Am I a civil engineering expert?

I was asked recently, “Are you a civil engineering expert?”

I thought, civil engineering is such a broad field of study how can anyone be an expert?  But then I realized I have knowledge in the field enabling me to form an opinion that will assist the fact finder.  I have degrees and experience in civil engineering and the fact finder doesn’t.  My knowledge is greater in some areas of civil engineering and less in others, but still greater than the fact finder’s.

I was also quick to realize that I had considerable knowledge relevant to the issue being discussed at the time prompting the question of me.  Gaining that knowledge over the years provided insight into some of the sub-disciplines of civil engineering that many civil engineers might not get.

(Civil engineering is a discipline that applies physical and scientific principles to the design, construction, and maintenance of the built and natural environments.  Everything you see around you in the course of a day.  Its history goes back 1,000s of years)

Civil engineering sub-disciplines

You might still wonder if I’m a civil engineering expert when you see a list of some of the sub-disciplines of civil engineering:

  • Structural engineering
  • Foundation engineering
  • Geotechnical engineering
  • Environmental engineering
  • Coastal engineering
  • Water resources engineering
  • Forensic engineering
  • Geomatics engineering
  • Construction engineering
  • Earthquake engineering
  • Industrial engineering
  • Hydraulic engineering
  • Municipal or urban engineering
  • Transportation engineering

So many, and there’s still others.  But, look how a civil engineer can learn about different sub-disciples and be quite useful to a trier of fact:

How we learn about the sub-disciplines

I studied land surveying for two years before studying civil engineering and was licensed as a provincial land surveyor on P.E.I..  My summer work and for a year after I graduated from engineering was construction surveying for municipal water supply and sewage collection pipeline construction.  I also assisted construction surveying for 1.5 years during construction of an oil refinery.

So, some good insight gained into refinery construction, municipal work and geomatics engineering, formerly known as survey engineering.

I did highway engineering design work for a year in Vancouver.  I also got introduced to geotechnical engineering in Vancouver that included field testing of the sub-grade soils along 200 miles of highway in the Yukon.  I did foundation design and structural engineering while in Adelaide, Australia, and geotechnical engineering investigation of embankment failures in Brisbane and northern Australia.

All relatively short periods of time but real good introductions to the sub-disciplines.

I’ve not done hydraulic engineering or industrial engineering but that’s okay; you can’t do them all even if you do a lot.  (I did investigate the ground conditions for construction of hydraulic structures like dams and canals)

I eventually specialized in geotechnical engineering and did graduate work in the U.K. where I practiced for three years then continued in Canada.

Geotechnical engineers investigate and identify the different layers of soil beneath a planned construction site and test and measure the physical properties of these materials.  The soil properties are then used by engineers to design foundations that will safely support the structure planned for the site.

Geo engineers also design and monitor construction of earthwork structures like embankments, filled ground and highway cut slopes.

They must talk with owners, architects, site engineers, environmental engineers, structural engineers, foundation engineers, construction engineers – all sub-disciplines of one kind or another – to learn about the structure that must be supported on the ground.

Structures like low- and high-rise buildings, roads, bridges, dams, canals, retaining walls, towers, wharves, harbours and breakwaters, earthwork embankments and highway slopes.

Civil engineers get informed

You can just imagine as the years go by, how a civil engineer becomes quite well informed about these engineering sub-disciplines, and the different structures forming the built environment we live in.

(Hope your eyes are not glazing over yet – it really is like this in civil engineering)

Geo engineers overlap with environmental engineers

If you work in geotechnical engineering it’s not too long before you’re overlapping with environmental engineering.  Environmental engineers have a big interest in everything to do with water in the environment.

Surface water and ground water (the water table) changes the physical properties of soil and rock.  Sink holes like those in Oxford, Nova Scotia are a prime example.  Gypsum bedrock will support foundations quite nicely when dry but dissolves when exposed to ground water.

If you work in geotechnical engineering it’s also not too long before you’re doing Phase I, II and III ESAs – Environmental Site Assessments.  As a civil engineer, I’ve done a few of these over the years.  There’s a lot of overlap between the geotechnical and environmental sub-disciplines.

Sub-disciplines connect with their co-sub-disciplines

It’s the same with the other sub-disciplines and how they connect with their co-sub-disciplines:

  • Foundation engineers learn something about geo work, structural engineering and environmental engineering:
  • Highway engineers learn about geomatic engineering, and quite a lot about geotechnical engineering because highways sit on the ground;
  • Municipal engineers learn about geo engineering too because pipelines are buried in the ground;
  • Many sub-disciplines learn a little something about environmental engineering because engineering the built environment alters the natural environment
  • Structural engineers soon learn about earthquake engineering
  • Coastal engineers learn about the requirements of foundation engineers and environmental engineers

It goes on and on, the inter-relationship of the civil engineering sub-disciplines.

The principal engineer

However, it’s important for a civil engineer to know when to assume the position of principal engineer. (Ref. 1)

Principal engineers coordinate the work of other engineers and specialists to a common goal – in forensic engineering, to determining the cause of a collapse or accident in the built environment.  A principal engineer might be directing the efforts of construction engineers, structural engineers, mechanical engineers and crane operators in removing the collapsed crane from the multistory building in Halifax. (Ref. 2)

I’m not qualified to do structural and construction engineering but can develop some of the parameters enabling them to do their work, particularly soil and rock properties for foundation design.  I am qualified in earthworks design and also done a lot of materials testing and site inspection (earthworks and concrete construction).

I’m certainly qualified in knowing when to step back into the position of principal engineer, and well out of the way of those who know better.  I know when to retain one or more of the sub-disciplines because I’ve worked with them.

For example

I investigated a nail gun accident a few years ago.  It was easy for me to check if the nail gun appeared to work properly because I used one when I built my house from the ground up.

But, were hidden parts of the nail gun worn?  I’m not a mechanical engineer so I retained a specialist in nail gun repair to take it apart and tell me.

Was it poorly designed or manufactured?  I was ready to retain specialists in these fields.

First however, I decided to have the victim re-enact the nail gun accident while I took a video.  I take a lot of pictures and video in my expert work and this was easy for me to do as principal engineer.  The video of the re-enactment was insightful to say the least.

In other cases, I retained a structural engineer to guide me in underpinning a structure.  I retained a specialist in concrete design to guide me in retaining wall design.  I’ve got a call to a structural engineer now about bracing a deck structure so it won’t fall over.

Family doctors as principal investigators

The concept of principal investigator is not unique to civil engineering.  The medical profession adopts this approach all the time.

Your family physician takes a patient history, does a physical examination, may order some tests and may refer you to a specialist if s/he sees a potential problem.  He would coordinate the investigations of the other doctors and specialists into the problem.  The specialists would carry out thorough investigations and explain their findings in detail.  (Ref. 3)

It’s similar in construction when a general contractors hires carpenters, electricians, plumbers and roofers to do a job.  The general is the principal, the trades are the specialists.

***

So, what did I say?

Thinking through all of the above got me comfortably to the stage of answering the question put to me, “Are you a civil engineering expert?”.  What do you think I said?

References

  1. Lewis, Gary L., Editor, Guidelines for Forensic Engineering Practice, American Society of Civil Engineers (ASCE) Reston, Virginia 2003
  2. Why do I think the crane collapsed in Halifax?, posted September 20, 2019
  3. Personal communique with Dr. J. Nasser, Halifax, NS. September, 2019

Why do I think the crane collapsed in Halifax?

I’m not surprised the crane collapsed in Halifax during Hurricane Dorian, and an initial hypothesis of cause is easy.

The crane was set up for construction of a multistory building next to The Trillium, 1445 South Park Street.  A friend of mine happens to live in The Trillium.

In collapsing on September 7, the crane just lay down against the street side of the approximately 12 story, unfinished building.  It then went over the top and down the side facing The Trillium, the top of the crane scraping the side of The Trillium on it’s way down.

It looks like a kinked, yellow ribbon thrown over the multistory building.  I counted at least six kinks in the ribbon/crane.  It would speak well for the structural design of the multistory building if it hasn’t been damaged structurally on being whipped by the falling crane.  It seemed to resist the horizontal push of the falling crane quite well.

Google crane collapse Halifax for excellent photographs and video of the crane draped over the building.

***

Cranes are good at lifting vertical loads/weights not in resisting horizontal loads, like wind.  And if the horizontal load on the crane is a frequent gust of wind from different directions – Dorian was characterized by frequent wind gusts rather than a steady blow - then you’ve got an oscillating load, an on-again, off-again load on the crane.  Worst still.

These kinds of oscillating loads caused three, 1.5 metre deep, steel bridge girders, that were connected to a crane, to fail by bending sideways in Edmonton in 2015. (Refs 1 to 4)

The steel bridge girders were new yet they bent under an oscillating load.  The word on the street is that the Halifax crane was rusted and perhaps not so new.  Not good.

But you say, the open lattice-type construction of the crane doesn’t provide much surface for the wind to push on.  Still some, and Dorian’s wind gusts were not light weight by any stretch.  Have you seen a thin, hanging rope, steel chain or cable swinging back and forth in the wind?

Given the preliminary evidence, an initial hypothesis as to why the crane collapsed is wind load in excess of the crane’s capacity to resist.  A wind load characterized by frequent, strong gusts from different directions.

The resulting oscillation of the crane would cause metal fatigue - a well known cause of failure in engineering – and the crane to break at the location of the first kink.  The upper kinks in the yellow ribbon/crane would form as a result of hitting the stronger multistory building.

***

I examined the collapsed crane from outside the security fence near the corner of The Trillium.  I also talked with a man who was evacuated from a building near the collapse and another man at The Trillium.

Hands-on examination of the crane and more evidence is certain to result in revision of my initial hypothesis as to cause, but I know I’m close.  Regarding more evidence, it’ll be interesting to learn the condition of the crane – the rust factor you hear on the street.

***

This is what scientists do, an initial hypothesis on an issue, a simple thought, sometimes on the basis of the skimpiest evidence.  They’ve got to start somewhere.  Then, based on more evidence, they tweak, revise and modify their initial thought, and sometimes throw out the initial hypothesis completely.

Applied scientists like forensic engineers and medical doctors do this too – ask your doc next time you see him or her about differential diagnosis.

It’s important for clients of forensic engineers and experts to realize that an initial hypothesis is not the last word on cause.  It’s just a good start.

References

  1. Wind, construction crane and inadequate cross-bracing caused Edmonton bridge failure.  An initial hypothesis.  Posted March  27, 2015
  2. Why, in a recent blog, didn’t I seem to consider foundation failure as a possible cause of the Edmonton bridge collapse?  Posted April 3, 2015
  3. Bridge beams that fail are sometimes like balloons filled with water – squeeze them and they pop out somewhere else.  Posted May 20, 2015
  4. Bridge failure in litigation due to inadequate bracing – City of Edmonton.  But, inadequate for what?  Posted March 15, 2016

Basic advice to U.S. experts supports simple, approximate methods in Canada

Reasonableness jumped out at me when I read some words of advice from a US attorney to experts regarding Criteria for Admissibility of Expert Opinion Testimony Under Daubert and Its Progeny: (Ref. 1)

“Remember the three R’s:

  • Reliability, 
  • Reasonableness and
  • Repeatability.

Every step of the expert’s investigative process should pay attention to these three factors:

  • The reliability of the investigative procedures used;
  • The reasonableness of the conclusions formulated; and
  • The ability to demonstrate, through repetitive analyses, that the investigative method and resulting opinions are scientifically valid and worthy of being presented to the trier of fact. — Elliot R. Feldman, Esq., Cozen O’Connor”

(Quote altered to break up a big paragraph and make more readable)

These factors allow for simple, approximate methods of investigation if decided appropriate by a reasonable person.  Thank heaven, because not everything is clean and pretty, and exact and precise in forensic engineering investigation.  Think everything to do with the messy ground, and the structures supported there, and the natural environment in general

I defended simple, approximate investigative methods in a recent blog on the standard of care that had a reasonableness theme.  (Ref. 2)

For example, the drag sled method for determining the skid resistance of a floor – the simple coefficient of friction of the floor material in high school physics.  You drag a known weight across a floor, measure the drag, divide the one by the other and you got your coefficient of friction/skid resistance.  It can’t get more simple and scientific than that.

The method meets the criteria for the admissibility of expert evidence in the U.S. and I’m sure in Canada.  It’s reliable in giving an approximate answer based on repetitive testing that would be noted in the conclusions. Approximate investigative methods are reasonable in some situations, and scientifically valid.

As an experienced civil engineer, I like reasonable considering the failures and accidents we must investigate in the sometimes messy built and natural environments.  Explaining these investigations to non-technical people and the trier of fact is often the demanding part.

References

  1. As reported in Expert Communications, Dallas, Texas, August, 2019 (A consulting firm that provides marketing services to experts in the US)
  2. Is there a case for a multi standard of care? No.  Posted June 27, 2019

Why do I blog? One reason: A blog is sometimes like a mini expert report in story form

OVERVIEW

I’ve blogged for seven years now, two or three times a month to tell you about a field of engineering that I enjoy and that contributes to dispute resolution and claim settlement - a nice way to practice.

I want parties to a dispute or claim to know something about the nature and methods of forensic engineering investigation and about managing costs when you retain an expert.

You think-on-paper when you blog and that’s good practice when you must synthesize and analyse engineering evidence, draw conclusions and form an opinion.  Blogs are essays on a topic, sometimes technical, and not unlike mini expert reports in story form.  .

I also blog because I like that creative feeling when you write – producing a piece of literature that didn’t exist before.  There’s 200 of my blogs/essays/mini expert reports out there now varying from a few 100 words to several 1,000.

The following nine (9) reasons and comments elaborate on why I blog.  There’s a summary and references at the end if you’re quite busy and haven’t got a lot of time.  Reference 10 is a good read about managing cost.

The REASONS

REASON 1

I want parties involved in dispute resolution or insurance claim settlement to know something about the nature and methods of forensic engineering investigation – what you get when you retain an expert.  Not how to do the work, just to have some idea of what we do to help you solve your problem.

Comment: For example, the surprising value of one of the newer investigative methods like a low flying drone fitted with a GoPro camera taking video at the scene of a failure or accident in the built environment.  Older methods like terrain analysis – identifying features on the ground from the air and how they relate to your problem, but doing this much more reliably from a few 100 feet high rather than several 1,000 like in the past.  And simple methods like simple, high school math.

An aerial photograph taken from a low flying drone was key to assessing the pattern of drainage at a contaminated site and where the fuel oil went.  I was surprised at what I saw.  Aerial video of another site is helping me assess if the site is contaminated decades after a spill.  And still another, the geometric design and safety of a site.

Simple high school math was key to learning the disputed height of a feature in the landscape.

Smart phone video of the reenactment of a power tool accident showed how the accident likely happened.

I want to describe how we carry out reliable investigations, observe, test, study, synthesize, analyse, think-on-paper, draw conclusions and formulate objective opinions.  Then present reliable evidence to the parties involved in a dispute or claim, and to the court or tribunal, in simple, non-technical English.

Forensic civil engineering is not high tech but it does require reliable work and good expert report writing.

Why is Reason #1 a particularly good reason?  It’s because parties to a dispute have obligations with respect to the expert’s report or affidavit. (Ref. 1)

For example, parties in a litigious matter must learn about the technical subject to which the evidence relates in order to identify the relevant technical issues.  He or she has an important duty in the presentation of technical evidence to ensure it’s properly understood by the court or tribunal. (Ref. 1)

As well, parties to dispute resolution and claim settlement have an obligation to monitor  cost in view of the often small to medium size-sized disagreements in the Atlantic provinces – and their sometimes less than affluent nature.  This is because the extent and cost of an all-stages forensic investigation is often similar regardless of whether the engineering failure or personal injury is small, medium-sized, catastrophic or terrible.

It’s difficult for parties to a dispute or loss to carry out their obligations, and also monitor costs, without some understanding of how experts work.

REASON 2

I also want to help readers understand why a forensic engineering investigation can be expensive.

Comment: The expense has everything to do with carrying out a reliable investigation and rendering a well reasoned opinion, as expected of the expert.  At the very least, following routine investigative procedures in an effort to ensure that no stone is left unturned. (Ref. 3)

We don’t know when we start what we’re going to find that we must investigate – the surprise, follow-the-evidence situations.  Every failure and accident is different. (Refs 4, 5 and 6)  Not enough time and money is no excuse if we miss something.

Parties to a dispute or loss can assist, with some understanding of forensic work, by identifying and selecting the relevant technical issues early with the assistance of the expert.  This can be a big cost cutter.

REASON 3

To help parties to a dispute understand the importance of retaining an expert early in all matters, the different ways an expert can be retained and the importance of monitoring costs – starting when the merits of a potential issue are being assessed. (Refs 7, 8)

Comment: At present, experts are too often retained months or years after a case is taken and after the cost of the forensic investigation has been estimated by other than the expert.  This is contrary to the advice of some of the most senior members of the legal profession. (Ref. 9)

For example, I was retained by counsel 11 years after a personal injury.  I visually examined the site and reported on what could have been done to prevent the accident.  The case settled four (4) months later.  To give counsel credit, he instructed me on the relevant technical issues which reduced the cost in this case.  This type of instruction doesn’t happen very often.

REASON 4

To help the justice system understand what they should be getting for the money spent on forensic investigation: That is, reliable investigations, well thought out expert opinions, and well written reports.

Comment: Rules governing experts have placed greater emphasis on the investigation and the expert’s report, to encourage the settlement of cases without going to discovery and trial.

There are excellent guidelines on forensic investigation and also on writing an expert’s report.  And excellent books, in general, on writing well.  I’m not sure these are being consulted to the extent they should.  I recently saw poorly written reports by a forensic firm claiming to have 18 different experts on staff.

REASON 5

I want to understand the forensic engineering field better myself, to learn by writing the blogs and thinking-on-paper – particularly, on how addressing the technical issues supports the resolution of disputes.

Comment: Like all of us, I’m learning all the time.  Most recently about the value of low cost, initial hypotheses on the cause of problems based on very limited data.  This task could save counsel money – as long as it’s remembered they are initial hypotheses.

For example, I hypothesized with considerable confidence on the cause of a catastrophic bridge failure during construction (Edmonton) - based on study of photographs in a newspaper.  In another, the cause of the sloping, sagging floors in a multi-story building (Halifax) - based on a visual examination of the floors and knowing how these types of buildings are constructed.

Cases are also being settled today based on simple verbal reports after the technical issues are addressed.  In some cases not even a verbal report because counsel is on site and sees the results of the expert’s investigation unfold before his eyes.

REASON 6

I want to increase my understanding of the dispute resolution and claim settlement processes.

Comment: Experts have a duty to acquire some understanding of these processes.  The justice system expects this in civil litigation, for example.

I researched and posted 10 blogs on the role of a professional engineer in the civil litigation process for the benefit of counsel and their clients. (Ref. 8) I learned a lot during this research.  I was assisted by senior counsel in preparing drafts of two of these blogs.

It’s also been an eye-opener to learn of the dichotomy between the party’s right to justice and the expense of getting it.  Associated is the conflicting interests of the different parties to the process.

For example, the court, while encouraging counsel to expedite cases and control costs, wants good evidence and a reliable opinion – which takes time and money.  The expert needs to do thorough investigative work to get this evidence.  He expects to get paid according to his schedule of fees, his level of expertise and the responsibility he bears.  If the party has retained the expert on a fee basis, he doesn’t want to spend any more than necessary.  If counsel has taken the case on a contingency basis and retained the expert, he wants to protect the worth of the file to his firm.  Quite a mix of interests.

REASON 7

Because of a sense of obligation to my readers who have seen the blog for seven years now and perhaps have come to expect it – to fill a void that was there.

Comment: Feed back suggests you do get something from my descriptions of the nature and methods of forensic engineering, and my comments on related matters.

A senior lawyer in Atlantic Canada said, “I love that stuff..!!”.  Another senior legal chap on the east coast commented, “…like reading them.”  And an insurance claim consultant said, “I read every one”.  It’s hard to beat testimonials like that.

I mentioned above that two senior counsel helped me with two of the blogs on the role of professional engineers in the civil litigation process – critiqued the blogs before their posting.  One of these noted that experts are invaluable to civil litigation.

A fellow who blogs on business ethics, Dr. Chris MacDonald, Toronto, and has an international reputation in his field – Chris is on a list of 100 influential business people that includes Barack Obama - saw fit to advise his twitter followers of my blog.

A monthly periodical on engineering construction – with an international distribution of 10,000, sought permission to publish one of my blogs.  The issue had a forensic engineering theme.  They came back a couple of weeks later requesting permission to publish two additional blogs in the same issue.

In seven years, only about 10 readers asked to be removed from my distribution list.  This was because they were retired or the subject did not relate to their field of practice.

Overall, quite a good reception suggesting there was a void, I’m filling it and making a contribution to the dispute resolution and insurance claim settlement processes.

REASON 8

“It’s my soap box”, one colleague said.

Comment: There’s some truth in that particularly when I see inadequate forensic investigations, poorly written expert reports and questionable practices.  I vent but you don’t know it because it’s well disguised.  It feels good afterwards, and there’s almost always a lesson in my remarks.

REASON 9

For that satisfied feeling that comes from creating something – a piece of literature that did not exist before

Comment: A few months after I started blogging in June, 2012, I noticed a feeling of satisfaction after posting an item, a mild elation.  It was subtle but there.  On reflection, I realized I felt good because I had created something – a piece of literature that didn’t exist until I put pen to paper.  So, I blog for that satisfied, creative feeling.  You all know how elusive that feeling is in our busy work/social, balanced-challenged lives.

On further reflection, I realized the feeling was also about finally publishing information on a topic or technical issue useful to my readers – finally letting it go.  I like my blogs to be as clear and well written as possible - in a sense, like well written, mini expert reports.

SUMMARY

In summary, the reasons and comments on why i blog might look like this:

  1. To give you an idea of forensic engineering methods that help resolve disputes and settle claims
  2. Help you learn why forensic engineering is sometimes expensive
  3. Explain the importance of retaining an expert early and ways this can be done cost effectively
  4. To understand better myself how addressing technical issues resolves disputes and claims
  5. Increase my understanding of the forensic engineering field and how it  contributes to the resolution of disputes and the settlement of claims
  6. An obligation to my readers who enjoy the short essays on topics of mutual interest
  7. My soap box for venting on practices in our respective fields that are not good
  8. I like to write, to create something that didn’t exist until I put pen-to-paper
  9. For that satisfied feeling on creating a piece of literature that didn’t exist before

REFERENCES

  1. The Advocates` Society, Toronto, Ontario, Principles governing communicating with testifying experts June, 2014
  2. Peer review costs can be controlled.  Posted January 22, 2016
  3. Steps in the forensic engineering investigative process with an appendix on cost.  Posted July 15, 2013
  4. What do forensic engineers investigate in Atlantic Canada.  Posted October 9, 2014
  5. Forensic engineering practice in Eastern Canada.  Posted May 7, 2015
  6. How many ways can a building fail and possibly result in civil litigation or an insurance claim?  Posted July 10, 2014
  7. The role of a professional engineer in counsel’s decision to take a case.  Posted June 26, 2012
  8. A bundle of blogs: A civil litigation resource list on how to use forensic engineering experts.  Posted November 20, 2013
  9. Stockwood, Q.C., David, Civil Litigation: A Practical Handbook, 5th ed., 2004, Thomson Carlswell
  10. Principles governing the cost control of dispute resolution and claim settlement involving experts.  Posted July 30, 2019

 

The drones will get the alleged killers, if they’re there

I can’t help thinking that low level, aerial photography from drones then simple terrain analysis of what is captured in the video will find the alleged killers in northern Manitoba.  Even if they’re dead, as I can hardly imagine them otherwise in terrain like that.

I’ve worked in that kind of terrain here and overseas and it’s unforgiving.  Load heat-sensing gear on the drones and it’s a no-brainer finding them if the photography is  flown properly.

Terrain analysis involves identifying features on the ground and considering how they relate to your interests.

Aerial photography using drones and terrain analysis is well developed in civil engineering.  I know the police forces have picked up on the technology and learned well and are using it to good advantage in Manitoba.

I’ve used drone video on several forensic investigations including two kilometre-long sites, one covered by forest.  You can pick out a tennis ball with a drone flying at tree top level in that terrain – a few 10s of feet up.  A white face or hand would show quite nicely against the green forest floor.  I can imagine a pattern of foot prints across muskeg would show nicely too.

You can fly a drone across a couple of kilometres of terrain in minutes, study the video, analyse the terrain, stop and start the video every few seconds, take frame grabs, take out a magnifying glass and look closer still, etc., etc.

I flew the forested area in a recent case with people on the ground and got reams of data and evidence – not unlike what is possible in Manitoba and likely what is being done right now.

In a hunt like this, you track back and forth on a grid over the area of interest taking aerial photography as you go.  You can cover hundreds of kilometres of terrain with drone-mounted video cameras in the few days the searchers have been there.

I can’t help but think, if the alleged killers are still there, dead or alive, they would be found.  I don’t think they are else they would have been found by now with the aerial surveillance.  It may be time to move on to another hot-tip search area..

 

Principles governing the cost control of dispute resolution and claim settlement involving experts

OVERVIEW

The total cost of dispute resolution or claim settlement includes the cost of an expert’s services.  Incorporating these costs into a party’s total costs is essential to good management.  It helps to have some understanding of the nature and methods of expert investigation and how these costs develop - to know something about the services you’re buying.

Principles are needed to guide a party managing these costs.  I concluded this after noticing that experts were sometimes retained months after a dispute arose or a claim made, occasionally years after. 

I also noticed that an investigation was sometimes stopped when the cost of the expert’s services exceeded the budget set by the party involved – a budget with a technical component set by a non-technical person.  I couldn’t help but wonder if the dispute resolution or claim settlement was sometimes compromised as a result.

I identified the following seven (7) principles to help the parties to a dispute or claim manage their costs. There is a comment on each.  I say identified  because the principles have always existed but sometimes overlooked.

PRINCIPLES 1, 2 and 3 are fundamental.to cost management.  You can’t go wrong if you follow these three.

(There are also good reads in the References as cited in the Comments)

I think of a party as one or more of the following:

  1. Counsel, advocates
  2. Insurers
  3. Insurance claim managers and consultants
  4. Insurance claim adjusters
  5. Property owners
  6. Architects, engineers and builders
  7. Victims of accidents in the built environment
  8. Injured parties in general, for whatever reason

***

For a long time in the Atlantic provinces, expert witnesses have played an important role in civil litigation, dispute resolution and claim settlement processes.  You don’t hear about the majority of these because they involve small or medium-sized loses, failures and accidents in the built environment.  They’re not catastrophic and newsworthy.  Many are also less affluent. (Ref. 1)  But, affluent or not, they all require an expert to be thorough and reliable even when investigating just one, small technical issue.

It’s difficult to be thorough when you’re retained late in the process and impossible when your work is stopped mid-investigation.

A timely and reliable estimate of an expert’s costs, based on the forensic work he must do, is essential to good management – with informed input from the expert.  This is the case in civil litigation, for example, regardless of whether the file is taken on a fee or a contingency basis.

How serious is the omission?  Less than good management results when the expert’s invoices start to come in threatening the budget that the expert had no part in setting, and the expert’s services are suddenly stopped.

For example, I’m certain in one claim involving the disputed height of a feature in the landscape, to the detriment of any damages entitled the injured party.  A height disputed back and forth and up and down by three opposing parties with no good evidence, yet a height easily got by an expert with simple, high school math.  And in another involving a slip and fall accident that forced the injured party to change firms.  And in still another when a case settled four months after an expert was retained – 11 years after the case was taken.

Somewhat related, a confidential survey of remediation contractors for the National Research Council found that contaminated site remediation was costing more than it should, in many cases much more, for want of an expert. (Ref. 2)

It doesn’t have to be like this.  There’s enough guidance out there now to help a claim consultant or adjuster manage a claim or counsel manage the cost of civil litigation involving experts. (Ref. 3)  Guidance that allows the expert to do his work properly and serve the dispute resolution process well.

This can be done while ensuring, as required by common law, that experts: (Ref. 4):

  1. Be independent from the parties who retain them;
  2. Provide objective, unbiased opinion evidence in relation only to matters within their expertise; and
  3. Avoid assuming the role of advocates for the parties that retain them.

These requirements of experts are similar in all issues involving dispute resolution and claim settlement.

I realized that while there’s guidance in the literature, it needs to see the light of day.

I knew about the Principles Governing Communications With Testifying Experts. (Ref. 1) I identified the following Principles Governing the Cost Control of Dispute Resolution and Claim Settlement Involving Experts (the “Principles”) patterned on this document.  My Principles are intended to provide guidance in a similar way.

How did I identify The Principles?  For certain i was guided by the Principles Governing Communications with Testifying Experts.  But I also had insight from practicing forensic civil engineering in the Atlantic provinces since the late 1980s and blogging on the nature and methods of forensic engineering since 2012 – including about 18 blogs on the cost of civil litigation involving experts. (Ref. 5)

Prior to my forensic work, I practiced civil engineering, specializing in geotechnical and foundation work, and often enough also site environmental assessment and remediation.  I worked in eastern, western and northern Canada, off-shore Nova Scotia, and in the Caribbean, the U.K. and Australia.

Prior to engineering, I studied land surveying and practiced on Prince Edward  Island.

In addition, drafts of the Principles were read by colleagues in engineering and friends in law.  All offered good comments.  Those by a lawyer and a town planner were particularly helpful.  I’ll update the Principles based on additional comments by readers.

The Principles are not intended to address the cost of all disputes and claims but to provide some guidance on managing those involving experts. The Principles focus on:

  1. Early retention of an expert,
  2. Frequent conferring with the expert
  3. The estimated scope of an expert’s services and costs
  4. The experts’s greater qualification for assessing technical costs
  5. Incorporating the expert’s costs into the resolution process early.
  6. Frequent updating of cost as evidence comes in
  7. The shock of the financial realities in dispute resolution

As with the Principles Governing Communications with Testifying Experts, the hope is that by adhering to the following Principles, parties to a dispute or claim will fulfill their duties to their clients and customers at a well managed cost without compromising the work of experts.

The PRINCIPLES

PRINCIPLE 1

A party should consult early with an expert about the cost of investigating a dispute, an insurance claim, a failure in the built environment or an accident.  In the case of civil litigation, preferably before the case is taken during the merit-assessment stage.

Comment

The emphasis in Principle 1 is on “consult early”.  This can’t be emphasized too much.  Too many cases are taken and disputes go forward only to find months or years after the fact – when an expert is finally consulted – that more investigation is needed than there is budget.

Managing the cost of an issue starts with an initial cost estimate, and the technical component of the cost can only be estimated by an expert.  Expert consultation at an early stage costs money but very little compared to the cost of a technically weak dispute or insurance claim found out too late.

Properly managing cost starts by identifying the different expenses contributing to the cost.  When one of the expenses is a personal service like an expert, engaging with the expert early is good management.

PRINCIPLE 2

A party should recognize that the expert is the person best qualified to estimate the cost of his or her services based on their assessment of the scope of an investigation.

Comment

The cost of an expert’s services can only be estimated by the expert and only after he or she has estimated the scope of their work by doing such things as:

  1. Taken a briefing by the party on the matter,
  2. Reviewed available documentation,
  3. Visually examined the site,
  4. Identified the technical issues in the matter.

Emphasis must be placed on estimated because not even the expert knows where his investigation will lead if he follows the evidence.

It helps if a party confers with the expert and gains some understanding of the investigative process and how cost develops.  This in a manner similar to how an expert is expected to have an understanding of the judicial process in a civil litigation matter.

PRINCIPLE 3 

A party should confer often with the expert during the investigation and get frequent cost-to-date and estimated cost-to-complete at key stages during the forensic investigation.  Add these to the cost-to-date and cost-to-complete the entire process to get up-to-date total costs.  

Comment

This is a key and ongoing task in the cost control of civil litigation, for example, and in dispute and claim resolution in general.

Conform to this principle and you’ve got hard data for controlling your costs.

The scope of an investigation may change and be greater or less than initially assessed.  The importance of some conventional tasks may fade while unexpected follow-up tasks may need to be considered – as in follow-the-evidence.

Care must be taken with undue focus on a budget.  There’s no question one needs to be set but it must not be perceived as a fixed price for which an expert agrees to do all that is necessary.

In civil litigation, for example, counsel and expert must each have some understanding of the other’s role to make it work.  Key stages in both the legal process and the forensic process are well known.

Also well known in the well developed field of project management is that cost-to-complete a project is very approximate at the beginning, gets better as a project goes to completion and is quite accurate towards the end.  This applies to all dispute and claim resolution involving experts.

It doesn’t help, of course, that we have situations where estimating the cost to investigate a catastrophic failure or a terrible accident is not always difficult, nor estimating the cost to investigate a simple failure always easy.  (Ref. 6)

It helps to learn why it’s difficult for an expert to identify and estimate the cost of all the various tasks in a forensic investigation.  It varies from easy to difficult, to very difficult, to impossible. (Ref. 7)

It’s important for a party to have a plan for managing the cost of investigating the technical issues.  For “taking the measure” of the dispute resolution or claim settlement and expert costs at key stages in the process.  This in the spirit of, “If you can measure it you can manage it” that’s cast-in-stone in engineering. (Ref. 8)  Such a plan is reflected in Principle 3. 

PRINCIPLE 4 

A party to a dispute involving experts must recognize that he is managing a potentially expensive process.

Comment

Remember in civil litigation, for example, that “…most clients are unfamiliar with the technical and procedural aspects of litigation.  They are also unfamiliar, and shocked, by the financial realities”. (Ref. 4)

“It’s necessary to fully explain the “facts of life” at an early stage using a delicate touch so that the client does not become completely discouraged from enforcing his rights.” (Ref. 4)

I believe David Stockwell’s comment speaks in part to the fact that the cost of civil litigation, and all dispute and claim resolution, including that involving experts, can be controlled but only to a limited extent – part of the financial realities.

“A lawyer just doesn’t walk into court – a lot of preparation is necessary beforehand”.  (Ref. 9)  Similarly, an expert just doesn’t write a report and render an opinion – a lot of investigation is sometimes necessary beforehand.  Some cases don’t go forward  properly until the expert’s work is done, and some don’t go forward at all.

PRINCIPLE 5 

Counsel can manage costs better by retaining an expert according to the needs of the case, basically as a consulting expert or a testifying expert.

Comment

Rules governing experts are resulting in more out-of-court resolution of disputes.  As a result experts will be increasingly retained as consulting experts.  There are different ways this can be done with different costs. (Ref. 10)

There’s a big difference in expert costs between a case where you retain an expert to simply peer review the work of another and report verbally.  To one where an expert does a detailed forensic investigation, collects and analyses data, draws conclusions, formulates an opinion and writes and submits a report compliant with the Rules.

There are differences between the cost of a verbal report and a written report at any stage of an investigative.  There are also differences between a factual report when the expert gives the data only, and an interpretative report when the expert analyses the data and gives the analysis as well.

The “hot tub” method of resolving differences between expert’s findings and opinions is another cost effective way of working with consulting experts. (Ref.11)  Experts for the different parties in a dispute or claim meet with their different reports, discuss these and agree a single report on the matter.

PRINCIPLE 6 

A party should confer with the expert to understand the technical issues and help identify the key one(s) that must be investigated.

Comment

Start this process – it could be ongoing as investigative data comes in and the technical issues change - as soon as the expert has been briefed on the dispute and had a chance to assess an initial scope of investigation.  There will be good control of an expert’s costs if only one or two technical issues must be investigated compared to several.

In the case of civil litigation, cost is well managed when an expert has some understanding of the judicial process and counsel is similarly informed about the forensic investigative process, and they talk often about the relevant technical issues.  This understanding serves all the Principles well.

PRINCIPLE 7

Beware the tyranny of the bottom line – the effect of undue focus on the worth of the file to the firm on the thoroughness, reliability and objectivity of an expert’s work and also on any damages due the injured party. (Ref. 12)

Comment

A firm must make money else there won’t be someone there to represent the interests of the injured party.  But care must be taken that a balance is struck that is consistent with good practice and the appropriate interests of the injured party.

References

  1. The Advocates Society, Principles Governing Communications With Testifying Experts, Ontario June 2014
  2. Jorden, Eric E., How to Reduce Oil Spill Damage Claims; Early Study Results, Atlantic Claims Journal, The Official Journal of the Insurance Claims Association of Nova Scotia, November 12, Winter 2002
  3. Kerzner, PhD, Harold, Project Management; a Systems Approach to Planning, Scheduling and Controlling, 8th ed, 2003, John Wiley and Sons, Inc., Hoboken, New Jersey
  4. Stockwood, Q.C., David, Civil Litigation, A Practical Handbook, 5th ed, 2004, Thompson Carswell
  5. A Bundle of Blogs: How to Manage the Cost of Civil Litigation Involving Experts.  Posted August 31, 2017
  6. (Fairly easy) estimating the investigative cost of a catastrophic engineering failure. Posted August 13, 2013
  7. Difficulty estimating the cost of forensic engineering investigation.  Posted July 23, 2013
  8. “If you measure it you can manage it” – and do thorough forensic engineering, and cost effective civil litigation.  Posted June 18, 2015
  9. “A rose by any other name …”, Primers for lawyers.  Posted December 19, 2016 (Note comment by Ron Rizzo, Pink Larkin, Lawyers, Halifax)
  10. How to retain an expert in a cost effective way.  Posted November  30, 2018
  11. “Hot tubing” experts reduce the cost of civil litigation and ensure objectivity.  Posted March 31, 2018
  12. Professional ethics and the tyranny of the bottom line.  Posted October 11, 2012

 

Is there a case for a multi standard of care? No.

I thought there was a case for a multi standard of care, one that varied according to the stage of a forensic investigation.  But that’s not so.  However, there is a risk some people don’t understand this, or aren’t interested..

The standard of care in a nutshell is “…the degree of care a reasonable person should exercise”. (Refs 1, 2)

A reasonable engineer would do only what is appropriate to the stage of a forensic investigation which includes exercising common sense.  Others might do something different depending on their vested interests.

For example, a reasonable person might do a simple, approximate test of a material property in the early stage of an investigation, using readily available, inexpensive equipment .  Then later, if needed, after some results are in, a more accurate test with more expensive equipment.  The standard remains the same: – What a reasonable engineer would do at each stage.  What changes in this example is the test accuracy required and the test equipment used.

In general, this process is the scientific method.  It also reflects differential diagnosing in medicine.

It goes without saying that what is needed in an application of the standard of care is for the reasonable person to be suitably qualified and unbiased.

***

These thoughts were prompted by slip and fall accidents that I’ve investigated over the years, and the inevitable rebuttal of my reports on the accidents.

A fairly typical investigation of a slip and fall accident proceeds as follows:

I visit the scene three times.  The first visit to reconnoiter and visually examine the scene, walk around and “kick the tires” so to speak.  The second visit to have the victim re-enact the accident.  Also to simply slide the shoe the accident victim was wearing at the time across the floor and get some idea of how slippery it was.  The third visit to carry out manual drag sled tests to measure the skid resistance of the floor.  Drag sled testing is simple and inexpensive, exactly what a reasonable engineer would do at the start.

(You drag – pull – a known weight across the floor, measure the pull, divide the one by the other and get the skid resistance – the coefficient of friction like in high school physics)

In one case the victim was bare foot so I got a piece of pig’s belly, which is very similar to human skin, and pulled that across the floor – again, exactly what a reasonable engineer would do.  Pretty hard to drag a person’s bare foot across a floor.

When the tested skid resistance during a third visit is close to the lowest value possible for a material and well below that required for the floor and it’s foot traffic, I stop testing.  The skid resistant might be higher using a more precise and expensive test than drag sled testing but not at all high enough to classify the floor as safe.

How do i know?  The more expensive, precise test machine basically removes human error and bias from the testing.  The cheaper, less accurate drag sled testing removes a lot when we carry out a lot of tests.

The police do 10 tests with a drag sled when testing the skid resistance of a road at the scene of an accident.  I do 10 tests at each drag sled test location on a floor.  I also test several locations on a floor and test in different directions at each location, 10 times at each location and in each direction.

The rebuttal of my reports often reflects some knowledge of skid testing but the phraseology sometimes reflects bias in favour of the client too.  It’s also possible the writers have knowledge of the concept of the standard of care.  Unfortunately, the biased phraseology might call that knowledge into question.

***

There are several stages in all forensic investigation, from the simple to the complex.  Assessing cause also goes from the simple to the complex.  From a simple, initial walk over and visual examination of the exposed surfaces of a site to detailed intrusive examinations, measuring, testing – including full scale tests – and re-enactments of accidents.  For example, from estimating distance by pacing it off, to measuring distance with a tape, to using electronic measuring devices.

Forensic investigations stop at different stages too.  For example, after a simple walk over survey.  They can also stop after an investigator has done only simple testing.  Also after the extra cost of more accurate testing is not justified by the slight refinement in the test results.

Through it all the standard of care remains the same, “…the degree of care a reasonable forensic engineer should exercise”.  It doesn’t vary according to the stage of an investigation, the methods used or the cost.  Not at all.  There’s only one standard, not many,

References

  1. Garner, Bryan A., Ed., Black’s Law Dictionary 4th edition 1996
  2. How the standard of care is determined when a failure or an accident occurs in the built environment Posted June 28, 2014.  Updated October 2017

Bibliography

  1. Nicastro, P.E. David E., ed., Failure Mechanisms in Building Construction, American Society of Civil Engineers (ASCE) 1997
  2. Black’s Law Dictionary, 4th pocket edition 2011
  3. Kardon, J. B. 2000, 2010 Chapter 7, Standard of Care in Forensic Structural Engineering Handbook, R. T. Ratay, Editor-in-Chief, McGraw-Hill, New York.
  4. Thompson, D. E. and Ashcraft, H. W. 2000, 2010 Chapter 9 Page 9.17 in Forensic Structural Engineering Handbook R. T.  Ratay, Editor-in-Chief, McGraw-Hill, New York.
  5. Association of Soil and Foundation Engineers (ASFE) 1985 Expert: A Guide to Forensic Engineering and Service as an Expert Witness
  6. Mangraviti, Jr., James J., Babitsky, Steven, and Donovan, Nadine Nasser, How to Write an Expert Witness Report, SEAK, Inc., Falmouth, MA 2014
  7. Kardon, Joshua B., Editor, 2012 Chapter 3, The Standard of Care in American Society of Civil Engineers, Reston, Virginia
  8. Tronto, J. C. (1993), Moral Boundaries: A Political Argument for an Ethic of Care, Routeledge, New York.
  9. Kardon, J. B. (2005), The Concept of “Care” in Engineering.  American Society of Civil Engineers, Journal of Performance of Constructed Facilities, Vol. 19, No. 3, pp. 256-260.

 

 

 

How is death investigation like forensic engineering investigation?

I was struck by a death investigator’s remark because it seemed to echo our care in forensic work to avoid any perception of bias.  I wondered, does a medical examiner need to be on guard investigating death?  Like, is there sometimes pressure to lean one way or the other in their findings?

Now, a few days later, I’m thinking the death investigator was referring to the pressure to work fast.

I was touring the medical examiner services facility in Halifax and also took in a talk by Dr. Eveline Gallant, one of the examiners.  This is where medical examiners do autopsies to determine the cause and manner of death after examining a body at the scene.

Examiners can do four autopsies at a time at this facility, one of the best in the country, I understand.  The facility also has a restful place for the examiners considering the work they do and the way they get their hands dirty and blood on their boots.  They also have a comfortable room for the family of the dead.

The fact there must be a capability to do four autopsies at the same time makes me think there’s a time-pressure on an examiner.

My tour was in connection with work I do for the Halifax Regional Police Victim Services unit.  I was one of a number on the tour that included RCMP officers as well.

Dr. Gallant’s power point was excellent.  Good graphics and good fill-in comment by Eveline.  At one point I was struck by something she said to the effect, “We answer to no one when investigating death”, prompting this short blog. The thorough pursuit of the cause and manner of death is what it’s all about.  I’m thinking now she and her colleagues push back against the pressure of time.

(I did a tiny bit of push-back myself recently in a case I’ve got providing expert services in a dispute involving a structure and a looming court date, and my well informed client understood when I explained)   .

I thought, how Dr. Gallant’s understanding of the way it must be in her work was like the charge to an expert to serve the court thoroughly and objectively.

Another comment by Dr. Gallant resonated with me, “100% certainty is not necessary in death determination.”  That is also true in forensic work.  We often deal with messy nature and the answers are less than 100% certain.  .

Also, I noted how the many specialists a medical examiner like Eveline must rely on at times echos the many a forensic engineer must call on.  The two of us in our respective fields know quite a lot, including not forgetting we are principal investigators who call on other specialists when required – we don’t know everything.

I think death investigators and forensic engineers also know – while mindful of the time constraints on our associates and clients – that investigations can’t be hurried.

***

Death investigation is a lot like forensic investigation as I learned during Dr. Gallant’s remarks and her guided tour, right down to being careful of perceived bias.  Actually, right down to the fact we’re both investigating a problem with a structure in the built environment – the one, a body structure and the other, for example, a building structure.

Bibliography

  1. Gallant, Eveline, MD, Lecture and Tour: Death Investigation at the Medical Examiner’s Facility, Halifax 2019
  2. Siegel, Jay A., Forensic Science, the Basics, 2nd ed., Chap. 10, Forensic Pathology, CRC Press, Boca Raton, Florida 2010
  3. Cooper, Chris, Eye Witness Forensic Science, DK Publishing, New York 2008

 

 

 

Categorizing slip, trip and fall accident locations

There’s more to slip, trip and fall accidents than the skid resistance of flooring and the tread of the footwear.  The cause of an accident also varies with the location of the accident and these can be categorized. (Refs 1, 2)  When an expert is asked about cause at the case- or insurance-claim assessment stage, he wants to know about accident location.  The category tells him a lot

He thinks differently according to the category.  This is the same as him thinking differently according to the type of structure, component or material that fails in the built environment, as posted in earlier blogs. (Ref. 3)

You mention location in your briefing on the accident and the expert goes through the same process in forming an initial hypothesis on cause – an initial oral report – as for a structure that fails.  He considers::

  • Your briefing - The location, category, technical issues and facts in your description of the accident
  • His experience – What he’s learned investigating slip, trip and fall accidents
  • Published material – The helpful information out there – a lot – on the different categories of accident location

There are many categories. (Refs 1, 2):

  1. Level walkway surface
  2. Level walkway surface and water
  3. Floor mats - For example, mats can move as I found in one case
  4. Changes in level
  5. Lawns - Example, wet grassy slopes
  6. Ice and snow - Including black ice on a sloping asphalt driveway that I slipped and fell hard on last winter.  Also skating ice that I fell on a couple years ago but I was wearing my ski helmet and only hurt my pride
  7. Ladders - Reaching too far when on the upper rungs of a ladder and falling which happened to me a few years ago
  8. Porches and balconies
  9. Roads and sidewalks
  10. Parking areas
  11. Trucks - Getting in and out of trucks and also hurting yourself when securing load
  12. Work place and construction sites
  13. Residences (single and multi-family)
  14. Play grounds and recreational facilities
  15. Swimming pool decks and locker and shower rooms - Note how many have “Caution: slippery-when-wet signs”, and skid-resisting mats on dry sauna floors
  16. Saunas - Floors can get wet from water bottles and dripping bathing suits
  17. Ramps - I was very conscious recently of a very slight ramping-up to the entrance of a car show room.  It was subtle but there – and it was wet. 
  18. Bathrooms - Examples: walk in showers and tubs
  19. Kitchens
  20. Stairs
  21. Handrails and guardrails - Examples: rail graspability also rails that are too far apart on wide stairs
  22. Elevators - For example, when they don’t stop exactly at floor level
  23. Escalators

You might be interested in knowing that falls in the work place are the number one preventable loss type.  And in public places, falls are far and away the leading cause of injury. (Ref. 1)  There are lots of work places and lots of public places as can be seen in the above list.

I haven’t seen them but I’m certain percentages have been worked out for the occurrence of accidents at each of the above locations.  Also, on looking closer at each location, I’m certain percentages have been worked out for the following different elements in a slip, trip or fall accident at each location: (Ref. 4):

  1. Surface covering
  2. Lubricant
  3. Shoe (slider)
  4. Ambient parameters
  5. Activity

And looking closer still at each location, I’m certain percentages exist of accidents that can be traced back to each of the following: (Ref. 1):

  1. Design of the physical location
  2. Managing the location
  3. Maintaining it
  4. Monitoring the location

Categorizing the location of slip, trip and fall accidents like this can help determine the cause of an accident.  This is similar to categorizing the structures in the built environment as a means of determining the cause of failure of one of the structures there or one of the components.  This categorizing is why an expert can give you some understanding of cause at the case- or claim-assessment stage.

We categorize people to help a society function – and this works when done thoughtfully.  Why not categorize accident locations to help determine cause?

References

  1. Di Pilla, Steven, Slip, Trip and Fall Prevention; A Practical Handbook, 2nd ed., CRC Press, Boca Raton 2010
  2. Sotter, George, Stop Slip and Fall Accidents!: A Practical Guide, 2nd ed., Sotter Engineering Corporation, Mission Viejo, CA 2014
  3. Jorden, Eric E., Update: Where does an expert’s initial hypothesis come from?  Posted March 18, 2019
  4. Sebald, Jenn, System oriented concept for testing and assessment of the slip resistance of safety, protective and occupational footwear, Berlin 2009

 

Update: Sinkhole news highlights a problem that can be fixed

Blog Update

I was remiss last week in not commenting on how the situation in sinkhole country relates to the interests of many of you in civil litigation and insurance.  I remember a vague feeling at the time that something was missing from my blog – I neglected to refer to the standard of care. (Ref. 1)

Last week’s blog commented on what an experienced engineer would do in an area susceptible to the formation of sinkholes – see below.

You’re certain to want to know for a failure in the built environment or an insurance claim that the standard of care was observed at a construction site.  We check this during a forensic investigation.

The standard of care for an undeveloped building site in an area with known foundation problems – like the risk of sinkholes – requires, at the very least, carrying out a geotechnical investigation.  Something similar applies to a developed site.

The investigation can be fairly routine for a compact site like a single building, bridge, wind turbine, etc. and the results can be quite accurate.  The investigation can also be inexpensive considering the cost of these structures.

Reference

  1. How the standard of care is determined when a failure or accident occurs in the built environment. Posted June 28, 2014 and updated October, 2017

***

Sinkhole news highlights a problem that can be fixed

(Originally posted last week, March 31, 2019)

That was quite a picture in the newspaper a few days ago of a sinkhole that appeared last August in Oxford, Nova Scotia. (Ref. 1)  And the pictures of the sinkholes in British Columbia a few weeks ago (Ref. 2) and before that – back to Nova Scotia – some time ago in Falmouth..

Striking pictures but sad too when homes are lost, and scary at the thought of potential injuries and death.

But it’s time to stop.  There’s no need for the formation of sinkholes to surprise anyone nor pose a risk..  Nor be a “…a money pit”. (Ref. 1)  There would be no news and no pictures if experienced engineers were involved before these areas were developed.  And every chance some of these areas would have been undeveloped.  Engineers would carry out a standard geotechnical investigation of the ground at a site proposed for construction.  Simple as that.

The news story mentioned a geophysical survey.  That’s an engineering technique that’s been around a long time.  The fact that this is sinkhole country – Karst terrain – has been known a long time too.

Karst is an irregular limestone area with sinkholes, underground streams and caverns. (Ref. 3)

Remote sensing geophysical surveys – sort of like MRIs in medicine – detect features in the ground of interest to land owners.  Features like voids or conditions conducive to the formation of voids.  Sinkholes start as voids in the ground.

Limestone bedrock, gypsum and salt dissolve in the water in the ground to form voids, caverns and underground streams.  The voids get larger with time and eventually the top, or roof of the void, appears at the ground surface – a sinkhole. The voids are said to migrate to the ground surface.

The most recent picture shows red soil around the perimeter of the sinkhole.  This is glacial till – soil deposited by glaciers 1,000s of years ago.  The soil is heavy and would cause the top of a void to break and appear at the ground surface sooner rather than later.

Investigating undeveloped Karst country for sinkholes

What would an engineer do if asked to investigate the foundation conditions at a proposed construction site?  For example, the site of a building, or any of the structures in an urban area, or a residential subdivision or a strip mall.  This would be an engineer experienced in geotechnical or geological work.

They’re not always asked – and it appears not always in Karst country – but what would he do if he were?

He would first check.the published geology maps and aerial photographs of the area available to all of us.  It’s called terrain analysis in engineering.  He would see in the maps that a large area of Nova Scotia – many square kilometres – is underlain by Karst terrain.  He would also see in the photographs evidence of large sinkholes like the one in the picture.  He would tell you that the area is susceptible to the formation of sinkholes.  He would also tell you that he can’t predict where the sinkholes will appear in a large area.

But tell him approximately where you want to construct a subdivision or strip mall and he’ll give you a pretty good idea of the risk of sinkhole development in a small area like that.  Not the location of all future sinkholes but the location of some, and the risk of others.  He would do this after carrying out a geophysical survey.  The survey could be expensive for an area proposed for a subdivision or strip mall.

I did a geophysical survey of an airport runway on South Andros Island in the Bahamas one time.  I was looking for voids that might form sinkholes.  A runway is not unlike a residential street or a strip mall.  You can be sure I ran a lot of closely spaced survey lines down the runway looking for voids.

Tell the engineer precisely where you want to build a house, a multistory building, a bridge, a road, etc., a tiny area, and he will tell you if and where sinkholes will form and undermine your structure.  He would do a geophysical survey.  This wouldn’t be that expensive for a single structure and a good investment considering construction costs.  You might consider relocating the structure after the survey..

If the risk of sinkholes forming is low and you still want to build there then he would drill boreholes at the location of your structure and any features of interest found during the geophysical survey.  Boreholes retrieve samples of bedrock like limestone or indicate when the borehole passed through a void.  It’s called ground proofing in engineering work that relies on non invasive, non destructive geophysical surveying and terrain analysis.

Summarizing, this is what the experienced engineer might do depending on what you need:

  1. Terrain analysis of a large area of Karst country – square kilometres in size – using published maps and photographs
  2. Geophysical survey of a small area possibly with a few boreholes
  3. Geophysical survey of a tiny area - a proposed construction site – plus some boreholes  .

It wouldn’t take a “money pit” of money to investigate for sinkhole-forming voids if you know the precise location of your proposed structure.

Investigating developed Karst country for sinkholes

If you are concerned about the stability of a developed area, particularly foundation stability, then, depending on the size of the area and the preciseness of the information wanted, the engineer would go through the above steps.  The emphasis would be on Step #2 if you are concerned about a small area.  Or Step #3 if you are concerned about a single structure and wanted precise information.

***

The approach for developed or undeveloped land would be much the same – that of a fairly routine engineering investigation by an experienced person.  It wouldn’t be so expensive for a single structure, a tiny area – a few 1,000s of dollars rather than many 10,000s.  But more, of course, for a larger area, particularly if a lot of precise information was wanted.

It wouldn’t be so newsworthy either particularly if undeveloped land was being investigated.  The reporter’s eyes would glaze over at the thought of covering an engineering story like that.

That’s where we need to get to in Karst country – investigate before at reasonable cost not after when newsworthy sinkholes and problems develop.

References

  1. The Chronicle Herald, Thursday, March 14, 2019 page A3
  2. What’s wrong with this (sinkhole) picture near Vancouver. Posted February 20, 2019
  3. Merriam-Webster dictionary, March, 2019