(c) The engineer plans to remove the surcharge when the measured settlement under the embankment fill and the surcharge equals to the calculated settlement due to the embankment fill only. Briefly explain the potential problem for adopting such criterion in determining the time to remove the surcharge in respect of post-surcharge primary settlement. What would be your advice to him on the earliest time to remove the surcharge so as to eliminate the post-surcharge primary settlement? (10) If the engineer now decides to remove the surcharge before it completes the primary consolidation under the embankment and the surcharge. He decides to remove the surcharge when the average effective vertical stress at middepth of the clay layer reaches 166 kPa. What is the effective surcharge ratio of the clay layer at the time of surcharge removal? The time required to complete the primary rebound following surcharge removal is 2.5 months. What is the secondary consolidation settlement of the clay layer 30 years after the surcharge removal