Elevated Structures on US Floodplains?

[Zaune]

Yeah that's the thing; you need pillars to hold the house in place... but a big Mississippi class flood will be washing thousands of trees, cars and other heavy debris downriver. Those will hit the pillars and rip them apart unless you install some really heavy duty stuff. Even if the pillar holds, the foundation will likewise need to be very substantial to avoid being undermined by the current scouring around it. A tidal marsh has a lot less big debris and lots of space to bring in heavy pile drivers. This idea could work in known slack water areas of flood plains, but not just anywhere. I can see doing it in a marsh because it'd be nice and private, but not worth it just to live with a bunch of other poor people in the US mid west.

Fair point, though the initial costs might be slightly reduced if you designed the pillars and even the foundations to survive one flood and then be replaced. And presumably the people designing these houses have given some thought to withstanding a storm surge on the scale of the one in 1953. I'll see what I can dig up on them.

[madd0ct0r]

mmmm. mega-engineering porn.
Are two storey houses popular?

Bottom level is garage and other stuff that matters less in a flood.
All wiring running high, with sockets downstairs (if they have to be there) waterproofed and on a separate loop, with the cut off switch high.

Vent shafts for sewage ect run high or are fitted with a flood plug.

loading from flooding and current increases (but not much. pillars create a lot of drag). Hurricane resistance increases, tornado might...

but this would involve a lot of reinforced concrete, which is the standard way of building for much of the world. If anyone would like some photos of Vietnamese concrete stilt houses, they only have to ask.

[Alerik the Fortunate]

Of course my solution would be to house the majority in arcologies, which are such a big investment in construction anyway that one could design massive flood control structures as part of their base structures. Currently, though, people don't seem too keen to live in them, which is a pity. I personally think of arcology life as a desirable alternative rather than as a dystopian prison to which people are confined by undesirable necessity.

[Sky Captain]

How expensive is concrete in the US? Here concrete when converted to US $ costs ~70 - 90$ per m3. A typical two level house would require perhaps somewhere from 50 - 100 m3 so it is not that much in terms of the costs for basic structure of the house. Probably would be more expensive than wood frame structure, but you would get a house that does not rot (a major problem when wood becomes soaked in flood) and could last for many decades.

In Japan when tsunami hit concrete buildings survived it while wood frame buildings were totally demolished and I would expect tsunami currents were moving far more quickly and thus put much more pressure on buildings than currents in typical river flood or hurricane storm surge would. Also having a house that can stand up flood currents can save your life if for example flood protection dam breaks creating sudden flash flood.

[Broomstick]

Of course my solution would be to house the majority in arcologies, which are such a big investment in construction anyway that one could design massive flood control structures as part of their base structures. Currently, though, people don't seem too keen to live in them, which is a pity. I personally think of arcology life as a desirable alternative rather than as a dystopian prison to which people are confined by undesirable necessity.

If everyone in such an archeology had spacious living quarters and the amenities of a high rise luxury apartment perhaps, but I suspect most fear they would be like the high rise public housing slums - dimly lit corridors, malfunctioning elevators, and crime everywhere. Those high rises weren't intended to be like that, but that's how they wound up.

[Kanastrous]

Sounds like a good use for all those TBMs abandoned in-place at the end of boring projects. If you could somehow figure out how to get them back to the surface, again. Economically.

[Alerik the Fortunate]

If everyone in such an archeology had spacious living quarters and the amenities of a high rise luxury apartment perhaps, but I suspect most fear they would be like the high rise public housing slums - dimly lit corridors, malfunctioning elevators, and crime everywhere. Those high rises weren't intended to be like that, but that's how they wound up.

Of course people would have to have ready access to all amenities. I think the thing is that the arcology must be fully integrated with all the functions that a small city would have, including having people of all socioeconomic classes living together within it. To my knowledge most housing projects to date have still largely followed the model of isolation of social classes, with the poor members all living in one area, which may not be well served with schools, employment opportunities, and good social gathering places. That is what must really be fixed. In addition, good architectural design should maximize light and air and interconnectedness of spaces so that people don't feel confined in their high rise cubicles.

[madd0ct0r]

http://en.wikipedia.org/wiki/Le_Corbusier

Le Corbusier would love you. He also nearly ruined Paris, and created many monuments to design without consideration of what humans ACTUALLY want. He was a genius visionary of Modernism, and a complete wanker.

there's a reason most people don't want to live in arcologies, they aren't houses. The projects of the 60s were supposed to move all of the slums vertically, in new, spacious, light and airy buildings surrounded by green parkland.
The thing is, when you are in this big open grass space with massive structures rising up around you, you feel scared. People (outside of architects) never complained about the small twisting streets with houses rubbing up against each other. They quite like it, you feel safe and enclosed.

(the slums building standards ect desperately needed improving, but that's a different story).

High rise apartment blocks are making a return in the UK now, but aimed at luxury living. This seems to be working better, although nearly all the inhabitants move out when they have children or when they want to settle down in their 'own space'.

[Sea Skimmer]

How expensive is concrete in the US? Here concrete when converted to US $ costs ~70 - 90$ per m3. A typical two level house would require perhaps somewhere from 50 - 100 m3 so it is not that much in terms of the costs for basic structure of the house. Probably would be more expensive than wood frame structure, but you would get a house that does not rot (a major problem when wood becomes soaked in flood) and could last for many decades.

The cost of working in concrete is far more so the cost of paying for the rebar and people to assemble all the rebar properly then the mere cost of the concrete material. It also makes putting in the utilities and wall framing ect... harder and thus more expensive. If you want concrete floors for multiple stories then costs go even higher and you start needing steel beams. If you use wood floors then a flood will ruin them anyway.

In Japan when tsunami hit concrete buildings survived it while wood frame buildings were totally demolished and I would expect tsunami currents were moving far more quickly and thus put much more pressure on buildings than currents in typical river flood or hurricane storm surge would. Also having a house that can stand up flood currents can save your life if for example flood protection dam breaks creating sudden flash flood.

Sure, the structure of the buildings survived, being built to withstand heavy earthquakes making them even more expensive. But anything that floods still needs to be totally gutted and rebuilt internally which is serious money. If the flood is deep enough it will tear off your roof too. Just because your walls don't rot doesn't mean the place wont be ruined as a habitable structure. This is false economy.. if you think the flooding is such a high risk that you want walls that wont wash away then just build somewhere else. Silts would most likely be cheaper; but just today CNN was filming some houses on 15ft silts which had still flooded to the windowsills. Not a lot you can do about that. Wood is cheap, the US has hoards of wood. Everywhere on earth people will usually use wood if they can get it. Concrete and masonry is more common in Europe because Europe was almost completely deforested centuries ago. Japan meanwhile is still mostly wood outside of the high rise areas because they can get more of it easily from Siberia and Alaska.

I say spend the money on levees, which protect not just homes but roads, pipelines, farmland, power lines and a whole lot of other collective value. Any way about it the US levee system needs a serious injection of cash to remain effective, and a lot of more minor levee systems like those of California are just plain crap at this point. None of the systems are intended to withstand more then once in a hundred year events either. As it is the US Army Corps of Engineers is being asked to do all its work on only 4.6 billion a year, and that includes maintaining river and harbor channels, cleaning up nuclear waste dumps and a bunch of other stuff besides flood protection. Only about 1.5 billion goes into new construction of all kinds. Its impressive the system works as well as it does.

[Alerik the Fortunate]

http://en.wikipedia.org/wiki/Le_Corbusier

Le Corbusier would love you. He also nearly ruined Paris, and created many monuments to design without consideration of what humans ACTUALLY want. He was a genius visionary of Modernism, and a complete wanker.

there's a reason most people don't want to live in arcologies, they aren't houses. The projects of the 60s were supposed to move all of the slums vertically, in new, spacious, light and airy buildings surrounded by green parkland.
The thing is, when you are in this big open grass space with massive structures rising up around you, you feel scared. People (outside of architects) never complained about the small twisting streets with houses rubbing up against each other. They quite like it, you feel safe and enclosed.

High rise apartment blocks are making a return in the UK now, but aimed at luxury living. This seems to be working better, although nearly all the inhabitants move out when they have children or when they want to settle down in their 'own space'.

I'm quite familiar with Le Corbusier and the other modernist wankers, such as Mies van der Rohe, who had such a large influence in the United States. They were really hypocrites in that they unabashedly followed their own aesthetic vision without concern for use while pretending to be the acme of rationalism and not motivated by aesthetic theories at all. At least I admit I am motivated by aesthetic concerns, and they are very different from the concerns of the modernists. I am somewhat intrigued by the hyper rationalists who actually have a decision making process based on use and not on aesthetic theories. However, I think that adding symbolic forms and deliberate aesthetics to the basic arrangements they obtain would be a net gain. I am more influenced by Paolo Soleri, despite his qualitative analysis and strange flowery language, than I am any other visionary. What I am proposing is something more like the traditional city, but on a greater vertical scale. No more so than New York, but with far greater integration and pedestrian accessible interconnectedness at all levels to reduce dependence on automobiles. Of course not everyone will want to live in them, and I don't propose demolishing all historic cities and all suburbs to make way for them. I don't really have any designs worked out in detail, but I am thinking of something quite different than what most modernists had in mind, and not altogether different from what people are already used to in cities in Europe and Asia. My near term goal is to spend time living in a relatively densely developed city to get a better experiential view of what to look out for.

[madd0ct0r]

http://en.wikipedia.org/wiki/Le_Corbusier
. No more so than New York, but with far greater integration and pedestrian accessible interconnectedness at all levels to reduce dependence on automobiles. Of course not everyone will want to live in them, and I don't propose demolishing all historic cities and all suburbs to make way for them.

So, Singapore? I don't have any first hand experience of New York so it's a bit of a guess.

Will read up on the stuff you linked. I just get paid to build it, the design theory tends to happen at higher levels. Emphasis on high sometimes

[Alerik the Fortunate]

Although I might be more of an architect by temperament, I'm nearly finished with a civil engineering degree. I hear the instructors complain about architects wanting the Taj Mahal mounted on toothpicks; in my own job experience I see the client's vision of multi tiered roof over mostly glass structure with projecting bays and balconies, all made of the cheapest 2x4 construction, transformed by the engineer into mostly plywood box with decorative elements, and then some compromise reached. I'd rather have an internal model of practical constraints to guide me from the start, but admittedly I have a very long way to go. The undergraduate curriculum consists mostly of calculating basic loads on beams and columns of different materials and analyzing water flow though pipes and channels. I probably should have gone elsewhere and multi majored, but I'll have to study things on my own at this point.

I'm also coming from the perspective of living in the exurbs of Southern California, which I intend to abandon as soon as possible. I've spent some time in Germany, and lived in New York for a while, but I was too reclusive at the time to get any useful experience in the city. I'm particularly concerned about land use and zoning. The moderately low density suburban development eats up a lot of land for relatively little gain in productivity and living conditions, but it makes cheap land profitable to develop and gives lots of people the possibility of owning land, which is seen as part and parcel (literally) of the American Dream. I admit owning property can be nice, but I don't think it makes sense for everyone. You really have to orient your lifestyle around maintaining the property. If you're into gardening, grow a lot of your own food, or keep a lot of animals, I can see the advantages, but I don't think most people really exploit the possibilities. I own a fairly large lot in an old neighborhood in Lancaster, and I just don't have the time to maintain it properly. I'd happily live on a lot half the size, as I did with my parents previously, if it meant I had more everyday uses within walking distance. I'd be able to better exploit a smaller property with less effort if it were laid out conscientiously. I'd even live in an apartment like my aunt's in Munich, if I could just walk to the local public transportation hub and be to any historic or social center in a short time without having to fuel up or look for parking.

What is really needed is a sharper gradient between a density somewhat higher than typical for American small towns near the town center, through a very shallow buffer zone where suburbia is possible, to a truly rural agricultural and naturally maintained landscape. This is for ecological and psychological reasons: by deliberately withdrawing from the landscape as a whole, one preserves its integrity with seriousness, and embraces urbanity seriously. It also makes true countryside much closer physically; one does not have to cross dozens of miles of suburbia, exurbia, and semi rural development to get to land that isn't crisscrossed by a one mile grid of roads. However, people will have to modify their conception of land ownership for this to really work, possibly replaced by their ownership of a stake in the city itself. I have never really lived in a city with a true civic sense, and I would like to experience it.

With respect to the OP, this concentration of development reduces drastically the amount of territory that needs to be defended while significantly raising the value of the area that is, making more intensive construction of flood management infrastructure economically worthwhile. Unfortunately, at this point I don't have any detailed economic analysis to back things up, so I admit my argument is not that strong yet.

[Broomstick]

High rise apartment blocks are making a return in the UK now, but aimed at luxury living. This seems to be working better, although nearly all the inhabitants move out when they have children or when they want to settle down in their 'own space'.

A major difference between wealthy people living in a high rise and poor people living in a high rise is that if the wealthy person wants a change of scenery or more space to move around in it is laughably easy for them to go someplace else for awhile. On the other hand, one of the problems of being poor is decreased mobility, even when mass transit is available. This also applies to problems with neighbors - if you're wealthy and can't stand the neighbors you can move, poor people in housing projects are stuck. Not only can't they move, it's a lot harder to put distance between you and the crazy neighbors even for a couple hours.

Yes, you still have that problem somewhat in traditional slums, but low-rise housing is much less population dense. This is decried as inefficient by some, but it is better in that it imposes a lot less social stress on the inhabitants.

[Broomstick]

It also makes true countryside much closer physically; one does not have to cross dozens of miles of suburbia, exurbia, and semi rural development to get to land that isn't crisscrossed by a one mile grid of roads.

Got news for you - rural America is thoroughly criss-crossed by a grid of roads. I've flown over hundreds of miles of genuine rural America in the Midwest and there is still a road grid.

While I applaud your visionary ideals, I think you lack real-world experience. Even when city living is pleasant there is extra stress from higher ambient noise levels, more social interaction (not all of it positive), crowding, and other issues. I don't think it's impossible to have good city living - I lived in Chicago for 15 years, most of them were quite good - but it's not as simple as you seem to think it is.

[madd0ct0r]

yeah, well just caught up on the news re Mississippi.

colour me converted - that flood is too damn big to do anything about except move, or build a small hill for a town.

[madd0ct0r]

there's no shortage of news stories about now, but this one has a nice picture.

http://www.guardian.co.uk/world/2011/ma ... ppi-floods

pertinent parts:

"Even if it destroys my trailer I'm going to come back. I'll just build me a house boat."

Over the years, individuals and communities moved increasingly into flood-prone areas around the Mississippi because land is cheap, and because they were persuaded the risk of floods is low.

It is becoming evident that the Army Corps of Engineers and other forecasters have underestimated the frequency of severe flooding along the Mississippi.

"We had a 500-year flood in 1993, a 70-year flood in 2001, and a 200-year flood in 2008. What blows my mind is that I just published this paper in 2008 and every year since then we have had another 10-year flood," said Robert Criss, a hydrologist at Washington University in St Louis. "The observed frequency of flooding is completely incompatible with the Army Corps estimates."

The forecasts at the time were based on a relatively short historic record.

His home, south of the city, is in what is known as a 100-year flood area. That does not mean it will flood only once every 100 years, but that there is a 1% chance of flooding each year.

That is more than it seems at first. A house in a 100-year flood area has a one in four chance of getting flooded in the life of a standard 30-year mortgage.