Geotechnical Engineering MCQ Unit 4 | Basic Civil Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Geotechnical Engineering”.

                                                                    unit 4 

                                                                                                                           

1)The vertical stress at depth z directly below the point P is ( k is constant) …

• k P/z
• k P/z³
• k P/z²
• k P²/z^1/2

2)The intensity of vertical stress σ₂ at a depth z due to point load Q acting on the surface of a semi-infinite elastic soil mass is ….

(a) directly proportional to depth 

(b) inversely proportional to depth 

(c) directly proportional to the square of depth

(d) inversely proportional to the square of depth

3) σ_z is the vertical stress at depth equal to z in the soil mass due to surface point load Q . The vertical stress at depth equal to 2z will be……

(a) 0.25σ_z

(b) 0.5σ_z

(c) 1.0σ_z

(d) 2.0σ_z

4) The change in the vertical stress in the soil mass estimated by Boussinesq’s equation when Poisson’s ratio of soil changes from 0.3 to 0.5 will be….

(a) reduction by 30%

(b) increase by 50%

(c) reduction by 20%

(d) no change

5) A concentrated load of 50 t acts vertically at a point on the soil surface. If  Boussinesq’s equation is applied for computation of stress , then the ratio of vertical stresses at depth of 3 m and 5 m respectively below the point of application of load will be ….

(a)  0.36

(b) 0.60

(c) 1.66

(d) 2.77

6) Consider,

(1) Modulus of elasticity

(2) Poisson’s ratio

(3) Homogeneity of soil

Main difference between Boussinesq’s and Westergaard theory is due to ….

• 1 alone
• 2 alone
• 1 and 3
• 2 and 3
• 
  

7) The contact pressure distribution under a rigid footing on a cohesion less soil would be …

(a) Uniform throughout 

(b) Zero at center and maximum at edges  

(c) Zero at edge and maximum at center

(d) Maximum at edges and minimum at center

8) Whether the bulb of pressure under a strip footing forms in the direction of its length ?

(a) Prandtl’s

(b) Skempton’s

(c) Westerguaard’s

(d) Boussinesq’s

9) Pick out incorrect statements :

(1) The vertical stress distribution on a horizontal plane is bell shaped

(2) The vertical stress first increases and then decreases with depth asymptotically

(3) New mark charts can be compute vertical stress, horizontal stress and shear stress

(a) 1 only

(b) 3 only

(c) 2 and 3 

(d) n.o.t.

10) Westergaard’s formula for vertical stress gives greater value of stress than that by the Boussinesq’s formula, when r/z exceeds ….

(a) 1.5

(b) 2.5

(c) 3.5

(d) 4.0

11) A point load of 650 kN is applied on the surface of a surface of a thick layer of clay. Using Boussinesq’s elastic analysis, what is approximate value of the estimated vertical stress at a depth 2 m and radial distance of 1.0 m from the point of application of load ?

(a) 55 kN/m²

(b) 44 kN/m²

(c) 41 kN/m²

(d) 37 kN/m²