Comprehension check

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

1. Bridges must carry dead loads, live loads and resist natural forces.

2. The traffic loading is the same for all kinds of bridges.

3. Maximum conceivable load may be achieved on short and long spans.

4. If engineers estimate maximum load for spans over several thousand feet, the cost of a bridge will be very high.

5. Usually engineers use probable loads as basic for design.

6. On short spans the dead load weight is greater than the live loads.

7. Long spans must be designed to minimize dead loads.

8. Longer spans are built with arches, trusses, hollow boxes.

9. Forces from nature are essentially vertical loads.

10. Dynamic and static wind loads push a bridge sideways.

11. Vibrations can cause a bridge to fail.

12. The use of expansion joints in the deck along with bearings at the abutments increase the expansion and contraction of a bridge materials.

13. Bearings and hinges reduce stresses caused by temperature movement.

II. Answer the questions.

1. What are dead and live loads?

2. What must be taken into consideration designing a bridge?

3. Why is the maximum conceivable load different for short and long spans?

4. How do the loads differ on short and long spans?

5. What are shorter spans built with?

6. What questions arise as spans get longer?

7. What loads does the wind load?

8. What static wind load?

9. What is does dynamic wind load cause?

10. What can happen if a deck is thin and not properly shaped?

11. What is done to reduce stresses caused by temperature movement?

12. Why do structures with light dead weight withstand earthquakes better?

LANGUAGE FOCUS

III. Match the meaning of the terms with their definitions.

Live load, dead load, load

1. The weight or force supported by a structure or any part of it.

2. The load that a bridge must support in addition to its own weight.

3. A permanent and fixed load, such as the weight of a bridge or building.

IV. Match the words with their synonyms.

1. carry a. evaluate

2. resist b. perilous

3. estimate c. withstand

4. conceivable d. project

5. unreasonable e. thinkable

6. evolve f. develop

7. dangerous g. bear

8. design h. imprudent

V. Match the words with their opposites.

1. permanent a. minimum

2. finally b. unessential

3. heavy c. thick

4. maximum d. temporary

5. important e. loop

6. vertical f. light

7. thin g. at first

8. hinge. h. horizontal

VI. Fill in correct prepositions.

1) … the same time; 2) … each directions; 3) to give rise … sth; 4) to react … sth; 5) … general; 6) to arise… sth; 7) to be proportional … sth; 8) to set … sth; 9) to pass … sth.

Follow up Activities.

Speak on:

Materials used in bridge construction.