Ejercicios Geotecnia

Problems for solution in home. Two of this exercises will be evaluate in classroom
2-1. A water content test was made on a sample of silty clay. The weight of the wet soil plus container was 17.53 g, and the weight of the dry soil plus container was 14.84 g. Weight of the empty container was 7.84 g. Calculate the water content of the sample. 2-2. During a plastic limit test, the following datawere obtained for one of the samples: Wet weight + container = 22.12 g Dry weight + container = 20.42 g Weight of container = 1.50 g What is the PL of the soil? 2-3. A sample of fully saturated clay weighs 1350 g in its natural state and 975 g after drying. What is the natural water content of the soil? 2-4. For the soil sample of Problem 2-3, compute (a) void ratio and (b) porosity. 2-5. For thesoil sample of Problem 2-3, compute (a) the total or wet density and (b) the dry density. Give your answers in Mg/m', kg/m3, and lbf/ft3. 2-6. A 1 m3 sample of moist soil weighs 2000 kg. The water content is 10%. Assume p, is 2.70 Mg/m3. With this information, fill in all blanks in the phase diagram . 2-7. For the information given in Problem 2-6, calculate (a) the void ratio, (b) the porosity, and(c) the dry density. 2-8. The dry density of a compacted sand is 1.82 Mg/m3 and density of the solids is 2.67 Mg/m3. What is the water content of the material when saturated? . 2-9. A 100% saturated soil has a total density of 2050 kg/m3 and a water content of 25%. What is the density of the solids? What is the dry density of the soil? 2-10. What is the water content of a fully saturated soilwith a dry density of 1.70 Mg/m3? Assume p, = 2.71 Mg/m3. 2-11. A dry quartz sand has a density of 1.68 Mg/m3. Determine its density when the degree of saturation is 75%. The density of solids for quartz is 2.65 Mg/m3. 2-12. The dry density of a soil is 1.65 Mg/m3 and the solids have a density of 2.68 Mg/m3 Find the a) water content, b) void ratio, and (c) total density when the soil is saturated.2-13. A natural deposit of soil was found to have a water content of 20% and to be 90% saturated. What is the void ratio of this soil? 2-14. The void ratio of clay soil is 0.5 and the degree of saturation is 70%. Assuming the density of the solids is 2750 kg/m3, compute (a) the water content and (b) dry and wet densities in both SI and British Engineering units. 2-15. The volume of water in a sampleof moist soil is 0.056 m3. The volume of solids Vs is 0.28 m3. Given that the density of soil solids p3 is 2590 kg/m3, find the water content. 2-17. Derive an expression for ps in terms of the porosity n and the water content w for (a) a fully saturated soil and (b) a partially saturated soil. 2-18. Derive an expression for (a) dry density, (b) void ratio, and (c) degree of saturation in terms ofp, ps> pw, and w. 2-19. Develop a formula for (a) the wet density and (b) the buoyant density in terms of the water content, the density of the soil solids, and the density of water. 2-20. From Archimedes' principle show that Eq. p' = psat - pw, is the same as (ps - pw)/(l + e). 2-21. The "chunk density" method is often used to determine the unit weight (and other necessary information) of aspecimen of irregular shape, especially of friable samples. The specimen at its natural water content is (I) weighed, (2) painted with a thin coat of wax or paraffin (to prevent water from entering the pores), (3) weighed again (Wt + WWax), and (4) weighed in water (to get the volume of the sample + wax coating—remember Archimides?). Finally, the natural water content of the specimen is determined. Aspecimen of silty sand is treated in this way to obtain the "chunk density.*' From the information given below, determine the (a) wet density, (b) dry density, (c) void ratio, and (d) degree of saturation of the sample Given Weight of specimen at natural water content = 181.8 g

Weight of specimen + wax coating = 215.9 Weight of specimen + wax in water = 58.9 Natural water content = 2.5% Soil...