Fill in the gaps with the right word.

a) periphery e) moves i) blanket

b) drainage f) prevent j) upper

c) less g) Drains k) drain

d) toe h) water

 

1)_______ usually consist of a rock toe or a drainage 2)_______ of coarse material in which seepage water collects and 3)_______ to a point where it can be safely discharged. To 4)_______ movement of fine materials from the dam into the 5)_______, the drain material is graded from relatively fine on the 6)_______ of the drain to coarse near the centre. A 7)_______ blanket extends farther under the dam than a rock 8)_______ does. If a pervious foundation layer is overlain by a 9)_______ pervious layer, relief wells or drain trench through the 10)_______ layer may be necessary to permit escape of seepage 11)_______.

 

 

69. Fill in the table giving short answers to the questions.

Kinds of dams   Questions	Masonry dams	Embankment dams
Gravity dam	Arch dam	…	Earth-fill dam	…
1. What is a shape of the dam?
2. What does a dam consist of?
3. What is the dam built of?
4. What types of the dam are there?
5. Where is the dam built? What foundation does the dam require?
6. What forces are the most and the least important in the dam?
7. What should the attention be paid to in order to reduce leakage?
8. Choose the best for every kind of dams: a) - the most expensive, b) - less expensive as less concrete is used, c) - usually expensive as well as a gravity dam because of formwork and reinforced steel, d) - less expensive than masonry dams, e) - the cheapest if proper material is available
9. Can you give the examples of every kind of dams? (names)
10. Are there other kinds of dams? What are they? (give as many as possible)