Q5: a) The first time an engineer collected soil samples and tested the soil it took 39.5 days to complete the work. The second time the engineer did the work, it took 36.8 days. Using an improvement rate based on individual units, answer the following questions: a. How long will it take the engineer to complete the work for the 9th and 12th project? b. How much longer will it take to do the work on the 10th project than the 11th project? Q5: b) The cumulative average time to design 35 foundations is 5.2 days per foundation. The rate of learning for the activity is 0.87. a. How many days will be consumed in designing the first three foundations? (T1-3) b. How many days will be consumed in designing the 8th foundation? (Ts) 15 points 10 points

Repeat Problem 2.11 with the following data. 2.11 The grain-size characteristics of a soil are given in the following table. a. Draw the grain-size distribution curve. b. Determine the percentages of gravel, sand, silt, and clay according to the MIT system. c. Repeat Part b using the USDA system. d. Repeat Part b using the AASHTO system.

For soils that are classified by the following USCS symbols, what would be the most likely AASHTO symbols? (Reference: Liu, 1970) Gravels: GW, GP, GM, GC Sands: SW, SP, SM, SC Fines: ML, CL, MH, CH

Three groups of students from the Geotechnical Engineering class collected soil-aggregate samples for laboratory testing from a recycled aggregate processing plant in Palm Beach County, Florida. Three samples, denoted by Soil A, Soil B, and Soil C, were collected from three locations of the aggregate stockpile, and sieve analyses were conducted (see Figure 2.35). (a) (b) Figure 2.35 (a) Soil-aggregate stockpile; (b) sieve analysis (Courtesy of Khaled Sobhan, Florida Atlantic University, Boca Raton, Florida) a. Determine the coefficient of uniformity and the coefficient of gradation for Soils A, B, and C. b. Which one is coarser: Soil A or Soil C? Justify your answer. c. Although the soils are obtained from the same stockpile, why are the curves so different? (Hint: Comment on particle segregation and representative field sampling.) d. Determine the percentages of gravel, sand and fines according to Unified Soil Classification System.

Refer to Problem 2.C.1. Results of the sieve analysis for Soils A, B, and C are given below. To obtain a more representative sample for further geotechnical testing, a ternary blend is created by uniformly mixing 8000 kg of each soil. Answer the following questions. a. If a sieve analysis is conducted on the mixture using the same set of sieves as shown above, compute the mass retained (as a percentage) and cumulative percent passing in each sieve. b. What would be the uniformity coefficient (Cu) and the coefficient of gradation (Cc) of the mixture?

Redo Problem 2.7 according to the AASHTO system (Table 2.3). 2.7 The particle characteristics of a soil are given below. Draw the particle-size distribution curve and find the percentages of gravel, sand, silt, and clay according to the MIT system (Table 2.3).

What is the purpose of a soils report, and how can the information it contains assist the estimator?

How is the moisture content of a soil identified?

For the soils that are classified by the following AASHTO symbols, what would be the most likely USCS symbols? (Reference: Liu, 1970) Gravels sands: A-l-a, A-l-b, A3, A-2-4, A-2-5, A-2-6, A-2-7 Fines: A-4, A-5, A-6, A-7-5, A-7-6

In what ways can the properties of the soil be modified to improve its characteristics?