravel and clayey alluvium of the Ljubljana field at a northern part. There are two groundwater levels at the site. The geological soil structure gave rise to a choice of technology for protection of the deep excavation by braced thick diaphragm wall and technology of top-down structure construction.