Help with a curved bridge

[ReMark]

The same way I've mentioned previously (twice) via extruded profiles.

 

It's possible you are getting a different result because your side profile is tilted just ever so slightly.

[GemmaEBaird]

Hmmm - I am definitely doing it that way.

 

 

The difference I'm seeing is that both your top and bottom lines are parallel - and mine are at a different angle to each other

[ReMark]

Maybe you should rethink your design.

 

I have to call it a day in a moment but before I do I believe I was able to solve the dilemma by rotating my side profile to match that of the angle of the front edge.

 

A top view of my ramp. Note the end circled in red. It extends 500 units beyond its counterpart on the other side thus creating an angled front edge.

 

 

Top view of resultant solid with angled edge.

 

 

Sorry, but my time is up. I'll check this thread tomorrow (Sunday) morning after I've had a cup of coffee (or ten) to clear my head.

 

Good luck.

Edited December 20, 2014 by ReMark

[GemmaEBaird]

Its not my design - its an existing overpass

[GemmaEBaird]

Thank you for all your help.

 

 

I see your point - but the two ends are at different angles to each other so unfortunately this isn't going to work.

 

 

It's past midnight here so I'm off myself.

[ReMark]

I disagree. In the last two images posted the two ends are NOT parallel to each other. I think it can be done you just have to work at it some more.

[nestly]

I disagree. In the last two images posted the two ends are NOT parallel to each other. I think it can be done you just have to work at it some more.

 

I think you're looking at the wrong part of the drawing. OP said the curved overpass 9M high, in front of the 3D structure. I'm not exactly sure how to solve it myself, but made a spline starting at the left end of the overpass, then progressing to the right to the 6500 elevation line, then the 9M line (9000 elevation) then to the 6000 elevation line, then back to grade at the right end of the ramp. Repeat for the other side of the ramp, then LOFT. Unfortunately, this is just a rough concept of how it may be done, as there aren't enough control points to make the spline follow the exact curvature of the ramp.

 

[ReMark]

Still don't see it as being an insurmountable problem. Wouldn't the ramp be banked?

[GemmaEBaird]

ReMark - I'm pretty sure it can't bank as it is a road.

 

 

nestly, that works ! - except how do I now give it a thickness, and solidity from the 6500 point down to the ground ?

[nestly]

You can try THICKEN command to turn the surface into a solid. Give it a thickness of -9000 (or whatever it's highest point is above the beginning/ending elevations), then SLICE off anything below 0 elevation.

[GemmaEBaird]

That doesn't seem to work - with + or -

[nestly]

OK... Thicken didn't work for me either on that surface.

 

Copy the surface down 9000 units, then LOFT the two Surfaces (try using the MOde > Solid option) If it doesn't loft a solid, use SURFSCULPT command to turn all the surfaces into a Solid, then SLICE off what's below grade.

[GemmaEBaird]

AMAZING

 

 

It worked !!!!!!

 

 

Now I just need to work on the void below - but I'm pretty sure I understand that concept

 

 

Thank you

[GemmaEBaird]

So I've cracked it with all of your amazing help. It's not quite finished - but the main form of the bridge is there THANK YOU !!!

[BIGAL]

Re its a road no Banking sorry thats wrong we have a lot of curved bridges and they are banked if the road design calls for super elevation the road will have precedence over bridge surface. Check out Westgate Bridge Melbourne Australia opposite banking on the two sides.

 

I was trying to find this image which is along the suggestions by Remark. Nestly Nice job.

 

[GemmaEBaird]

BIGAL - I didn't know that. I don't know if it's the same I'm the UK - I'll have to look it up. Interesting

[ReMark]

We have banked highways and roads in some parts of the U.S. One such road is called the Kangamangus highway in northern New Hampshire a 34 mile ribbon of asphalt stretching between Lincoln and Conway. It's a favorite ride of motorcyclists who like a good dose of speed. It's such a thrilling ride motorcyclists have been known to drive it in one direction then turn around and immediately drive it in the other without a pause. At 100 mph it's a blast!

[BIGAL]

Remark I just drove our equivalent "The Great Ocean Road" yeah but in my bus, at this time of year nothing unusual to see 200+ motorbikes in Lorne. The speed limit is now 80Kmh so when a guy goes past me doing 70 in bus in 3rd then throttling off from about 120+ for a 45kmh bend it wakes you up. And his 3 mates pass you on the next 100m straight. Yeah 100m!

 

The road is on the edge of the coast so big drop off's, with so many bike crashes hence low speed limit the guard rails have a infill piece in the bottom so the motorcylist does not go under. Passed a ducati once all that was left was a blob as it caught fire both rider and pillion were bruised but ok.

 

One of the staff here was a bit mad about bikes and he gave the ultimate sacrifice going the back way from Lorne another lets see how fast we can go road.

 

Last word before low speed limits in my car full sideways in a bend trying to avoid ducks crossing the road.

[ReMark]

What is the point of having an undulating main bridge?

 

Wouldn't the roadway ramps leading to/from the bridge look more aesthetically pleasing if they were supported by something other than a triangular mass of concrete?

 

Why is there a bridge in the middle of what looks like a residential area? Are those condos or apartment houses?