Exam Ihsuan Ho No exam 212pdf Adobe Acrobat Reader DC File

Exam I-hsuan Ho No exam 212).pdf - Adobe Acrobat Reader DC File EditView Windaw Help Home Tools Exam I hsuan Ho Sign In -)(#) 75% 4. (4) Tbe primary objective of a geotechnical site investigation is to a) Delermine the characteristics of the soil profile b) Detenmine the suitability of the soil for growing corn c) Determine the permeability of the o rock d) Find the most economical source of fill materials e) Find the most economical source of aggregates for concrete 5. (4) Please explain the Overconsolidated and Normally consolidated soils in terms of overconsolidation ratio (OCR). 6. (4) Fora quickcondition to develop in a soil mass: a) The soal must be a uniform sili b) The pore water pressure is negative c) The effeetive stress is zero d) The soil must be a sand c) The soilus be a clay loam 7. (4) Disturbed soil samples slhould NOT be used for: n) Atterberg limit tests b) Grain-size disbut on tests c) Direct sbear tests ou sand d) Standard and modified Proctor density tests e) Sliear strengt tests on clay 8. (4) A sample of clay soil for testing in theiaxial compression test can BES be obtained by sampling with a: a) Standard penetration test b) Shelby tube sampler cSplit spoon sampler d Vane shear test e) Cone penetration test 0 Type here to search 7:10 PM 3/12/2018

Solution

4. (A)

5. The over-consolidation ratio(OCR) is defined as the highest past stress experienced divided by the current stress by the soil.

when the soil is normally consolidated, OCR = 1

when the soil is over consolidated , OCR >1

6. (C)

Quick sand condition - it is the condition of flow in which vertical upward seepage flow causes floating condition of particals in cohesion less soils such as sands and fine gravels due to loss of shear strength in between particals, Quick sand condition is not a type of sand. If the seepage pressure becomes equals to the submerged weight of soil, then effective stress is reduced to zero. In this condition a cohesionless soil loses all its shear strength and the soil particles have a tendency to move along the direction of flow.

7. (C)

  direct shear test is performed on three or four specimens from a relatively undisturbed soil sample.

Disturbed soil can be used for grain size distribution, liquid and plastic limit (Aterberg limit), specific gravity, compaction tests (procter test),moisture content, organic content determination and soil classification test experimented in the lab.