Identification of Cracks

1.

  a.

• It is the form of flexural failure due to reversal of stress during earthquake
• During stress reversal support top experience compression and bottom experience 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 insuffiecnt devleopment length of reinforcemnet in joints
• During earthquake the horizontal movement of structure makes this condition worse and detached the beam member from column
• Providing anchorage is very difficult. So not repairable

   c.

• Its a plastic 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 handlle 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 no-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 efffect
• This leads to failure especially if the connection is unintentional and not accounted in design
• The failure given  in the picture is not all repairable