Finish the following statements according to the text.

1) Rock-fill dams have characteristics both ….

2) The rock-fill dam has two structural components ….

3) The embankment consists of ….

4) The impervious membrane is constructed of ….

5) The membrane is sometimes poured as a monolith without … but with …..

6) Rock-fill dams are subject to ….

7) The greatest disadvantage of rock-fill dams is ….

8) A rock-fill dam has high resistance to ….

9) Less material is required for … than for ….

10) Foundation requirements for rock-fill dams are more … than for earth dams.

11) Rock-fill dams are cheaper than concrete dams and can be constructed more rapidly if ….

Answer the following questions.

1) What are the two main structural components of the rock-fill dam?

2) What does the embankment usually consist of?

3) Should the rock be capable of resisting erosion and strong enough to withstand loads of high intensity even when wet?

4) Where can large stones of regular shape be used?

5) Why do most membranes have expansion joints at intervals of about 50 ft with asphaltic joint filler?

6) Where is slab thickness greater?

7) What may settlement result in?

8) What can leakage be controlled by?

9) Does a rock-fill dam of good design and careful construction have high or low resistance to earthquakes?

10) Why are foundation requirements for rock-fill dams more rigid than for earth dams?

11) Are rock-fill dams cheaper than concrete dams?

12) Can you name the most famous rock-fill dams in the world?

Read the text again, make a plan of it. Write down an abstract for text E.

Match the words with their synonyms.

Match the words with their opposites.

Using the dictionary add as many words as possible into the table.

Translate the following phrases into English.

Основные структурные компоненты, свободная каменная наброска, выдерживать нагрузку, десять метров в диаметре, получать ровную поверхность, построенный из бетона, монолит без деформационных швов, горизонтальное и вертикальное направления, подвергаться значительной осадки, основной недостаток плотины, во многих случаях, регулярный ремонт мембраны, более строгие требования к основанию, доступный строительный материал, уменьшать утечку, заделывать швы эмульсией, из-за узкой ширины основания,

Find the translation of the following terms and memorize them.

Read the text to get the gist of it. Answer the following questions.

Are cofferdams permanent or temporary structures?

What timbers are the most durable?

Text F                                                       Miscellaneous Types of Dams

A timber crib dam is made of timber bolted into cribs and filled with rock. The life of a timber dam varies from 10 to 40 years depending upon climatic conditions and the type of timber used. Cedar, redwood and cypress are the most durable timbers. Where there is an adequate supply of timber, crib dams are quite inexpensive and generally satisfactory for heights not exceeding about 20 ft.

Cofferdams are temporary structures used to divert water from an area where the construction operations are to be conducted. A cofferdam must be relatively low in cost but as watertight as possible. The simplest kind of cofferdam is a single wall sheet-pile type, sometimes strengthened by an earth fill on both sides. A single wall sheet-pile cofferdam can be used only in very shallow water. For depths over about 5 ft cellular cofferdams are commonly used. These consist of circular sheet-pile cells filled with earth. A mixture of sand and clay is the best filler since clay itself tends to wash out through the gaps between the piles while sand is too permeable. Timber-crib dams are sometimes used as cofferdams. The simplest embankment often requires too much room because of the large base width necessary for an embankment of any height.

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

1) A timber crib dam is made of timber bolted into cribs and filled with earth.

2) The life of timber dam is limited to 10 years.

3) Cedar, redwood, cypress are the most permanent timbers.

4) A cofferdam must be relatively low in cost but as hermetic as possible.

5) For depths over about 5 ft sheet-pile dam are commonly used.

6) A mixture of clay and sand is the worst filler.

7) The simplest embankment often requires too much place because of the large base width.

Answer the following questions.

1) What is a timber crib dam made of?

2) What does the life of a timber dam depend upon?

3) What are the most durable timbers?

4) What are cofferdams used to?

5) A cofferdam must be relatively low in cost but as watertight as possible, mustn’t it?

6) What is the simplest type of cofferdam?

7) Where can it be only used?

8) Why is the mixture of clay and sand the best filler?

9) Does the simplest embankment often require too much room? Why?

Make а short summary of text F.

Find in the text the synonyms of the following words.

Find in the text the opposites of the following words.

Build up the correct words.

Model: amd → dam

Fill in the necessary preposition then choose any five items and make sentences.

1) to be made ___timber; 2) to use only ___ shallow water; 3) to be filled ___ rock; 4) a kind ___ cofferdam; 5) to vary ___ 10 ___ 40 years; 6) mixture ___ clay and sand; 7) to depend ___ conditions; 8) to wash out _____ the gaps; 9) to be low ___ cost; 10) to be used ___ cofferdams; 11) to be ___ watertight ___ possible; 12) because ___ the large base width; 13) to consist ___ circular sheet-pile cells; 14) to be necessary ___ an embankment ___ any kind.

Translate from Russian into English.

1) Из лесоматериала делается ряж, который заполняется землёй.

2) Срок службы дамбы зависит от климатических условий и типа выбранного лесоматериала.

3) Коффердам должен быть как можно более водонепроницаемым.

4) Однорядная шпунтовая перемычка может использоваться только на мелководье.

5) Самый лучший наполнитель – смесь глины и песка.

6) Даже самой простой плотине нужно много места из-за большой ширины основания, необходимой для плотины любой высоты.