2015-10-14
744
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) |
