Identification of Cracks

Question1:

1.0

AIM:

To analyse the mode of failure or damage of the beams in the pictures.

INTRODUCTION:

In this challenge, theory related the failures of structure is explained. With that type of failures, observations of image and state of the structural elements like it is repairable or not is explained.

PROCEDURE:

OBSERVATION:

As we can see that:

1. Concrete crushed and the reinforcement is exposed.
2. Concrete spalled beyond the reinforcement which may be a sign of rupture.
3. Beam top portion looks safe because of the flange advantage from slab.
4. The crack developes from bottom to top means rebar yeilding occurs in support bottom only.

RESULT:

1. Its form of flexural failure due to reverse of stress during earthquake.
2. During stress reversal reversal, support top experiences compression and bottom experiences tension.
3. 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.

2.0

AIM:

To analyse the mode of failure or damage of the structural elements in the pictures.

INTRODUCTION:

In this challenge, theory related the failures of structure is explained. With that type of failures, observations of image and state of the structural elements like it is repairable or not is explained.

OBSERVATION:

1. Cracks along Beam- Column edge.
2. Cracks seem to have developed thrugh the structure as it looks much wider.
3. Beam looks separated from the column at joints.
4. Concrete is not severely crushed.

RESULT:

1. Its a Beam pull out failure due to insufficient developmen length of reinforcement in joints.
2. 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 its not repairable.

3.0

AIM:

To analyse the mode of failure or damage of the structural elements in the pictures.

INTRODUCTION:

In this challenge, theory related the failures of structure is explained. With that type of failures, observations of image and state of the structural elements like it is repairable or not is explained.

OBSERVATION:

Cracks are exactly at the joint of column- Beam.

Cracks in Beam developed through its entire width.

Slab also developed more cracks along the beam width direction.

RESULT:

Its a plastic hinge failure.

The damage occured only in the joint zone first of all.

Cyclic lateral loading and stress reversal at the joints led to damage.

Even the slab participated to its best to handle the tension . Slab is severly cracked means it has undergone tension with its flange condition. But unable to control the damage.

The joint can be strengthed therefore repairable.

Question 2:

1.0

AIM:

To analyse the mode of failure or damage of the structural elements in the pictures.

INTRODUCTION:

In this challenge, theory related the failures of structure is explained. With that type of failures, observations of image and state of the structural elements like it is repairable or not is explained.

OBSERVATION:

1. Concrete damaged at top of the column.
2. Concrete damaged all round the column face.
3. Beams are safe.
4. The location of column looks at edge of the building.
5. No walls are built along the column means it is probably at ground floor, for parking car movement access.

RESULT:

Its a soft story failure, Technically plastic hinge formation.

Due to absence of infill walls at the ground floor,The plastic hinge forms at the top of ground story column durin lateral movement.

Based on the development of crush of concrete it can be either repairable or non repairable.

2.0

AIM:

To analyse the mode of failure or damage of the structural elements in the pictures.

INTRODUCTION:

In this challenge, theory related the failures of structure is explained. With that type of failures, observations of image and state of the structural elements like it is repairable or not is explained.

OBSERVATION:

1. Concrete developed complete breakage diagnolly.
2. Longitudnal reinforcements are intact.
3. Shear reinforcement spacing looks wider which means probably lesser shear rebar provided.

RESULT:

Its a pure shear failure.

Inadequate shear reiforcement compels concrete takes all the shear stresses.

3.0

AIM:

To analyse the mode of failure or damage of the structural elements in the pictures.

INTRODUCTION:

In this challenge, theory related the failures of structure is explained. With that type of failures, observations of image and state of the structural elements like it is repairable or not is explained.

Observations:

Column failed completely.

Failure at top of column.

There are two slabs connected to columns , probably one at mid of the column.

The wooden piles might be a post failure support after column failed, providing temporary prop to avoid collapse of the entire structure.

RESULT:

Its a short column failure.

An additional slab or a beam connected to a column in mid height leads to its effects.

This leads to failure especially if the connection is unintentional and not accounted in designs.

The failure shown in the picture is not at all repairable.