Answer Happy

QUESTION 3 (35 marks) A soil profile at a site is shown in Figure 1. A soil specimen is taken from the middle of the clay layer and subjected to a consolidation test, and following properties are reported. • Moisture content of clay - 13% • Specific gravity of soil grains = 2.7 • OCR-4.0 • Compression Index (C.-0.5 Recompression Index (C)=0.04 a) Calculate the effective vertical stress at the middle of the clay layer (10 marks) b) Calculate the pre-consolidation pressure (5 marks) c) A compacted fill placed on the ground surface will increase the stress at the middle of clay layer by 200kPa. What would be the final consolidation settlement? Dividing the clay layer into sublayers is NOT required. (12 marks) d) If the OCR of clay is .X, what is the expected settlement of clay due to the same fill layer? (8 marks) Water table Ground Level Year=21. OkN/m Sand Year=20.4kN/m 2. Om Clay edrock Figure 1 6