463 MIDTERM Summer 2019 Take Home Due August 7th 11 pm Work individually or groups of at most 2 Name:____________________________ Name:____________________________ 1. Follow the link to the compaction video and study it. https://www.youtube.com/watch?v=T37uJ5m5Zdg&t=9s 2. Compaction tests were conducted on a certain soil with specific gravity of solids = 2.69. One set of tests was conduction with a modified Proctor setup, another was conducted with a standard Proctor setup, and the last set was conducted with a low energy hammer. Modified Proctor ρd (gm/cm3) w (%) 1.873 9.3 1.91 12.8 1.803 15.5 1.699 18.7 1.641 21.1 Standard Proctor ρd (gm/cm3) w (%) 1.691 9.3 1.715 11.8 1.755 14.3 1.747 17.6 1.685 20.8 1.619 23 Low Energy Hammer ρd (gm/cm3) w (%) 1.627 10.9 1.639 12.3 1.74 16.3 1.707 20.1 1.647 22.4 (a) Plot the three compaction curves on the same graph. (b) Explain in one paragraph why the curves place the way they do on the graph. You will need to visit some references (cite them). (c) Identify the maximum dry density and optimum water content for each test. (d) Compute the degree of saturation at the optimum point for each test set. (e) On a separate graph, plot the zero air voids curve along with the data for test set A. 3. Compaction tests were conducted at a site with specific gravity of solids = 2.69. The standard Proctor test was carried out in the laboratory and the following data were recorded. Diameter of mold Height of mold Mass of mold Specific gravity Mass of wet soil and mold (gm) 6257 6356 6400 6421 6400 101.40 mm 116.70 mm 4196.60 gm 2.69 Mass of can and wet soil (gm) 105.05 100.69 114.71 134.26 109.34 Mass of can and dry soil (gm) 103.10 97.90 110.70 128.50 104.80 Mass of can (gm) 42.10 40.90 42.70 42.50 41.80 NOTE: The can was similar to the cup with we used to dry the soil in the oven for the plasticity II laboratory experiment. (a) Plot the compaction curve and the zero avoids curve. (b) Determine the maximum dry unit weight and optimum water content. (c) Compute the degree of saturation at the optimum water content. 4. Watch the sand cone video (https://youtu.be/ojH0W3xq3P0). (note: Referencing a textbook may be useful, cite if you use one) A sand cone test was conducted for quality control during the compaction of sandy clay. The data are as follows. Calibration to find dry unit weight of the standard sand Mass of Proctor mold (gm) 4178 Mass of Proctor mold and sand (gm) 5609 3 Volume of mold (m ) 0.00095 Calibration of sand cone Mass of sand cone apparatus and jar filled 5466 with sand (gm) Mass of sand cone apparatus with remaining 3755 sand in jar (gm) Sand cone test results Mass of sand cone apparatus and jar filled 7387 with sand (gm) Mass of excavated soil (gm) 2206 Mass of sand cone apparatus with remaining 3919 sand in jar (gm) Water content of excavated soil (%) 9.2 (a) Determine the dry unit weight. (b) The standard Proctor maximum dry unit weight of the sandy clay is 17.8 kN/m3 at an optimum water content of 10%. The specification requires 95% Proctor dry unit weight at acceptable water contents ranging from 9% to 10.8%. Is the specification met? Justify your answer. 463 MIDTERM Summer 2019 Take Home Due August 7th 11 pm Work individually or groups of at most 2 Name:____________________________ Name:____________________________ 1. Follow the link to the compaction video and study it. https://www.youtube.com/watch?v=T37uJ5m5Zdg&t=9s 2. Compaction tests were conducted on a certain soil with specific gravity of solids = 2.69. One set of tests was conduction with a modified Proctor setup, another was conducted with a standard Proctor setup, and the last set was conducted with a low energy hammer. Modified Proctor ρd (gm/cm3) w (%) 1.873 9.3 1.91 12.8 1.803 15.5 1.699 18.7 1.641 21.1 Standard Proctor ρd (gm/cm3) w (%) 1.691 9.3 1.715 11.8 1.755 14.3 1.747 17.6 1.685 20.8 1.619 23 Low Energy Hammer ρd (gm/cm3) w (%) 1.627 10.9 1.639 12.3 1.74 16.3 1.707 20.1 1.647 22.4 (a) Plot the three compaction curves on the same graph. (b) Explain in one paragraph why the curves place the way they do on the graph. You will need to visit some references (cite them). (c) Identify the maximum dry density and optimum water content for each test. (d) Compute the degree of saturation at the optimum point for each test set. (e) On a separate graph, plot the zero air voids curve along with the data for test set A. 3. Compaction tests were conducted at a site with specific gravity of solids = 2.69. The standard Proctor test was carried out in the laboratory and the following data were recorded. Diameter of mold Height of mold Mass of mold Specific gravity Mass of wet soil and mold (gm) 6257 6356 6400 6421 6400 101.40 mm 116.70 mm 4196.60 gm 2.69 Mass of can and wet soil (gm) 105.05 100.69 114.71 134.26 109.34 Mass of can and dry soil (gm) 103.10 97.90 110.70 128.50 104.80 Mass of can (gm) 42.10 40.90 42.70 42.50 41.80 NOTE: The can was similar to the cup with we used to dry the soil in the oven for the plasticity II laboratory experiment. (a) Plot the compaction curve and the zero avoids curve. (b) Determine the maximum dry unit weight and optimum water content. (c) Compute the degree of saturation at the optimum water content. 4. Watch the sand cone video (https://youtu.be/ojH0W3xq3P0). (note: Referencing a textbook may be useful, cite if you use one) A sand cone test was conducted for quality control during the compaction of sandy clay. The data are as follows. Calibration to find dry unit weight of the standard sand Mass of Proctor mold (gm) 4178 Mass of Proctor mold and sand (gm) 5609 3 Volume of mold (m ) 0.00095 Calibration of sand cone Mass of sand cone apparatus and jar filled 5466 with sand (gm) Mass of sand cone apparatus with remaining 3755 sand in jar (gm) Sand cone test results Mass of sand cone apparatus and jar filled 7387 with sand (gm) Mass of excavated soil (gm) 2206 Mass of sand cone apparatus with remaining 3919 sand in jar (gm) Water content of excavated soil (%) 9.2 (a) Determine the dry unit weight. (b) The standard Proctor maximum dry unit weight of the sandy clay is 17.8 kN/m3 at an optimum water content of 10%. The specification requires 95% Proctor dry unit weight at acceptable water contents ranging from 9% to 10.8%. Is the specification met? Justify your answer.
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