Identification of Cracks

1.(a)

• It's 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 the provided reinforcement
• Since the reinforcement got yielded, it can not be repaired

1.(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 length between the two existing concrete is very difficult. So not repairable

1.(c)

• It's 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 It's best to handle the tension slab is severely cracked means it has undergone tension with its flange condition but unable to control the damage
• The joint can be strengthened

2.(a)

• It's 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

2.(b)

• it's a pure shear failure
• Inadequate shear reinforcement compels concrete takes all the shear stresses

2.(c)

• It's 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 the picture is not at all repairable