首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
DEVELOPMENTS IN THE CONSTRUCTION OF TALL BUILDINGS 1 Until the nineteenth century, most tall buildings were constructed of loa
DEVELOPMENTS IN THE CONSTRUCTION OF TALL BUILDINGS 1 Until the nineteenth century, most tall buildings were constructed of loa
admin
2012-01-14
90
问题
DEVELOPMENTS IN THE CONSTRUCTION OF TALL BUILDINGS
1 Until the nineteenth century, most tall buildings were constructed of load-bearing masonry walls. Masonry walls had to be thick, particularly at the base, to support a building’s great weight. Stoneworkers built these walls by placing stone upon stone or brick upon brick, adding strength and stability by placing layers of mortar or cement between the stones. Floors and roofs had to be supported by wooden beams, but the major vertical
force
of buildings was supported by thick masonry walls. This imposed serious limitations on the number and size of windows.
2 In the 1850s, an alternative was emerging that would eliminate the need for exterior weight-bearing walls: a three-dimensional grid of metal beams and columns. The introduction of metal construction made it possible to build larger interior spaces with fewer columns than before. The new construction was capable of supporting all the loads to which a building might be subjected, including the vertical forces caused by the weight of the floors and the horizontal forces caused by the wind or earthquakes.
3 The first buildings to depart from the load-bearing wall tradition were iron-framed. Wrought iron, shaped by hammering the heated metal or roiling it under extreme pressure, contains almost no carbon, and when used as floor beams, it can support a great deal of weight. An interior wrought iron skeleton supported all of the hnilding’s weight. Exterior walls of reinforced concrete acted mainly as weatherproofing.
As masonry yielded to concrete, walls that once bore weight evolved into thin curtain walls that would allow more windows.
These modifications produced sturdier, lighter, and taller buildings that quickly became known as skyscrapers. Skyscrapers satisfied the growing need for office space, warehouses, and department stores. Buildings of eight or more stories quickly transformed the city skyline and dominated the central business districts of American cities such as New York, Chicago, and St. Louis.
4 Skyscrapers differed from previous tall structures with their use of technical innovations such as cast iron and the elevator. The development of cast iron technology, in which molten iron is poured into a mold, made modern plumbing possible. Cast iron pipes, fittings, and valves could deliver pressurized water to the many floors of tall buildings and drain wastewater out. The invention of the mechanical elevator made it possible to construct even taller buildings. Before the elevator, office buildings were rarely more than four or five stories high. In 1857, the first passenger elevator equipped with safety brakes prevented the elevator from falling to the basement when a cable broke. The elevator made the upper floors as
rentable
as the first floor, liberating architecture from dependence on stairways and human muscle.
5 Not only did these innovations have important uses in the engineering of tall buildings, but
they
also erased the traditional architectural distinctions separating the bottom, middle, and top of a building. Architects designed towers that reached to the heavens in a continuous vertical grid. Iron construction established the principle of repetitive rhythms as a natural expression of construction, as well as the idea that buildings could be made of new materials on a vast scale.
6 Construction techniques were
refined
and extended over the next several decades to produce what architectural historians have called "true skyscrapers," buildings over twenty stories high. The invention of steel was particularly significanti as steel T-beams and I-beams replaced iron in these new structures. Steel weighs less than half as much as masonry and exceeds both masonry and iron in tension and compression strength as well as resistance to fatigue. Steel rivets replaced iron bolts and were in turn replaced by electric arc welding in the 1920s. The skyscraper’s steel skeleton could meet all of the structural requirements while occupying very little interior space. Exterior curtain walls could be quite thin, since their only function now was to let in light and keep the weather out.
The word rentable in paragraph 4 is closest in meaning to
选项
A、strong
B、beautiful
C、large
D、desirable
答案
D
解析
Rentable means desirable in this context. Clues: The elevator made the upper floors as rentable as the first floor The elevator meant that people no longer had to climb numerous stairways to the upper floors. Thus, people desired (wanted) to rent the upper floors as much as the first floor. (1.4)
转载请注明原文地址:https://www.kaotiyun.com/show/qwyO777K
0
托福(TOEFL)
相关试题推荐
Completethesummary.ChooseNOMORETHANTWOWORDSfromthepassageforeachanswer.Instrumentssimilartotheguitarhavebee
TheHistoryoftheGuitarTheword’guitar’wasbroughtintoEnglishasanadaptationoftheSpanishword’guitarra,’whichwas,
ChooseTHREElettersA-G.Writeyouranswersinboxes37-39onyouranswersheet.WhichTHREEofthefollowingarefeatu
HowdesertsareformedA.Adesertreferstoabarrensectionofland,mainlyinaridandsemi-aridareas,wherethereisal
TheInnovationofGroceryStoresA.Attheverybeginningofthe20thcentury,theAmericangrocerystoresofferedcomprehen
Whatkindofcourseisthemanseeking?Whatproficiencylevelisthestudent?
Whataretheparkingregulationsoncampus?
Completethetablebelow.WriteAiftherepairwillbedoneimmediately.Biftherepairwillbedoneduringthefollowingweek
Completethenotesbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswerENVIRONMENTALCHANGEDISCUSSIONInSouthe
随机试题
A、弥散障碍B、第一秒用力呼气率减低C、两者均有D、两者均无慢性阻塞性肺气肿
患者,男性,6l岁,突然出现头痛、呕吐、意识不清,血压27/16kPa,右侧瞳孔散大,左侧偏瘫,头颅CT显示右侧大脑半球3cm×3cm×6cm高密度影。最可能的诊断是
从拱的合理拱轴分析,下述属于无推力拱的是()。
为减少截流施工难度,改善分流条件的措施有()等。
商业银行的分支机构不能开展个人理财业务。()
某企业生产刹车油、齿轮油和防冻液三类产品,分别冠以“红云”“红星”“红箭”品牌,这种品牌战略属于()。
宋代王安石《伤仲永》一文提到,方仲永从小聪明伶俐,5岁作诗,然而最后却“泯然众人矣”。这说明()。
下列联系中属于直接联系的有()
下面程序的功能是计算折旧年限。假设一台机器的原价值为100万元,如果每年的折旧率为3%,多少年后它的价值不足60万元。则横线处应填入()。y=0:p=100:x=0.03Dop=p*(1一x):y=y+1Lo
Mr.Mageisalways______onappearinghisviewstheseyears.
最新回复
(
0
)