CE 467L Geotechnical Engineering Spring 2010 Homework 9 Due: Thursday, April 22, 2010 1. The following data were obtained from an oedometer test on a sample of clay: Void ratio, e Vertical effective stress (kPa) 0.953 20 0.948 40 0.938 80 0.920 160 0.878 320 0.789 640 0.691 1280 0.719 320 0.754 80 0.791 20 0.890 0 (a) Plot a graph of void ratio versus log effective stress; (b) Determine the preconsolidation pressure, σ c ′ , using the Casagrande method, and (c) the compression index, C c , and the expansion index, C e . 2. A 5-m thick layer of clay has the following properties: σ c ′ = 140 kPa, σ vo ′ = 100 kPa, C c = 0.64, C e = 0.077, e o = 1.04. A load Δσ is to be applied over the clay over a large area (i.e. settlement will be 1-D). Determine the expected consolidation settlement, s c , for: (a) Δσ = 30 kPa; and (b) Δσ = 60 kPa. 3. Two meters of a granular fill ( ρ = 1.9 Mg/m 3 ) are to be added over a large area atop a 7.5-m thick layer of saturated, normally consolidated (NC)
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This note was uploaded on 09/13/2010 for the course CE 467L taught by Professor Rechenmacher during the Spring '10 term at USC.