We investigate a considerable variety of accidents and engineering failures. No two are exactly alike.
Also, our work is ‘small’ and ’medium’-sized as opposed to ’big’ and newsworthy. Not like the collapse of the Elliot Lake Mall in June 2012. Nor like the landslide in Oso, Washington in March of this year. We investigate tragedies like these but fortunately infrequently.
The various failures and accidents also stretch across different engineering disciplines. For example, civil engineering and related specialities like foundation, geotechnical, and environmental engineering, and also structural, electrical, and mechanical engineering.
Similar for civil litigators and insurance personnel?
I can easily imagine that this variation is not too much different from the mostly no-two-are-alike, small and medium size cases civil litigators handle in Atlantic Canada. Also those files handled by insurance claims managers, consultants, and adjusters.
(If you are quite busy you can get a quick idea of the variety – just in the forensic civil engineering field alone - by scanning the 16 thumbnail sketches in the list below. There are links in the References to detailed descriptions of four cases)
I thought to blog on this question when I was recently asked by counsel to briefly describe some of the engineering failures and accidents that I’ve investigated. I noted 22 individual cases including a couple that were newsworthy. I was struck by the variety.
Getting an idea of the magnitude of the variation in forensic work
To get some idea of the magnitude of the variation in forensic engineering investigation you might first look at a blog I posted a few weeks ago on the different ways buildings can fail - 34 and counting. (Ref. 1) The author of the book that prompted the earlier blog missed a good number involving the structural and foundation failure of buildings.
Then think about the fact that a building is just one type of structure in the built environment that can have a problem.
Our built environment comprises hundreds of different structures. For example, bridges, dams, wharves, roads, railways, embankments, transmission towers, power stations, drainage systems, retaining walls, and all the attendant infra structure and mechanical and electrical services. All have their long list of different ways of failing.
A step ladder is a structure to an engineer. Also a pile of salt on the road, particularly if it’s a factor in a fatal motor vehicle accident.
Risk of personal injury accidents
It’s not difficult to imagine with such an elaborate and complex built environment that there is also considerable risk for different types of personal injury accidents to occur, as distinct from failures.
For example, there is an extensive literature just on slip, trip and fall accidents alone – many thousands of these types of accidents occur every year in North America, with a number of these in Atlantic Canada.
Questioning a forensic engineer
All this variation might beg the question, “How can any one forensic engineer know how to investigate so many different types of failures and accidents?” Well, if we stay within our respective disciplines and specialties – civil engineering for me - we can do it. The basic investigative principles are the same within a specialty regardless the problem. I suspect the principles are also similar across the different engineering disciplines. .
What do we investigate in Atlantic Canada?
The following categories of cases will give you some idea. The cases are selected from my files. Each category represents one to several cases. The Cases are described, in general, and the kinds of Technical issues that might need to be addressed are noted.
No two cases are exactly alike as noted above, and some are very different. The floor surfaces in the slip and fall accidents are all different. And slip and fall accidents are very different from a soil-steel bridge failure and also different from toxic fumes in buildings. And these in turn are different from inadequately underpinned buildings, collapsing retaining walls, landslides, tunnel failures, and vibrating buildings.
Most of the cases were in Atlantic Canada but two were at airports in the Bahamas. Four cases did not result in litigation but are quite illustrative of the variation in forensic engineering investigation.
Floods: Cases Frequent land flooding and drainage problems, and flooding of nearby structures. (In addition, we investigate many basement flooding problems – too numerous to mention) Technical issues Generally, determine whether or not construction on adjacent properties caused flooding and an increase in drainage on adjoining properties. And, in one case, caused a three foot deep flood in the pump room of a recreational facility with a swimming pool.
Vibrating buildings: Cases The very odd occasional case like a building that vibrates in winter – not in summer, as occupants walk from one end to another. And ceiling-wall joints open up in winter then close in summer. Technical issues Determining the cause of this odd behaviour. (Difficult to refrain from telling you that it was due to differential frost action on the foundations) (Ref. 2)
Inadequate remediation of fuel oil contaminated sites: Cases Suspected inadequate clean-up of contaminated sites at excessive cost. Technical issues Confidential interview of 11 clean-up contractors in Atlantic Canada to determine the problems with clean-up operations, the cause of the problems, and the cause and magnitude of cost over-runs.
Collapsing fuel oil tanks: Cases Occasional situations are investigated where a structure is undermined by adjacent construction work. In one case, a domestic fuel oil tank collapsed into an excavation near the foundation of the tank. Technical issues Determine the reason why the ground gave way and undermined the tank’s foundations.
Slip, trip and fall accidents resulting in injuries: Cases Slip and fall accidents in apartment buildings, recreational facilities, retail outlets, and on sidewalks. Technical issues (a) Appropriateness of the floor surfaces – the skid resistance, for the intended usage of the area. (b) Source of contaminants on floors – a factor in some slip and fall cases. (c) Maintenance of an area.
Accidents resulting in fatalities: Cases Accidents resulting in fatalities on highways, dining rooms, and airports. Technical issues (a) Whether or not a structure on a highway was a factor causing a vehicle to run off a highway and over a sea cliff. (b) Whether or not a defect in a ladder caused a worker to fall. (c) Which wing of an aircraft struck the ground first. (Ref. 3)
Bridge collapses: Cases Occasional failures involving the collapse of soil-steel bridges – corrugated culverts spanning at least 10 feet in North America, as great as 20 to 25 feet in some locations in Atlantic Canada. Technical issues The cause of the collapse. And in one case, the flood level of the stream the bridge was spanning.
Landslides: Cases Collapsing slopes – either catastrophic, a slow movement of a mass of material, or the simple sloughing of surface soil, all damaging other structures at the top, on, or at the bottom of the slope. Technical issues (a) The cause of the landslide. (b) Occasionally, design and overseeing stabilization of the slope.
Falling objects: Cases Objects falling off different structures, e.g., ice from a building injuring a pedestrian below. Technical issue Whether or not construction and maintenance of the structure was a factor in causing the object to fall. (Ref. 4)
Toxic fumes: Cases Occasional toxic odours in buildings requiring closing off of a part of a building or vacating the building completely. Technical issues Determining the source and cause of the toxic fumes.
Retaining wall collapses: Cases Frequent enough collapse or movement of retaining walls located inland or on the coast affecting the wall or property and other structures above or below. Technical issues (a) Determining the cause of the collapse, or (b) damage to property and if the damage is related to a failing retaining wall. (Ref. 5)
Swimming pool failures: Cases Occasional failure of a swimming pool, for example, by movement of the liner. Technical issues Determining the reason a liner floated away from the side of the swimming pool.
Excessive foundation settlement: Cases Frequent enough cases involving settlement of foundations damaging the structure above or affecting its performance. For example, in one case, rapid, excessive settlement of a swimming pool - many inches in a few months. And in another case, slow, excessive settlement of a processing plant – many inches in a few years. Technical issues (a) Determining the cause of the excessive settlement. (b) Occasionally design remedial work.
Inadequately underpinned buildings: Cases Frequent enough cases of buildings not being underpinned properly during construction work to fix other problems. For example, the underpinning of a house associated with remediation of a fuel oil spill. Also the underpinning of an apartment building during construction of a second multistory apartment building on adjoining property. Technical issues (a) In some cases simply determining the adequacy of the underpinning. (b) In occasional cases, designing and overseeing construction of adequate underpinning.
Tunnels: Cases Very infrequent case of a tunnel being driven off line. Technical issues Determining the cause of the misalignment (In one case I investigated, this was because a very dynamic tunnelling method was completely incompatible with the liquefiable soils the tunnel was being driven through – the saturated soils turned to ‘liquid’ when vibrated)
Airport runways: Cases A rare case where quite large holes – one to several feet across and deep, were appearing in the surface of a runway. Technical issues (a) Determining the cause of the holes – they turned out to be what are called ‘banana’ holes in the Bahamas. (b) Identifying a method to locate potential hole locations. (c) Designing remedial measures.
- How many ways can a building fail? http://www.ericjorden.com/blog/2014/07/10/how-many-ways-can-a-building-fail-and-possibly-result-in-civil-litigation-or-an-insurance-claim/
- Investigating a vibrating building http://www.ericjorden.com/blog/2013/04/25/investigating- a-vibrating-building/
- Investigating a fatal MVA http://www.ericjorden.com/blog/2013/03/06/forensic-engineering-investigation-of-a-fatal-mva/
- Falling roof ice injures man http://www.ericjorden.com/blog/2013/01/18/falling-roof-ice-injures-man/
- Gabion retaining wall collapse results in litigation http://www.ericjorden.com/blog/2013/02/09/gabion-retaining-wall-collapse-results-in-litigation/