To estimate the primary consolidation settlement of a site, a clay sample from construction site was taken to laboratory for one-dimensional consolidation test. During the consolidation test, the changes of sample thickness against the initial sample thickness were recorded in corresponding time as follow: Time (min) Change in thickness (mm) 0 0.25 Initial thickness 0.14 0.5 0.19 0.26 1.0 2.25 4.0 6.25 0.36 0.47 0.59 Time (min) Change in thickness (mm) The thickness of the specimen was measured as 16.24mm at stage of 400 minutes. 9.0 12.25 16.0 20.25 30.25 49 144 0.70 0.83 0.93 0.99 1.05 1.10 1.14 400 1.18 (i) By using of the Root Time method, plot a graph against the specimen thickness, and determine the coefficient of consolidation (c, in m/year) of the clay sample. (Consider one year is 365 days.) (26 marks) (ii) By adopting the c, determined in (i), find the time (in years) to reach 30% and 60% primary consolidation, provided that the thickness of the clay is 12m with sand on top and heavily fractured rock layer at bottom. (16 marks) (iii) By adopting the c, determined in (i), determine the permeability, k (in m/s), by assuming that my is 0.004m/kN. (8 marks) Consolidation settlement comprises primary and secondary consolidation settlements, briefly explain the different (10 marks)