Test: Soil Mechanics - GATE MCQ

Difference between upstream and downstream water levels for a weir is 3m. The discharge per metre width of sheet pile is K = 0.2 m²/s. Coefficient of permeability for soil at base of weir is 0.1 m/s. Calculate the number of flow lines when the number of equipotential head drops is 12?

In an aquifer extending over 200 Hectares, the water table was 20m below the ground level. The specific yield and specific retention of aquiter are 0.15 and 0.25 respectively. If due to rainfall the water table rises by 2m, calculate the change in storage of aquifer?

A 20m thick clay layer is aandwiched between gravelly layer at the top and impermeable layer at the bottom. The layer experiences 10mm settlement in 2 years. If coefficient of consolidation is 0.004 cm²/s, the deposit will experience a total of 15mm settlement in next ____ years.

(Important - Enter only the numerical value in the answer)

In a consolidated drained triaxial test, a specimen of clay tails at a cell pressure of 100kN/m². The effective shear strength parameters are c' = 20kN/m² and φ' = 300. 

Determine the major principal stress?___________kN/m²

(Important - Enter only the numerical value in the answer)

A soil sample has a mass of 3kg and volume of 0.0016 m³ in natural condition. After being oven dried in an oven, the mass of the sample is  2.6kg. Specific gravity (G) is 2.7. Unit weight of water is 10 kN/m³. The air content of the soil is:

The void ratio at the densest, loosest and natural states of a sand deposit are 0.3, 0.8 and 0.4 respectively.
The relative density of the deposit is :

Sieve analysis on a soil sample showed 40% of the soil passed through 4.75mm sieve and 8% of the soil passed through 75μ sieve. The liquid limit and plastic limit of soil are 40% and 24% respectively. The soil may be classified as:

Two identical soil samples are subjected to falling head permeability test in laboratory under identical  conditions. The fall of head was measured after t sec in 1st specimen and it was observed that ratio of initial to final water heads was 1.5. The fall of head was measured after 2t seconds in 2nd specimen and it was observed that ratio of initial to final water heads was 5. Find the ratio of coefficient of permeability of specimen 1 to specimen 2?

(Important - Enter only the numerical value in the answer)

Water flows from A to B through two soil samples. The rectangular cross section of the two soil layers have depth of 10cm and 20cm respectively and inside width of 15cm. Over a period of 1 hours, volume of water collected through section PQ is 3600 mL. The flow condition can be assumed to be steady state. If the coefficient of permeability of layer 1 is 2 × 10^-5 m/s, the coefficient of permeability through layer 2 is ____kN.

(Important - Enter only the numerical value in the answer and express the amswer in decimal form only)

The sand layer is found at 10m depth below the sea water level. The void ratio and specific gravity of soil solid is 0.4 and 2.7. The specific gravity of sea water is 1.1 and unit weight of fresh water is 9.81 kN/m³. Find the effective stress at 20m depth into the sand layer?

The specific gravity and in-situ void ratio of soil deposit are 2.67 and 0.8 respectively. The value of critical hydraulic gradient is:

The virgin compression curve for a soil is shown in the figure below. What is the compression index of the soil?

A vertical cut is to be made in a saturated clay with C = 15 kN/m², φ = 300 and γ_t = 18 kN/m³. What is
the theoretical depth to which the clay can be excavated without side collapse?

A slope is to be constructed at an angle of 30⁰ to the horizontal from a soil having properties, e = 20 kN/ m², φ = 30⁰, γ= 19 kN/m³. Taylor’s stability numbers is 0.05. If the factor of safety of 1.5 is required, then the safe height of the slope (in m) will be______

(Important - Enter only the numerical value in the answer)

A deposit of sand has a porosity of 35% and G = 2.7. The soil is dry in the top 2m depth, it has 20% moisture content in the next 2m depth and it is submerged below it. Find the effective stress at 5m below the ground surface.__________kN/m².

(Important - Enter only the numerical value in the answer)

The soil is compacted at the dry side of optimum. The sensitivity of the soil compacted at dry side when
compared to compacted at wet side is?

When a vertical face excavation was made in a clayey silt, having density of 20 kN/m³, it failed at a depth of excavation of 4 m. What is the cohesive strength (in kN/m²) of the soil, if its angle of internal friction was 30^∘?

A soil fails under an axial vertical stress of 200kN/m² in unconfined compression test. The failure plane makes an angle of 50⁰ with horizontal. The shear parameter ‘c’ and ‘φ’ respectively will be:

A clay sample is tested in triaxial apparatus in consolidated drained conditions at a cell pressure of 100 kN/m². What will be the pore water pressure at a deviator stress of 60 kN/m²?

A square footing (4m × 4m) is subjected to an inclined point load P, as shown in the figure below. The water table is located at a great depth below the base of footing. Considering two way eccentricity that is e^x = 0.2m and e^y = 0.3m, the net safe load carrying capacity of the footing for a factor of safety of 2.5 is ____kN.
The following factors may be used:

Bearing Capacity factor :

N_q = 34,

N_γ = 25

Shape factors : F_qs = F_γs = 1.5

Depth factors : F_qd = F_γd = 1.2

Inclination Factors : F_qi = 0.4, F_γi = 0.04

(Important - Enter only the numerical value in the answer)
 

The square footing (2m × 2m) is located at a depth of 1.5m from the ground level. Unit weight of soil γ_t = 20 kN/m³. The backfilling is not done after laying the footing.

Find the safe load that can be carried by footing considering the factor of safety of 3. 

φ⁰= 400 → N_q = 10, N_γ= 6 ; c = 0  ___________________ kN

(Important - Enter only the numerical value in the answer)

Calculate the effective stress at point A 12m below the Ground level. The Saturated bulk unit weight of soil is 20 kN/m³ and unit weight of water is 10 kN/m³.