Questions and answers for exam Preparation

MCQs

Total Questions : 153 | Page 9 of 16 pages

Question 81. Which failure occurs when the net horizontal force above any plane in the dam or at the base of the dam exceeds the frictional resistance developed at that level?

Overturning
Crushing
Sliding
By development of tension

Discuss Question

Answer: Option C. -> Sliding
Answer: (c).Sliding

Question 82. What is the maximum permissible tensile stress for high concrete gravity dam under worst conditions?

500 KN/m²
500 kg/cm²
5 kg/m²
50 KN/m²

Discuss Question

Answer: Option A. -> 500 KN/m²
Answer: (a).500 KN/m²

Question 83. Which failure occurs when the minimum stress exceeds the allowable compressive stress of the dam material?

Overturning
Crushing
Sliding
By development of tension

Discuss Question

Answer: Option B. -> Crushing
Answer: (b).Crushing

Question 84. The major principal stress at the toe of a gravity dam under full reservoir condition neglecting the tailwater effect is given by ____________________

Pᵥ
Pᵥ tanQ²
Pᵥ secQ²
Pᵥ sinQ²

Discuss Question

Answer: Option C. -> Pᵥ secQ²
Answer: (c).Pᵥ secQ²

Question 85. Tension cracks in the dam may sometimes lead to the failure of the structure by?

Sliding of the dam at the cracked section
Overturning about the toe
Crushing of concrete starting from the toe
Both overturning and crushing

Discuss Question

Answer: Option C. -> Crushing of concrete starting from the toe
Answer: (c).Crushing of concrete starting from the toe

Question 86. The governing compressive stress in a concrete gravity dam which should not be allowed to exceed the permissible value of about 3000 KN/m² while analyzing full reservoir case is ____________________

the vertical maximum stress at the toe
the major principal stress at toe
the shear stress at the toe
the principal stress at the heel

Discuss Question

Answer: Option B. -> the major principal stress at toe
Answer: (b).the major principal stress at toe

Question 87. The bottom portion of a concrete or a masonry gravity dam is usually stepped in order to _______

increase the overturning resistance of the dam
increase the shear strength
decrease the shear strength
increase the frictional resistance

Discuss Question

Answer: Option B. -> increase the shear strength
Answer: (b).increase the shear strength

Question 88. Which of the following criteria has to be satisfied for no tension at any point on a gravity dam?

The resultant of all the forces must always pass through the mid-point of the base of the dam
The resultant force for all conditions of loading must pass through the middle third of the base
The resultant of all the forces must pass through the upstream extremity of the middle third of the base
The resultant of all the forces must pass through the downstream extremity of the middle third of the base

Discuss Question

Answer: Option B. -> The resultant force for all conditions of loading must pass through the middle third of the base
Answer: (b).The resultant force for all conditions of loading must pass through the middle third of the base

Question 89. When the reservoir is empty, the single force acting on it is the self-weight of the dam which acts at a distance of ____________