To some extent, all I could see were technical issues when I was out west earlier this month. Technical issues like we investigate in civil litigation, forensic engineering and for insurance claims. The size of Vancouver impressed me – so much built environment, so many potential technical issues. I had similar thoughts in Edmonton a few days later and in Toronto after that.
They say in Edmonton that they have two seasons, a winter season and a construction season – building more built environment everywhere you look.
How many technical issues you might ask? I have no real idea. But the engineer in me thought 10% to 20% – a range that crops up often enough in matters to do with human nature. Technical issues can often be traced back to the people involved in design, construction and maintenance engineering.
Percent of what? How about the 1,000s of structures and their infrastructure and the 10s of 1,000s of components comprising these structures? It’s the structures and their components that fail giving rise to the technical issues that we investigate.
I was in Vancouver to attend the birthday party of a close friend, Sheilagh Simpson, a writer. I stayed with another close friend, John Hughes, also an engineer.
The mountainous scenery in the Vancouver area overwhelms, particularly on the drive to the Whistler ski resort and also to Princeton in the interior. A different and quite beautiful scenery in Edmonton – flat, treeless grazing land, and farm crops as far as the eye can see. And in Toronto? Dense urbanization – structures and infrastructure everywhere.
Being struck by the potential for technical issues is different when gazing on beautiful scenery. Not quite what you would expect. Some examples might justify my view.
1. John referred a friend to me. His friend has an environmental spill problem in Vancouver. The spill’s plume of contamination needs to be located. (Liquid contaminants sometimes flow through the ground in the shape of a bird’s feather – a plume) Hopefully the plume is still on the owner’s property and hasn’t migrated to adjacent property where it could be a technical issue.
2. I saw near-vertical rock faces cut into the hillside during construction of the new highway to Whistler. I know how these rock slopes are assessed in geotechnical engineering – to an acceptable degree of risk like in all engineering, in this case the risk of a rock slide. But a risk nevertheless, and a potential technical issue.
3. I told you earlier this year about the Groat Road bridge failure in Edmonton. (Refs 1, 2 and 3) I visited the site while there and it’s been fixed. But there are hundreds of bridges in the Edmonton area and new ones are being constructed every day.
4. Steel bridge beams can fail as we saw but so can the deep bridge abutment fills – in the sense of not performing as they should. Abutment fills are those deep layers of soil that support the road up to the bridge. They were several 10s of feet deep in the new construction I saw in Edmonton.
Layers of soil fill settle a little or a lot depending on the degree of compaction they get during construction. The soil is compacted with construction equipment to make it denser, more rigid, and less compressible. For certain, the fills are being well compacted almost all the time so there is minimal settlement at the road surface.
But still there is risk. A little less compaction than needed in one of the abutment fills resulting in settlement and deterioration of the road surface – poor performance, and we have a technical issue. Car drivers sometimes experience poor compaction and fill settlement when they hit a bump at the end of a bridge deck. Also when they drive across those little depressions in the road surface. We experience the depressions almost every day on our highways.
5. I also drew your attention last year to the many dozens of ways a building and its components can fail – collapse or perform inadequately. 209+ ways to be exact. (Ref. 4) Buildings are just one of dozens of different types of structures in the built environment. So it was okay for me to think technical issues when driving back and forth in the dense urban environment of Toronto. They are there. Some unknown, others known but accepted, and a few the technical issues in civil litigation.
With so much built environment how could the forensic engineer in me not see technical issues when I was out west? But for the most part the built environment works. The engineering design has been constructed properly, and only a small percentage will show up as technical issues in civil litigation. I’m sure much less than 10% to 20%.
- Wind, construction crane and inadequate cross-bracing caused Edmonton bridge failure: An initial hypothesis. Posted March 27, 2015
- Why, in a recent blog, didn’t I seem to consider foundation failure as a possible cause of the Edmonton bridge failure? Posted April 3, 2015
- Bridge beams that fail are sometimes like balloons filled with water – squeeze them and they pop out somewhere else. Posted May 20, 2015
- How many ways can a building fail, and possibly result in civil litigation or an insurance claim? Posted July 10, 2014