Identification of Cracks

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

During stress reversal, support top experienced compression and bottom experienced tension.

Top compression is managed by slab advantage. Bottom tension was not satisfied by the provided reinforcement.

Since the reinforcement got yielded it can not be repaired.

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

During earthquake the horizontzl movement of structure makes this worse and detached the beam member from column.

Providing anchorage length between two existing concrete is very difficult . So not repairable.

c) Its a plastic hinge failure.

The damage occured only in the joint zone first of all.

Cyclic lateral loading and stress revarsal at the joints led to the damage.

Even the slab participated to its best to handle the tension (slab is severely cracked means it has undergone tension with its flange condition)but unable to controll 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 coumn 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 unintensional and not accounted in design.

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