I’m trying to insert a multi-span arch bridge into HEC-RAS (with 3 openings) and I can’t seem to figure out how to do it. I also can’t seem to find anything on Google. I thought it would be as simple as setting the spring level, soffit level and radius of the arch for each opening but no luck so far.
Bridge geometry is entered as deck/roadway, piers, and sloping abutments (as applicable). Deck data are entered as station and elevation to provide the opportunity to define any shape. You’ll need to define the entirety of the high and low chord of the bridge deck, including the arches, using station and elevation data. Station = distance along the bridge.
I had the same situation a year ago when I got to a model where I had to insert a bridge that has three arches in it. The way I had it modeled is to use a semi-circle equation that shows like this: r^2=x^2+y^2. Here r stands for the radius of the circle, and so, for our bridge it is half the value of the span of the arches. You can isolate y (the elevation in meters or feet) in the equation and calculate the values for a list of x’s that are bounded between the first and last point of each arch in your bridge. The more you use small steps between x and x+1, the more you get a well defined arch.
This reply was modified 1 year, 10 months ago by vincent tremblay.