1. Fig 1 shows a Constant Head Permeability Test apparatus a) Considering that the datum passes...

       

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1. Fig 1 shows a Constant Head Permeability Test apparatus a) Considering that the datum passes through point B, determine the Elevation Head, the Pressure Head and the Total Head at points A and B (5 points) Point Elevation Head Pressure Head A 20 B RO 30 Total Head 40 30 0 (5 points) b) Determine the Pressure Head at mid-point of specimen length AB c) Determine ko for a measured flow rate of 7 litres per minute. The average diameter of the soil sample is 50mm. The flow rate is measured at 30°C = 1.002 mPa.s, no 0.798 mPa.s. lp (6 points) 1.0. d) The Intrinsic Permeability K of a soil is expressed in the equation k=- density and viscosity of the fluid: k is its Coefficient of Permeability Determine the SI units of K. i Explain the importance of K as a parameter. 40cm B L=20cm 30cm Fig 1 a) Explain how the Relative Density (i e. the x- ordinate) was computed. b) Explain how they coordinate was obtained. RU TH 4 100 2. Fig 2 compares the state of compaction achieved with depth, during a trial compaction of a soil subjected to 2, 5, 15 and 45 roller passes. Optimum Moisture Content ranges between 12-15% Kog 7 where p, n are the The project consultants have recommended that a relative density of 80% be maintained, for a particular compacted highway embankment fill of 2.5m height c) Determine the number of roller-passes and the compacted thickness you would recommend (6 marks) d) Write a method specification detailing out the procedure to carry out the said activity. (4 points) (5 points) 3. Fig. 3 shows the variation of settlement versus time, for a 2.5m fill placed over a peaty formation. The dotted part of the curve is the estimated settlement behaviour beyond 100 days. The 20m thick layer drains both ways due to the presence of two permeable formations. T 1.781-0.933 logo(100-U%) for U > 60% (c) Compute the time for the settlement corresponding to a Degree of Consolidation of 65%. and e a) Estimate the Initial Compression, Primary Consolidation settlement and the Secondary Compression for the 10,000-day period. Show your graphical constructions in Fig. 3. (7 points) b) Compute its in-situ Coefficient of Consolidation; state its units of measurement. for U<60% = 2.723. (6 marks) (6 marks) 2 (7 marks) (6 points) d) Estimate the Coefficient of Secondary Compression, C. by considering the gradient of the relevant Ae portion of the curve. ca (6 points) A log10 (6 points) 95 0 to 1 Depth (ft.) WN 6 Depth (ft.) 95 0 Irutial fill density Dry density (lbf/ft³) 100 105 Settlement (m) 40 50 60 O Irutial fill density Relative density (%) Dry density (lbf/ft³) 100 105 O (a) 2 roller passes 40 50 60 0.00 0.20 0.40 0.60 0.80 1.00 70 80 90 100 1.20 1.40 1.60 1.80 110 (c) 15 roller passes 70 90 100 80 Relative density (%) bo 110 Depth (ft), 10 95 0 1 5 Depth (ft.) 6 95 0 1 6 Initial fill density Dry density (bf/ft³) 100 105 O 40 50 60 70 80 90 100 Relative density (%) Irutial fill density (b) 5 roller passes Dry density (lbf/ft³) 100 105 o ad Fig. 2: Density-depth relationship for a 5670kg roller operating at 27.5Hz for a 240cm lift height (after D'Appolonia, et al., 1969). 110 00 20 100 3 (d) 45 roller passes 70 40 50 60 90 100 80 Relative density (%) 110 1000 Time (days) 10000 Fig 3 4. Fig 4(a) shows a plot of e-loge, obtained during a One-dimensional Consolidation Test The sample had an initial height, Ho 20mm, average diameter 50mm, eu 2.93; total settlement, AH =2.805mm. Void Rano, e 3.0 20 22 20 1.8 16 14 10 100 1.5m 1000 10000 Effective Consolidation Stresse (kPa) a) Compute the Compression Index for the above plot. b) Comment on its compressibility c) Determine the Pre-consolidation pressure. Fig. 4(b) shows the 16m thick clay layer subject to a 1.5m surcharge fill. The sample location corresponding to the above test results is at a depth of 8m (ie. Sample A) d) Determine the effective overburden stress. e) State whether the soil is Normally Consolidated or Over Consolidated f) Compute the expected total settlement of the clay layer." Clay You 19.2kN/m³) % 2.93 You 18.5kN/m³ Bm water table 16m Fig. 4(a) Dense sand Fig. 4(b) (4 points) (4 points) (4 points) (4 points) (4 points) (5 points) 1. Fig 1 shows a Constant Head Permeability Test apparatus a) Considering that the datum passes through point B, determine the Elevation Head, the Pressure Head and the Total Head at points A and B (5 points) Point Elevation Head Pressure Head A 20 B RO 30 Total Head 40 30 0 (5 points) b) Determine the Pressure Head at mid-point of specimen length AB c) Determine ko for a measured flow rate of 7 litres per minute. The average diameter of the soil sample is 50mm. The flow rate is measured at 30°C = 1.002 mPa.s, no 0.798 mPa.s. lp (6 points) 1.0. d) The Intrinsic Permeability K of a soil is expressed in the equation k=- density and viscosity of the fluid: k is its Coefficient of Permeability Determine the SI units of K. i Explain the importance of K as a parameter. 40cm B L=20cm 30cm Fig 1 a) Explain how the Relative Density (i e. the x- ordinate) was computed. b) Explain how they coordinate was obtained. RU TH 4 100 2. Fig 2 compares the state of compaction achieved with depth, during a trial compaction of a soil subjected to 2, 5, 15 and 45 roller passes. Optimum Moisture Content ranges between 12-15% Kog 7 where p, n are the The project consultants have recommended that a relative density of 80% be maintained, for a particular compacted highway embankment fill of 2.5m height c) Determine the number of roller-passes and the compacted thickness you would recommend (6 marks) d) Write a method specification detailing out the procedure to carry out the said activity. (4 points) (5 points) 3. Fig. 3 shows the variation of settlement versus time, for a 2.5m fill placed over a peaty formation. The dotted part of the curve is the estimated settlement behaviour beyond 100 days. The 20m thick layer drains both ways due to the presence of two permeable formations. T 1.781-0.933 logo(100-U%) for U > 60% (c) Compute the time for the settlement corresponding to a Degree of Consolidation of 65%. and e a) Estimate the Initial Compression, Primary Consolidation settlement and the Secondary Compression for the 10,000-day period. Show your graphical constructions in Fig. 3. (7 points) b) Compute its in-situ Coefficient of Consolidation; state its units of measurement. for U<60% = 2.723. (6 marks) (6 marks) 2 (7 marks) (6 points) d) Estimate the Coefficient of Secondary Compression, C. by considering the gradient of the relevant Ae portion of the curve. ca (6 points) A log10 (6 points) 95 0 to 1 Depth (ft.) WN 6 Depth (ft.) 95 0 Irutial fill density Dry density (lbf/ft³) 100 105 Settlement (m) 40 50 60 O Irutial fill density Relative density (%) Dry density (lbf/ft³) 100 105 O (a) 2 roller passes 40 50 60 0.00 0.20 0.40 0.60 0.80 1.00 70 80 90 100 1.20 1.40 1.60 1.80 110 (c) 15 roller passes 70 90 100 80 Relative density (%) bo 110 Depth (ft), 10 95 0 1 5 Depth (ft.) 6 95 0 1 6 Initial fill density Dry density (bf/ft³) 100 105 O 40 50 60 70 80 90 100 Relative density (%) Irutial fill density (b) 5 roller passes Dry density (lbf/ft³) 100 105 o ad Fig. 2: Density-depth relationship for a 5670kg roller operating at 27.5Hz for a 240cm lift height (after D'Appolonia, et al., 1969). 110 00 20 100 3 (d) 45 roller passes 70 40 50 60 90 100 80 Relative density (%) 110 1000 Time (days) 10000 Fig 3 4. Fig 4(a) shows a plot of e-loge, obtained during a One-dimensional Consolidation Test The sample had an initial height, Ho 20mm, average diameter 50mm, eu 2.93; total settlement, AH =2.805mm. Void Rano, e 3.0 20 22 20 1.8 16 14 10 100 1.5m 1000 10000 Effective Consolidation Stresse (kPa) a) Compute the Compression Index for the above plot. b) Comment on its compressibility c) Determine the Pre-consolidation pressure. Fig. 4(b) shows the 16m thick clay layer subject to a 1.5m surcharge fill. The sample location corresponding to the above test results is at a depth of 8m (ie. Sample A) d) Determine the effective overburden stress. e) State whether the soil is Normally Consolidated or Over Consolidated f) Compute the expected total settlement of the clay layer." Clay You 19.2kN/m³) % 2.93 You 18.5kN/m³ Bm water table 16m Fig. 4(a) Dense sand Fig. 4(b) (4 points) (4 points) (4 points) (4 points) (4 points) (5 points)

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Elevation head vertical distance between datum level and point Pressure head height of water table f... View the full answer