Jan 6, 2009

Sưu tầm các đoạn văn ngắn

THE GREAT WALL OF CHINA (wiki.answers.com)
The constructed height varied from 5 to 8 meters (16 to 26 feet), depending on terrain and other factors. Its thickness ranges from about 4.5 to 9 meters (15 to 30 feet).

The Great Wall is one of the largest building construction projects ever completed. It stretches across the mountains of northern China, winding north and northwest of Beijing. It is constructed of masonry, rocks and packed-earth. At its greatest extent, it was over 5,000 km (=10,000 Li) long.

The Great Wall was built beginning around 241 BC and continued for several centuries. The wall was built mostly by making wood frames and packing them with dirt. In some places, notably near mountain quarries, the wall is made of stone.
________________________________________________
Transportation Systems (bachkhoadanang.net)

Transportation has always been one of the most important, aspects of civil engineering. One of the great accomplishments of the Roman engineers was the highway system that made rapid communication possible between Rome and the provinces of the empire. The first school that offered training specifically in engineering was the Ecole des Ponts et Chaussees, the school of Bridges and Highways established in France in 1747. and in England, Thomas Telford, roadbuilder, became the first president of the Institution of Civil, Engineers in 1820.
Modern highways are still built according to the principles laid down in the eighteenth and early nineteenth centuries by a French man, Pierre Tresaguet, the Englishman Telford, and a Scot, John L. McAdam, whose name has passed into English in the words macadam macadamize, and tarmap. These men designed the first modern road that had a firm footing, the surface on which the foundation rested. Their roads also included good drainage and a wearing surface the penetrated by water. Both tresaguet and Telford used a heavy foundation of stones, on top of which a base course of lighter crush stones and a wearing surface of still smaller stones were built up. Their roads were also slightly curved in a crown or camber so that the water would run off. Mc Adam realized that the soil itself could bear the weight of the road when it was compacted or pressed down, a long as it remained dry. He was able therefore to eliminate the heavy cost of the stone foundation by laying a base course of crushed stone on top of a compacted footing. The iron wheels of the carriages of his day ground the stones of the top level into a continually smoother an more watertight surface....
__________________________________

No comments:

Post a Comment