Question

The best design of an arch dam is when __________________

(a) all horizontal water loads are transferred horizontally to the abutments

(b) the dam is safe against sliding at various levels

(c) the load is divided between the arches and cantilevers and the deflections at the conjugal points being equal

(d) the deflections of the cantilevers are equal at different points

I had been asked this question in class test.

My query is from Arch Dams topic in chapter Arch and Buttress Dams of Irrigation Engineering

Answer 1

The correct answer is (c) the load is divided between the arches and cantilevers and the deflections at the conjugal points being equal

To explain I would say: In the trial load method, deflections for the arches are calculated at the points where the cantilevers cross it in each trial. If the deflection calculated at these points from cantilever elements is within reasonable limits and same, then the assumed distribution of load is correct. If not, then the calculations are repeated using a different set of load distribution until the condition is satisfied.