Challenge

Identification of Cracks

Question 1:

What is the mode of failure or damage of the beams in the figure above? Are the damages repairable? Elaborate

Answer:

Observation:

Concrete seems crushed and RCC is exposed to the air in the picture.
The failure seems to reach very deep into the structure. Even though the failure ain't looking very bad as the beam is still intact at its position.
The failure is created from bottom to top.

Conclusions:

It is a form of flexural failure.
This type of failure occurs due to the reversal stresses of the earthquakes.
When the reversal stresses acted on the beam, the upper part was taken care of by the slab but the lower part didn't overcome the forces and a failure was observed.
As the reinforcements seem not to be yielded and a permanent deformation can be seen, this failure is nonrepairable.

Observation:

A photograph of the whole structure can be seen.
There seem very big and deeper cracks in the structure.
It seems like the beams are totally separated from the columns and are about to fail completely.
Even though the concrete structure has failed, it seems that the reinforcement is holding up the whole structure.

Conclusions:

This type of failure is created due to the very less development length of the RCC bars provided in the structural frame.
When the seismic forces act, the beams try to pull themselves out of the beam, and due to the less development length provided over here the structure failed.
Ad the cracks are wide open and the development length provided is very less, the structure is not repairable again.

Observation:

Cracks can be observed over the whole width of the beams, and columns and are about to start to spread all over the slab.
The cracks are developed at the JOINT.

Conclusions:

A very high load had acted on the structure.
All the components have tried their level best to overcome the forces.
As it can be observed that the slab has also developed cracks due to the forces.
As the cracks are very minor, this whole situation can be covered back.
This is a repairable condition.

Question 2:

Answer:

Observation:

The columns structure seems to be damaged over here.
As there seems no wall constructed near it, it may be a column of the ground floor or parking area.
No failure has occurred on the beam.

Conclusions:

As the column is on the ground floor, and when the seismic force would have acted, a plastic hinge may have been created over there due to the absence of the walls.
This may have caused the failure.
It doesn't seem so bad that it can't be repaired.
This type of failure must be assessed first before doing anything to it.

Observation:

Conclusions:

Improper RCC calculation is done while providing the shear bars to the structure.
This is a clear case of the shear failure.
No repairing can be done over here.

Observation:

Complete column failure.
The upper part is failed.
Wooden piles have been added to give support to the slabs.
There seem two slabs being supported on one column. The lower slab may be of the landing of the stairs.

Conclusions:

This is surely a short column failure.
The design might not be taken into the analysis consideration before constructing it.
This is surely not repaorable.

Ship work like this
in your own course.