Newbie in a pickle! :(
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Hi everyone.
First of all, let me introduce myself, my name's Hindatu but friends call me "hindee". I'm an architecture student in my final year of my bachelor's program studying in italy.I'm stuck! I'm working on my thesis which i'm meant to hand in by next week, i was having some problems designing a suitable ramp for my project which is to design a hospital in nigeria. After a lot of thinking, i realised having a spiral staircase at the waiting area may very well solve my problems. Considering that the project is not large, it just has 2 floors. I really cannot figure out how i can design a proper spiral ramp that helps me move from the ground floor to the first floor and how to actually calculate the degrees needed.
I'd really appreciate it if someone can help me out, i'm out of ideas and basically going out of my mind, cause my professors seem not interested in helping me out... please help a sister out
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Greetings Hindee. Hopefully some of the more architecturally inclined folks will chime in but here's something that may help. In the US, at least, ramps must have a pitch of not more than 1:12. So for 1 meter of rise, the ramp would need to be 12 meters long. There are also requirements for landings (horizontal spaces) at given intervals. Maybe there's a similar specification in Nigeria or Italy. In any case, for your spiral ramp, you would probably figure the length of the inside curve to be at least 12 times the total rise plus the total length of the landings. This could result in a rather long. large diameter spiral. I don't know the distance between your floors but suppose it's 6 meters. That's 72 meters plus something for landings, maybe a total of 80 meters. If you make the spiral in two turns your ramp with have an internal diameter of about 12 meters.
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What about headspace ?
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Yes, and head space will have to be considered.
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I wonder--never checked but it could be possible to have a ramp that is non-accessible (not for wheelchairs). Still higher than 1:12 is not great as a ramp for anyone. Is this a necessary part of design? A relatively small diameter ramp is not good for accessibility either as you have cross slopes, the whole ramp surface is warped too much. This is what accessible elevators are for.
I read that the Guggenheim (NY) ramp is 1:20. Of course it is at the outside of the space for the largest diameter.
But spiral ramps, and stairs are a popular subject here. You should get the modeling help you need, once you have a plan. You'd think you'd see more of them in the world for all the people who like to model 'em
Edit: I just read all of Dave's post:"If you make the spiral in two turns your ramp with have an internal diameter of about 12 meters." Yikes! How did he figure that out? So my point was already made, in a way.
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In the UK anything steeper than 1:20 is considered a ramp and subject to special rules [as opposed to it being a piece of gently sloping path or floor !].
Access to, escape from, and movement within a building all require ramps at changes in level where steps would be required otherwise, OR alternatively lifts/elevator-platforms for wheelchair users...
It can't be steep than 1:12 - 1:20 is much better.
If it has to be very short and steeper than 1:12 there must be steps associated with it for semi-ambulant users who will find steps easier to negotiate compared to a very steep ramp.
The provision of landings after a maximum 'rise' is a complex assessment based on a graph/calculation - as the steeper the ramp the more frequently you need landings.
A ramp at 1:12 can't be longer than 2m, so it has to have landings every ~167mm that it rises - so these are used for small changes in level only.
A ramp at 1:20 can be up to 10m long, so it could rise 500mm between landings. - used for larger changes in level where length is less critical...
The length of the landings is typically at least the the width of ramp or 1.2m at top/bottom.
Intermediate landings used as wheelchair passing places must be at least 1.8m square.
The headroom is >=2m on all ramps/landings [it's measured vertically].
Doors can't open over a ramp or landing.
A ramp should be >=1.5m wide, and have ~1m high handrails/guarding to both sides which extend 300mm beyond the top/bottom of the slope, and an upstand 'curb' of >=100mm at edges.
Very wide ramps will need subdividing to give accessible handrails to both sides.
Technically external rails should be warm to the touch - e.e. NOT metal...
There is a maximum rise that an external access-ramp can have before a proper lift/platform is also required - I think it's ~2m...
If a ramp is 'helical' then the 'pitch-line' - i.e. where the slope is measured is the inside curve - the steepest part.
So if a 2m wide 1:20 ramp rises 4m floor-to-floor then it needs 8 flights [500mm each] plus 2m landings. Some simple maths shows that to get 2m headroom should a ramp turn back over itself as it rises in a storey height then you need 5 flights ~2.5m rise [you cann't forget that the ramp itself will be say 300/500mm thick!]. So for a ramp to arrive back where it started on each consecutive floor a dogleg or 'square' spiral is needed - an eight-flight ramp will have trouble overlapping within a storey. A square ramp+landings will need a hole in the floor slabs ~26m externally in plan - it's central 'well' is then ~22m square [this of course does not need to be 'open and could be infilled with 'rooms'... BUT because the access id only off the storey landing and the ramp wrapping around this area prevents alternative lateral emergency-escape the occupancy/use will be limited]; a dogleg ramp+landings needs to be in a hole in the floor slabs ~50m long and ~4.5m wide [allowing for a modest 'well' gap where opposing flights pass each other] - it takes up the minimum space as its 'well' has considerably less area. -
Wow Tig that's a lot of detail. That's basically the whole code section and then some.
"A ramp at 1:12 can't be longer than 2m" Here we use 30 feet (30" rise). 2m seems tight.This is for architecture school. Isn't it supposed to be unrealistic?
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Sometimes architecture schools set technical issues to test logical thinking as well as artistic flair esquises...
Accessible ramps have become very strict in recent UK Regs/Acts... 1:10 used to be allowed but now a tiny 1:12 is the minimum with a 1:20 preferred. Often we try to make approaches flatter than 1:20 so the regs are avoided all together !
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Well you have less terrain in UK.
What's that high mountain Snowden?1:20 is a walkway, without requirements (except width cross-slope, surface finish, traffic lane warnings, headroom, obstructions....)
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A footpath is 1:20.001 [or flatter] in the UK ! Otherwise it's a ramp !
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