Prestressed Concrete Structures Multiple Choice Questions on “Structural Forms for Irrigation”.
1. The concrete, aqueducts and siphons are required for ____________
a) Storage of water
b) Transportation of water
c) Distribution of water
d) Blockage of water
Answer: b
Clarification: Reinforced concrete is ideally suited and widely adopted for the construction of large gravity dams like Bhakra dam, Hirakud dam, Rihand dams and canals, aqueducts and sympones are generally required for transportation of water for irrigation purposes over long distances.
2. The concrete tabular aqueducts prestressed both longitudinal and transversal serves how many purposes?
a) One
b) Three
c) Dual
d) Five
Answer: c
Clarification: Prestressed concrete box sections with longitudinal deep girders and cross girders with slab between the girders and concrete tabular aqueducts prestressed both longitudinally and transversely with diameter in the range of 3-5m and spans varying from 30-50m and this structural form serves the dual purpose of water transportation in the tabular duct and the top portion is used for the road way and prestressed concrete circular sections wit loop cables for transverse prestressing to resist water pressure as in the case of siphons.
3. An example of the application of prestressed concrete in aqueducts in India is?
a) Yamuna
b) Gomati
c) Krishna
d) Penna
Answer: b
Clarification: An example of the application of prestressed concrete in aqueducts in India is Gomati aqueduct having 12 equal spans of 31.8m and the structure is designed as a box section of 12.8m by 6.7m and carries a discharge of 357 cumecs and the depth of the two main prestressed concrete girders is 9.9m and weights as much as 550 tones per girder per span.
4. The girders are supported on which type of well foundations?
a) Double D shaped
b) Trapezoidal shaped
c) T shaped
d) Dome shaped
Answer: a
Clarification: The girders are supported on double D shaped well foundations having a size of 12m by 27m sunk to a depth of 32m below the low water level and Gomati aqueduct as the distinction of being the biggest and the longest aqueduct in India constructed by Hindustan construction company ltd and Bombay for the Uttarpradesh irrigation department and the top of the aqueduct has been planned to serve as a roadway.
5. The circular shape was planned at Bhima aqueduct reduced ____________
a) Factor of safety
b) Rugosity coefficient
c) Tension coefficient
d) Deflection
Answer: b
Clarification: The Bhima aqueduct constructed near solapur, Maharashtra has a continuous precast concrete circular tube prestressed both longitudinally and circumferentially and the circular shape was planned to reduce the Rugosity coefficient facilitating easy passage of water and the aqueduct is 947m long with spans of 41.5m having a truncated circular cross section of 4.8 diameter with 3.75m roadway at top and the average thickness of the circular tube is 200mm and this aqueduct is an excellent example of planning hydraulic and highway elements in a single structure.
6. Virendeel girders are widely used in ____________
a) America
b) Singapore
c) Europe
d) France
Answer: c
Clarification: Virendeel girders developed by Arthur Virendeel in 1896, is an open web trussed girder with horizontal top and bottoms with vertical web members and rigid joints and these girders have been widely used in Europe and particularly in Belguim, where free unobstructed space is required between the top and bottom chords such as in clerestory lighting in churches and also for main girders on factories and warehouse sheds.
7. Prestressed concrete domes with which type of beam provides an ideal solution to cover such large containment vessels are ____________
a) Ring beam
b) Trapezoidal beams
c) Elliptical beams
d) Transverse beams
Answer: a
Clarification: Most of the atomic power plants have containment structures of circular shape having diameters in the range of 40m and prestressed concrete domes with a ring beam provides an ideal solution to cover such large containment vessels prestressed concrete circular tanks are widely used for the storage of water, oil, granular materials like cement and other liquids.
8. The capacity of prestressed concrete tanks may vary from ____________
a) 600 to 60000m3
b) 400 to 40000m3
c) 200 to 20000m3
d) 500 to 50000m3
Answer: b
Clarification: The capacity of such tanks may vary from 400 to nearly 40000m3 and economical dimensional proportions for water tanks as reported by the preload engineering company, Newyork and theses tanks are provided with reinforced concrete domes having a thickness ranging from 50-110mm with a prestressed concrete ring beam at the junction of the cylindrical tank walls and spherical dome.
9. The example of prestressed concrete reservoir is ____________
a) Ball tank built at trombay, Maharashtra
b) Ball tank built at trombay, Assam
c) Ball tank built at trombay, Goa
d) Ball tank built at trombay, Madhya pradesh
Answer: a
Clarification: Typical example of prestressed concrete reservoir having a capacity of 4 million liters can be found in the ball tank built at trombay, Maharashtra and the spherical tank was designed and built by STOP consultants and Gammon India ltd for the department of atomic energy and the diameter of the tank is around 10m and it is prestressed in the circumferential and meridional directions.
10. The prestressed concrete is ideally suited for the construction of ____________
a) Medium and long span bridges
b) Short span bridges
c) Lined span bridges
d) Curved span bridges
Answer: a
Clarification: Prestressed concrete is ideally suited for the construction of medium and long span bridges and at present the reinforcements and prestressed concrete bridge decks from a major percentage of the several types of bridges constructed throughout the world.