Geology and Soil Mechanics 55401 /1A (2002-2003) Mark the best answer on the multiple choice answer sheet. 1. Soil mechanics is the application of hydraulics, geology and mechanics to problems relating to? A. rock B. soil C. building D. foundation 2. Which of the followings are the three basic geotechnical engineering problems? i) Stability ii) Deformation iii) Water A. i) only B. i) and ii) only C. i) and iii) only D. i), ii) and iii) 3. The three main rock types are 4. Hard rigid coherent deposit forming part of the earth s crust. 5. An inert soil layer between the topsoil layer and bedrock. 6. Weathered down remains of rocks that have undergone no transport and do not retain any structures of the parent rocks. The following answers are for questions 7 to 9 A) Alluvial Soils B) Cohesive Soils C) Cohesionless Soils D) Mechanical Weathering 7. Soils containing clay/silt particles which prossess some forms of cohesion and plasticity. 8. The disintegration of rock by purely physical means. 9. Materials such as sands and gravels deposited from rivers and stream. i) Igneous Rocks ii) Metamorphic Rocks iii) Sedimentary Rocks A. i) only B. i) and ii) only C. i) and iii) only D. i), ii) and iii) The following answers are for Questions 4 to 6 10. Grade III soil means A. Fresh rock B. Moderately decomposed rock C. Completely decomposed rock D. Residual Soil 11. Which of the followings is true in the unit solid volume model. A) Rock B) Soil C) Subsoil D) Residual Soil A. V T = 1 B. Ms = 1 C. Vs = 1 D. Vv = 1
12. In a specific gravity test, the mass of density bottle is 0.040 kg. Mass of density bottle+ dry soil is 0.485 kg. Mass of density bottle+dry soil+water is 0.946 kg Mass of density bottle+ water is 0.674 kg. The specific gravity found is A. 2.57 B. 2.62 C. 2.67 D. 2.72 Questions 13 to 17. Given Mass of wet soil : 1.25 kg Mass of dry soil : 1.00 kg Volume of the soil : 714.29 cm 3 G s = 2.7 13. The bulk density of the soil is A. 0.543 B. 0.928 C. 1.543 D. 1.928 17. The degree of saturation is A. 1.243 B. 1.709 C. 2.842 D. 3.550 18. Which of the followings is not the component of coarse grained soil? A. cobbles B. gravels C. sands D. silt. A. 3150 kg/m 3 B. 1750 kg/m 3 C. 1400 kg/m 3 D. 350 kg/m 3 14. The dry density of the soil is 19. The particle size of sand ranges from A. 2mm to 60 mm B. 60 mm to 2 mm C. 60 mm to 60 mm D. 2 mm to 60 mm 3150 kg/m 3 1750 kg/m 3 1400 kg/m 3 350 kg/m 3 15. The water content of the soil is Questions 20 to 21 The following information are obtained from a grading curve of a soil. D 10 = 1 mm D 30 = 6 mm D 60 =9 mm 2.25 1.25 1.00 0.25 16. The void ratio of the soil is 20. The coefficient of uniformity of the soil is A. 9 B. 6 C. 1.5 D. 0.666
21. The coefficient of curvature of the soil is A. 36 B. 13.5 C. 4 D. 0.018 22. The minimum water content at which soil will flow under its own weight is called : D. liquid state 26. A fine grained soil has a Liquid Limit (LL) of 40% and a plasticity Index of 30%. The soil can be classified as A. CL B. CI C. CH D. MI A. Plasticity Index B. Shrinkage Limit C. Plastic Limit D. Liquid Limit 27. In a cone penetrometer test to find the liquid limit of a fined grained soil, the liquid limit is the moisture content under which the penetrometer can penetrate into the soil about Questions 23 and 24 The liquid limit and plastic limit of a fine grained soil are 50% and 32% and the natural water content of the soil is 22%. A. 15mm B. 20mm C. 25mm D. 30mm 23. What is the plasticity Index (PI) of the soil? A. 8% B. 10% C. 18% D. 28% 24. The Liquidity Index (LI) of the soil is 28. The maximum void ratio of a soil is 2.0 and its minimum void ratio is 0.5. The in-situ void ratio of the same soil is 1.0. The relative density or Density Index of this soil is A. 1.5 B. 1.0 C. 0.67 D. 0.5 A. -0.55 B. -1.55 C. 1 D. 1.8 25. A fine grained soil has a liquidity Index (LI) of 0.45. The soil is in A. semi-plastic solid state B. solid state C. plastic state 29. A sand replacement test was done in a filled layer. The Mass of sand used to fill the dug hole only is 1.75 kg and the density of the sand is 1.35. The dry soil recovered from the dug hole is 2.5kg. The dry density of the filled site about A. 1900 kg/m 3 B. 1930 kg/m 3 C. 1950 kg/m 3 D. 2000 kg/m 3
For questions 30 and 31. The diagram below shows the results of a standard compaction test. 30. The O.M.C. of the soil is A. 12% B. 17.5% C. 18% D. 22% 31. The maximum dry density of the soil is A. 1850 kg/m 3 B. 1830 kg/m 3 C. 1600 kg/m 3 D. 1500 kg/m 3 32. The driving power which forces the water in a soil sample flows through is called A. Energy height B. hydraulic difference C. hydraulic head D. energy head 34. The hydraulic head between levels A and B in the following diagram is A 4m 6m B A. 2 m B. 4 m C. 5 m D. 6 m 35. Ground water table is defined at a level where water pressure is A. the smallest B. zero C. the same as the soil stress D. the highest The following soil profile is for questions 36-38. The ground water level is at 9m below ground 33. Total head of a soil is the sum of elevation head, pressure head and velocity head. In soil engineering, the velocity head is often omitted because the velocity head is A. too large. B. too small. C. undetermined. D. the same as the pressure head. 36. What is the total stress at the bottom of the blue clay (i.e. at 23m below ground)? A. 464 B. 327 C. 244 D. 137
37. What is the pore water pressure at the bottom of the blue clay (i.e. at 23 m below ground)? A. 464 B. 327 C. 244 D. 137 42. Given the following parameter of a clay layer. m v = 1x10-4 m 2 /kn c v = 0.4 m 2 / month; and g w = 10 kn/m 3 The clay layer is double drained and is 8 m thick. 38. What is the effective stress at the bottom of the blue clay (i.e. at 23 m below ground)? A. 464 B. 327 C. 244 D. 137 39. The internal frictional angle of a soil is 30 o. The corresponding coefficient of active soil pressure (Ka) is A. 0.33 B. 0.5 C. 1.5 D. 3 What is the ultimate settlement of the clay under an excess load of 100 kn/m 2? A. 0.08 m B. 0.032 m C. 0.2 m D. 0.32 m 43. The following outcrop pattern shows a 40. The internal frictional angle of a soil is 30 o. The corresponding coefficient of soil pressure at rest (Ko) is A. 0.33 B. 0.5 C. 1.5 D. 3 A. vertical bedding B. horizontal bedding C. vertical dip D. horizontal dip 44. The following outcrop pattern shows a 41. A flow net consists of 30 hydrualic drop (Nd) and a total of 5 channels (Nf). The permeability (K) of the soil is about 1.0 mm/s. The hydraulic head is 8 meters. The quantity of water flow (q) per linear meter will be A. 1.333x10-3 m 3 /s/m B. 48 m 3 /s/m C. 240 m 3 /s/m D. 960 m 3 /s/m A. vertical bedding B. horizontal bedding C. vertical dip D. horizontal dip
45. Which of the followings is/are true? i) A strike line on a rock outcrop is perpendicular to the sea level. ii) The dip direction of a rock outcrop is always 90 o from the strike line iii) The dip angle of a vertical dip is always 0 o A. i) only B. ii) only C. i) and iii) only D. i), ii) and iii) Qn Answer Qn Answer Qn Answer Qn Answer Qn Answer 1 B 11 C 21 C 31 B 41 A 2 D 12 A 22 D 32 C 42 A 3 D 13 B 23 C 33 B 43 B 4 A 14 C 24 A 34 B 44 A 5 C 15 D 25 A 35 B 45 B 6 D 16 B 26 B 36 A 7 B 17 Na 27 B 37 D 8 D 18 D 28 C 38 B 9 A 19 Na 29 B 39 A 10 B 20 A 30 B 40 B