Force distribution...

[CanCer]

Does anyone know of any engineering/geometry/physics stuff that you could use to work out where the force is applied while riding on northshore?
The kind of stuff that could be used to work out high stress areas and areas you need more support etc.?
And where to put the nails and things...
Or anything similar that can have a similar sort of use?

 

[Binaural]

Does anyone know of any engineering/geometry/physics stuff that you could use to work out where the force is applied while riding on northshore?
The kind of stuff that could be used to work out high stress areas and areas you need more support etc.?
And where to put the nails and things...
Or anything similar that can have a similar sort of use?

I seriously doubt a FEA (finite element analysis) program of the sort used by engineers would make your structures the slightest bit better unless they are the height of a rollercoaster.

Follow good basic principles and you don't need anything else. Here are a few:
1. Triangulate your supports
2. Use proper bolts in preference to nails if you can
3. Solid footings rather than just resting supports on the ground
3. Maintain whatever you build properly!

 

[S.]

Stresses in any structure (due to bending moments, which are what you need to be accounting for here) are ALWAYS the highest at the actual points where the loads are applied - this includes reaction forces from your supports. Basically this means that you want to brace up the areas around your vertical supports, in all directions. Generally for NS stuff, if it feels stiff to walk on (or even just push on sideways) then it's probably fairly strong. You will usually encounter sway/flex problems before the structure is weak enough to outright break - keep in mind that the same factors affect stiffness as strength, so for most practical purposes they are fairly closely related.

 

[arpit]

I seriously doubt a FEA (finite element analysis) program of the sort used by engineers would make your structures the slightest bit better unless they are the height of a rollercoaster.

Follow good basic principles and you don't need anything else. Here are a few:
1. Triangulate your supports
2. Use proper bolts in preference to nails if you can
3. Solid footings rather than just resting supports on the ground
3. Maintain whatever you build properly!

and 4. Use the right type of wood, particularly if part of it is going to be buried in the ground.
HAve a look at what type of wood people use for building pergolas and you'll notice they use a weather resistant wood for the parts which are in the air, and an EVEN MORE weather resistant wood for the parts which are buried.

5. DOn't just hammer bits of wood everywhere. Go for triangles and end up with a structure which is strong but not massive. An overly complex structure will be difficult for others to maintain.

 

[No Skid Marks]

Salvage old timber from costruction demo jobs of old houses,don't under any circumstances use treated pine as every one knows it's poisonuss and will frown apon it. Use raw timber not paited.
Like S said if it feels solid under foot it should be stiff/strong enough. Just use your head and picture what will happen if you push in a certain spot,and therfore how to brace that up.Oh yeah and screws not nails.

 

[Binaural]

Treated pine is acceptable so long as you're not handling it every day and don't eat the cuttings (linky linky). Still, avoid if possible, since it's not good to handle too much of the stuff, and native Australian hardwood will last longer.

Some techniques to avoid:
1. Avoid using those platest you hammer onto joints when you build a wooden house frame (name escapes me) - they don't seem to handle being repeatedly stressed very well.

2. Don't make the ramp pointlessly high, because it will require exponentially more material to make it stable. If you want to boost/drop off something, try and use the natural terrain to reduce the height of the structure.

3. Don't use trees for support or reinforcement - they're usually pretty flexy anyway. S.'s advice notwithstanding, leave living trees alone.

4. Ramp entrance points always get sketchy over time, usually sinking away and creating a destabilising bump as you get on (probably the majority of NS crashes are just after you get past this). Avoid this by using carpet on rocks or a half-buried onramp

 

[beginner_giantDH]

you can work out the moments and bending stresses on any ramps and shore u wanna build but there would be no point unless you are really short on materials and want to maximise strenght with less supports. i wouldnt bother thingking bout the maths. it would be a waste of time. the other problem is that u will want trhe safety factor from your shore. so i wouldnt go skimping on materials or fasteners. basically just keep to the golden rules the other have posted up and work to what u consider is stable.
ir, if u can run and jump up and down and stamp on it and it doesnt move or shake i would consider that the mathematical calculation. keep with the triangles too

 

[jock180]

try to have more than one nail in each joint. this will reduce the shee stresses and reduce the chance of the nail snaping. also simple things like the supports being triangles. wood works better if it is in trensin (being stretched) rather than compression (being compressed).

 

[rowdyflat]

Treated pine is good for the deck cross pieces that you ride on esp if it is offcuts scrounged from the tip +which are unable to be recycled -it is durable , not slippery , easy to cut + nail with galvanized decking nails 65 mm or screws.It rusts nongalvanized nails quickly though.
Native hardwood is good but splits easily + difficult to nail unless it is predrilled so bring a battery drill.
Termites love oregon + untreated pine so dont use it near soil.
Pallets can be used as well but must be reinforced.
Bikes are usually smoother on a structure than walking.
It is best to overengineer everything to be safe we have had motorbikes use our bridges!!!!STUPID.
Bracing w timber , waterproof ply or metal strapping is essential.

 

[Big_Chief]

when connecting the north shore to the ground. lay the bridge on a hesian bag filled with sand/cement. and then it will not move.

when nailing/screwing/bolting try to keep the fittings as far away fom each other to avoid splitting the wood.

and triangles are a very strong shape!

make sure you brace every joint strongly.

 

[Macr]

1. Avoid using those plates you hammer onto joints when you build a wooden house frame (name escapes me)

Gang nails.

 

[Oppy]

http://www.outdoorstructures.com.au/pdf/boardwalk_design_guide.pdf

 

[Humfreyoncrak]

I am not an engineer, but I have found that using galvanised bolts, large outer diameter washers and nyloc nuts seems to maintain structural integrity more effectively than coach screws, nails and so forth.

Invest in a second hand drill with 2 batteries, a fast charger and a drill bit sharpener. Sharp drill bits make life so much easier.

Invest in a string line, line level, spirit level and make a heap of plumb bobs from some string line and old bits of metal ect. Getting levels for gradient etc is helpful imo.



Yeah, it will cost more, but I feel more confident in the future riding on a structure that has been bolted together where possible.

If you have to move the structure, you can unbolt sections and recycle

 

[J-Dogg69]

when your building your NS you can generally tell where you might need more support. Remember that the triangle is the strongest geometric shape and that truss designs are favoured for their structure which alows for greater spans, however incorporating a truss structure may be impractical. if you still want to do the math of it all: you add all of the ( force x perpendicular distance from exerted force to supports )'s together to get a moments and (you'll already know) the direction in which the structure will want to move. You really shouldn't need this though, just go with other peoples advice and ur gut to tell if ur dream trail is rigid and sturdy enough to ride. otherwise youll be spending more time building it than riding it - just ride it siic!