Help with a curved bridge

[GemmaEBaird]

I am fairly new to 3D and am having problems with a curved overpass.

 

 

It begins at ground level and curves both in plan but also elevation to reach 9m at its highest point.

 

 

I just cant work out the concept of creating such a form. Anny help would be much appreciated

 

 

You can see the plan of the bridge in front of the 3D structure.

 

 

Thank you

Bridge.dwg

[ReMark]

My initial response, without seeing your drawing, would be to suggest creating a plan view profile and a side view profile then extrude both. Run the INTERFERE command and the intersection of the two profiles should result in a curved bridge. Can't be 100% sure of this approach until I try it myself.

[GemmaEBaird]

Thank you ReMark, but the two sides have a different profile as it curves in plan too ....... so I can't make that work.

 

 

I've attached my drawing - and a screenshot if that helps.

 

 

Any other ideas ?

[ReMark]

I don't see that as being an insurmountable problem. The plan view profile could be drawn as though both sides were the same then slice away the portion you don't need.

[GemmaEBaird]

I understand that bit - but how do I get the curve the other way ?

[ReMark]

At the very least you would need a top and side profile.

 

Another option might be the use of sequential profiles and the LOFT command.

[GemmaEBaird]

Sorry - could you explain a little more please

[ReMark]

Gemma:

 

Do you have a couple of minutes? I'm going to upload a DWG for you to take a look at. I'll be back.

[GemmaEBaird]

Thank you - that would be fantastic !

[ReMark]

OK...I'm back

 

Take a look at the attached drawing and tell me what you think. The drawing has been saved in 2010 file format so you should have no trouble opening it.

 

You are familiar with rotating a 3D object are you not?

 

Curved ramp.dwg

 

I've got to grab a bite to eat so I am stepping away from my computer for 20 minutes or so. Time now: 5:13 p.m. EDST on the east coast of the U.S.

[GemmaEBaird]

Ok - that makes sense

 

 

ive sort of got it but with one problem ......

[GemmaEBaird]

where it hits the ground it has a sort of step where it turns a corner

[ReMark]

^^^Not sure exactly what you are referring to. Do you want to add this "step" or delete it?

[GemmaEBaird]

delete it - the bridge should come down flush with the ground

[ReMark]

Not sure how you got it to be higher on one side than the other to begin with.

 

I only know of two solutions. 1) Do it over. 2) Cut off what you don't need using the SLICE command.

 

Sorry, but I have to step away from my computer again. May be about 15 minutes or so. Time now is 5:42 p.m.

[GemmaEBaird]

the issue is - in plan he 2 ends of the bridge aren't parallel - so when creating the elevational plane to trim it by the arc is slightly higher at the more narrow side of the curve ....... if that makes any sense at all

[ReMark]

In plan the ends of my ramp aren't parallel either yet I maintain a uniform thickness throughout.

 

I guess I'm not "seeing" why you should have a problem tapering the end of the ramp to the point of where it is for all practical purposes flat.

[GemmaEBaird]

I must be doing something wrong - I'm just not sure what

[ReMark]

My curved ramp but this time I've tapered one end. Note that it is flat across the entire width.

[GemmaEBaird]

ok - how on earth did you do that ?