@centondollar - I agree, it is not a very accurate representation of a reinforced concrete arch of a tunnel. What would you suggest is a good way to idealise a tunnel so that the calculations for bending moments and axial loads are feasible to do by using hand calculations?
I am trying to model a tunnel as a three-hinged arch and I want to find out the bending moments (and shear forces) associated with a three hinge arch with a uniform distributed load on the top. See the below picture.
How can I calculate the bending moments? I have used the formula in the...
