Fumbling to put on your mask as you step outside into the sunlight for the first time in 6 months, you stumble and break your leg after falling into a deep pot hole. While waiting for your leg to heal, you decide to fill in the pot, hole with some gravel so no one else gets hurt. You go to the garden store to buy gravel but no one has heard of the USCS system. That does not matter since they only have one type anyway. You buy a bag and run a sieve test on a 470g sample that produces the following data. Plot the grain size distribution curve, identify the coefficients of curvature and uniformity, and classify according to USCS. Explain why either a poorly graded gravel or a well graded gravel would be better for this application. Sieve size (mm)
63
37.5
19
13.2
9.5
6.7
4.75
2.36
1.18
0.6
0.212
0.075
Mass retained (g)
0
26
28
18
20
49
50
137
46
31
34
30
3. Your leg finally heals and you decide to celebrate by going back to check on your roadway remedy. To your surprise, not only has the gravel disappeared, but the pot hole is now three times the original size. You realize your mistake: since this is a transportation application, you should have classified the gravel according to AASHTO. Reclassify the soil according to the AASHTO classification system. 4. After some intense physical therapy, your leg is better than ever. You get on the bike trail Monday morning during rush hour and are struck by a car on St. Rita's Lane, sending you flying into Lake LaSalle. Emerging from the lake, you notice that you are now covered in a dark green soil that smells like decaying organic matter. You reassure yourself that coronavirus surely could not survive in a lake this toxic. You save a sample to bring back to the soils lab to run a few tests. The liquid limit is 48 naturally and 24 when oven dried. The plastic limit is 16 and 95% of the material is less than 0.075mm in diameter. Unsure if this is a transportation problem, you decided to classify according to both USCS and AASHTO.