EXAMPLE OF PROTECTION OF DEEP FOUNDATION PIT IN COMPLEX URBAN AND GEOTECHNICAL CONDITIONS

In the construction of new buildings with several underground floors, in urban areas, a special problem is the protection of deep foundation pit and adjacent structures, especially when it comes to old, shallow and masonry structures that lack adequate stiffness. If complex geotechnical conditions are met, in the form of high groundwater level, high water permeability of the soil, and proximity of the river, which is in a hydraulic connection with the site, the complexity of building underground part can be overcome in many ways over the complexity of the above-ground construction. This paper presents a very complex problem of protecting the deep foundation pit for the three-storey underground garage of the residential and business building "Pupin's Palace" in Novi Sad, in Boulevard Mihajla Pupina, with total area of about 43,000m(2), and very diluted floors. On the construction line of the future facility were multistorey, old, shallow-grounded and masonry buildings. The groundwater level at the site was relatively high, in a direct hydraulic connection with the Danube river, which is about 800m away, and a large subterranean water supply through the permeably and easily mobile sediments of the Danube sand. Several conceptual designs of the protective structure were analyzed, the advantages and disadvantages of the solution were considered, and the adopted solution for protection of the foundation pit and adjacent objects was described in detail. At the moment of writing this article, the underground part of the building was successfully completed, and the results of the measured shifting of the protective structure were within the estimated limits.