On 31st Mar 2016 Kolkata Flyover collapse

1. Kolkata Flyover Collapse 31 Mar 2016
Prepared by:
Vinay Kumar G

2. Agenda
Introduction
Accident
Root Cause Analysis
Aftermath

3. Introduction
 Kolkata is the capital city
of West Bengal state.
It covers an area of
approximately 185sq.km and
current population around 14
million.
Fig 1: Howrah Bridge

4.  To overcome the traffic
congestion on the major
roads in the City.
 The Govt has undertaken
construction of several
flyovers which has eased
the traffic flow in certain
localities. Fig 2: Ultadanga Flyover

5. One of the recent ones is a
2.2km stretch in Central
Kolkata, having 2 serviceable
roads.
 The flyover is located at the
hub of the wholesale market
for spices, garments and
plastics, BurraBazar.
Fig 3. Proposed Vivekananda Flyover

6. Details of Flyover
Name of flyover : Vivekananda Road Flyover
Length of flyover : 2.2km
Budget : ₹164.3 crore
Construction Company : IVRCL LIMITED.
( Hyderabad based Company)

7. Foundation laid : 2008
Scheduled Date of Completion : 2012
Project Began : 24th Feb 2009
Date of Accident : 31st March 2016
Location : Girish Park
Fatal : 50+
Non-fatal injuries : 80+

8. Accident Description
 At 12:40 pm on 31 March 2016, a 150 m (490 ft) steel 60th
span of the bridge collapsed, trapping many pedestrians and
vehicles underneath.
 The accident was caused when two arms of the T-shaped
pillar, identified as Pier no. 40(C), buckled. Piers are vertical
structural braces that hold up the elevated length of road in
flyovers.

9. Fig 4: Aerial View of Collapsed Vivekananda Flyover

10. Fig 5 : Collapsed Vivekananda Flyover

11. Fig 6: Aerial View of Collapsed Vivekananda Flyover

12. ROOT CAUSE ANALYSIS
Kolkata government appointed the RITES (Rail India
Technical and Economic Service) for the investigation
The team visited the location collected primary evidence and
their initial impression was because of Absence vertical
supports for Girders, Low grade Quality of steel, Poor welding
at the joints and Lack of supervision leads to the accident

14. HOW PIER 40(C) COLLAPSED
On top of column 40(c), cantilever 2 was found out to be
comprising of inadequate bracing ( horizontal and
vertical) between the girders
Which due to lateral buckling collapsed and whole
cantilever 2 experienced a full fracture

15. Since the flanges of girders were unrestrained with
cantilever 1, with a complete rotation the cantilever 1
came down with causing a buckling in the column 40(C)
as well , along with the 150m segment which followed

16. Aftermath
Three employees of IVRCL, The state government
suspended two senior engineers of the Kolkata
Metropolitan Development Authority which was IVRCL's
joint venture partner in the project. The police have
registered a case of murder and attempt to murder
against IVRCL.

17. Structure has since remained untouched as the
government failed to decide whether to build the rest of
the flyover or pull down the entire structure.

18. Latest Images

19. Thank you!