Question

Case study of failure concrete structures, select 1 case and discuss in a report whith showing picture of the failure (4 pages minimum)

Answer 1

Vivekananda Flyover Collapse ,Kolkata (India)

Introduction

This incident occured on 31st March, 2016 in the district of Kolkata in West Bengal(India) when a major segment of an under construction bridge collapsed. As many as 26 people were killed and more than 100 people were injured during this incident. The bridge was supposed to be a relief for vehicle movements in the market area of Burrabazar, one of the largest and most congested market place in Asia. Some people also described it earlier as the “Gateway to Kolkata”. The collapse of the bridge caused a major uproar in the country and lots of investigations followed to know about the exact cause of the failure. Many conclusions have been drawn and cases filed against the responsibles but the blame game still continues with each party shifting the allegations on others.

Picture of the incident

Design of bridge

The flyover consisted of 2 carriageways constructed compositely with reinforced concrete deck slab supported over steel plate girders which were in turn supported on steel piers situated at regular intervals aling the length of the flyover. Its foundation was laid in 2008 and the construction of the flyover started in February 2009. It was proposed to be 2.5 km long.

Cost of project

The project was stated to be costing INR 164 crores. Though the earlier released amount was less but due to the complaints of construction firm and many types of delays the cost of project was lifted.

Investigation report

Many investigators and Civil Engineers published their reports in this tragedy all pointing towards the fault of the construction firm and Kolkata Metropolitan Development Authority. Their reports said that that the bridge had many design flaws. The bridge which was supposed to carry over thousands of vehicle collapsed under its own weight. This clearly pointed towards irregularity in the construction materials, poor quality, approval of faulty design, no quality check and improper execution plan by the firm and concerned authorities.

Investigators suggested that the use of cantilver piers was unneccessary as cantilever piers are one of the most unstable structures and are usually avoided and should be employed if absolutely necessary. These type of piers need meticulous design and need perfect implementation with strict quality check of materials. As one of the piers had some connection problem , then what was running on two pillars (at the start of the bridge) converged on to one pillar but this single pillar did not have adequate strength to put up with load and it failed with 100 m long section crashing down on a crowded street. Luckily the casualties were less otherwise situation could have been worst considering the the congestion in the area.

Report of the construction firm

The construction firm denied all allegations put up on them trough investigations and deemed the failure as “ Act of God” . Their reports say that they had an experience of 27 years in bridge construction and such event had never occurred. They ensured proper quality and design check at regular intervals and such failures are impossible to ascertain. They had undergone all processes for design approval and employed many private and government authorities for the design and material testing.

Goverment Action

The Chief Minister of West Bengal, Mamta Banerjee ensured investigation and speedy trial on this tragedy with strict punishments to the guilty party. Monetary aid was also provided to the familiy members of the demised. However it has been 4 years since the incident and the trial is still going on.

Conclusion

It is certain and evident that with all the progress we have made today in the field of construction such incident should have been prevented and clearly shows the lack of conviction and greediness of the construction firm and quality investigation authorities. We must know that Civil Engineers are pioneers of todays generation as their works last many generations and therefore their work should be matter of pride for them and not a source of money.