If most disputes are settled on the court house steps – I’ve seen 94% mentioned, one source said 98% – then the mistakes experts make during investigating and reporting are the ones that must be found out and corrected. This as compared to how tidy their CV looks, for example, or their demeanor and how well they answer questions during Discovery.

I would think the report is the hard evidence on the cause of the failure or accident, particularly if it’s been peer-reviewed. I repeat, if it’s been peer-reviewed. Wouldn’t this carry the day even if the expert messes up during Discovery?

The different categories of mistakes experts make and the numbers within each category have been identified, yet guidance for experts by different groups has emphasized report writing. There are lots of manuals out there including one big book that is 560 pages long, as well as guidance for experts by the judicial process on writing an opinion. It seems to me that says something wrt report writing.

I was prompted to comment on this when I saw the topic for the upcoming conference in St. Andrews, New Brunswick by the Atlantic Provinces Trial Lawyers Association (APTLA). It’s comprehensive and the speakers cover a lot on preparing an expert for Discovery – I wish I was free to attend – but it seems light on the expert’s Achilles heel – his report.

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada, May 31, 2022. ejorden@eastlink.ca)   

I was sorry to learn about the Regina design engineer, Scott Gullacher, being implicated in a bridge failure in Saskatchewan in 2018. I wasn’t too surprised. CBC News reported on the failure at the time. Then again on May 13 about the engineer facing a disciplinary hearing by the Saskatchewan Professional Engineering Association.

The bridge carried a rural road over the Swan River at Clayton, 300 km east of Saskatoon. It was supported on a piled foundation – screw piles. These are good like driven piles in suitable foundation soils that are determined during a geotechnical investigation. Except in this case the piled foundation failed causing the bridge to collapse a few hours after opening. Pictures of the collapsed bridge are striking at:

https://apple.news/A7HQ38AtqQsWr2lMpAIFHkQ

Surveys have found “that most foundations failures are due to inadequate geotechnical investigation”. (See Appendix) This type of engineering investigation determines the physical properties of the ground used in designing suitable foundations for support of a structure – a bridge in this case. (Ref 1)

Based on what I’ve read, it’s another example of the pushing and pulling among the vested interests with their respective bottom lines – both government and private. The tug of war this time over a geotechnical investigation of the foundation soil conditions – should we or shouldn’t we, spend the money?

Too often in situations like this the design engineer is caught in the middle of the quandary and seen as the arbitrator in the war. S/he knows an adequate investigation should be carried out.

What’s adequate? Only the geotechnical engineer knows for sure. Was a geotechnical engineer consulted in this case? Hopefully the disciplinary hearing will report on this – if they do their job properly.

References

1. What is geotechnical engineering? Posted December 21, 2021

Appendix

Long ago I learned “that most foundation failures are due to inadequate geotechnical investigation”.  This was based on a study in England.  The source was reliable enough that I referenced it in a chapter for a publication planned by the Canadian Geotechnical Society at the time. 

The surficial geology in England is more variable than here; you can’t take a couple steps across a construction site over there without the soil conditions changing.  Still, you’ve got to be careful in Canada too as the bridge failure attests. 

(Google earth pictures of the river and bridge site might raise alarms about possible poor foundation soil conditions to anyone with a basic knowledge of terrain analysis. For example, I would suspect weak foundation soils on the bed of a meandering river)

There’s no glamour in the ground Karl Terzaghi said – the father of soil mechanics.    

I’ve also got the idea over the years that construction engineers are happy campers when they get construction out of the ground – dirt doctors don’t mind being down there.  Also that below ground construction is a disproportionately higher part of the project cost. 

I’m not surprised the design engineer ran into trouble and strife on the Saskatchewan bridge failure, regardless of who is reported as responsible at the end of the day. He was there in the thick of it.

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada, May 25, 2022. ejorden@eastlink.ca)   

I was reminded by the report in The Washington Post on Monday of the catastrophic bridge collapse in Hassanabad, Pakistan that failures large and small are predictable. (Ref. 1) And most are preventable. For sure, probably not this one but knowing it could happen goes a long way to preventing loss of life.

The cause this time was a lake flooding at the toe of a glacier and spilling out to charge the river beneath the bridge. The flooding, as easily explained by glaciologists, was due to record heat and a melting glacier – climate change. The bridge had no problems with flood waters for decades; it was the magnitude this time.

I can imagine the glaciologists raised the alarm but who listens to such esoteric scientists? For that matter, to engineers and applied scientists, in general, about problems in the built environment?

I thought about the Saint John river flood a few years ago when I read about the bridge collapse in the Post. This flood, due to snow melt raising the level of the Mactaquac Dam reservoir, was predictable and not so unlike what happened in Pakistan. The flooding was often prevented in the past by the periodic release of water from the Dam to keep the reservoir level down. But there is a trade-off between keeping the water level down to prevent flooding and up to generate electricity.

So so so many problems in the built and natural environments are predictable based on simple engineering and physic’s principles – simple physics like in high school. Problems like bridge failures, ground subsidence in Karst terrain, construction crane collapses, foundation failures, floods, slip and falls, etc. You name it, what can wrong can often be predicted.

But sadly not prevented in the short term as climate change wreaks it’s wrath waiting for the world to catch on.

References

1. Patel, Kasha, The Washington Post, Monday, May 9, 2022

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada, May 11, 2022. ejorden@eastlink.ca)