Civil Engineering MCQJE Level Civil Engineering
Rankine''s active earth pressure coefficient Ka for a cohesionless soil with friction angle φ is:
Soil MechanicsSoil MechanicsMEDIUM
Choose the correct answer
A
Ka = tan²(45° + φ/2)
B
Ka = tan²(45° − φ/2)
C
Ka = 1 + sinφ
D
Ka = 1/(1 − sinφ)
Correct Answer
B. Ka = tan²(45° − φ/2)
Why is this the answer?
Ka = tan²(45° − φ/2) = (1 − sinφ)/(1 + sinφ). This gives the minimum earth pressure (active case) when wall moves away from soil (failure by forward movement). Active pressure pa = Ka·γ·z − 2c√Ka. For φ = 30°: Ka = tan²30° = 0.333.
Related Soil Mechanics MCQs
More solved Soil Mechanics questions for AE/JE Civil Engineering exams.
- The 'Hvorslev parameters' c_e and φ_e in soil mechanics refer to:
- The 'International Building Code' (IBC) and IS codes classify building sites for...
- 'Vibro-flotation' (vibro-compaction) is used to densify:
- The 'primary consolidation' of a clay layer settles because:
- The 'IS 2911' code series covers:
- The 'shear strength' of soil measured in an 'undrained triaxial test' (UU test) is:
Practice more Civil Engineering questions
This MCQ belongs to JE Level Premium Test Series. Full tests include timed attempts, rank comparison and subject-wise analysis.