Irrigation Engineering Practice Test 8

1. The surcharge storage in a dam reservoir is the volume of water stored ________________

between the minimum and maximum reservoir levels

between normal and maximum reservoir levels

below the minimum pool level

between the minimum and normal reservoir levels

2. Calculate the value of minimum base width for an elementary triangular concrete gravity dam supporting 72 m height of reservoir water and full uplift? (Take specific gravity of concrete as 2.4 and coefficient of friction as 0.7)

36.28 m

39.77 m

73.5 m

51.5 m

3. The design annual rainfall for the catchment of a proposed reservoir has been computed to be 99 cm. The catchment area contributing to the proposed reservoir is 1000 sq.km having a mean annual temperature of 20°C. Calculate the annual design catchment yield for the reservoir using Khosla’s formula.

894 m³

8.94 M.m³

89.4 M.m³

894 M.m³

4. What is the value of horizontal destabilizing force caused by the formation of waves in a storage reservoir having a fetch of 52 km due to high wind of 172 km/h?

60 KN

30 KN

180 KN

130 KN

5. For full reservoir condition in a gravity dam, the critical combination of vertical and horizontal earthquake accelerations to be considered for checking the stability is ________________________

vertically downward and horizontally downstream

vertically upward and horizontally upstream

vertically upward and horizontally downstream

vertically downward and horizontally upstream

6. A concrete gravity dam having a maximum reservoir level at 200 m and the RL of the bottom of the dam 100 m. The maximum allowable compressive stress in concrete is 3000 KN/m² and the specific gravity of concrete is 2.4. Calculate the height of the dam and check whether it is a high dam or low dam.

H = 90 m Low gravity dam

H = 214.2 m Low gravity dam

H = 90 m High gravity dam

H = 214.2 m High gravity dam

7. The capacity-inflow ratio for a reservoir _________________

increases with time

is a constant factor overtime

may increase or decrease with time

decreases with time

8. 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 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

The resultant force for all conditions of loading must pass through the middle third of the base

9. Bank storage in a dam reservoir _________________

increases the compound reservoir capacity

has no effect on computed reservoir capacity

sometimes increases and sometimes decreases the computed reservoir capacity

decreases the computed reservoir capacity

10. Leakage through the transverse joints in a gravity dam is prevented by ____________

keyways

galleries

shear keys

water stops