BLAR 12052: Geotechnical Calculations - Soil Phase Relationships, Strength, Permeability and Bearing Capacity - Engineering Assessment Answers

Internal Code: H_AH_CDFD_CD

Geotechnical Calculation - Soil Phase | Engineering Assignment

Question 1  Briefly discuss differences in terms of soil characteristics and properties (e.g. void ratio, moisture content, etc.) between the following soil types:

1. Loose uniform sand and dense uniform sand
2. Stiff clay and soft clay

Question 2  The wet mass of one of the standard Proctor test samples is 1806 grams at a water content of 15%. The volume of the standard Proctor test sample is 9.44 * 10-4 m3.

1. Determine the bulk and dry unit weights
2. Discuss how you would design an experiment using the standard Proctor test to determine the maximum dry unit weight of soil samples (including illustrations, sketches and/or photos)
3. How does the maximum dry unit weight play a role in designing a building?

Question 3 

• Determine k20°C (Conductivity at 20°C) of clay using the data below from a falling-head test: Cross-sectional area of soil = 80 cm2 Length of soil = 10 cm Initial head = 100 cm Final head = 80 cm Duration of test = 0.20 hour Diameter of tube = 6 mm Temperature = 23 °C
• Your project team members realize that a soil conductivity test can play a very significant role in any building project development. They seek your professional advice regarding when the falling-head test should be applied other than other conductivity tests. Your response may cover soil conditions of a project, as well as other project and design considerations such as cost, time, quality, etc.(including illustrations, sketches and/or photos)

Question 4 

• Research and briefly describe the following items about soil compaction (including illustrations, sketches and/or photos).

1. Effect of soil type (sandy silt, silty clay, poorly graded sand, etc.) on soil compaction
2. Compaction equipment in field 

• Assume you perform a compaction task in a construction site and you found the initial void ratio before the compaction was 0.85. Once you finished the compaction, you measured the void ratio and found that it changed to 0.57. Based on the knowledge of soil components and phase diagram, discuss (increase or decrease) following soil characteristics based on the calculated values:

1. percent of volume change of the soil due to the compaction
2. percent change in the field unit weight
3. percent change in the degree of saturation