Identification of Cracks

1(a) ans :-

• Its from of flexural failure due to reversal of stress during earthquake.
• During stress reversal , support top experiences compressions and bottom experience tension
• Top compression is managed by slab advantages, bottom tension was not satisfied by the provided reinforcement.
• Since the reinforcement got yeilded, it can not be repaired.

1(b) ans:-

• 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 length between two existing concrete is very difficult so not repairable.

1(c) ans:-

• Its a plastic hinge failure.
• The damage occured onlyt in the jopint zone first of all
• Cyclic lateral loading and stress reversal at the joints led to the damaged
• The joint can be strengthened.

2(a) ans :-

• 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 the ground storey columns durinmg lateral movements.
• Based on the development of crush of concrete it can either be repairable or non-repairable.

2(b) ans:-

• Its a pure shear failure
• In adqeuate shear reinforcement compels concrete takes all the shear stresses.

2(c) ans:-

• Its a short column failure
• An additional beam connected to a column in mid height leads to this effect
• This leadds to failure especially if the connection is unintentional and not accounted in design
• The failre given in the picture is not at all repairable.