Identification of Cracks

(a)

ans:-

• 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 .bottom tension was not satisfied by provided reinforcement.
• since the reinforcement got yielded,it can not be repaired.

(b)

ans:-

• It Beam pull out failure due to insufficient development length of reinforcement in joints.
• During Earthquake, the horizontal movement of structure makes the condition worse and detached the beam member from column.
• Providing anchorage length between two existing concrete is very difficult .So not repairable.

(c)

ans:-

• It's a plastic hinge failure'
• The damage occurred only in the joint zone first of all'
• cyclic lateral loading &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)

ans:-

• It's a soft storey failure ,Technicaally 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)

ans:-

• It's a pure Shear failure.
• Inadequate shear reinforcement compels concrete takes all the shear stresses.

(c)

ans:-

• It's a short Column Failure
• An additional Slab Or a Beam Connected to a Column In mid-height leads to this effect.
• The leads to failure especially if the connection is unintentional and not accounted in design.
• The failure Given in the picture is not at all repairable.