Based on the sieve data below and data on the fines that pass a #40 sieve (liquid limit = 30, plasticity index = 20), what type of soil is this? Use the American Association of State Highway and Transportation Officials (AASHTO) soil classification system. In general, would you consider this a well-graded or poorly graded soil? Explain your reasoning. Percent passing 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 100 10 1 0.1 Sieve opening (mm) Sieve opening sizes: #10: 4.76 mm openings; #40: 0.42 mm openings, # 200: 0.074 mm openings Table 2-3. AASHTO system of soil classification (Courtesy of BOMAG Americas) Group Number A-1 A-2 A-1-a A-1-b A-2-4 A-2-5 A-2-6 A-2-7 A-3 A-4 A-5 A-6 A-7 Percent passing No. 10 sieve 50 max. No. 40 sieve 30 max 50 max. No. 200 sieve 15 max. 25 max. 35 max. 35 max. 35 max. 35 max. 51 min. 10 max. 36 min. 36 min. 36 min. 36 min. Fraction passing No. 40 Liquid limit Plasticity index Typical material 6 max. 6 max. Gravel and sand 40 max. 41 min. 10 max. 10 max. 11 min. 11 min. Silty or clayey sand or gravel 40 max. 41 min. Fine 40 max. 10 max. Silt 41 min. 10 max. Silt 40 max. 11 min. Clay 41 min. 11 min. Clay sand