VIII. Read and translate the text

The construction by French engineers of the 500-foot cast in situ concrete arch near Caracas in Venezuela was one of the boldest and most spectacular exploits in bridge engineering. It has been said of the way this bridge was built that "if the builder knew enough about the behavior of such a structure he would not dare to undertake it. Yet if he didn't know his business exceptionally well he couldn't complete it".

The crown of the arch is 220 feet above the gorge below. The normal way of building up falsework trestles from the bottom of the gorge would have been extremely costly and slow. The quarter spans on each side were concreted out from the abutments on centering. Each side was supported by six temporary steel rope guys, anchored back to the massive vertical end piers also rising from the abutments. Between the quarter spans thus built remained a gap of half the span.

To complete this gap, the engineers hit on a daring solution never attempted before: they built the centering for the gap on the floor of the gorge 220 feet below the bridge. It was 265 feet long by 75 feet wide and weighed 250 tons. Four winches on the two ends of the completed quarter spans let down steel ropes or "falls" to be attached to the four corners of the 250-ton falsework structure below. After eight hours of cautious and steady lifting, the center arch falsework was eased into place and secured. In the concreting that followed, the engineers worked with great care symmetrically from the center outward to avoid any movements and sway. When the concrete had set, the false work was lowered back to the floor of the gorge.

IX. Read the text about the New Orleans Bridge and fill in the given phrases:

at great speed a reinforced concrete cap

was completed a prestressed concrete deck

the total weight consists of

were erected assembly line

Over windswept Lake Pontchartrain there runs a bridge 2 4 miles long. A white concrete ribbon vanishing into the distance, it stands a tribute to the imagination and skill of the bridge

builder. The bridge____________ (1) in 1956; amazingly, itiook only 15 months to build. This

required mass production and____________(2) both in design and in construction.

Some figures will show the magnitude of the work:_______________(3) of the structure is

600 000 tons. The bridge_______________ (4) 2215 identical bents, parts of which were precast

on shore and barged out onto the lake where they____________(5). Each bent is like a huge

football goal and comprises 2 large cylindrical prestressed concrete piles, on top of which there

rests_____________(6). Finally, spanning between caps is a____________(7). The casting yard

occupied 40 acres; it was a marvel of mechanization. Every detail was worked out beforehand, and the job was done_______________(8).

X. Read the text below and think of the word which best fits each space.

The Golden Gate Bridge

The Golden Gate Bridge has linked San Francisco and the Marin Peninsula for more______50 years. However, building it was no easy task. The idea of linking the two places was not a new one but it wasn't_________1917 that the first workable design was produced. It would ____ 20 years to complete the bridge, and from the outset there were__________difficulties: rough waters, foggy conditions and the danger of earthquakes all combined to make constructing this bridge a________trickier business than building New York's George Washington Bridge. The Golden Gate Bridge,________was then_________largest in the world, was finished May 27^th, 1937. Californians flocked to their new showpiece and walked from one end to the_______.The next day it was opened to cars.____the past 58 years it_________been part of daily life for millions of commuters. Of course, its paintwork must___________kept_____good condition. A 28-man team is responsible_________this.

Cast in situ concrete arch on the Caracas-La Guaiara highway, Venezuela.

VIII. Read and translate the text - student2.ru

XI. Discussion.

A new subway line is being built in the center of the city, but the route is obstructed by a ship- going river. You have to decide whether to build a tunnel or a bridge.

Study the arguments in favour or against. Think of some more

	A tunnel	A bridge
For	1. No obstruction for shipping. 2. Little space is needed for the approaches.	1. The construction of a bridge is cheaper. 2. It takes less time. 3. Later it can be widened if necessary. 4. The traffic capacity of the bridge per hour is higher.
Against	1. Too costly. 2. Limited capacity. 3. Difficulties of constriction. 4. No opportunity for later widening.	1. Obstruction to shipping. 2. Some people think that bridges spoil the view.