10 reasons of collapse
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10 Reasons of Collapse
of
Feature WallAt Anushriya Villa, Noida Sector 128
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COVER NOTE
Structural Failures occur due to a combination of reasons.
Structures are anyways designed with factors of safety, by all structural consultants,
So, a failure of this type, is due to many factors, which work in tandem.
Our team visited site the same day (May 16) when the client informed us of the wall
Failure. What the team found was that the structural failure was cased due to lack of
Basic structural norms being followed, despite intimations on several past occasions.
The details hereunder have been put together methodically to explain and pinpoint the
Cause of the failure on faulty workmanship and lack of procedural norms in civil const-
Ruction.
The following slides are easy to understand and can establish without any doubt that
The civil contractor and supervisor need to be pulled up.
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Drawing Title: Feature Wall Column and Beam DetailDate of Issue: 10thSep. 2012
This is the Structural Drawing showing details of Structural members for the said wall.
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This is the Architectural Drawings for the said wall showing all structural members in elevation.
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Proposed Foundation Design
of the Feature wall, which is
showing it starting from1metre below the Natural
Good earth Level.
The executed foundation to
be re-excavated & checked /
verified for adherence to this
drawing.
There are serious doubts of
unsettlement in this
foundation, due to
foundations not being on
compacted earth, as per
norms. Also the grade of
concrete used therein, may
need to be examined at a lab
to see if it matches norms.
1. The FOOTINGS
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ON SITE STATUS
Photograph taken on 31st
Aug. 2012.
Earth Filling where the
Feature wall to come is
half done without proper
Compression of soil.
Good Earth is far below
this filling, from where
the foundation wasproposed.
This leads to the doubt in
Slide 1.
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Proposed Column detail
and Elevation with all the
structural members &
levels marked, can be
seen.
Please note there are 4
columns proposed and
several tie beams
between columns and to
the 90 Degree adjacent
wall.
Drawing Title:
Feature Wall Column & Beam Layout
Date of Issue: 10thSep. 2012
2. Number of
Columns & Tie Beams
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Photograph taken on 15th
May. 2013.
a. Shocking to note even
plaster is intact and no tie
up, even in brick work, is
visible; also no bar
connectivity with existing
columns is visible.
b. Site showed ONLY THREE,
instead of FOUR Columns
proposed.
c. One of these 3 Visible
Columns was wrongly
erected from above the
Plinth beam, WITHOUT
necessary foundation.
ON SITE STATUS
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Photograph taken on 15thMay.
2013
a. Plinth Beam not connected
with Existing Column
b. Plinth beam level is not as
per drawing . Top of plinth
beam and internal road levelshould match as per drawing.
WITHOUT THESE THE WALL
WOULD ALWAYS SHEAR AWAY
& FALL.
3. No PLINTH BEAM
with Adjacent wall
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Photograph taken on 15th
May. 2013
1. Plinth beam
terminates here. Not
connected with
Existing Column
2. The weight seems to
be on a brick
foundation that was
hastily made; but as
mentioned earlier,excavation would
need to be done, to
know the exact
picture.
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Photograph taken on 15th
May. 2013
All overlaps of steel rods
in column placed at same
place, contrary to the
norms that overlapping
should be at different
places for proper
strength.
This explains how thecolumns have separated
so easily, as encircled and
shown here.
4. Reinforcement
against Structural
Norms
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Photograph taken on 15th
May. 2013
Forget Rod Lapping not
done here. .. The fact is
that there is NO
CONNECTION at all.
With an inexplicable gap
of 6 atleast between the
two rods!
This is not at allacceptable and is a
serious breach of
established norms.
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Photograph taken on 15th
May. 2013
Ring distance and
overlapping are uneven
and deviated from
drawings. 150mm c/c
In some cases, it is
200mm and in some
more Proper chiselling
of concrete will show theexact spacing.
These appear to be
methods of saving cost
and steel, at the cost of
structure.
5. Ring Distance not
as per norms
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Photograph taken on 15th
May. 2013
Ring Distance and Main
Vertical rods distance not
as per drawings.
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Photograph taken on 15th
May. 2013
Steel development length
where column meet
beam not provided as per
norms.
This results in weakness
at joints and ease of
shearing off, resulting in
structural failure.
6. No Steel
development
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Photograph taken on 15th
May. 2013
Middle Beam, on
Adjacent wall, was not
connected properly with
the Existing Column.
Picture shows that
middle beam was merely
touching the Adjacent
wall. No hooking or
welding of steel
reinforcement at all
noticed; maybe wire or
even that was not used.
7. Middle beam not tied up.
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Photograph taken on 15thMay. 2013
Top Beam was not
connected properly with
the Existing Column and
Beam.
Picture shows that no rod
extension provided and
lapped with the adjacent
wall.
8. Top beam not tied up
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This is the Column detail
as per drawing issued.
Please Note: This tie rod
is missing in Column
reinforcement, in some
places.
Drawing Title: Feature Wall Column and Beam Detail
Date of Issue: 10thSep. 2012
9. The Tie rod Missing
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Photograph taken on 15th
May. 2013
Apart from structural RCC
issues, the contained infill
brickwork is also not
acceptable.
Material cement : sand ratiois not at all proper, as visible.
Curing not done at all,
apparently, as all bricks
appear to have separated
from each other very simply.
Also, note that the Concrete
quality is very poor. Lab
analysis of this may be done
to analyse crushing strength.
10. No Curing
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Contractors will always want to cut corners and find ways of saving money.
Apart from this, all the evidence shows that there was:
1. Lack of Supervision at Site During execution.
(It Has been always suggested & advised, by us often, to appoint dedicated Project
Managers / Supervisors)
2. Poor workmanship and lack of acceptable level of expertise in Construction
(An on site engineer would have ensured the basics of construction are enforced)
3. No attention was paid to Curing of the Structure during and after the construction.
(Attachment and sense of ownership to project may be lacking due to constant
useage of different teams and labour contractors)
4. Cost Constraints given to Contractors, as informed by contractors, on site.
(This results in compromise in cement sand mixes, steel, curing and several other
malpractices)
5. Non adherence to and / or Comprehension of the Drawings, provided.
The End Note
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