Risk Management in Engineering
Conduct a risk assessment to quantitatively verify the magnitude of the risk exposure in terms of deaths/injuries/damages/costs using recognised methods in one of the case study prepared.
▪ Theoretical background (literature review)
▪ Research methodology
▪ Implementation and results (case study)
▪ Conclusion and future works
CASE STUDY – QUEBEC BRIDGE COLLAPSE – 1907
The famous Quebec bridge was one of the longest project which spanned over 20 years in making starting from the starting of the company Quebec Bridge Company in 1887 up until the bridge collapse in 1907. This was supposed to be one of the most feasible construction design in order to cover the icy waters of St Lawrence rivers. The width of the river was approximately about 3.2 km which was a huge problem as Quebec was in need of an easier mode of transportation in order to fulfil the trade needs and compete with Montreal at that time which was already ahead with its railway system set in place. Interest of building the bridge was risen from the late 1850s but the committee was set in motion from 1887. In 1898, after going through different sit inspections, Chaudire site was shortlisted as the official location of Quebec bridge which was then followed by incorporation of different design proposals. It was late stated by the chief engineer of the project that cantilever superstructure plan will be best suitable for the budget of the project which was indeed very much restricted.
When and How it Happened
While the construction was going on, workers and site engineers noticed a few deflections in midpoint in some chords which was noticed to increase in deflection overtime in dome of the heaviest compression members. The deflections were reported to the chief engineer of the project which were then riveted to line up with the joints which further reported out that the joints failed to close. They just assumed that the deflections are happening due to some unknown condition which was later ignored. After a few months, the deflecting chords were increasing in number which later rose the question of how it happened. It was later admitted by the chief designer that he never checked the chords for deflections and assumed they must have come form the chord ribs in the shop. This later emerged out to be a disturbing pattern of load distribution in the highest compressive loads which later were seen to be gradually buckling. Another theory was suggested by chief engineer that the chords were being hit by the suspended beams which were used to put the chord in place. This theory was investigated and no proof supporting his theory was found which made it false. While the discussion was going on about what to do next, the bridge collapsed in 1907 n resulted in death of 33 workers and 11 were injured. Investigation was set in motion and various causes of failure were drawn as follows
|Workers||– Health and wellbeing
– Safety and precautionary measures
– Well informed with what is going on
|Site engineer||– Supervision and monitoring
– Communication to higher management
|Project Manager, consultant||– Well specified layout of plan
– Site investigations
– Timeline and management
|Quebec Bridge committee||– Budgeting and going for cheaper option
– Hiring professionals who are good and perfect fit for the job
Influence vs importance
|Quebec bridge committee||2||6|
Inherent Risks Involved
Several risks were seen from the start of the project which raised several ethical concerns. The major one being that the deflection was noticed in the beginning and instead of stopping the operation they were just trying to find out plan B for work to be continued.
On-site engineers debated about the cause amongst themselves.Although the staff who did not return to work due to the deformations lacked the technical skills, they seemed to be the only ones who knew what was actually happening to the bridge.There was no criticism of consultants actions, even though they appeared odd.An Independent consultant may not have permitted superior design than standard stress.
Financial constraints also pays a major role in the process as it delayed all the analytics part and forced to ignore the safety part of the project leaning toward adopting unconventional aspects of construction.
The ultimate goal of engineering security is to keep human lives safe in all aspect, whether it is physical, mental, social. With two very different case study above we can say that although there are a lot of reasons and aspects that are in need of consideration but we also need to factor in the most ignored, although important aspect of engineering failure, that is human error. We are so much reliable and dependent on technology and boundaries of projects that sometimes we forget to use our own head and rule out the basics that should be kept in mind.