考博英语 课外读物.doc

When an eight-lane steel-truss-arch bridge across the Mississippi River in Minneapolis collapsed during the evening rush hour on August 1st 2007, 13 people were killed and 145 were injured. There had been no warning. The bridge was 40 years old but had a life expectancy of 50 years. The central span suddenly gave way after the gusset plates that connected the steel beams buckled and fractured, dropping the bridge into the river. Eight-lane车道, 行车线2小路, 小巷Truss一捆,一束,构架Arch拱, 拱门Expectancy期待;期望Span 跨度, 跨径Give way撤退,让路,退让,垮掉,倒塌,屈服,跌价Gusset 衣袖,甲胄Plate盘Beam梁, 横梁Buckle 带扣Fractured断裂的In the wake of the catastrophe, there were calls to harness technology to avoid similar mishaps. Anthony Falls bridge, which opened on September 18th, 2008 and replace the collapsed structure, should do just that. It has an embedded early-warning system made of hundreds of sensors. They include wire and fibre-optic and displacement gauges, accelerometers, potentiometers and corrosion sensors that have been built into the span to monitor it for structural weaknesses, such as corroded concrete and overly strained joints. ,inthewakeof就是随后/因某件事.的意思Harness Inthewakeofthecatastrophe,there werecallstoharnesstechnologytoavoidsimilarmishaps. 灾难过后，有人提出用技术手段避免类似的不幸。Mishaps 灾祸；不幸事故The new Minneapolis bridge joins a handful of “smart” bridge that built-in sensors to monitor their health. Another example is the six-lane Charilaos Ttikoupis bridge in Greece, which spans the Gulf of Corinth, linking the town of Rio on the Peloponnese peninsular to Antirrio on the mainland. The 3km-long bridge, which was opened in 2004, has roughly 300 sensors that alert its operators if an earthquake or high winds warrant it being shut to traffic, as well as monitoring its overall health. These sensors have already detected some abnormal vibrations in the cables holding the bridge. Engineers then installed additional weights as dampers. Alert adj.警觉的，警惕的，注意的；思维敏捷的；活泼的n.警报；警戒状态vt.向报警warrant n.授权证；许可证；正当理由；依据vt.保证，担保；授权，批准；辩解overall adj.全部的；全体的；一切在内的；综合的adv.全面地；总地；总的说来n.工装裤；罩衫；英（军官的）紧身军裤vibrate 振动颤动cable (船只、桥梁等上的)巨缆, 钢索(尤指10英寸或10英寸以上的)缆索；钢丝绳damper 减震器The next generation of sensors to monitor bridge health will be even more sophisticated. For one thing, they will be wireless, which will make installing them a lot cheaper. The kilometers of wire needed to connect sensors to central computers can add significantly to the systems cost, according to Jerome Lynch of the University of Michigan, Ann Arbor. Sophisticated 精细的 2 高级的、先进的Dr Lynch is the chief researchers on a project intended to help design the next generation of monitoring systems for bridges. He and his colleagues are also looking at how to make a cement-based sensing skin than can detect excessive strain in bridge. Individual sensors, says Dr Lynch, are not ideal because the initial cracks in a bridge may not occur at the point the sensor is placed. A continuous skin would solve this problem. He is also exploring a paint-like substance made of carbon nanotubes that can be painted onto bridges to detect corrosion and cracks. Since carbon nanotubes conduct electricity, sending a current through the paint would help engineers to detect structural weakness through changes in the pai