Finish the following sentences according to the text.

1) An arch dam is built in a convex arch facing …

2) It owes its strength essentially to …

3) In the arch dams, stability is obtained by …

4) If the upstream face is vertical the entire weight of the dam must be carried to the foundation by…

5) An arch dam is … in plan.

6) An arch dam carries post of the water load horizontally to …

7) The thrust requires that sidewalls of the canyon be capable of …

8) Arch dams can be used only in …

9) Practically all arch dams are of …

10) Uplift forces are less important for arch dams than for gravity ones because of …

11) The simplest approach to arch analysis is …

12) Arch dams must be built on …

13) Abutments are grouted in …

14) Since the cross-section of an arch dam is relatively thin care must be taken in …

15) Concrete is placed by techniques similar to …

16) A layer of mortar is usually placed between …

17) Small arch dams are provided with …

18) Large arch dams are provided with …

19) All joints must have … and …

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

1) An arch dam is built in a curved arch facing the reservoir.

2) An arch dam owes its strength essentially to its form.

3) Stability of an arch dam is obtained only by gravity action.

4) If the upstream face is horizontal the entire weight of the dam must be carried to the foundation by gravity.

5) The distribution of the normal hydrostatic pressure will depend upon the strength of the dam.

6) An arch dam is curved in plan.

7) An arch dam carries most of the water load horizontally to the abutments by arch action.

8) The thrust doesn’t require that sidewalls of the canyon be capable of resisting the arch forces.

9) Arch dams can be used both in narrow and broad canyons.

10) All arch dams built recently are made of concrete.

11) Arch dams have failed less than other types of dams.

12) Uplift forces are less important for gravity dams than for arch ones.

13) Ice pressure and temperature changes are more important in arch-dam design than in gravity-dam design.

14) The horizontal water load is carried by arch action alone.

15) Seams and pockets in the foundation and abutments are not grouted.

16) The cross-section of an arch dam is rather thick.

17) The section in the upper part of an arch dam is very thin.

18) Only radial construction joints are used in small arch dams.

Answer the following questions.

1) What type of dam depends on its own weight?

2) What type of dam gets its strength essentially to its form?

3) Is the stability of arch dams obtained by a combination of arch and gravity action?

4) Must the entire weight of the dam be carried to the foundation by gravity or arch action?

5) When is the distribution more complicated?

6) An arch dam is curved in plan, isn’t it?

7) What does an arch dam carry horizontally to the abutments by arch action?

8) What must be capable of resisting the arch forces?

9) Arch dams can be used in any site, can’t they?

10) What are all arch dams made of now?

11) Have a lot of arch dams failed?

12) What forces act on arch dams?

13) Why are uplift forces less important for arch dams than for gravity dams?

14) What internal stresses may become quite important in arch-dam design?

15) What must arch dams be built on?

16) In what manner are seams and pockets in the foundation and abutments grouted?

17) Why must care be taken in the mixing, pouring and curing of the concrete?

18) Where may I0-ft lifts be placed at?

19) What is placed between lifts? Why?

20) What kinds of joints may be used in arch dams?

21) What must be used to prevent leakage?

22) What is it necessary to do to minimize temperature stresses?

23) Can you name the most famous arch dams in the world?

Make a plan and then a short summary of the text.

Choose the odd word.

1) shape / profile / form / silhouette / outline / surface

2) to obtain / to achieve / to gain / to create / to acquire

3) to act / to carry out / to execute / to fail / to function / to work

4) approach / attitude / manner / technique / achieve

5) to stand / to remove / to withdraw / to displace / to eliminate / to delete

6) to resist / to move / to confront / to counteract / to oppose / to withstand

Find in the text the synonyms of the following words.

Match the words with their opposites.

Fill in the correct prepositions then choose any five items and make sentences.

1) to be curved ___ plan; 2) to be capable ___ resisting; 3) to be ___ concrete; 4) ___ comparison ___ sth.; 5) because ___ the narrow base; 6) an approach ___ arch analysis; 7) to be designed ___ this basis; 8) ___ a usual manner; 9) to take care ___ sth.; 10) to be similar ___ sth.; 11) to provide ___ sth.

Make adjectives from the following words then choose any five items and make your own sentences.

stiffness, hydraulics, horizon, importance, strength, to close, to minimize, width, narrowness

Translate the following words into Russian.

Строительные работы, собственный вес, слегка изогнутый, напор воды, распределение давления, непроницаемое основание, отводить воду, уменьшать утечку воды, размеры плотины, заливать поочередно, сбрызгивать водой, боковая поверхность, предотвращать сцепление блоков, соседние секции, обеспечивать доступ, просачиваться в плотину, ремонт затворов и клапанов, достигать стабильности, особенно эффективный, вертикальные и горизонтальные направления, береговые устои, многочисленные разрушения, замешивание и выдерживание бетона, слой раствора, гарантировать лучшее сцепление, давать усадку, выделять тепло, обладать устойчивостью, тонкое поперечное сечение.

Find the translation of the following terms and memorize their meaning.

Read the text carefully paying attention to the words in italics. Answer the following question.

What parts does a buttress dam consist of?