1. During Atterberg limit tests in the soil mechanics laboratory, the students obtained the following results from a clayey soil. Liquid limit tests: Number of Moisture blows, N content (%) 14 38.4 16 36.5 20 33.1 28 270 Plastic limit tests: Students conducted two trials and found that PL = 172% for the first trial and PL = 17.8% for the second trial. a. Draw the flow curve and obtain the liquid limit. b. What is the plasticity index of the soil? Use an average value of PL from the two plastic limit trails.

Soil mechanics

A carefully-weighed 52.9 gram soil sample was dispersed for particle-size analysis using the Bouyoucos hydrometer method. The laboratory was held at a constant temperature of 20 C (68 F). The hydrometer reading after 40 seconds was 20.1 and the hydrometer reading after 8 hours was 5.1. What percentage of particles in the soil sample were clay-sized? Your Answer: Answer units

1.4 A test for the relative density of soil in place was performed by digging a small hole in the soil. The volume of the hole was 400 ml and the moist weight of the excavated soil was 9 N. after oven drying, the weight was 7.8 N. Of the dried soil, 4N was poured into a vessel in a very loose state, and its volume was found to be 270 ml. The same weight of soil when vibrated and compacted had a volume of 200 ml. Determine the relative density.