久久久无码人妻精品无码_6080YYY午夜理论片中无码_性无码专区_无码人妻品一区二区三区精99

Towers of wood, not steel

Updated: 2013-10-20 08:02

By Henry Fountain(The New York Times)

  Print Mail Large Medium  Small

The movement to construct tall buildings largely with wood as an environmentally friendlier alternative to steel and concrete has received a boost from an unusual source - a leading architectural firm known for its towers of steel and concrete.

Skidmore, Owings & Merrill, the Chicago-based firm that has designed a long list of skyscrapers, including the new One World Trade Center in Lower Manhattan, has developed a structural system that uses so-called mass timber - columns and thick slabs that are laminated from smaller pieces of wood. In a report this year, the firm showed how the system could be used to build a 42-story residential tower that would have a lower carbon footprint than a conventional structure.

"We wanted to see what we can do to help on the sustainability side," said William F. Baker, a partner in the firm. With its system, about 70 percent of the structural material is wood; most of the rest, including the foundation, is concrete.

Benton Johnson, an engineer who worked on the report, said wooden high-rises could help solve the problem of providing adequate housing to the billions of people living in cities - while also addressing climate change.

"We know that we need to build a lot more buildings," Mr. Johnson said. "And we know that we need to lower CO2."

Until now, tall wooden buildings had been championed by architects and engineers mostly from smaller firms outside the United States. They welcomed the Skidmore, Owings & Merrill report.

Michael Green, an architect in Vancouver, British Columbia, who helped devise a different structural system for wooden towers that was detailed in a report last year, said: "This is the first new way to build in a hundred years. "

Few modern tall wooden buildings have been built around the world, and only one, an apartment building that was completed this year in Melbourne, Australia, has reached 10 stories. Mr. Green's design of a 27-meter mixed-use building in Prince George, British Columbia, will make it the tallest wooden building in North America when it is completed next year.

Constructing more and taller towers will require changes in building codes - most of which limit wood structures to four

stories or fewer - and construction methods. Architects, engineers, contractors and, crucially, developers will have to be convinced that wooden buildings can be safe, attractive and profitable. (They are generally more expensive than conventional towers, although in some areas of construction there can be savings because the slabs can be erected fairly quickly.) Fire protection is a particular concern, but advocates for wooden buildings say mass timber does not ignite easily and forms a layer of char that slows burning. They say wooden towers can meet fire safety standards for steel or concrete buildings.

Towers of wood, not steel

Production of steel and concrete produces significant amounts of the greenhouse gas carbon dioxide, while wood holds the carbon from CO2 removed from the atmosphere through photosynthesis. So using wood in the structural elements can help offset the carbon emissions from the other parts of the construction process and from the operation of the finished building. This is not conventional frame construction, in which thin elements are nailed together, but more akin to building with concrete slabs. The use of so much wood raises the issue of the potential impact on forests if wooden buildings were to become prevalent. Mr. Baker said as long as forests were managed, sustainable wooden buildings should not have much of an impact. There are also millions of fir trees in North America that were killed by a beetle infestation and that could be used to produce the timber panels.

The Skidmore, Owings & Merrill system uses a type of engineered wood called glued laminated timber, or glulam, for the building columns, and cross-laminated timber slabs for the central core, floors and shear walls, which provide stiffness against wind loads. But the concept calls for concrete beams along the perimeter of each floor and elsewhere to allow for longer spans and more flexibility in layouts.

Mr. Green, in his report, presents a system that could be used to build towers in seismically active areas like Vancouver. Rather than concrete, he uses some steel beams to allow the building to better respond to earthquake forces.

Andrew Waugh, a British architect whose nine-story apartment building in London, completed in 2009, has become a showpiece of the wooden-tower movement, said both reports would help build momentum for buildings taller than 10 stories.

"It's such an exciting time," Mr. Waugh said. "It feels like the birth of flight - it's one of those kinds of moments in engineering."

The New York Times

Towers of wood, not steel

(China Daily 10/20/2013 page9)

久久久无码人妻精品无码_6080YYY午夜理论片中无码_性无码专区_无码人妻品一区二区三区精99

    欧美午夜一区二区| 欧美视频完全免费看| 国产精品免费免费| 91网上在线视频| 一区二区三区电影在线播| 欧美日韩综合在线| 久久精品国产精品亚洲红杏| 国产亚洲精品资源在线26u| 99久久er热在这里只有精品15| 一区二区三区日韩精品| 欧美一区二区三区影视| 国产在线精品不卡| 亚洲啪啪综合av一区二区三区| 欧美日韩一区二区三区在线| 久久成人久久鬼色| 亚洲欧洲成人av每日更新| 欧美午夜一区二区三区免费大片| 老司机精品视频导航| 中文字幕欧美日本乱码一线二线| 在线亚洲一区二区| 精品一区二区综合| 最新久久zyz资源站| 91精品国产色综合久久久蜜香臀| 国产一区二区免费视频| 一区二区三区在线观看网站| 日韩欧美国产wwwww| 91在线国产观看| 蜜桃一区二区三区在线观看| 国产精品久久久久久久久久免费看| 精品污污网站免费看| 国产精品888| 亚洲成人av电影| 国产三区在线成人av| 欧美色偷偷大香| 国产成人精品三级麻豆| 亚洲成人自拍一区| 欧美国产精品v| 91精品国产美女浴室洗澡无遮挡| 成人午夜激情视频| 日本一不卡视频| 国产精品传媒入口麻豆| 欧美一区二区三区日韩视频| bt7086福利一区国产| 美女视频网站久久| 亚洲激情av在线| 久久久久99精品一区| 欧美日韩国产免费| 不卡欧美aaaaa| 久久精品国产免费| 亚洲国产精品久久久久秋霞影院| 日本一区二区三区四区在线视频| 欧美精品久久一区| 97se亚洲国产综合在线| 激情六月婷婷久久| 亚洲第一会所有码转帖| 国产精品麻豆网站| xf在线a精品一区二区视频网站| 欧美亚洲国产bt| jlzzjlzz亚洲女人18| 精品一区二区三区不卡 | 国产a级毛片一区| 日韩不卡免费视频| 亚洲男人电影天堂| 欧美激情一区二区三区全黄| 日韩欧美国产综合| 欧美日韩高清影院| 91电影在线观看| 99免费精品在线| 国产在线观看免费一区| 日韩电影在线观看电影| 一区二区三区日韩欧美| 中文字幕日韩一区| 欧美激情综合在线| 精品国产乱码久久久久久老虎| 欧美日韩国产另类一区| 欧美性一级生活| 97久久超碰国产精品| 成人性生交大片免费看中文| 国内久久精品视频| 久久99久久久久| 日本少妇一区二区| 偷窥少妇高潮呻吟av久久免费| 一区二区三区四区激情| 国产精品成人网| 亚洲国产精品激情在线观看| 久久久久久久久免费| 精品国产91洋老外米糕| 日韩视频一区二区三区在线播放| 欧美精品亚洲一区二区在线播放| 色综合久久天天| 91在线精品一区二区三区| 97se亚洲国产综合自在线不卡| eeuss鲁片一区二区三区在线看| 成人美女在线视频| 成人av资源在线观看| www.亚洲在线| 99久久久无码国产精品| voyeur盗摄精品| 91麻豆精东视频| 91福利资源站| 欧美色偷偷大香| 欧美精品日韩一本| 日韩女优视频免费观看| 精品剧情在线观看| 久久在线免费观看| 国产日产欧产精品推荐色| 久久―日本道色综合久久| 久久婷婷国产综合国色天香| 久久久精品国产免大香伊| 国产午夜亚洲精品不卡| 欧美韩国日本综合| 国产精品久久久99| 亚洲图片另类小说| 亚洲精品免费在线观看| 亚洲国产视频网站| 日韩中文字幕亚洲一区二区va在线| 午夜伦理一区二区| 免费高清成人在线| 国产一区二区三区精品视频| 97久久精品人人做人人爽50路| 国产精品综合一区二区三区| 国产麻豆成人传媒免费观看| 成人午夜视频在线| 日本高清视频一区二区| 欧美日韩小视频| 日韩欧美一区二区免费| 国产亚洲成av人在线观看导航| 日本一区二区三级电影在线观看| 国产精品丝袜久久久久久app| 成人免费小视频| 亚洲与欧洲av电影| 青青青爽久久午夜综合久久午夜| 黑人巨大精品欧美黑白配亚洲| 国产精品一级二级三级| jlzzjlzz亚洲女人18| 欧美三级乱人伦电影| 日韩视频在线一区二区| 欧美高清在线一区二区| 亚洲高清免费在线| 久久er精品视频| 99久久婷婷国产综合精品电影 | 欧洲视频一区二区| 91精品国产欧美一区二区| 国产清纯美女被跳蛋高潮一区二区久久w | 国产高清亚洲一区| 91在线国内视频| 91精品国产91久久久久久最新毛片| 久久精品人人做人人爽97| 亚洲乱码国产乱码精品精98午夜| 日韩精品一级二级| 国产精品一区免费视频| 91福利国产成人精品照片| 精品国产免费久久| 伊人夜夜躁av伊人久久| 九色|91porny| 色噜噜狠狠色综合欧洲selulu| 日韩欧美一区在线观看| 成人欧美一区二区三区| 免播放器亚洲一区| 91在线一区二区| 日韩免费观看2025年上映的电影| 亚洲欧洲日产国码二区| 青青国产91久久久久久| 91蜜桃传媒精品久久久一区二区| 日韩一区二区三区电影 | 国产精品视频你懂的| 亚洲第一二三四区| 成人动漫视频在线| 欧美一区二区三区播放老司机| 中文字幕中文字幕中文字幕亚洲无线 | 国产乱码精品一区二区三| 欧美亚洲一区二区在线| 国产日韩欧美在线一区| 天天影视网天天综合色在线播放| 成人免费视频一区| 欧美一级日韩一级| 亚洲精品美国一| 国内精品视频一区二区三区八戒| 在线观看日韩国产| 国产欧美一区二区精品秋霞影院| 五月婷婷综合网| 91麻豆福利精品推荐| 久久这里只有精品首页| 日韩影院免费视频| 91成人在线精品| 国产精品日产欧美久久久久| 青青草国产精品亚洲专区无| 色婷婷综合久久| 欧美激情一区二区三区在线| 美日韩一区二区| 欧美日韩精品一区二区天天拍小说| 国产精品私房写真福利视频| 国内精品第一页| 欧美丰满美乳xxx高潮www| 亚洲激情图片qvod| 99久久婷婷国产综合精品电影| 国产性做久久久久久| 狠狠狠色丁香婷婷综合激情| 91精品国产综合久久福利 | 亚洲线精品一区二区三区 |