At the Intersection of Structural Engineering and Sustainable Urban Design
Monday, March 30, 2009
Unsung Indy
In honor of the launching of Unsung Indy and Urban Indy's call to share your neighborhood experiences, I am putting a double-post in today.
First up: The Appeal of Urban Neighborhoods I can't possibly begin to explain how great it is when you find a place that fits you. I strongly encourage people to start investigating their own city, and find an urban neighborhood that you feel welcome in. Inspiration is all around us.
Second: Irvington Yet another post about the neighborhood of Irvington. I live here, so I'm kind of biased, but I want to share as much as I know about it during the Unsung Indy campaign.
Five miles to east of Monument Circle, the neighborhood of Irvington and its residents enjoy urban living in a quaint, small-town setting. Even though annexed in 1902 by Indy, it retains a level of independence from Indianapolis proper.
Walkscore "walkability heat map" of downtown Indy and Irvington to the East
This historic enclave evokes a charming romanticism that can be felt throughout the neighborhood. The authenticity of this neighborhood is unquestionable, the old majestic homes display their age with a patina that cannot be replicated.
The old commercial buildings reward pedestrians with strange and wonderful shops and hidden treasures. Brick lined streets, cast iron streetlamps under a canopy of leaves, and the ever-present laughter of children remind Irvingtonians that the good things in life can be found right at home.
Irvington started as a dream among a group of idealistic families, people who believed the concepts of the American Romantic movement could be used to perfect the built environment. Naming the town for Washington Irving and many of the streets for literary heroes, the founders did not waver in their conviction. Laying out streets and estates according to the existing landscape rather than the typical grid system left Irvington with a unique streetmap. Glades and creeks were incorporated into the plan rather than pushed aside. One family even ceded their home and property to protect the magnificent Kyle Oak tree that still anchors one corner of the neighborhood.
Though bisected by the Historic National Road (under the name of Washington Street), the neighborhood is forever joined across this axis by the two circles on Audubon Street. This bold gesture has kept the neighborhood united even as the population has moved from horses to streetcars to automobiles.
The street layout protects pedestrians by encouraging all non-essential traffic to remain on primary roads without resorting to cul-de-sacs or speed bumps. Funneling the traffic down through the commercial corridors provides additional business opportunities for the Irvington merchants along Washington Street. Distinctive restaurants and coffee houses nestled inside the taller buildings lend a sophisticated urban feel. The antique shops and live music venues provide a destination during the day and night. Art shows, farm markets, and cultural opportunities are easily found and always satisfying.
A large portion of the neighborhood is a designated historic district. The residents in these areas have agreed to maintain their homes to a higher standard of historic character, using traditional materials and preserving architectural features. As Irvington developed home styles changed with each era, and it is not uncommon for a single block to include an original mansion, a traditional American four square or Victorian farmhouse, and a stately duplex nearby. Even old fraternity and sorority houses remain from when Butler University was an Irvington institution. There is such a mixture of home sizes and features that families in any situation can find a home that will fit their needs.
Perhaps Irvington's most enduring defining feature is the people who live here. Passionately devoted to their community, they are not afraid to extend a hand of friendship to anyone they meet. Founded by outspoken abolitionist politicians, Irvingtonians have never abandoned their duties to society. While the commutes are typically shorter, Irvingtonians tend to get around just the same. All of them understand their role as ambassadors of the Eastside, and are quick to share their experiences. Why not stop by for a visit soon?
Spring has officially arrived in Indianapolis, and all sorts of yearly rituals are being renewed. Flowers blooming, people out in the neighborhood, romances beginning, and probably some people are looking to buy or rent houses in the Indianapolis region. I'm hoping that everyone in the last category is taking a serious look at housing within the urban core or the inner suburbs.
These established neighborhoods offer an experience that is hard to beat by the outer ring of suburbs. Personally, I have lived in Avon and Carmel, but I have found Irvington to be a much more satisfying place. Not only Irvington, but almost every urban neighborhood scores much higher on a walkability scale. Sidewalks and old style storefronts promote pedestrian accessibility and neighborhood interaction.
Living inside the I-465 loop also has more esoteric attractions. It is about belonging to a community. You aren't just living in the Metropolitan Statistical Area - you are living in Indianapolis. Every time you put that address on a letter or a form, you can feel proud of your contributions as a citizen. The parades, the halloween festivals, the lighting of the Christmas tree on the Circle, these are all events happening in your town.
People are often concerned about the quality of urban schools, public safety, and property taxes. To be honest, I think these issues scare people needlessly. The school system, with its magnet schools, charter schools, and other great opportunities, is really turning around. My neighborhood feels very safe, and I know I am surrounded by helpful neighbors watching out for me. The property taxes, well, they are dropping significantly with the new round of tax reform. They might make me give up my membership to the Cato Institute, but haven't minded paying taxes. I feel I am getting such a good deal for the cost, why would I complain?
Hopefully I've convinced you to consider an urban setting for your next residence. So which neighborhood, what house to buy or rent? Everyone has different needs and different expectations, so there is no simple answer. When it comes down to it, you need to be doing a lot of research. People always say a house is your most important investment, so treat it like one. Research the Walkscore map, find restaurants to visit in different neighborhoods, and read all the neighborhood posts on sites of bloggers like these guys:
Now these options are by no means a complete listing of all the neighborhoods in Indy. I encourage you to visit the Walkscore site for Indianapolis and start your research. The heat map can give you clues to two important features of any neighborhood: 1) neighborhoods that have somewhere to go (economic activity), 2) a way to get there. Armed with this information and a good realtor, you will be successful. Welcome to city life!
Update 2009-04-03: Comment from Virginia suggested the Nuvo Neighborhood Guide (2008). It looks like another great resource, and coming from an independent source should be very honest.
Skyscrapers topping out early, some just tapping out
Here's a heartwarming story about a construction defect that was discovered halfway through completion. Reinforcing for the concrete columns wasn't installed correctly (don't know exactly what that means, but could be pretty expensive to fix). The novel solution: just stop building...
But, in these times of economic woe, it seems like everyone is scaling back their plans. Not just the unlucky builders who hire incompetent contractors. Even the famous Chicago Spire is now just a smoking hole in the ground. The fun thing is that so many of these "super-tall structures" or "towers of babel" are associated with equally large egos. Schadenfreude to the max.
I posted a few weeks ago about how I disapproved of ASCE's infrastructure report (here and here). I just wanted to clarify how I feel about it, now that I've had a while to ponder the situation. Basically I still disapprove. Without qualifications.
First off, I think it blurs the line between our role as protecting the public welfare and a new role of setting policy for political gain. To me it is similar to the issues that top military leaders must deal with. It is clear that you must have soldiers to fight wars. Getting their opinion on military matters is essential. But clearly, you can't let the military decide which wars should be fought. Not only is that a question they can't answer, it's a question they don't want to. It's a conflict of interest.
In this democratic republic we call the United States of America, there is only one group that can set policy and that is the citizenry. We vote to elect leaders to represent our wishes; on the other hand ASCE has not been elected, appointed, or chosen to act in any representational capacity on this issue (other than by us clever engineers).
Because they have no official right to set policy in this matter, ASCE is acting as a lobbyist group. And what are they lobbying for? More money. They want the US public to spend more money on civil engineering projects. Who will this benefit? Well, that's a complicated issue. If it results in "bridges to nowhere" then additional spending won't benefit anyone but builders and engineers. Then 20 years down the road those unneeded bridges and roads will be "crumbling" and used to justify more spending. The ability for this report to be pushed in front of the public to proclaim how much we need more bridges and superhighways is another reason I hate it.
The final reason I just wish ASCE would quit this is because it makes an implicit appeal (sometimes explicit) that spending more on infrastructure projects will provide more safety for the public. This is downright dangerous. If the last report card from 2005 had somehow convinced lawmakers to invest USD$2Trillion into all these projects, could we have averted the most famous disasters since that time? Would Minnesota's I-35W bridge still be up? Would the city of New Orleans have been spared? The answer is no. But I have still seen these issues used to justify additional infrastructure spending.
My opinion is that until ASCE can prove that not a single member will profit from its recommendations, ASCE should refrain from making these alarmist reports on infrastructure.
This year's Building Green Symposium at the IMA (March 12-13) was a great success. I attended the full Friday session, and definitely felt positive about the future of sustainable design as well as inspired to get something done.
The introduction by Mayor Greg Ballard obviously focused on Indy's efforts towards becoming "the most livable big city" in the US. The Office of Sustainability, recently announced by the Mayor, got some more press. He discussed the recent deal that will result in a group of new LEED Certified buildings. This is great progress. It's far short of a commitment to build every new public structure as LEED Gold Accredited (we can dream, right?), but it's a start. It's clear that the gears are turning in the City-County building, but an entrenched bureaucratic system is difficult to change overnight. I believe that a lot of city planners are now understanding that green design involves a holistic approach that increases up-front costs but has the chance to decrease long-term costs.
Actually, that may be the best way to summarize this event. Over and over again, each presenter stressed the fact that a well-planned design that considers life-cycle costs and productivity can reduce costs. And not just a small amount, a huge amount. Greenhouse gas emissions are lowered, people are happier and healthier, commercial activity and tax revenue increases... the benefits go on and on. Green design is the opportunity that we have to reinvent our built environment to serve communities and the people who live in them. Green design is the best way to advance our nation's economy and keep our current standard of life.
Ed Mazria was the keynote address. An architect with a long list of carbon neutral projects, he also authored the Architecture 2030 goal which seeks to eliminate greenhouse gas emissions as quickly as possible. He brought a lot of data to show what our CO2 problem is, what it will be with no action taken (global disaster, basically), and what it can be if the construction industry fully embraces green design. Basically the message is business-as-usual can't continue, so prepare to adapt once again.
The first breakout session I attended was about the new federal building in San Francisco. This one was probably the most inspirational for me as a structural engineer. An architect from Morphosis discussed the design and construction and highlighted the green design accomplishments. This is the first naturally ventillated building on the West Coast since air conditioning was invented. This one fact allowed the designers to throw out all the mechanical equipment typically used for an office tower, saving a huge amount of floor space and overhead space (not too mention cutting energy use to 1/2 of a normal office). Exposed concrete shear walls and gravity systems help regulate the temperature, and the operable windows allow the occupants to set their own level of thermal comfort.
My favorite feature, however, was the skip-step elevator system. This meant the main elevator only stopped at a lobby every third floor, and a staircase was used to go up or down a floor for most occupants (the secondary elevator next to this one stopped at every floor). This allowed the designers to create these fabulous three story tall elevator lobbies with grand staircases that linked three floors into a smaller community, sharing resources like conference rooms and vending machines and encouraging interaction between the different federal agencies.
Leith Sharp was the next presenter. She discussed her appointment at Harvard's Green Campus Initiative (now the Office for Sustainability) and her experiences dealing with change in a huge organization.
I kind of bummed around for the next few hours eating lunch, attending presentations, and visiting vendors. I finally settled into a great presentation on "green streets" by Kevin Perry. Here's a great write-up on some of his efforts.
This was probably my favorite of the day, as it really got to the point about remaking our built environment at a very inexpensive cost but high benefit. I strongly encourage anyone considering stormwater treatment, streetscaping, or similar activities to check out his recent publication on sustainable streets.
If you have been in Indianapolis recently, or perhaps seen the Indianapolis Colts on TV this year, then you have likely seen the latest edition to the Indy skyline: Lucas Oil Stadium.
Lucas Oil Products bought the naming rights for USD$121M
September 2008 - The Stadium is now open for business
My appreciation for this structure has nothing to do with the game of football or the events inside, I just totally love the way it was conceived, designed, and built. HKS was the Architect and Walter P. Moore was the Engineer of Record. The structure was finished in August of 2008 and has already been used for one full season of American Football and for many other conventions and events. It replaced the innovative RCA dome (or Hoosier dome) used as the Colts stadium since 1984. The RCA dome stood alongside its finished replacement for a few months before being imploded in December of 2008.
A last view to the old RCA Dome
I'll leave it to other critics (try Circles and Squares or DIG-B) to decide the merits of the architecture of the stadium, I am only writing this post to discuss the structural system and design of a few key elements I find interesting. Also, I strongly recommend anyone who is interested in this stadium to review most of the documents on the IndyStar stadium page. They have some great photo galleries (like this one, but view in reverse order) and a great time-lapse video that shows construction from groundbreaking to completion (see below, I recommend muting and going full-screen).
As you can see from the video, this is a huge structure and it took a long time to complete it. It's most famous feature is the retractable roof. A lot of stadiums these days have retractable roofs, but Indy's stadium is the first with a gable roof system that splits lengthwise. It also has sliding end-zone panels that reveal downtown Indy just to the northeast. Beyond that, it's a pretty typical football stadium, seating 63,000+ spectators on precast stadium risers. It also has all of the standard "jumbo-tron" equipment and luxury suites that modern stadiums use. But let's discuss the shell and roof of the stadium because that's what appeals most to me.
So what makes the Lucas Oil Stadium an achievement worthy of celebration? Why do I think it's the best modern "dome" stadium? Partially I think it's just a feeling, but I've got some good substantive reasons, too:
The overall form pays tribute to the massive sports arenas of the region such as the Hinkle Fieldhouse at Butler University
The material choice reflects the common materials used in downtown Indianapolis
The structural system uses enormous portal frames similar to the large industrial buildings throughout downtown
It all comes down to context. The building isn't removed from the city surrounding it either by form, material choice, or structural system. Everything just seems to fit. That was the one complaint about the RCA dome, it appeared as though an alien spaceship had landed in the midwest. I fear the Dallas Cowboy New Stadium went down the alien path, however. It is unique in its own way, but mostly Dallas just needed something BIG. (aside: I grew up in Texas; yes everything is bigger; no don't mess with us) The bigness was very important when both Dallas and Indy were competing for 2011 Superbowl. Dallas won out because more fans = more money.
I actually prefer smaller stadiums. Both Heinz Field in Pittsburgh (USD$281M) and the Columbus Crew Stadium (USD$28M) are regional stadiums that have successfully met the requirements of their tenants. The smaller stadium size allows fans to get very close to the action, and lowers tickets costs and maintenance. Having attended games at all of these locations, and being caught in thunderstorms, heavy snow, and hot sun, I can say that Lucas Oil Stadium's (USD$720M) famous roof was well worth the effort. The Lucas Oil Stadium stayed with the small stadium formula but optimized the fan experience.
To be honest, a good stadium design hasn't changed much in the past 2000 years. The Roman Colosseum could seat 50,000 spectators. This structure used earth-moving processes and concrete construction similar to today's efforts. The complex system of trap-doors and ability to convert to a lake for water battles are pretty notable. The structure had a lot of versatility built-in. Architectural historians are pretty sure the stadium even had a retractable fabric roof, either supported from poles or using catenary action in an inverted dome sytem. Throw in the advanced plumbing system, beer and bread vendors, and free admission (yes, free) and you might even think our designs have regressed.
Cross Section of the Flavian Amphitheatre (Colosseum)
Cross Section of the Lucas Oil Stadium
But there is a huge difference between the Lucas Oil Stadium and a simple outdoor stadium (modern or ancient). Lucas Oil Stadium gives the power to completely control the weather element. During nice weather, the stadium is open at the top and side. During extreme weather events or hot/cold seasons, the stadium can be closed up and operated as a conditioned space. This doesn't matter as much for a simple game like football which should be played outdoor as much as possible, but for other events like RV shows, Final Four basketball games, or high school band competitions it is essential. The real benefit here is certainty. Indy can guarantee that large events can be hosted anytime of the year without worry. The added bonus of holding the event in a sports stadium lends a certain amount of clout to the event as well. This gives a huge advantage in securing conventions and events. Versatility is the key here, and it only costs money.
Enclosing a volume such as Lucas Oil Stadium is no easy task. The wind force on such a large surface area can build up to incredible levels. There are no floor diaphragms to help distribute the loads evenly around the building. The brick facade and sensitive roof mechanisms demand a very stiff frame, as any movements can cause cracking or throw off the alignment of the retractable roof system. This is where the experience of Walter P. Moore as a company is tremendously important. The structural system concept was based on previous successful methods, but also different from any previous system because of the unique roof configuration.
If you refer to the photo above you can see the most important piece of structure: the Supertruss. There are two of these above each sideline in the North-South direction, and they support a large percentage of the roof loading. The supertrusses are essentially portal frames, which means they resist moment at the transition from vertical to horizontal. This behavior is in contrast with a typical post & beam system which allows the beam ends to rotate freely. The advantage of using the portal frame is a much stiffer structural member; the penalty is dealing with the insanely large forces that develop inside the member. I recall a Walter P. Moore designer telling me that the moment in Reliant Stadium supercolumns were being measured in "kip-miles", I would assume a similar situation would occur in the Lucas Oil Stadium.
The Supertrusses develop internal forces using truss behavior, with top and bottom chords, diagonal web members, and gusset plates tying everything together. I don't know the dimensions of the members used, but the weight of even a single gusset plate on one of LOS's supertrusses is probably heavier than a typical truss used in one of my projects. The supertrusses are massive in every sense of the word.
Here you can see the supertruss as it connects to the foundation system. I should probably point out that major projects like the LOS stadium can have well past 50% of the structural cost in foundation costs. In this particular case, the civil engineers had to account for underground utilities including a new pedestrian tunnel linking to the convention center in addition to all sorts of wastewater, electrical, and telecom trunk lines. Just locating all these services is a major task unto itself. Accommodating them or building around them certainly adds a challenge to the already difficult situation. In the case of the LOS, one entire corner of the building had to supported by an underground bridge across an existing CSO line.
When you look at Lucas Oil Stadium, try to visualize a huge network of piers, concrete pads, and a huge mass of soil supporting all the weight. Buildings don't just sit on the ground, they interact with them and become part of the earth. Just like the root system of a tree, a building is truly part of the subsurface environment. But referring back to the photo of the supertruss base connection, I can't tell you how thrilled I was to see they left this part exposed. Here is the exact location where most of the weight and wind force is transferred into the foundation. It is an incredibly important structural relationship, and I am glad they celebrated it.
I have included a few shots of the supertruss as it continues up the levels and transitions to a horizontal member. I am so glad they left this portion exposed, these components are usually hidden behind walls and gypsum, so it quite special to see it. It really is a great representation of the strength of the building. Next up is the minor trusses. They aren't "supertrusses", but they aren't so bad, either.
Steel framing under construction
You can see the truss poking out at roof level
The smaller trusses intersecting at right angles to the supertrusses serve a few purposes. First, they carry the wind loads down to the framing in the other direction. Next, they prevent buckling of the supertrusses. Finally, they provide a rail for the roof to travel along and set the gabled roof profile. Most importantly, though, they look pretty cool. There are five of these trusses in the East-West direction. You can see them on the inside of the building or poking out from the top of the walls.
Going back to the construction video, you can see several phases of construction. The first is the foundation and earthwork. The playing surface of the stadium was lowered a few stories for some practical reasons. The stadium seating starts first, and then the first supertruss (west side) starts going up. The temporary erection structures for the supertruss are large enough to be considered a separate project, I would imagine. As time progresses, the gable trusses are installed in pieces. The other supertruss (east side) goes up, and the gable trusses are finished. About this time, you can see the cladding being applied. This isn't fake brickwork or metal panels painted brick red (well, not very many at least). The masons assembled brickwork into large panels which were then lifted and set into place. I thought that part was pretty clever too, it sped things up and kept the masons safely on the ground.
The final parts of the video show the roofing, windows, and finishes being installed. The finish installation is a pretty rapid process compared to the overall project, but it probably is the most rewarding for the builders. Up until that point, everyone is really operating on faith that the designers knew what they were doing, so seeing the actual product assembled and functioning takes a lot of stress off of everyone involved. And besides, it's pretty freakin sweet just to see the biggest operable window in the city opening up.
East side entry lobby - insert huge fan pun joke here
I also wanted to show some photos of the general interior. The huge fans were a great touch, they really push the whole industrial feeling of the space, and they certainly get the job done. I wish they had more stairwells or escalators, but most spectators will get to their seats using a really long ramp system. It's wacky and kind of boring, definitely the biggest missed opportunity of the design.
Makes a person wonder... where the hell am I, and where am I going?
I have successfully passed the LEED NC examination, so as a reward I am now reviewing the LEED 2009 program. I didn't let myself look at it until today, I was worried I would get the old and new mixed up right before my test. But now it's all good...
The new LEED 2009 (or version 3) program look pretty solid. They have completely changed all of the certification thresholds and added regional credits. The old credits have been altered so the ones that are more effective are weighted heavier. Check it out sometime.
I'll be back next week to bask in the glory of new business cards and a busy work schedule. Until then, I am heading out of state for a vacation.
I am a structural engineer focused on building a better future. I love the construction industry because it offers the potential to transform our communities into engines of development. It also gives us the opportunity to reaffirm our responsibility to a sustainably engineered human world.
