Geo-technical Engineering PYQs, GPSC Civil Previous Year

1. As per Jacky formula, K_o (coefficient of earth pressure at rest) is determined as :

A) K_o = 1 – cosφ
B) K_o = 1 – sinφ
C) K_o = 1 – tanφ
D) K_o = 1 – cotφ

Check Answer

B) K_o = 1 – sinφ

2. If top of earth retained in horizontal, the coefficient of passive earth pressure for retaining wall become :

A) K_p = (1 – sinφ)/(1 + sinφ)
B) K_p = (1 + sinφ)/(1 – sinφ)
C) K_p = (sinφ – 1)/(sinφ + 1)
D) K_p = (sinφ + 1)/(sinφ – 1)

Check Answer

B) K_p = (1 + sinφ)/(1 – sinφ)

3. Culmann’s graphical method for active pressure calculation can be used for

A) a broken backfill surface
B) a plain inclined backfill surface
C) a layered backfill with different densities
D) all of the above

Check Answer

D) all of the above

4. A pure clay deposit (having φ = 0) behind a retaining wall has cohesion of 40 kN/m², the depth of tension cracks will be

A) 4.0 m
B) 2.0 m
C) 1.0 m
D) 0.5 m

Check Answer

A) 4.0 m

5. For a cantilever sheet pile wall, the earth pressure below the dredge line are

A) only active
B) only passive
C) active and passive both
D) neither active not passive

Check Answer

C) active and passive both

6. A dry soil has mass specific gravity of 1.35. If the specific gravity of solids is 2.7, then the void ratio will be

A) 0.5
B) 1.0
C) 1.5
D) 2.0

Check Answer

B) 1.0
Explanation : Gm = G/(1 + e)

7. Consistency as applied to cohesive soils is an indicator of its

A) Density
B) Moisture content
C) Shear strength
D) Porosity

Check Answer

C) Shear strength
Explanation : Soil consistency is the strength with which soil materials are held together or the resistance of soils to deformation and rupture. It is related to shear strength of the soil.

8. A flownet is drawn to obtain

A) Seepage, coefficient of permeability and uplift pressure
B) Coefficient of permeability, uplift pressure and exit gradient
C) Exit gradient, uplift pressure and seepage quantity
D) Exit gradient, seepage and coefficient of permeability

Check Answer

C) Exit gradient, uplift pressure and seepage quantity
Explanation : i, p, s

9. Phreatic line in an earth dam is

A) The topmost flow line with zero water pressure
B) The bottommost flow line with water pressure equal to atmospheric pressure
C) An equipotential line
D) An equiflow line

Check Answer

A) The topmost flow line with zero water pressure
Explanation : The top flow line of a saturated soil mass below which seepage takes place, is called the Phreatic line.
Hydrostatic pressure acts below the phreatic line whereas atmospheric pressure exists above the phreatic line
This line separates a saturated soil mass from an unsaturated soil mass
It is not an equipotential line, but a flow line

10. Which one of the following soil types is most likely to be subjected to liquefaction under seismic forces?

A) Soft saturated clays
B) Loose saturated sands
C) Murum
D) Fractured rocky strata

Check Answer

B) Loose saturated sands

11. Laboratory vane shear test can also be used to determine

A) Shear parameters of silty sand
B) Shear parameters of sandy clay
C) Liquid limit of silty clay
D) Plastic limit of clayey silt

Check Answer

C) Liquid limit of silty clay

12. A dry sand specimen is put through a tri-axial test. The cell pressure is 50 kPa and the deviator stress at failure is 100 kPa. The angle of internal friction for the sand specimen is

A) 15°
B) 30°
C) 45°
D) 55°

Check Answer

B) 30°
Explanation :
σd = deviator stress
σ3 = σc = cell pressure
σ1 = σc + σd
sinφ = (σ1 – σ3)/(σ1 + σ3)

13.

A)
B)
C)
D)

Check Answer

A) નાગભટ્ટ-II

14.

A)
B)
C)
D)

Check Answer

A) ભાવનગર

15.

A)
B)
C)
D)

Check Answer

C) ઔરંગઝેબ