Identification of Cracks

1.a)-its form of flexural failure due to reversal of stress during earthquake.

-during stress reversal, support top experiences compression and bottom experiences tension.

-top compression is managed by slab advantage.buttom tension was not satisfied by the provided reiforcement.

-since the reinforcement got yeilded, it can not be repaired.

b)-its beam pull out failure due to insufficient development length of reinforcement in joints.

-during earthquake, the horizontal movement of structure makes this condition worse and detached the beam member from column.

-providing anchorage lenth between two existing concrete is very difficult. so not repairable.

c)-its a plastic hinge failure.

-the damage occurred only in the joint zone first of all.

-cyclic lateral loading and stress reversal at the joints led to the damage.

-even the slab participated to its best to handle the tension but unable to control the damage.

- the joint can be strengthened.

2.a)-its a soft storey failure, technically plastic hinge formation.

-due to absence of infill walls at the ground floor , the plastic hinge forms at the top of ground storey columns during lateral movement.

-based on the development of crush of concrete, it can either be repairable or non-repairable.

b) -its a pure shear failure.

-inadequate shear reinforcement compels concrete takes all the shear stresses.

c)- its a short column failure.

- an additional slab or a beam connected to a column in mid-height leads to this effect.

-this leads to failure especially if the connection is unintentional and not accounted in design.

-the failure given in picture is not at all repairable.