Identification of Cracks

1)

(a) It is flexural failure in the beam due to reversal of stress during earthquake. Due to stress reversal, top beam experiances compression and bottom beam experiences tension. Due to tension in bottom, provided reinforcement is not enough to resist this tension, so reinforcemnt is yielded.

It cannot be repaired because bottom reinforcement is yielded. so it is no use.

b) This crack is developed due to insufficent development length in joints. so It is beam pull out failure.Due to insufficent development length, beam is deteched from column during earthquake horizontal moment.

It is not repaired beacuse we cannot provide anchored length outside of these structure.

c)It is a plastic hinge failure. Cyclic laterial loading and reversal stress at the joints led to the damage during earthquake.crack is developed even in slab portion because even slab is unable to control the damage.

The joint cab be strengthened.

2)

a) It is soft storey failure. Due to absence of infill walls at ground floor, stiffness of this floor is low and plastic hinge form athe the top of ground floor column during lateral movement.

It can be repaired or not depends upon the development of crush of concrete.

b)It is a pure shear failure. It causes due to wider spacing of shear reinforcement.

It is not repaired.

c) It is short column failure.As we know that short column attracts higher shear force, so it is not designed to be considered as short column. So this failure occured.

It is not repaired.