Finish the following sentences.

1) A dam is a barrier across flowing water that ….

2) Dams may be classified according to ….

3) The selection of the type of a dam for the site is a problem in both ….

4) Feasibility is governed by ….

5) According to height, there are ….

6) A dam must be capable of ….

7) The material underlying a dam must be capable of ….

Decide whether the following statements are true or false according to the text.

1) A dam is a barrier across flowing water that obstructs, directs or retards the flow, without creating a reservoir, lake or impoundment.

2) Topography, geology and climate govern the engineering feasibility and cost.

3) A low dam is more then 30 m high and a medium-height dam is less 100 m then high but more then 30 m high; and a high dam is over 100 m high.

4) The height of a dam is defined as the difference in elevation between spillway crest and the highest part of the excavated foundation.

5) Gravity is the weight of a dam which is the product of its volume and the specific weight of the material.

6) Ice pressure is exerted on the downstream face of a dam.

7) Most failures of dams have been caused by failure of the foundation.

8) Construction of dams and reservoirs requires the closest cooperation of different specialists in order to ensure a maximum degree of safety of the dams.

Answer the following questions.

1) What is a dam?

2) How may dams be classified?

3) What is a spillway?

4) What are the types of dams?

5) How is the height of a dam defined?

6) Why are dams built?

7) Dams provide head for generating hydroelectric power, don’t they?

8) Does a dam protect against flooding from rivers and the seas?

9) Must a dam be relatively impervious to water?

10) What forces must a dam be capable of resisting?

11) Must a dam be relatively impervious to water?

12) What forces must a dam be capable of resisting?

13) What must the material underlying a dam be capable of?

14) What has been caused by failure of the underlying material?

15) What does the construction of dams and reservoirs require?

16) Why?

 

Fill in the table according to the text.

DAMS	Principle of classification	Types of dams, examples
according to structure	gravity dams, …
…	…
…	…
…	…

Make the plan of the text.

Choose the best title to the text. Explain your choice. You may propose your own title.

a) Dams.

b) Construction of dams.

c) Forces acting on dams.

d) Dam classification.

e) Main features of dams.

Make a summary of the text.