Subject 2022 Question Paper — Government College of Engineering and T…

The 2022 Subject previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.

Instructions

Q1. (a) What are the various steps considered in the planning of sub-surface exploration programme ? (b) Compute the area ratio of a thin walled tube samples having an external diameter of 6 cm and a wall thickness of 2.25 mm. Do you recommend the sampler for obtaining undisturbed soil samples ? Why ? [20 marks]
Q2. Differentiate between : (a) Percussion boring and rotary drilling (b) Auger boring and wash boring. [20 marks]

Q3. A retaining wall $6\text{ m}$ high, with a smooth vertical back is pushed against a soil mass having $c' = 40\text{ kN/m}^2$ and $\Phi = 15^\circ$, $\gamma = 19\text{ kN/m}^3$. What is the total Rankine passive pressure, if the horizontal soil surface carries a uniform load of $50\text{ kN/m}^2$ ? What is the point of application of the resultant thrust ? [20 marks]
Q4. (a) An embankment is inclined at an angle of $35^\circ$ and its height is $15\text{ m}$. The angle of shearing resistance is $15^\circ$ and the cohesion intercept is $200\text{ kN/m}^2$. The unit weight of soil is $18.0\text{ kN/m}^3$. If Taylor's stability number is $0.06$, find the factor of safety with respect to cohesion. (b) Explain the method of slices for stability analysis of slopes. How can steady seepage be accounted for in this method ? [20 marks]

Q5. Compute the ultimate load that an eccentrically loaded square footing of width $2.1\text{ m}$ with an eccentricity of $0.35\text{ m}$ can take at a depth of $0.5\text{ m}$ in a soil with $\gamma = 18\text{ kN/m}^3$, $c = 9\text{ kN/m}^2$ and $\varphi = 36^\circ$, $N_c = 52$; $N_q = 35$; and $N_\gamma = 42$. [20 marks]
Q6. A continuous footing of width $2.5\text{ m}$ rests $1.5\text{ m}$ below the ground surface in clay. The unconfined compressive strength of the clay is $150\text{ kN/m}^2$. Calculate the ultimate bearing capacity of the footing. Assume unit weight of soil is $16\text{ kN/m}^3$. [20 marks]

Q7. (a) A square pile group of 9 piles passes through a recently filled up material of $4.5\text{ m}$ depth. The diameter of the pile is $30\text{ cm}$ and pile spacing is $90\text{ cm}$ centre to centre. If the unconfined compression strength of the cohesive material is $60\text{ kN/m}^2$ and unit weight is $15\text{ kN/m}^3$, compute the negative skin friction of the pile group. (b) Distinguish between driven and bored piles. Explain why the settlement of a pile foundation (pile group) will be many times that of a single pile even though the load per pile on both cases is maintained the same. [20 marks]
Q8. (a) A reinforced concrete foundation, of dimensions $18\text{ m} \times 36\text{ m}$, exerts a uniform pressure of $180\text{ kN/m}^2$ on a soil mass, with E-value $45\text{ MN/m}^2$. Determine the value of immediate settlement under the foundation. (b) What is 'active zone' in soil ? Explain it with reference to the pressure bulb concept. [20 marks]