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Sammanfattning: This thesis compares foundation methods for buildings on low-strength, limited-depth soil. The study focuses on soil replacement and piling, specifically concrete and steel piles. The studyaims to answer the key questions about the possibility to use short piles on limited depth, cost-efficiency, and environmental impact of these methods. Geotechnical and structural calculations are used to assess the loads on the piles and evaluate their strength. WIN-statik Frame Analysis helps analyze deformations, moments, and stresses. The foundation transfers vertical loads to three piles, generating horizontal loads at the pile tops. However, the challenge lies in short piles in clay, which experience low earth pressure and may rotate due to bad stabilization. The analysis reveals that concrete piles are unable to transfer loads to solid rock effectively. Without fixed anchorage points, they are prone to rotation due to insufficient stiffness and lateral earth pressure. In contrast, steel piles are preferred because they can be drilled into the rock, providing fixed anchorage at the clay-rock transition and enabling them to withstand loads transferred through the foundation. Soil replacement is considered as an alternative method but proves economically expensive, approximately three times more than piling with steel piles. From an environmental standpoint, piling contributes only slightly more carbon dioxide emissions, about 0.4 tons, compared to soil replacement. Considering the significant cost advantage and minor environmental impact difference between soil replacement and piling, piling with steel piles is recommended as the optimal foundation method. Concrete piles are dismissed due to their instability. This choice ensures stability, cost-efficiency, and reduced environmental impact for buildings on low-strength, shallow-depth soil.