Question

QO vreme (b/n) (6) 3. A 40 ft layer of silty clay is overlain by 5ft of 1000 2000 3000 4000 sand. The base of the clay layer lies over an impervious siltstone bedrock. Water table is at ground surface and is hydrostatic in the clay layer. The initial vertical effective stress do'and maximum past pressure profiles with depth are plotted in the Figure to the right. Initial void ratio e, -0.95. One- dimensional consolidation test results yielded the following: lab C virgin compression index - 0.55 and recompression index=0.072. TH A vertical surcharge load of 1000 lb/ft is placed on the ground over a wide area due to an embankment. To estimate the settlement in the clay, 4 sublayers are used each 10 ft in thickness Layer 1 is from 5 to 15 depth, layer 2 from 15 to 25 depth, layer 3 from 25 to 35 and layer 4 from 35 to 45' depth (a) Use the Figure above to estimate the initial and maximum past pressures con' at the midpoint of layer 2 (b) Estimate the final consolidation settlement for layer 2 due to the surcharge loading Idon't estimate settlement for the other 3 layers).

Answer 1

Sand دهند Clay Layor 1 Clay Cayer - 2 soft. Clay Layer-3 بلد لا Clay Layer-4 Impervious siltstone bedrock. La Midpoint of Layer-2 will be at (5+10 + 10 = 20 ft.) depth. Now, from given Stressers depth graph, for midpoint of Layer-2 initial vertical effective Struss, Evo = 1000 lb/ft? and, Maximam past pressure, bum = 1800 lb/ft? <b> for layer. 2 5vo = dooo ba? A5 = 1000 lb/ft2 1.6: 1000 + 1000 = 2000 16/542 Here, 50o < 5va <o SH = Goh og C + levels of ) = 0.072% do 10g (10) + over 109.(Foto) +0.95 0.223 ft. &