An oedometer test on a saturated clay soil gave the following results: Cc = 0.2, Cr = 0.04, OCR = 4.5. The existing vertical effective stress in the field is 130 kPa. A building foundation will increase the vertical stress at the center of the clay by 50 kPa.
The thickness of the clay layer is 2 m and its water content is 28%.
(a) Calculate the primary consolidation settlement.
(b) What would be the difference in settlement if OCR were 1.5 instead of 4.5?