Extracted text: 3. The settlement analysis for a proposed structure indicates that 6 cm of settlement will occur in 4 years and the ultimate, total settlement will be about 25 cm. The analysis is based on the assumption that the compressible layer is drained at both its top and bottom surfaces. However, it is suspected that there may not be drainage at the bottom surface. For the case of single drainage, estimate (a) the ultimate total settlement and (b) the time required for 6 cm of settlement.