Explore topic-wise MCQs in Civil Engineering.

This section includes 22 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

A 10 m deep canal is constructed in purely cohesive soil having c = 0·2 kg/cm2, θ = 0°, G = 2·5, e = 0·5. The stability number is 0·1. In a canal running in full condition, the factor of safety w.r.t. cohesion against failure of side slopes will be

A. 1·0
B. 1·5
C. 2·0
D. 2·5
Answer» D. 2·5
Discussion
2.

Failure of slopes occurs only when a total shear force is

A. Equal to total shear strength
B. Greater than total shear strength
C. Less than the total shear strength
D. None of these
Answer» C. Less than the total shear strength
Discussion
3.

In a clayey soil having 50 kN/m2 as unit cohesion and 18 kN/m3 as unit weight, an excavation made with a vertical face. Taking Taylor’s stability number as 0.261, what is the maximum depth of excavation so that the vertical face remains stable?

A. 5.30 m
B. 7.06 m
C. 10.6 m
D. 12.4 m
Answer» D. 12.4 m
Discussion
4.

For the construction of a highway a cut is to be made as shown in the figure.The soil exhibits c’= 20 kPa, ϕ’ = 18°, and the undrained shear strength = 80 kPa. The unit weight of water is 9.81 kN/m3. The unit weights of the soil above and below the ground water table are 18 and 20 kN/m3, respectively. If the shear stress at Point A is 50 kPa, the factors of safety against the shear failure at this point, considering the undrained and drained conditions respectively, would be

A. 1.6 and 0.9
B. 0.9 and 1.6
C. 0.6 and 1.2
D. 1.2 and 0.6
Answer» B. 0.9 and 1.6
Discussion
5.

During stability analysis, the term mobilised shear strength means

A. Shear strength
B. Applied shear stress
C. Maximum shear stress
D. Minimum shear stress
Answer» C. Maximum shear stress
Discussion
6.

In a reinforced concrete retaining wall, a shear key is provided if the

A. Shear stress in the vertical stem is excessive
B. Shear force in the toe slab is more than that in the heel slab
C. Retaining wall is not safe against sliding
D. Retaining wall is not safe against overturning
Answer» D. Retaining wall is not safe against overturning
Discussion
7.

An embankment in clayey soil of 5 m height is to be constructed using factor of safety of 2.5. It is to be assumed that stability number is 1/45 and unit weight of soil is 18 kN/m3. Find the minimum cohesive strength (in kN/m2) which the soil should have. Choose correct answer from the following:

A. 30
B. 5
C. 10
D. 15
Answer» C. 10
Discussion
8.

In a reinforced concrete retaining wall, shear key is provided if

A. shear stress in the vertical component is excess
B. shear force in the toe slab is less than that in the heel slab
C. Retaining wall is not safe against sliding
D. shear force in the toe slab is more than that in the heel slab
E. Retaining wall is not safe against over-turning
Answer» D. shear force in the toe slab is more than that in the heel slab
Discussion
9.

Instability analysis of slopes, factor of safety with respect to height is given by

A. \({{\rm{F}}_{\rm{H}}} = \frac{{2{\rm{H}}}}{{{{\rm{H}}_{\rm{C}}}}}\)
B. \({{\rm{F}}_{\rm{H}}} = \frac{{{{\rm{H}}_{\rm{C}}}}}{{2{\rm{H}}}}\)
C. \({{\rm{F}}_{\rm{H}}} = \frac{{{{\rm{H}}_{\rm{C}}}}}{{\rm{H}}}\)
D. \({{\rm{F}}_{\rm{H}}} = \frac{{\rm{H}}}{{{{\rm{H}}_{\rm{C}}}}}\)
Answer» B. \({{\rm{F}}_{\rm{H}}} = \frac{{{{\rm{H}}_{\rm{C}}}}}{{2{\rm{H}}}}\)
Discussion
10.

For stability analysis of slopes of purely cohesive soils. the critical centre is taken to lie at the intersection of

A. The bisector of the slope and the locus of the centre
B. The perpendicular drawn at the one-third slope from the toe and the locus of the centre
C. The perpendicular drawn at the two-third slope from the toe and the locus of the centre
D. Directional angles
Answer» E.
Discussion
11.

An earthen dam of height H is made of cohesive soil whose cohesion and unit weight are c and γ, respectively. If the factor of safety against cohesion is Fc, the Taylor’s stability number (Sn)

A. \(\frac{{\gamma H}}{{c{F_c}}}\)
B. \(\frac{{{F_c}\gamma H}}{c}\)
C. \(\frac{c}{{{F_c}\gamma H}}\)
D. \(\frac{{c{F_c}}}{{\gamma H}}\)
Answer» D. \(\frac{{c{F_c}}}{{\gamma H}}\)
Discussion
12.

An embankment has a slope of 30° which was constructed with soil having C = 30 kN/m2, ϕ = 20° and γ = 15 kN/m3. The height of the embankment is 20 m. Using Taylor’s stability no 1/40, the factor of safety with respect to cohesion is

A. 0.25
B. 2
C. 4
D. 1.5
Answer» D. 1.5
Discussion
13.

By approximate method, the computation of N-component at the time of sudden drawdown condition, the weight is considered as:-

A. Dry unit weight
B. Saturated unit weight
C. Bulk unit weight
D. Submerged unit weight
Answer» E.
Discussion
14.

A 10 m high slope of dry clay soil (unit weight = 20 kN/m3), with a slope angle of 450 and the circular slip surface, is shown in the figure (not drawn to the scale). The weight of the slip wedge is denoted by. W. The undrained unit cohesion (Cu) is 60 kPa.The factor of safety of the slope against slip failure, is

A. 1.84
B. 1.57
C. 3.68
D. 1.67
Answer» D. 1.67
Discussion
15.

A slope is to be constructed at an angle of 30° to the horizontal from a soil having the properties, c = 15 kN/m2, γ = 19 kN/m3. Taylor's stability number is 0.046. If a factor of safety (with respect to cohesion) of 1.5 is required, then the safe height of the slope will be

A. 25.7 m
B. 17.2 m
C. 12.8 m
D. 11.4 m
Answer» E.
Discussion
16.

An infinitely long slope is made up of a c-φ soil having the properties: cohesion, C = 20 kPa, and dry unit weight, γd = 16 kN/m3 . The angle of inclination and critical height of the slope are 40° and 5 m, respectively. To maintain the limiting equilibrium, the angle of internal friction of the soil (in degrees) is _________________

A. 22.4°
B. 20.8°
C. 19.4°
D. None of the above
Answer» B. 20.8°
Discussion
17.

In friction circle method of slope stability analysis, if r defines the radius of the slip circle, the radius of friction circle is:

A. \(r\sin \phi \)
B. r
C. r cos ϕ
D. r tan ϕ
Answer» B. r
Discussion
18.

A canal with depth 7 m and side slopes 1:1 has the following properties:Cohesion 10 kN/m2, angle of internal friction 20° , voids ratio 0.6 and specific gravity 2.7. Stability numbers for a slope 1:1 with angle of internal frictions 20° and 10.3° are 0.062 and 0.125 respectively.Factor of safety of the slope with respect to cohesion when the canal runs full is

A. 0.564
B. 1.0964
C. 1.138
D. 2.21
Answer» E.
Discussion
19.

A cut is to be made in clay for which the cohesion is 30kN/sq.m and negligible friction angle. If the density of the soil is 20 kN/cum and the factor of safety for the design is 1.5, the maximum depth for a cutting of side slope 1.5 : 1 is (Assume stability number as 0.17)

A. 6.28
B. 5.88
C. 3.36
D. 4.88
E. 5.3
Answer» C. 3.36
Discussion
20.

A long slope is formed in a soil with shear strength parameters: c' = 0 and φ' = 34°. A firm stratum lies below the slope and it is assumed that the water table may occasionally rise to the surface, with seepage taking place parallel to the slope. Use γsat = 18 kN/m3 and γw = 10 kN/m3. The maximum slope angle (in degrees) to ensure a factor of safety of 1.5, assuming a potential failure surface parallel to the slope, would be

A. 45.3
B. 44.7
C. 12.3
D. 11.3
Answer» E.
Discussion
21.

Identify the incorrect statementThe stability of a slope is decreased by

A. Removal of a part of slope by excavation
B. Shock caused by an earthquake
C. Pore water pressure in the soil
D. Providing a berm at the toe
Answer» E.
Discussion
22.

A canal of 4 m deep has side slopes of 1 : 1. The properties of the soil are c = 15 kN/m2, ϕ = 15°, e = 0.76 and G = 2.7. Taylor’s stability number for that sudden drawdown = 0.136. The factor of safety with respect to cohesion in the case of sudden drawdown will be

A. 0.64
B. 1.43
C. 2.22
D. 3.01
Answer» C. 2.22
Discussion