Find the relevant information in the texts to answer these questions.

1. What does the erection technique of a bridge superstructure depend on?

2. Which erection techniques are used for suspension spans?

3. What erection technique is employed for single beam spans?

4. Where are standard reinforced concrete beams produced?

5. Which erection technique is used for long continuous bridge spans?

6. Why do beams have metal pieces welded on their top flanges?

7. What is a plate girder?

8. What is a launching nose?

9. What are the disadvantages of erection by the protrusion method?

10. Do arch bridges need the most complicated construction technology?

Complete and translate the following sentences:

Usually metal spans are erected from (типовые балки) or (типовые решетчатые фермы). The length of a standard girder is 55 m, and of a unified lattice truss it is between 33 and 132 m. Both structures may be (разрезные или неразрезные) ones. (Металлические балки) are lighter than those made of reinforced concrete, so they may be mounted by one or two (кран). When a girder is 55 m long, it is cut into four blocks to facilitate its delivery to the (строительная площадка). A temporary pier is specially built in the middle of the span. These blocks are placed by cranes on (временная опора и постоянная опора) (fig. 14.1a). They (соединяться) by high strength bolts (earlier the builders drove rivets).

Standard trusses are mounted of separate elements: top and bottom chords of a truss (раскосы, подвески, стойки, диагональные связи). A part of the span can be mounted on temporary piers built under the (узлы фермы). Three or four segments are used as a (противовес) for further span erection. A (деррик-кран) moves along the mounted top chord using the cantilevering method. The truss joint elements are jointed by (болты, фасонки, накладки) and other flat elements. Continuous metal girders may be erected as well as reinforced concrete beams by pushing them towards the designed position with a (домкрат).

The erection of a bridge superstructure afloat is one building technique. The superstructure’s blocks which are mounted at the plant site and delivered to the riverbank, by special heavy trucks, are transhipped to the (баржа). This operation is carried out with special equipment, and a barge carries the structures to the place.

Describe superstructure erection methods. Remember the following word combinations: