In design of any structure, Soil properties had been taken into accounts?

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.

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

State whether the following are true or false. a. In the AASHTO classification Table 4.1, the soils that are more suitable for roadwork are located on the left than right. b. In AASHTO classification system, the better performing fine grained soils are the ones with lower group indices. c. In AASHTO classification system, sands are classified as grains with 0.075-4.75 mm diameter. d. The USCS symbol for clayey gravel is CG. e. A soil with USCS symbol SM is sandy silt.

Since laboratory or field experiments are generally expensive and time consuming, geotechnical engineers often have to rely on empirical relationships to predict design parameters. Section 6.6 presents such relationships for predicting optimum moisture content and maximum dry unit weight. Let us use some of these equations and compare our results with known experimental data. The following table presents the results from laboratory compaction tests conducted on a wide range of fine-grained soils using various compactive efforts (E). Based on the soil data given in the table, determine the optimum moisture content and maximum dry unit weight using the empirical relationships presented in Section 6.6. a. Use the Osman et al. (2008) method [Eqs. (6.15) through (6.18)]. b. Use the Gurtug and Sridharan (2004) method [Eqs. (6.13) and (6.14)]. c. Use the Matteo et al. (2009) method [Eqs. (6.19) and (6.20)]. d. Plot the calculated wopt against the experimental wopt, and the calculated d(max) with the experimental d(max). Draw a 45 line of equality on each plot. e. Comment on the predictive capabilities of various methods. What can you say about the inherent nature of empirical models?

In AASHTO, which group are the following soils likely to fall into? a. A well graded gravel with approximately 10% fines. b. A well graded sand with approximately 10% fines. c. A uniform fine sand. d. A high plastic clay.

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

From the plate load test (plate dimensions 1 ft × 1 ft) in the field, the coefficient of subgrade reaction of a sandy soil is determined to be 60 lb/in3. What will be the value of the coefficient of subgrade reaction on the same soil for a foundation with dimensions of 20 ft × 20 ft?

Repeat Problem 2.8 using the following data. 2.8 The following are the results of a sieve and hydrometer analysis. 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 according to the USDA system. d. Repeat Part b according to the AASHTO system.

What general categories of information must be dimensioned on a slab foundation?