Question

The degree of static indeterminacy of a rigidly jointed frame in a horizontal plane and subjected to vertical loads only, as shown in figure below, is

• A. 3
• B. 6
• C. 4
• D. 1

Answer 1

The correct option is A 3


The structure is in horizontal plane and loading is purely vertical. Hence, this condition can be taken similar to a 2D frame with inplane loading for indeterminacy calculation. As one cut will make the structure determinate. Hence,
$D_s=3\times 1=3$