2015-07-21
400
substantial, continuous, material, away, complete,
multi-arch, falsework, size, rigidly,
to maintain, beam bridges, hindrance
1. The construction of an arch requires…. The type of falsework depends on the… of which the bridge is made and the… of the bridge. Massonry arches need… support and this type of falsework is called centring. For large bridges, the centring will be a … structure in its own right and will be expensive. For a … bridge it is desirable to re-use the centring for each span. In the case of a bridge across a river the centring will be in the form of a tied arch … it integrity.
2. … are generally in the form of plate girders, box girders or trusses. In all cases, a common construction method is to build the beam … from the final position and slide or lift it into place as a … unit.
3. A great advantage of cantilever is that it can be built out from a support without a … to traffic or navigation below. The technique depends on whether the cantilever is attached … to a free standing tower.
IV. Translate the words in brackets.
A major improvement over the single (балка) was the circular (арка), the basic design which was perfected by the ancient Romans. Because the (силы) on an arch bridge extend outward as well as (вниз) a condition called (сжатие) they could be build with longer (пролёты) and with (каменные блоки) rather than with single (брёвна) or slabs of stone. A variant type of a (подвесной мост) is the cable stayed span in which the supporting (тросы) run directly from tall vertical (башни) to the horizontal deck. Besides design, the other great challenge in building (прочные) bridges has been in the methods and materials used in their construction.
