Need help with Funicular Study

We are considering arches in our CEB construction:

I need some help with a funicular study – thats the math that calculates the forces and force lines in an arch or vault! If you can help me learn how to do this, you can join the discussion on our forum. I made a video to ask too here


  1. noname

    hey David,
    what you need is a structural analysis, or simply statics done by a capable construction engineer.
    Just send me an e-mail, I`m just doing the same thing for One Community Ranch in California.

  2. Sepp

    Some simple but supremely important advice on building an arch (I have built a half-arch myself, which holds up a brick stairs)…

    An arch is self supporting. Round is best. The forces that are built up by the weight of the arch itself and by anything above the arch that sits on it are directed towards the ground, in the case of a complete half-circle arch. It’s also called a Roman arch. The old Romans used to build all kinds of large structures (aqueducts) and openings such as doorways as well as building-internal structural elements with it.

    In your illustration example (you have a partial arch, i.e. not a complete half circle) and that is when things get very much more complicated. Not too complicated, but … the more you cut off the complete half circle of the arch, the more your pressure is directed sideways, instead of downwards.

    To be clear about this, you will need a heavy structure that can withstand a substantial sideways thrust if you deviate from half round arches. Walls that continue in the same direction the arch is oriented in are the usual way to achieve this.

    The arches shown in your illustration would collapse, pushing the walls out sideways, unless you had substantial pressure-absorbing construction elements on each side.

    Probably the calculations you seek will tell you that, but the simple concept is that the more incomplete the half circle, the more sideways-pressure you will have to neutralize.

  3. drocj

    A funicular curve is a parabolic curve, those arches in your image are not parabola. I advise you redesign the arches to be catenary, they are most efficient this way.

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