Question

A direct shear test was run on a sample of sandy soil taken from the field. Assume the cohesion is zero,and the effective normal stress during the test was 100

kPa. If the shear stress at failure was found to be45 kPa, Determine the friction angle of the tested soil. The total unit weight of the soil in the field was 16.45 kN/m³, and the void ratio of the sample was e =0.95. Assume G, = 2.65. The effective normal stress on the sample is double the effective horizontal stress in the field. Assume that the water table is 3.5 m below the soil surface, the sand layer is homogeneous and very thick, and Ko == 1– sin o' describes the condition of the soil in the field. What was the burial depth of the sample? The following relationship will be helpful: \gamma_{\text {sat }}=\gamma_{w} \frac{G_{s}+e}{1+e}

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