Posts Tagged ‘seismic

08
May
08

Termite Tower Ultimately Sustainable

Termite Tower

What’s two miles high, a mile wide, and holds a million inhabitants? A termite tower reconceptualized for people. In gizmag, Loz Blain explores the implications of Eugene Tsui’s visionary approach to life on earth as it would be lived by upright bipeds in a group home designed by insects. Of course, termites don’t pay 150 billion dollars for their towers. Or maybe, in termite terms, they do? But here’s Blain, on why it’s so exciting anyway:

Designed to be virtually impervious to wind, water and earthquakes, the massive tower is conceived less as an architecture project but as a series of mini-ecosystems within which other architectural projects can be developed. And it offers some ingenious ideas on energy production, water use and intra-colony transport.

Of course, for now, the Ultima Tower remains in the realm of imagination. Lately, it no longer means anything to say a building looks science-fictional, because many now do. But this one really does. It belongs to a class of phenomena known as massive vertical solutions: huge megabuildings that actually contain whole towns, cities, or even countries. Eugene Tsui presents the tower as a framework in which many other smaller architectures can exist – including twelve large bodies of water. Plus, it sits in a lake, and the pedestrian bridges across the lake are curved, not straight. 120 levels are called for, each one of them as much as 50 meters high.

Tsui is famous for drawing inspiration from nature, though in a big-picture kind of way, it’s astonishing that looking to nature for workable, proven solutions should be considered unusual in any way. The idea for the tower came to him when engaged in a study of San Francisco, which clearly is in need of help if it is to remain livable. The architect says the whole area now has an “offensive countenance” – the best description of urban sprawl that’s been heard in a while.

The tower’s structural, water, energy, transport and safety issues are seen by the architect as the main challenges. That’s putting it mildly! Those categories cover just about everything.

So… how about those structural challenges? To distribute stress, you’ve got your double-helix cable network all around. Elsewhere, the tower described as a suspension cable bridge, only vertical. The aerodynamically valid shape resists earthquakes, and the whole thing is made from steel, concrete, stainless steel cable, anodized aluminum, ceramic, and glass.

Water? Tsui took a clue from how trees manage their hydraulics, and envisions a system of capillary action based on transpiration and cohesion to move water up. The cooling system imitates that of a termite mound, depending on water, though vegetation and windows also come into play. Also in the plans are natural water-cleansing systems and composting toilets.

Energy? The whole structure is covered with wind turbines and photovoltaic cells on walls of structural glass, and there will be a process called Atmospheric Energy Conversion. Energy comes from electricity, water or hydrogen gas, with nary a combustion engine to be found anywhere in the tower. One light source is the hollow, mirrored core and allowance is made for the need of plants to maintain tropism.

On the Ultima’s own site, we learn such interesting statistics as the amount of time an elevator takes to get to the top: about ten minutes. Of course, termites don’t have elevators. But, leaving that aside, should humanity emulate termites? Is this project feasible in the real world?

SOURCE: “Two-mile high termite nest proposed to counter the population challenge”05/05/08
photo courtesy of jonrawlinson , used under this Creative Commons license

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22
Apr
08

Very Tall Buildings, Imaginary and Real

Taipei 101, currently world\'s tallest

For Wired magazine, Rob Beschizza put together an interesting collection of pictures titled “Mile High Skyscrapers and Floating Cities That Never Were.” In contrast, we’ll also look at some of the proceedings of the Council on Tall Buildings and Urban Habitat. But first, the visionary products of several imaginations, considered by Beschizza, whose introduction goes like this:

With the space age entering its crassly commercial phase and science fiction dominated by gritty dystopian visions, you could be forgiven for giving up on the future. But not everyone has. With Dubai’s 800-meter-tall Burj Dubai skyscraper almost complete, starry-eyed visions of tomorrow’s cities are more popular than they’ve been in 50 years.

Here’s a collection of promised skylines we never got to see — and a few that may yet come to be — as seen from the imagined eyes of those who live there.

The collection includes the Illinois, which Frank Lloyd Wright never was able to build; a Moscow skyscraper whose construction only got as far as its enormous base before World War II intervened; various arcologies; proposed mile-high towers in Kuwait City and Jeddah; and the three-mile avenue with gigantic buildings along both sides which Albert Speer proposed for the Berlin city center.

The tallest building ever to boast a complete set of blueprints, Beschizza points out, was a proposed building called the X-Seed, which the Taisei Corporation designed back in the mid-Nineties. It would have exceeded Mount Fuji in height. He also looks at an abandoned North Korean project, the Ryugyong Hotel, which apparently had to be given up because the construction materials just didn’t hold together. Then there was the Ultima Tower, designed by Eugene Tsui, whose footprint would have covered two square miles.

Regardless of the difficulties, other very tall structures have emerged from the imagination into reality. On their website, the Council on Tall Buildings and Urban Habitat gives an overview of the recent 8th World Congress, whose theme was “Tall and Green: Typology for a Sustainable Urban Future.”

It was a record event for the Council, with 954 delegates including more than 50 members of the press in attendance…Amongst the attendees were a number of the most prominent faces in the architecture, engineering and construction industry…. In addition to panel sessions and workshops, attendees were invited to participate in technical tours to local tall buildings and mega projects including the Burj Dubai, now the world’s tallest building under construction…

Held in Dubai, the event drew experts in all aspects of tall building development, from 43 countries. For those who missed it, the website includes a complete list of all the papers and videos available for downloading. These range from “A Vision for the World’s Tallest” to “Engineering the World’s Tallest.” Topics considered by the Congress included all the same matters as would be taken into account with any building, yet with extreme altitude there are unavoidable differences, since certain problems do not grow arithmetically with height, they grow geometrically, exponentially.

The Congress explored everything from aesthetics to economics, looking at all aspects of sustainability, of which there are many, in relation to very tall buildings. How to save material in a tall building structure; how to be both tall and green at the same time. Is elevator technology keeping up with the need for it? What about ventilation? What kinds of energy can be harnessed, and how? What will wind and fire do? What are the options for evacuation in the event of disaster? What’s the psychological effect on the people who live and/or work in incomprehensibly elevated spaces? What kind of noise will the building require them to put up with? Papers were presented on “Nonlinear Dynamic Earthquake Analysis” and on hydraulic dampers to absorb seismic shock. One presenter issued a call for tall buildings to become less iconic and more specific. Another explored the concept of “the Vertical Farm: the sky-scraper as vehicle for a sustainable urban agriculture.”

There seems to be spirited debate in some quarters, over how high a building can or should be. Any additional thoughts are welcome here.

SOURCE: “Mile High Skyscrapers and Floating Cities That Never Were” 04/17/08
photo courtesy of leonghimwoh , used under this Creative Commons license

07
Apr
08

AGS Case Study: Restoring 215 Fremont Street, San Francisco, California

215 Fremont San Francisco

The venerable L-shaped industrial building had been around since 1927, and had suffered badly in the 1989 Loma Prieta earthquake, and then stood empty for a decade. Its rebirth is described in “Renovated Office Building at 215 Fremont Street, San Francisco California,” one of the case studies detailed in Architectural Graphic Standards, 11th Edition, from the American Institute of Architects, published by WILEY. The piece was written by four of the participants: James Kellogg, AIA, HOK; Lynn Filar, HOK; and Navinchandra R. Amin, SE and Vivian L. K. Wan, PE, both of Middlebrook + Louie.

The team that took on the revival of 215 Fremont faced real challenges. A large part of the project consisted of figuring out just what they were dealing with, hindered by the fact that many of the original drawings were either missing or indecipherable. When the nitty-gritty evaluation phase started, some unpleasant facts turned up. For example:

Since the original construction, the building had experienced differential settlements of up to 5 inches. Core samples and dynamic load tests of the existing floor slabs provided data necessary to evaluate the viability of components of the existing structure…

A large part of the evaluation process consisted of cranking up ETABS and SAP 2000, respected CAD programs that together gave a picture of how nicely the building would work and play with gravity and seismic loading. The prognosis wasn’t good. For starters, an earthquake would turn the ground beneath 215 Fremont into soup. How would they get this thing to stay up? Equally important was the need to satisfy ever-evolving building codes. We’ll let them tell it:

A new structural system needed to be developed for the project that would be sufficiently stiff to alleviate the induced internal forces in the existing floor slabs and punched exterior walls. Additionally, the structural system needed to use the full length and width of the structure to minimize the seismic overturning forces applied to the foundation…

As often happens, necessity gave birth to invention, and an elegant, innovative solution was arrived at.

This retrofit of an early twentieth century building led to the creation of a unique connection between steel braces and concrete columns, as a combination structural system comprised of steel-brace, frame-and-concrete shear walls was developed to meet all critical requirements.

The article explains exactly, and in great detail, how the team did it. And that’s not all. Every bit of 215 Fremont was remade into a paragon of sustainability and a fully compliant respecter of seismic requirements. What had once been basement storage space was now a much-needed parking facility. From bottom to top, from the new pedestrian-friendly retail arcade to the attractive rooftop terraces, the whole edifice was transformed. Impressed, the Structural Engineers Association of California gave the building its coveted Excellence in Structural Engineering Award.

215 Fremont, later also known as the Charles Schwab building and the Emporis building, was a showpiece as its neighborhood morphed into the happening “multimedia gulch.” When the project was finished in early 2001, a major corporation immediately occupied the entire building. The renovators had successfully made a statement: the cultural tone of the whole area had been elevated.

But any project of this kind also raises disturbing questions about the ultimate futility, in the event of catastrophic emergency, of even the strictest building codes.

SOURCE: “Renovated Office Building at 215 Fremont Street, San Francisco California” 2007
Photo courtesy of WILEY by Michael O’Callahan