excellent presentation

1. BUILDING FAILURES AND CAUSES:
CASE STUDIES
Theory of Structures

2. Introduction
• What does a structural failure mean?
– Building failure occurs when the building loses its ability
to perform its intended (design) function. Hence, building
failures can be categorized into the two broad groups of
physical (structural) failures (which result in the loss of
certain characteristics, e.g., strength) and performance
failures (which means a reduction in function below an
established acceptable limit) (Douglas and Ransom,
2007).

3. General causes of failure
• Failure of a structure can occur from many types of
problems, mostly unique to the type of structure or
to the various industries.
– Due to size, shape, or the choice of material, the
structure is not strong and tough enough to support
the load. Failure can occur when the overstressed
construction reaches a critical stress level.
– Instability, whether due to geometry, design or
material choice, causing the structure to fail from
fatigue or corrosion. These types of failure often
occur at stress points, such as squared corners or
from bolt holes being too close to the material's
edge, causing cracks to slowly form and then
progress through cyclic loading. conditions.
– Manufacturing errors, may be due to improper
selection of materials, incorrect sizing, improper
heat treating, failing to adhere to the design, or
shoddy workmanship.

5. Man made v/s natural causes
• Most of the structural failures are associated with materials and are the consequence of
human blunder involving a lack of know-how about materials or the combination of
contrary materials.
• There are structural failures that can be endorsed to irregularity in materials. Although too
much reliance is given on modern structural materials yet the manufacturing or
production faults may exist even in the most dependable structural materials, such as
standard structural steel or centrally blended concrete
V/S
• One of the major natural factors that result into building collapse is rainfall; others may
include temperature, pressure, etc.
• When there is a heavy downpour of rain, there is a possibility that one or more
buildings(completed or uncompleted), somewhere , would cave in (Chinwokwu, 2000).
• The fact remain that this is a natural factor that cannot be stopped, buildings therefore
need to be constructed adequately bearing in mind such uncontrollable factors.

6. City-Specific reasons
• Property prices and rent in Mumbai are among the highest in
Asia. Many citizens are forced to live in old, dilapidated
properties in a land-scarce city.
• And between 2008 and 2012, there were 100 building
collapses in the city in which 53 people died and 103 others
were injured, authorities say.
• The gradual decay of buildings is most commonly a result of
the lack of periodic maintenance, especially when the
buildings fall under the Rent Control Act.
• Building collapses are common in India due to
– substandard materials
– inadequate supervision in constructing multistorey structures.
– The incidents have highlighted shoddy construction and
violations of the building code, amid burgeoning demand
for housing in many parts of India and endemic
corruption.
• Adjoining is a timeline of building collapses in Mumbai in
2013, published in The DNA newspaper, dated 28.09.2013

7. Case study 1: Collapse due to human error
• ‘Canacona building collapse: Weak columns, strong beams
reason for disaster‘: January 8, 2014
– The under-construction five-storey building crashed
killing 18 workers, injuring 14 more.
– Poor workmanship, lack of soil analysis and substandard
quality of construction materials may have been largely
responsible for the tragic collapse of this building in Ruby
residency in Chaudi, Canacona.
– The debris of the collapsed building shows some beams
and slabs sitting on top of each, but not a single column.
"All the columns have been reduced to powder at the
site," a source said. It could be a case of weak columns
and strong beams.
– Sources said m20 grade of concrete appears to have
been used for the columns. "It is okay for the slabs but
not columns and m25 grade would have been better,"
another source pointed out.

10. Case study 2: Altaf Manzil,Mahim
• Altaf Manzil, the five-storey building on Cadell Road
collapsed late on Monday night after it rained
heavily in the city. A portion of the five-storey
building caved in, apparently due to rain, in Mahim.
• The Altaf Manzil building, that stands next to several
other old buildings, was built in 1984, and had never
since received any renovation.
• A car showroom that had come up in the ground
floor of the building. The car showroom had made
structural changes to the basement by removing
several pillars. This is what probably caused the
disaster, said a resident. A seven tonne hoarding on
top of the building could have also added to the risk,
reports say.
• The building however, was already on BMC’s list of
dilapidated/dangerous buildings, due to the
weakening of members as a result of monsoon
lashes.
•

13. General precautions/ measures

14. • Water cement ratio is to be controlled.
• Reasonable pace of construction adopted.
• Brick work over load bearing RCC members should be done after removal of shutting
giving a time gap.
• Brick walls between columns should be deferred as much as possible.
• Plastering of areas having RCC and brick members should be done after sufficient time
gap say one month or suitable groves provided in junction.
• Corroded reinforcement expands and cracks the concrete cover. To avoid this
phenomenon rich mix of concrete using proper quality of water and adequate cover
should adopted.
• Avoid bricks containing too much soluble sulphates (more than 5 %) and use rich mortar
in such cases.
• Use expansion and control joint at
closure intervals.

15. • Large trees growing in the vicinity of buildings cause damage in all type of soil conditions.
If the soil is shrinkable clay cracking is severe.
• This can be solved by taking precautionary radius around any present vegetation, as
non- buildable area.

16. THANK YOU
Garima Rajput 43
Manasvi Rane 44
Rithika Ravishankar 45
Shweta Salam 46
Shivali Sanap 47
Vishakha Savatkar 48