Designing High-Rise Buildings

Science Daily (Sep. 9, 2011) — A university professor who carried outa major study into the evacuation of the World Trade Centre after 9/11 says the "far-reaching impact" of the attacks is still being felt when it comes to the design of new high-rise buildings across the world.

 

Professor Ed Galea, from the University of Greenwich, led a three and a half year study into the evacuation of the twin towers, collaboration between the universities of Greenwich, Ulster and Liverpool.

 

The project included in-depth interviews with 271 survivors about their experiences of what it was like as they tried to leave the buildings. Their personal stories helped the research team to paint a comprehensive pictureof how people acted and what factors influenced their behaviour during evacuation, and assisted in identifying key safety issues that building designers need to address.

 

"The research is still ongoing and the data we have collected, both on the mechanics of a large-scale evacuation, and on the issues human behaviour, is being shared across the world, as a valuable international resource," Professor Galea says.

 

Using their building EXODUS evacuation software, the Greenwich team analyzed the evacuation dynamics of the events of 9/11 and also explored what may have happened if the buildings had been fully occupied. From this work, Professor Galea concluded that, for buildings above a critical population and height, stairs alone were not sufficient for safely evacuating the entire population.

 

Alongside colleagues Dr Peter Lawrence and Mike Kinsey, at the university's Fire Safety Engineering Group, Professor Galea went on to explorethe use of lifts for evacuations in high-rise buildings. As part of their building EXODUS software, the researchers have developed advanced human behaviour models, which simulate the choices people make in deciding to use a lift/elevator as part of their evacuation route in an emergency.

 

"Our studies suggest that buildings should utilize elevators and stairs, in combination," Professor Galea says. "We know stairs alone are not sufficient for full building evacuations, and since 9/11 there has been a trend to use specially designed elevators. But elevators, even fire safe elevators, raise the complex issue of human behaviour, and we know from our studies that many people do not trust using them, or will simply not wait for them, in an emergency.

 

"So it's vital to consider all aspects when designing new buildings. This means not just the mechanical issues of using elevators to evacuate people, but the whole issue of human behaviour, and this is what we have built into our computermodelling."

 

Professor Galea, Founding Director of the Fire Safety Engineering Group, warns that, ten years on from 9/11, people need to guard against complacency. "Evacuation drills and training always need to be taken extremely seriously, as successful evacuation depends in part on how quickly people respond," he says. "We found in our research that some people took many minutes to decide to evacuate the towers, while others didn't know where the stairs were, for example. The attacks have also highlighted the need for better information systems in buildings, with proper instructions in an emergency, rather than just an alarm going off.

 

"We intend that the information we have will help save lives, as it will help improve building design and evacuation procedures."

 

The original research project, known as HEED (High-Rise Evacuation Evaluation Database), was funded with a £1.6 million grant from the UK Engineering & Physical Research Council (EPSRC). (3600 знаков)

 

Words to Text 7

to carry out – выполнять, осуществлять

– доводити до кінця; виконувати

far-reaching impact – воздействие, влекущее серьёзные последствия

– далекосяжний вплив

high-rise building – высотное здание – висотний будинок

in-depth interview – глубинное интервью, углубленный опрос

– глибинне інтерв'ю

comprehensive picture – всесторонняя картина – всебічня картина

behaviour – поведение – поведінка

key safety issues – ключевые вопросы безопасности

– ключові питання безпеки

alongside – параллельно, наряду – пліч-о-пліч, поруч

to explore – исследовать, рассматривать, изучать, анализировать

– досліджувати, вивчати

advanced – современный, передовой – сучасний; досконалий

emergency – крайняя необходимость; крайность

– крайність; непередбачений випадок

to utilize – использовать, употреблять

– утилізувати, використовувати

to trust – доверять, полагаться – довіряти(ся)

complacency – удовлетворённость; самоуспокоенность

– самозадоволення, самовдоволення

to highlight – выдвигать на первый план – висувати уперед

 

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Engineers Test Effects of Fire on Steel Structures,

Nuclear Plant Design

Science Daily (Sep. 2, 2011) — Ten years after 9/11, researchers at Purdue University are continuing work that could lead to safer steel structures such as buildings and bridges and also an emerging typeof nuclear power plant design.

 

"I want people to understand that in the last 10 years we've not been quiet," said Amit Varma, a Purdue associate professor of civil engineering. "We've been working to make structures better and safer."

 

The researchers are using a custom heating system and a specialized laboratory for testing large beams and other components and have created models that could be used in designs to improve fire safety.

 

New findings are detailedin two research papers appearing this month as part of a special 9/11 issue of the American Society of Civil Engineers' Journal of Structural Engineering. The work has been led by Varma, doctoral student Lisa Choe and graduate student Emily Wellman.

 

Data will be used to potentially update design codes for steel structures and to test and verify computational building-design models.

 

The work is funded by the National Science Foundation, the U.S. Department of Commerce's National Institute of Standards and Technology, the American Institute of Steel Construction, and the American Iron and Steel Institute.

 

Building fires may reach temperatures of 1,000 degrees Celsius, or more than 1,800 degrees Fahrenheit, and the strength of steel structures drops by about 40 percent when exposed to temperatures exceeding 500 degrees Celsius.

 

Steel components in buildings are covered with fireproofing materials to resist the effects of extreme heating.

 

"So the air could be 1,000 degrees in a fire, but the insulated steel might be 500 degrees or less," Varma said. "However, once the steel gets beyond 600 degrees Celsius, there can be some major problems."

 

The Purdue researchers designed a system made up of heating panels to simulate the effects of fire. The heating system is being used to test full-scale steel columns at Purdue's Robert L. and Terry L. Bowen Laboratory for Large-Scale Civil Engineering Research. The panels have electrical coils, like giant toaster ovens, and are placed close to surfaces being studied. As the system is used to simulate the effects of fire, test structures are subjected to forces with hydraulic equipment to mimic the loads experienced in real structures.

 

"We wanted to build an experimental method that engineers can use to study the behavior of buildings in fire using a structures laboratory," he said. "Most of the previous work has been done in fire laboratories, which don't have the same experimental resources of a structures lab. We can subject the structures to failure and make more fundamental observations of behavior and failure to build models. Almost no tests or data like we have can be found in the public domain."

 

Doctoral student Anil Agrawal led work to create a model that shows precisely what happens to a steel member subjected to fire while forces are applied by the hydraulic cylinders. The model has been found to be accurate when compared to the experimental results from work led by Choe.

 

"These are very difficult experiments to perform," Varma said. "Having a dependable model to predict behavior means you don't have to do as many experiments when testing new designs."

 

Wellman led a portion of the work focusing on the effects of fire on a building's steel-and-concrete floor and its connections to the building. The composite design is the most common type of floor system used in steel structures.

 

"Conventional wisdom says the presence of concrete floors improves the fire resistance of a building," Varma said. "We found that this isn't necessarily true for the worst-case scenario, unless you set out to design the floor specifically to perform well in fire."

 

The aim of the research is to learn precisely what happens to the connections between a floor's steel beams and the building columns. Extreme heat causes the beams to sag.

 

"When it starts sagging, the question is, how do the connections perform? This has been a big question for the industry," Varma said.

 

The researchers analyzed critical joints after a floor system was subjected to extreme heat in a specialoven at Michigan State University. Results will be used to help researchers create a model of the steel-concrete floor system.

 

"It is far more difficult to model a floor system than it is to model columns," Varma said. "But we will eventually be able to do that."

 

Another paper to be published in December in the American Institute of Steel Construction's Engineering Journal shows how to use the models to create design specifications for columns. The paper was written by Agrawal, who also is involved in modeling the steel columns and the collapse of entire building systems. The work is ongoing.

 

Varma also has led research to test a new type of design for nuclear power plants. The work focuses on testing structures like those to be used in the Westinghouse Electric Co. AP1000 standard nuclear power plant design. Engineers tested components of an "enhanced shield building" that will contain the plant's main system components.

 

The building consists of an inner steel-wall containment vesseland an outer radiation shield made using a technology called steel-concrete-composite construction. Instead of using more conventional reinforced concrete, which is strengthened with steel bars, the steel-concrete approach uses a sandwich of steel plates filled with concrete.

 

The new design may reduce the cost of building nuclear power plants by speeding construction time. The composite construction method was first used more than a century ago, but no codes or standards for its use in nuclear power plants yet exist, said Varma, who is vice chair of an industry committee writing a new specification for composite structures in nuclear power plants.

 

Findings have shown the design withstands the seismic forces that would result from strong earthquakes. Data also indicate the construction method, also called armored construction, could be used to create structures capable of withstanding aircraft or missile attacks.

 

"When you have steel plates on the inside and on the outside, it's a structure that would hold up against an aircraft impact or extreme weather events, such as tornados," Varma said. "Nothing can easily punch through that sort of structure."

The Bowen lab is one of a handful of facilities where testing can be performed on full-scale structures instead of smaller-scale specimens, yielding more accurate data. The 66,000-square-foot laboratory is equipped with special hydraulic testing equipment and powerful overhead cranes. (6600 знаков)

 

Words to Texts 8 & 9

steel structure – стальная конструкция – стальна конструкція

emerging type – новый тип – новий тип

beam – балка – балка

fire safety – пожарная безопасность – (проти)пожежна безпека

to detail – детализировать; подробно описывать

– докладно спинятися, розповідати

to update – усовершенствовать, приводить в соответствие с

современными стандартами

– модернізувати; приводити у відповідність з

вимогами сучасності

to verify – поверять, выверять (измерительные инструменты)

– перевірят; підтверджувати

to expose – выставлять; подвергать действию (атмосферных

влияний)

– виставляти, показувати

fireproofing material – огнеупорный материал – вогнетривкий матеріал

to simulate – моделировать, воспроизводить (действительные

условия работы при испытании)

– моделювати, відтворювати

full-scale – в натуральную величину; полномасштабный

– повний, у повному обсягу

to subject to – подвергать (воздействию, влиянию и т.п.)

– піддавати (чомусь)

to mimic – копировать – імітувати; наслідувати

experienced – знающий, опытный, квалифицированный

– досвідчений, обізнаний, кваліфікований

failure – разрушение; крушение; авария

– пошкодження, розрив; зупинка; аварія

public domain – государственная собственность

– державна (публічна) власність

dependable model – надежная модель – надійна модель

concrete floor – бетонное перекрытие; бетонный пол

– бетонне перекриття, бетонна підлога

to sag – оседать; провисать – звисати, обвисати

joint – соединение; сочленение; шарнир

– точка сполучення, стик

eventually – в итоге, в конце концов

– кінець кінцем, зрештою

design specifications – технические условия на проектирование

– технічні умови на проектування

collapse – авария, выход из строя; крушение

– руйнування; обвал

nuclear power plant – атомная электростанция (АЭС)

– атомна електростанція (АЕС)

enhanced shield building– усиленное защитное здание, сооружение

– посилена захисна споруда

containment vessel – защитная оболочка (ядерного реактора)

– захисна оболонка

to reduce – понижать (напр. давление) , сокращать, уменьшать

– зменшувати, знижувати

composite structure – составная конструкция (из разных элементов)

– складена конструкція

findings – полученные данные, добытые сведения

– отримані відомості (дані)

armored construction – армированная конструкция

– армована споруда

to withstand – выдерживать (неблагоприятные условия среды)

– протистояти; витримувати

missile – реактивный снаряд; ракета

– реактивний снаряд; ракета

to punch – пробивать; перфорировать

– пробивати отвори; компостувати

full-scale structure – полномасштабная, (показанная или изображённая) в

натуральную величину) конструкция

– повномасштабна споруда

overhead crane – мостовой кран – мостова підойма

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