Govt. Exams
Entrance Exams
Three-hinged arch has 4 reaction components (2 at each support) and 3 equilibrium equations plus 1 condition that moment at internal hinge = 0, making it statically determinate.
Shear force diagram shows a vertical jump equal to the magnitude of the concentrated load at its point of application.
Relative stiffness (I/L) is used in distribution factor calculations when moments of inertia vary across spans.
Distribution factor = (stiffness of member)/(sum of stiffness of all members at joint). DF ∝ stiffness (4EI/L).
Carry-over factor = 0.5 for both fixed and pinned end conditions in slope-deflection method.
Element stiffness matrix is derived by applying unit displacements at nodes and calculating corresponding forces (unit displacement method).
Influence line for reaction at A is triangular, varying from 1 at A to 0 at B, representing the reaction at A due to unit load.
Two-hinged arch has 2 supports (each with 2 reactions) = 4 unknowns total (horizontal and vertical at each hinge).
IS 456:2000 recommends minimum 14 days of moist curing for normal Portland cement in normal temperature conditions.
Retarders delay the setting time of concrete, allowing more time for placement and compaction in large structures.
