Archive for the 'Substructure' Category

11
Apr
08

World’s Largest Green Building: the Palazzo Las Vegas

Palazzo Las Vegas

Nevada’s governor Jim Gibbons was there, and so was U.S. Department of Energy official David E. Rodgers. Along with many other exuberant well-wishers, they celebrated the awarding of a Silver LEED (Leadership in Energy and Environmental Design) Certificate to the largest “green” building on earth, the glitzy Palazzo Resort Hotel in Las Vegas. This announcement came via press release from Ron Reese and Mindy Eras, spokespeople for the Las Vegas Sands Corporation, which is justifiably proud of this recognition from the U.S. Green Building Council. Additionally, the building also received the “Energy Innovator’s Award” from the U.S. Department of Energy. This honor recognizes the successful use of energy-efficient, and/or renewable, technology.

The Palazzo employs such effective environmentally-efficient technologies that it conserves enough water to provide each Nevada citizen with 266 eight-ounce glasses of water for a year and saves enough energy to light a 100 watt light bulb for 12,100 years. It even promotes alternative modes of transportation by offering valet parking – for bicycles.

Features include showers, toilets and faucets that conserve a whopping 37%, and a watering system for the plant life that uses 75% less water. The swimming pools are solar-heated with enough left over to help out with the hot-water system for the rest of the hotel. In the Palazzo’s 3000 suites, the air conditioning is so smart, it cuts back when nobody’s around, and returns to the guest’s desired level when the room is occupied.

Architect James R. Rimelspach (The Stubbins Associates), developer Sheldon Adelson (incidentally, the third wealthiest man in the United States), and the rest of the team worked closely with consultants from LEED right from the start of the project. The framing used 66,000 tons of steel, averaging 95% recycled content, and the 10,000-yard core foundation pour utilized 26% recycled concrete. There are eight below-ground levels, allowing for a 4,400-space parking garage whose excavation took an entire year, displacing a million cubic yards. It’s interesting to look back to September of 2005 when, at the project’s inception, Las Vegas Sands Executive VP Brad Stone told reviewjournal.com that the excavation added as much as $60 million to the price tag.

“This was born out of necessity,” Stone said. “We wanted to have a certain size property and we only had so much land to work with. We realized we had to put the parking underground, so we came up with a plan and put it in place. When you look at the cost of an acre of land on the Strip, you need to make your best usage of that land.”

Supported by several hundred pilings 120 feet deep, the structure rises 50 stories above ground and encompasses over 60 luxury boutiques, along with 20 other high-end retail establishments, including the first Lamborghini dealership to grace the Strip. The Palazzo’s Grand Opening was celebrated in January of this year, with festivities that included a Diana Ross concert, fireworks, and an abundance of celebrity guests. That was a great event in its way, but this week’s validation from the U.S Green Building Council was a historically significant event. How long, we wonder, will it be before a new “largest green building” comes along?

SOURCE: “The Palazzo Las Vegas Named Largest ‘Green’ Building in the World” 04/09/08
photo courtesy of Bernardo Wolff , 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