Gravel Clay C Impermeable bedrock

Q 1) A concrete foundation rests on the surface of a soil mass. Determine the vertical stress increase at point A. 4 m 1 m 1.5 m PLAN 1.5 m Fondation Load 3000 KN 2 m SECTION A Soil

indicate the final answer in 3 decimal places.

Q1: Choose the correct answer 1. Lateral earth pressure (passive or active) is a dependent of A. the angle of internal friction the cohesion of soil b. c. the unite weight of the soil d. all of the above 2. Tension cracks occur a. b. within the active zone of a cohesive soil within the active zone of a cohesionless soil within the passive zone of a cohesive soil c. 3. d. within the passive zone of a cohesionless soil resist the applied earth loads only by their weight. a. Gravity walls b. Cantilever walls c. MSE walls d. Counterfort walls 4. The main disadvantage of using cohesive soils to backfill retaining structures a. decrease passive pressure b. cause tension cracks c. groundwater accumulation behind the wall d. increase active pressure 5. of clay is required when designing shallow foundations. a. Elastic settlement b. Settlement during construction c. Final consolidation settlement d. Secondary settlement

For the following statements: P: The lateral stress in the soil while being tested in an oedometer is always at-rest. Q: For a perfectly rigid strip footing at deeper depths in a sand deposit, the vertical normal contact stress at the footing edge is greater than that at its centre. R: The corrections for overburden pressure and dilatancy are not applied to measured SPT-N values in case of clay deposits. The correct combination of the statements is P Q R (a) True True False (b) False (c) False False True False False (d) True True True

Solve it

Calculate: a.) The unit weight of soil at a depth of 3m below the ground surface.  b.) The normal stress of soil at a depth of 3m below the ground surface. c.) The potential shear strength of the soil at a depth of 3m below the ground surface when the water table is at a depth of 3.5m and the soil is cohesionless. d.) The modified value of the shear strength if the water table reaches the ground surface. e.) The modified value of the shear strength if the water table reaches the ground surface but the soil has a cohesion of 12 kPa.

11.19 Refer to Figure 11.45. A square footing, 2 x 2 m in size, supports a column load of 300 kN. The soil characteristics are given in the figure. Field monitoring indi- cated that the foundation settlement was 19 mm during the first 12 months. a. Estimate the average stress increase in the clay layer due to the applied load. b. Estimate the primary consolidation settlement. c. What is the degree of consolidation after 12 months? d. Estimate the coefficient of consolidation for the pressure range. e. Estimate the settlement in 24 months. 300 kN 1m 2m x 2 m Ya = 14 kN/m3 I m Yu = 17 kN/m 24% G, = 2.74 LL = 46 2 m o'= 40 kN/m² C, = 1/5C. Sand Clay Figure 11.45 O Cengrge learring 2014