• Author / Uploaded
• Mikael Dionisio

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1.1a 5.2 It is proposed to carry out a laboratory compaction test on a 2.5 kg soil sample currently at a moisture content of 10.0%. How much water should be added to raise the moisture content to 16.0%?

5.3 Given Gs=2.75, calculate the zero-air-void unit weight for a soil in KN/m3 at w = 5%, 8%, 10 %, 12%, and 15%

5.4 The results of a standard Proctor test are given below. Determine the maximum dry unit weight of compaction and the optimum moisture content. Volume of Proctor mold (cm3) 943 943 943 943 943

Mass of wet soil in the mold (kg) 14.5 18.46 20.77 17.88 16.15

Moisture Content (%) 8.4 10.2 12.3 14.6 16.8

5.5 For the soil described in Problem 5.4, if Gs = 2.72, determine the void ratio and the degree of saturation at optimum moisture content.

5.6 The results of a standard Proctor test are given on the following table. Determine the maximum dry unit density (kg/m3) of compaction and the optimum moisture content. Volume of Proctor mold (cm3) 943.3 943.3 943.3 943.3 943.3 943.3 943.3 943.3

Mass of wet soil in the mold (kg) 1.68 1.71 1.77 1.83 1.86 1.88 1.87 1.85

Moisture content (%) 9.9 10.6 12.1 13.8 15.1 17.4 19.4 21.2

5.7 A field unit weight determination test for the soil described in Problem 5.6 yielded the following data: moisture content = 10.5% and moist density = 1705 kg/m3 . Determine the relative compaction.

5.9 A proposed embankment fill requires 3500 m3 of compacted soil. The void ratio of the compacted fill is specified as 0.65. Four borrow pits are available, as described in the following table, which lists the respective void ratios of the soil and the cost per cubic meter for moving the soil to the proposed construction site. Make necessary calculations to select the pit from which the soil should be bought to minimize cost. Assume Gs to be same at all pits. Borrow pit Void Ratio Cost ($/m3) A 0.85 9 B 1.2 6 C 0.95 7 D 0.75 10

5.10 The maximum and minimum dry unit weights of a sand were determined in the laboratory to be 17.5KN/m3 and 14.8 KN/m3. What would be the relative compaction in the field if the relative density is 70%?

5.13 For a sand with 3% fines, estimate the maximum relative density of compaction that may be obtained from a standard Proctor test. Given: the median grain size, D50 = 1.9mm.