Site Investigation Data A site investigation conducted on the proposed embankment location and surrounding valley has indicted three different soil types. The dam valley consists predominantly of Soil A, with pockets of Soil B and C found throughout. As such there is potential for all these soils to be used in construction of the embankment if they are deemed suitable. Data collected as part of the site investigation is present below for each soil. Soil A Specific gravity of 2.65 In situ bulk unit weight of 19 kN/m In situ moisture content of 9% Liquid and plastic limit of 34% and 16% respectively Maximum dry unit weight is 20.5 kN/m when compacted with a moisture content of 14% Data from sieve and hydrometer as shown in Table 1 Permeability testing data for compacted soil as shown in Table 2 Table 1: Particle size distribution data for Soil A: sieve data (left), hydrometer data (right) Mass retained (g) Elapsed time (min) Hydrometer Reading, R'n Sieve Size 4.75mm 2.36 mm 0.5 1 2 0 0 40 52 70 152 600 m 425 um 300 um 150 um 75 um 4 58 49 43 35 24 21 18.5 16 15 14.5 14 13.5 322 586 8 15 30 60 120 240 450 1440 Test temperature = 26C Meniscus correction = 0.5 Dispersant correction = 3 Hydrometer sample size = 100g Pan Table 2: Permeability testing data for compacted Soil A Test 1 2 3 Flow volume (ml) 32 33.5 32.5 Time (s) 120 120 125 Hydraulic head (mm) 455 455 450 Specimen diameter = 101mm; specimen length - 116mm Soil B Specific gravity of 2.7 In situ bulk unit weight of 18.5 kN/m In situ moisture content of 19% Liquid and plastic limit of 56% and 24% respectively Maximum dry density is 21 kN/m when compacted with a moisture content of 18% Data from sieve and hydrometer as shown in Table 3 Permeability testing data as shown in Table 4 Table 3: Particle size distribution data for Soil B: sieve data (left), hydrometer data (right) Mass retained (g) 0 0 Sieve Size 4.75mm 2.36 mm 600 um 425 um 300 um 0 0 0 10 150 m 75 um 20 970 Pan Elapsed time (min) Hydrometer Reading, R'n 0.5 59.5 1 59 2 56 4 53 8 51.5 15 49.5 30 46 60 44 120 42.5 240 42 450 41 1440 40.5 Test temperature = 20C Meniscus correction = 0.5; Dispersant correction = 3 Hydrometer sample size = 90g Table 4: Permeability testing data for Soil B Test 1 2 3 H. (cm) 171.4 171.5 171.7 Hz (cm) 156.0 150.6 133.4 Time (s) 1008 1422 2712 Specimen diameter = 10cm; specimen length = 12.73 cm; standpipe diameter = 1cm Soil C Specific gravity of 2.7 In situ bulk unit weight of 17 kN/m2 In situ moisture content of 9% Particle size distribution data in Table 5 Table 5: Particle size distribution data for Soil C Sieve Size Mass retained (6) 4.75mm 2.36 mm 1.18mm 405 120 155 600 um 425 um 300 um 150 um 75 um 120 50 40 70 40 15 Pan Your Task You are a geotechnical engineer working on this project and are tasked with interpretation of site investigation data, assessing a preliminary dam design, and providing recommendations and/or alternatives for an alternate design. Details of your assessment are to be presented in a geotechnical report that will be presented to the client. This assessment can be broken down into the following tasks. Task 1 (soil classification and selection/additional required information for construction) a) Determine the USCS classification of each of the different soils found in the site investigation. b) Which soil should be used for which portion of the dam construction and why? You must consider the feasibility of the material (i.e. workability) when making this recommendation. Site Investigation Data A site investigation conducted on the proposed embankment location and surrounding valley has indicted three different soil types. The dam valley consists predominantly of Soil A, with pockets of Soil B and C found throughout. As such there is potential for all these soils to be used in construction of the embankment if they are deemed suitable. Data collected as part of the site investigation is present below for each soil. Soil A Specific gravity of 2.65 In situ bulk unit weight of 19 kN/m In situ moisture content of 9% Liquid and plastic limit of 34% and 16% respectively Maximum dry unit weight is 20.5 kN/m when compacted with a moisture content of 14% Data from sieve and hydrometer as shown in Table 1 Permeability testing data for compacted soil as shown in Table 2 Table 1: Particle size distribution data for Soil A: sieve data (left), hydrometer data (right) Mass retained (g) Elapsed time (min) Hydrometer Reading, R'n Sieve Size 4.75mm 2.36 mm 0.5 1 2 0 0 40 52 70 152 600 m 425 um 300 um 150 um 75 um 4 58 49 43 35 24 21 18.5 16 15 14.5 14 13.5 322 586 8 15 30 60 120 240 450 1440 Test temperature = 26C Meniscus correction = 0.5 Dispersant correction = 3 Hydrometer sample size = 100g Pan Table 2: Permeability testing data for compacted Soil A Test 1 2 3 Flow volume (ml) 32 33.5 32.5 Time (s) 120 120 125 Hydraulic head (mm) 455 455 450 Specimen diameter = 101mm; specimen length - 116mm Soil B Specific gravity of 2.7 In situ bulk unit weight of 18.5 kN/m In situ moisture content of 19% Liquid and plastic limit of 56% and 24% respectively Maximum dry density is 21 kN/m when compacted with a moisture content of 18% Data from sieve and hydrometer as shown in Table 3 Permeability testing data as shown in Table 4 Table 3: Particle size distribution data for Soil B: sieve data (left), hydrometer data (right) Mass retained (g) 0 0 Sieve Size 4.75mm 2.36 mm 600 um 425 um 300 um 0 0 0 10 150 m 75 um 20 970 Pan Elapsed time (min) Hydrometer Reading, R'n 0.5 59.5 1 59 2 56 4 53 8 51.5 15 49.5 30 46 60 44 120 42.5 240 42 450 41 1440 40.5 Test temperature = 20C Meniscus correction = 0.5; Dispersant correction = 3 Hydrometer sample size = 90g Table 4: Permeability testing data for Soil B Test 1 2 3 H. (cm) 171.4 171.5 171.7 Hz (cm) 156.0 150.6 133.4 Time (s) 1008 1422 2712 Specimen diameter = 10cm; specimen length = 12.73 cm; standpipe diameter = 1cm Soil C Specific gravity of 2.7 In situ bulk unit weight of 17 kN/m2 In situ moisture content of 9% Particle size distribution data in Table 5 Table 5: Particle size distribution data for Soil C Sieve Size Mass retained (6) 4.75mm 2.36 mm 1.18mm 405 120 155 600 um 425 um 300 um 150 um 75 um 120 50 40 70 40 15 Pan Your Task You are a geotechnical engineer working on this project and are tasked with interpretation of site investigation data, assessing a preliminary dam design, and providing recommendations and/or alternatives for an alternate design. Details of your assessment are to be presented in a geotechnical report that will be presented to the client. This assessment can be broken down into the following tasks. Task 1 (soil classification and selection/additional required information for construction) a) Determine the USCS classification of each of the different soils found in the site investigation. b) Which soil should be used for which portion of the dam construction and why? You must consider the feasibility of the material (i.e. workability) when making this recommendation