How This Tower Barely Touches the Ground

this is 150 North Riverside a building here in Chicago that looks a little strange at its base it's almost like the tower's been eaten away leaving only its core behind you might think that this would make the entire building structurally unstable and you'd be right if this feature wasn't compensated for in the design and construction process you might also wonder why anyone would go to such trouble to cut out that part of the building what benefit does it serve and then I guess I have the follow-up question how how can a building so massive balance on this tiny little line the building was designed by getch Partners in architectural practice with a particularly spectacular office space in downtown Chicago is filled with models of buildings proposed and built all over the world it turns out that this unusual solution came from solving some relatively straightforward pragmatic problems that were inherent with the site that the building sits on I guess you have to have an interesting problem to have an interesting solution but that doesn't mean that the solution came easy the site is located on the Southeast side of the Confluence of the three branches of the Chicago River the stem the North Branch and the South Branch this natural configuration in the shape of an upside down peace sign can be found all over Chicago and it serves as its Municipal device that's also the shape that this Tower makes here at the ground a giant y shape that pierces the earth below then flares at the top to spring into 50 floors of Office Space on ground level we can experience the underside of the Y along the Riverwalk and in the lobby of the Tower when we designed it and the way this solution came about there's a short lightness to it from the side an airiness how it kind of almost distances itself from the ground for over 100 years the site was just a functional Rail Yard it was one of the few Rail Yards left from the days when they lined the river back in those days when the river was used mostly for transporting goods and services connecting water transport of the Great Lakes with the rail transport throughout the Midwest these tracks still exist they're just underneath this park and today they're used by Amtrak Travelers arriving to or leaving Chicago these tracks were actually one of the primary factors for why the tower only touches down the way that it does you know the site is it's probably before it was developed probably the largest open space in the city you see all the tracks had to stay exactly where they are and they had to stay fully operational during the construction of any building above so the overall footprint of the building was strictly determined by a series of requirements on each side of the site that when fully mapped out gives you the only place where the building could go there's the river and a city mandated 30 foot or nine meter wide continuous Riverwalk to the east then on the west you have the Amtrak tracks and the leftover buildable area is only 35 feet this is why the site sat relatively vacant for all those years it was vastly underutilized but this is the perfect place for a building otherwise we have all these different modes of transportations that are not even visible in some degree but we just had to L passing by you have boats on the on the river you have pedestrians moving of cars and then you have trains Subterranean and elevated so I mean that really makes the site incredibly interesting it was so isolated to some degree it has so many different levels it's it's very interesting and we try to translate that into the architectural to some degree but it seemed almost impossible to build anything substantial within such a limited space what's actually happening is the core has all of the vertical forces and then the perimeter columns are being transferred in and they're canceling each other out if we look above the eighth floor it's a regular building it's got perimeter columns it's got a core all the forces are very well organized because of what we're ultimately doing with the with the the core supported building we had to keep a very symmetrical building keep the forces organized so we get to the eighth floor we bundle all the forces together through this triangular truss and we we load them down into the core and then they've got to go all the way into the earth into the caissons there's almost a separation between the ground plane and what's happening above and it's the building very lightly touches the ground yeah only 25 percent of society are occupied actually by enclosed space everything else is open open to the public but I think here you get a good glimpse of experience of the overhang which isn't I don't know impressed uh oppressive at all I think it's very open and uh like how's the light channels in the tight physical constraintsment continuous challenges throughout the construction process for instance there's no place to put a construction Crane That Could anchor into the solid land so a barge was planted here for a couple of years it became such a staple around here that it's been immortalized in Google Earth a crane or a truck to park on the street you need all these permissions from the city and permits from the city to put an 80 foot square barge in the middle of a river I think it was it seems like they make it sound like it's just a phone call to the Coast Guard and they're all set the crane was instrumental in hoisting some pretty spectacular elements into place that includes the arms of the y shape which were made entirely out of steel these elements precariously spring out of the concrete core and transfer all of the loads of the outside floors above the forces are so great these steel members are the largest i-beams ever made they weigh one thousand pounds per foot of length it had to be specially designed and made for this project we would see people especially once the steel started going up take your lunch breaks out on the Randolph Street bridge and just watch this thing because it was on full display for everybody this y shape then produces some peculiar conditions inside of the building structurally for instance the outside of the tower wants to flare outward at the bottom pivoting on the steel members so the entire first office level is actually in tension being pulled apart which of course was designed into the building in its construction the tower deploys a technique called a tuned Mass damper which fundamentally is just a giant concrete water tank at the top of the building it sounds counter-intuitive that adding water weight to the top of a building would actually make it more structurally stable but gravity is an easy thing to overcome with a scheme like this the problem is wind the tower sits on such a small footprint that it needs to resist getting pushed over and that's where the tuned Mass damper comes in I created a bit of a demonstration here with these mola structural kits the water has a large moment of inertia it's heavy and it doesn't move very fast at the same time it sloshes around its weight can be distributed differently depending on where the water sloshes so what happens is if the building is pushed by the wind it bends a little bit but the water moves slower than the building does so its weight is back over the original center of gravity this basically pulls the building back into shape before it's allowed to bend too far it also sloshes at a different frequency than the building moves creating a dampening effect overall so it's a reverse pendulum effect so as the building moves this way the force moves that way so you get these these counteracting forces and we just want that water to hit the opposite wall within a force to push the building back so we stay mostly Plumb you can't go into that water tank at the top but you can go into the lobby which does its part to tell the story of the building as well I think you can feel the notion that it's almost like the core is holding up this element that's hovering above [Music] so if you have this darker Stone on the outside that wraps around but then when you when you slice it it becomes this light zone so it's almost like we're taking slices out of the core and revealing the you have the apple peel on the outside and then you reveal this the light Stone even so we had to create some enclosure we wanted to make it as transparent and permeable and connective between inside and outside is really creating this transparency to create a seamless transition between the inside outside we enclosed it with a curtain of glass hung from the tip of the truss and and draping down so it just kind of hangs from the edge of the building and as the building kind of tilts and turns this glass will kind of rise and fall out of a pocket heading up into the building so I think that's our elevator there's some unique spaces that come from this structure and the way that it projects out into the city yeah I think it's a very nice to have the fitness center in this part of the building there's a with the incline and and people doing their workouts looking looking out onto the river in a very special way is pretty cool then on the 18th floor the other side of the river becomes an incredible immersive Panorama I think this is actually a nice level of Lake via still in the city but you're not uh right some certain floors that's upper levels you're almost out of the cityscape sure here it's like you you still feel like you're in the Heart of the City and and all the elements we we already talked about this design reminds me of some other buildings with bases that are smaller than their towers some that come to mind are the Rainier Tower in Seattle and the City Corp tower in New York the Rainier Tower was designed by manureo yamasaki it looks like a miniature World Trade Center with bites taken out of the bottom locals call it the beaver building this solution was to maintain as much free space at the base as possible but the curved shape does Channel wins in powerful and unpleasant ways the overall effect is particularly unsettling as Seattle gets a lot of earthquakes but the building has gone through rigorous testing and was actually one of the safest buildings in the entire city but that is not the case of the City Corp Tower when it was built which lands on a series of columns that are offset from the corners visually the base looks smaller when viewed at an angle this building famously had a flaw in its steel details that slipped through the cracks during the design phase this critical mistake left the building in danger of collapse after construction welding Crews went through the building at night reinforcing all of the joints to make it safe luckily they were able to get it done in time before catastrophe struck 150 North Riverside is a bold structural solution to a constrained set of site conditions these kinds of Feats only become viable where real estate prices justify their cost that's the kind of equation that gives us hovering buildings and all sorts of urban environments here in Chicago it's not quite as common as say in New York where air rights transfers and Incredibly High square foot values will yield very complex concoctions but this version is an interesting and relatively subtle condition that you may or may not notice depending on how hard you look but I think that's the real sweet spot here a lot of engineering went into creating this Pleasant composition of space architecture and infrastructure without the spectacle getting in the way of enjoying it you'll give about 80 000 hours to your career 40 hours a week 50 weeks a year for about 40 years that's a lot of time and it means that your career is probably your biggest opportunity to make a positive impact on the world and getting that right is too important to leave to chance platitudes like Follow Your Passion they only get you so far and is it really the most Sound Advice that's where this video sponsor aptly named 80 000 hours can really help you out they are a non-profit absolutely free resource for navigating one of the most important decisions of your life what career path should you take with 80 000 hours you'll find a smart collection of resources including individualized data job boards podcasts and more all in service of finding you a career that will make the most positive impact on the world they've done over 10 years of research alongside academics at Oxford University to figure these things out because they take an evidence-based approach they're able to make concrete recommendations on questions like where should I work if I actually want to make a positive difference in the world or what can I do today to start planning a fulfilling career everything that they provide is free forever because they're a non-profit their only aim is to help people find the most impactful careers that they can to get started planning a career that works on one of the world's most pressing problems sign up now at eighty thousand hours.org Stuart Hicks and you'll immediately get a free in-depth career guide just for signing up if you enjoyed this video please consider hitting that like button subscribe to the channel for bi-weekly videos on the built environment in the meantime check out some of these other videos or the extended interviews and tour over on nebula see you over there foreign

Channel: Stewart Hicks

Views: 1,965,331

Keywords: architecture, design, architecture student, architecture design, architecture lecture for beginners, architecture 101, architecture documentary, architecture concept, architecture theory, stewart hicks, architecture talk, urban design, chicago, structural engineering, tuned mass damper, chicago architecture, chicago architecture tour

Id: kNph_SxgcPg

Length: 12min 50sec (770 seconds)

Published: Thu Mar 23 2023

Reddit Comments

[u/jesusdoeshisnails]

just here to say: underrated channel

[u/earther199]

His videos are incredible.

[u/poto101]

One of many great videos on his channel.

[u/LettuceAndTea]

I just started my job in this building on Monday.
It is as beautiful from the inside, as impressive it is on the outside.