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ПОСОБИЕ (гидротехнич строительство) 174.doc
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26. Finish the following sentences according to the text.

  1. A buttress dam consists of …

  2. There are several types of buttress dams, the most important ones …

  3. Flat-slab buttress dams may be constructed in locations where …

  4. In cross-section buttress dams resemble …, but …

  5. In a buttress dam a slab of reinforced concrete rests on …

  6. Closely spaced buttresses can be … and the slabs can be …

  7. Concrete beams of diaphragms may be utilized to resist …

  8. Hollow buttresses are used to increase …

  9. One of the most interesting features of the flat-slab dam is its …

  10. The joint between the slab and buttress is filled with …

  11. Flat-slab and buttress dams are adapted to …

  12. Placing the buttresses on spread footings one can reduce …

  13. Flat-slab dams may be built on materials ranging from … to …

  14. In the multiple-arch dams the cantilever action is commonly not taken …

  15. The design of a multiple-arch dam is more economical …

  16. Buttress dams are subjected the following forces …

  17. A buttress dam may be used on foundations which are …

  18. The height of a buttress dam can be increased by …

  19. Powerhouses and water-treatment plants are usually placed between …

  20. The first steps in the construction of buttress dams are …

  21. Great care must be taken in …

  22. Keyways are required in all …

27. Correct the following statements.

  1. Concrete-buttress dams reduce material in the wall itself without using support buttresses around the outside base.

  2. There is only one type of buttress dams.

  3. Only flat-slab buttress dams may be constructed in locations where the foundation rock is acceptable.

  4. In cross-section buttress dams don’t resemble a triangle.

  5. The thicknesses and spacing between buttresses don’t depend on the height of dam.

  6. If buttresses are closely spaced they can be more massive but the slabs can be thinner.

  7. Sometimes solid buttresses are used to increase the effective buttress width.

  8. The slab is always rigidly attached to the buttresses.

  9. Filling the joints between the slab and buttress with asphaltic putty permits each slab to act dependently.

  10. Even minor settlement of the foundation won’t seriously harm the structure.

  11. Flat-slab and buttress dams are used in narrow canyons.

  12. Placing the buttresses on spread footings one can increase the foun­dation pressures.

  13. The flat-slab dams require a better foundation than the multiple-arch dams do.

  14. In the designing of a multiple-arch dam cantilever action is always taken into account.

  15. Ice pressures and uplift forces are very important for buttress dams.

  16. Buttress dams are more expensive because a great deal of formwork and reinforcing steel is required.

  17. A gravity dam is less massive than a buttress dam.

  18. A cut-off wall extending to rock should be always provided.

  19. Powerhouses and water-treatment plants are usually placed near the buttress dams.

  20. Deck and buttresses are placed in lifts of not more then 3.7 m.

  21. The time for construction of gravity dams is usually less and the problem of water diversion somewhat simplified.