1. For leossial soil, given Gs 5 2.74. Plot a graph of gd skN/m3d versus liquid limit to identify the zone in which the soil is likely to collapse on saturation. If a soil has a liquid limit of 27, Gs 5 2.74, and gd 5 14.5 kN/m3, is collapse likely to occur?
2. A collapsible soil layer in the field has a thickness of 3 m. The average effective overburden pressure on the soil layer is 62 kN/m2. An undisturbed specimen of this soil was subjected to a double oedometer test. The preconsolidation pressure of the specimen as determined from the soaked specimen was 84 kN/m2. Is the soil in the field normally consolidated or preconsolidated?
3. An expansive soil has an active-zone thickness of 10 ft. The natural moisture content of the soil is 25% and its liquid limit is 60. Calculate the free surface swell of the expansive soil upon saturation.