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.  No, 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.

Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada, June, 27, 2019 ejorden@eastlink.ca                          

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

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 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

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada. April 30, 2019 ejorden@eastlink.ca)   

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

Routine engineering investigation – the fix – ensures sinkholes don’t undermine our buildings – the problem.

***

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

Some of you might be interested in the handbook, Practical Guide to Comparative Advertising: Dare to Compare, by Ruth M. Corbin et al. 1st edition 2018. (Ref. 1)  I haven’t read the book but mention it because Ruth Corbin writes well and jargon-free

I know this because I’ve read some of her work that is more closely related to my forensic engineering practice. (Refs 2, 3)  In addition, this is a handbook and they’re always nice to have on the shelf.  I also met and heard Ruth speak and present at the Expert Witness Forum East in Toronto last year.

Comparative advertising can be defined as a marketing strategy in which a company’s product or service is presented as superior when compared to a competitors. (Ref. 4)

Google the title and carefully read Ruth’s description of the contents and the handbook’s key features and her opinion of the readership.  You’re certain to be covered in the latter.  If I were one of you – a civil litigation lawyer, a judge, an insurance claims manager, an adjuster, a representative – and not a forensic engineer, I would take a good look at this handbook

Why am I mentioning this book?  Because I like to see good writers get published.  Also because the book does relate to the practice of some of you.  It’s by an author who I know writes well and, in addition, it’s a handbook – they’re always easy to understand.  Finally, I’m certain Ruth would associate with co-authors who are equally clear writers.

.

I commented last month on the basis for an expert’s hypothesis during the merit assessment stage and gave a few examples. (Ref. 1) You may remember that the hypothesis or initial oral report comes from:

1. Your briefing
2. The expert’s experience
3. Published data on causes

The examples of published data were quite informative. (Refs 2, 3, 4) The most detailed was about the 209 ways a building can fail – useful information and readily available to the expert when assessing cause. (Ref. 2)

There’s more.  A building is only one type of structure in the built environment.  There are actually about 18 different types as listed below. (after Ref. 4)  Each structure can fail in several different ways.  The causes have been researched and published for most of the 18 like the 209 causes for a building.

(It was Ref. 4 that prompted this blog update – it extends our understanding of failure and accidents to all types of structure)

Your urban environment where you live contains some or all of the following types of structure:

1. Bridges
2. Dams
3. Tunnels
4. Roads and highways
5. Embankments
6. Excavations
7. Natural, and man-made fill slopes
8. Buildings like residential, commercial, industrial and multi-story (There are more buildings in the world than any other type of structure)
9. Foundations
10. Basements
11. Retaining walls
12. Infra structures like pipelines
13. Water, storm and sewer pipelines
14. Tanks
15. Storage bins
16. Chimneys and stacks
17. Towers; both guyed and free standing

The causes of failure of these structures are categorized according to the:

• Structure – those listed above and again in the Appendix
• Main Component in the structure – beam and slab, an arch, long span roof, etc
• The component’s Material – steel, concrete, wood, masonry, etc.

The categorization is more detailed and technical than this but the above gives you an idea..

(The Appendix lists the different structures, their components and component materials)

The researchers identified the several different ways each Structure can fail.  For example, What causes bridges to fall down?  Towers to topple?  The foundations of multi-story buildings to settle and subside?

They then looked closer at the main Component(s) in each structure and identified the different ways these failed.  For example, What are the different causes of cracks in concrete floor slabs?  Why do roofs collapse?

Finally, they looked closer still at the different Materials used in the components of structures and how they failed.  Why does steel break?  It certainly does at times.  What causes concrete-wood connections to come apart?

The result is a wealth of published information for the expert to consider when forming a hypothesis – 100s of different ways a structure, it’s components, and the component’s materials can fail in the built environment.  All researched and published and available to guide the expert as you brief him during the merit assessment stage.

He’s thinking Structure, Component, Material as you talk and forming an initial hypothesis, or, more correctly, an initial oral report to guide you on whether to take the case or in assessing the claim.  It might be a rough report but it’s well founded on a lot of published data – and better than not talking to an expert.

(It occurs to me this late hour that similar data could be compiled and published on the causes of personal injury accidents like slip, trip and fall accidents)

References

1. Where does an expert’s initial hypothesis come from?  Posted February 25, 2019
2. Nicastro, David H., ed., Failure Mechanisms in Building Construction, ASCE Press, American Society of Civil Engineers, Reston, Virginia 1997 (Readily available by interlibrary loan from Memorial University, Newfoundland)
3. How many ways can a building fail, and possibly result in civil litigation or an insurance claim? Posted July 10, 2014
4. Janney, Jack R., Guide to Investigation of Structural Failures, ASCE (American Society of Civil Engineers) 1979, 1986

Appendix

(The following lists are after Ref. 4 with some additions based on what I’ve seen over the years)

Structure: Causes of failure have been researched and identified according to the following types of structure:

When you rely on an expert’s initial hypothesis during the merit assessment stage you rely on a well-founded hypothesis.  In fact, it’s more than a hypothesis – a guess – it’s an initial oral report based on the evidence. (Refs 1 and 2)

The evidence is

• Your briefing on the claim, accident, failure, dispute
• The expert’s experience
• Published data on the causes of failures and accidents in the built and natural environments

You telephoning and briefing an expert on a situation triggers his thoughts of past experiences and also modes of failure as published in the literature for different structures.  He’ll tell you, orally, what he thinks about cause, and it’ll be more than just a guess.

Tell me the issue is foundation subsidence on filled ground and I’ll tell you it’s likely inadequate materials testing and inspection during construction (experience) or inadequate geotechnical investigation (experience plus published research).

Brief me about a slip and fall accident on a wet floor in a dry sauna and I’ll tell you where the water came from (experience).

Tell me a site is still contaminated after an environmental assessment and remediation and I’ll identify three possible causes, one more likely than the other two (experience) .

Other experts in different branches of engineering and applied science can do the same.

There’s some interesting and helpful information in the following on where initial oral reports come from.

1. Your briefing You’ll describe the situation to the expert and report what you know about the claim, dispute, failure or personal injury.  This based on what you have learned from the parties involved, or your understanding if you are one of the parties or represent one.  Your briefing would include the technical issues as you might understand and perceive them.  Also what you believe must be investigated.

The expert will ask questions based on what he’s hearing.  He’ll ensure the Who? What? Where? When? Why? and How? of the situation are answered.  He’ll note technical issues that he might see at this early stage and comment on yours. The expert will sift through your briefing for hard and soft evidence.

Hard evidence might be the size and character of cracks in a damaged wall, the reported findings of an environment assessment of a contaminated site, the rainfall recorded the day of the flood, video of a property taken from a drone or the floor covering in the room where the slip and fall occurred.

Soft evidence might be what the real estate agent told you before you bought the property about how the high, steep slope down to the sea was really stable – only to have a landslide undermine your house later.

In a sense, I took a briefing from news reports a few days ago – quite soft evidence – on the appearance of sink holes in ground near Vancouver and the need to evacuate 14 homes from a subdivision.  Out of interest, based on my experience as an engineering expert, I hypothesized on what was wrong at the subdivision.

One conclusion: The ground should not have been built on in the first place.  Another conclusion: It was built on but something went wrong during the geotechnical investigation and/or the acceptance and implementation of the investigation’s findings.(Ref. 3)

2. The expert’s experience Our experience is grounded in our professional discipline and will include our successes and failures. (Ref. 4).

For example, disciplines like civil, mechanical, electrical and industrial engineering.  Civil engineering has in turn branched off to structural, foundation, geotechnical and environmental engineering.

My discipline and consulting practice has evolved to focus on civil engineering and the civil engineering branches except structural.  I have also practised as a generalist engineer overseeing an investigation and retaining specialists like structural, mechanical and electrical engineers. (Ref. 5)

For example, I investigated the cause of a power tool accident knowing full well at the start that I would likely retain experts in the design and manufacture of the tool.  As it turned out, a video taken of the re-enactment of the accident indicated the likely cause of the accident.

In another problem, I called on a structural engineer to guide my investigation of the stability of a concrete block wall and also the floor beams in the building.  These were elements in the environmental assessment and remediation of a contaminated site, one of my areas of practice.

Experiences like these guide me in advising you during the merit assessment stage. Ask me about problems like these and I should be able to help you.

Tell me it was a concrete block wall that collapsed and I’m sure I can tell you why.  Tell me the size of the cracks in a wall and the component material and I’ll tell you the likely cause of the cracks.  If a structure subsided I’ll tell you the likely cause with great certainty.

If you come to me during the merit assessment stage about the cause of a traffic accident I’m not going to say anything.  I’m going to refer you to one of three specialists in this work depending on the location of the accident.

In the last four or five years right up to the last three or four months I’ve got very suspicious of the quality of Phase II ESAs (Environmental Site Assessments) in the Atlantic provinces.  My suspicions are based on peer reviews I’ve done and experience with a drilling company and comments by the owner.  If your merit assessment involves a problem in the environment my initial oral report will draw attention to the Phase II ESA if one was carried out.

If your problem has anything to do with earthworks, foundations, the subsoils, surface and ground water, flooding, the terrain in general, I’ve got a wealth of experience to call on including education and practice as a land surveyor.  My experience was gained in Atlantic Canada, offshore NS, out west, up north and overseas.

It’s the same with experts in disciplines like mechanical, electrical and industrial engineering.  After a few years the experience is in our gut.  It just comes out during your briefing.  It’s hard to suppress it.

It comes out with considerable confidence too because we know there is a lot of published information that can be reviewed during a merit assessment..

3. Published data The principal modes of failure of buildings and civil, mechanical, electrical and environmental engineering structures and their components have been studied at length and published. (Refs 6, 7 and 8)  Some of the published material is fairly general and leads us in the right direction but doesn’t tell us what’s at the end of the trip. (Ref. 9)  Some other is quite specific and gives us a good idea where to look for the cause of the problem.

Fairly General  Researchers in the US and Europe reviewed the causes of hundreds of structural failures – that’s 100s, plural – and categorized the primary causes as follows:

• Human failure
• Design failure
• Material failure
• Extreme or unforeseen conditions or environments
• Combinations of the above

When professional engineers were at fault (human failure) the causes of failure could be classified as follows:

• 36%…Insufficient knowledge on the part of the engineer
• 16%…Under estimation of influence
• 14%…Ignorance, carelessness, negligence
• 13%…Forgetfulness, error
•   9%…Relying on others without sufficient control
•   7%…Objectively unknown situation
•   1%…Imprecise definition of responsibilities
•   1%…Choice of bad quality
•   3%…Other

When the percentage distribution of the failures were summarized the US and European research found that almost half were due to errors in the planning and design of a structure and a third occurred during construction:

• 43%…Planning and design
• 36%…Construction
• 16%…Use and maintenance
•   7%…Others and multiple factors

For example, I reviewed research a few years ago that found many, possibly most, foundation failures were due to inadequate geotechnical investigation of the ground and foundation soils.  In the above classification, that would be human error – the professional engineer – and the 36% with insufficient knowledge category.

Another example; if you’re got an earthworks failure, like on a highway or in an industrial park, I would look through the 11 different stages of the life cycle of a structure.  Based on my experience I would quickly focus on the materials testing and inspection during the construction stage.  In the above, that would be material failure and the 14% ignorance, carelessness, negligence category.

In a sense, yet another example; it doesn’t help when you’re hypothesizing on cause to know the following but important fact: The National Research Council (NRC) have found that the most complex structure in the built environment is a basement and it’s foundations – not the most glamourous structure just the most complex and rife with potential problems. (Ref. 10)

I can imagine dozens of possible problems down in the basement.  Where do you start looking for a cause?  If no go-to-answer, based on your briefing and experience, it’s important to get this out at the merit assessment stage – in spite of the aggravation.

Quite Specific The American Society of Civil Engineers (ASCE) published a book that categorizes 209 causes of component failure in buildings. (Ref.7)  It’s interesting that the basement was not looked at in detail by the researcher and editor, David H. Nicastro.  I can imagine he didn’t know where to start considering that there are 100s of ways a basement can fail..

The ASCE categorization is a detailed source of information for an expert hypothesizing cause.  To get an idea of this resource, take a look at the blog I posted July 10, 2014 entitled “How many ways can a building fail and possibly result in civil litigation or an insurance claim”. (Ref. 6)  If you’re up for it, take a look at the ASCE publication itself (Ref. 7)

Following are two examples from my blog on how an expert might use the book:  The examples are 2 of 209 ways a building can fail:

The item in red is one of the 209 ways selected from the alphabetical list down the pages of the book.  The items in blue are column headings across the pages.    They note the distress in the building when the failure occurs, the materials affected, and one or more typical case histories.

Example #1, A client’s structure experiences:

• Differential foundation settlement – the way in which his structure failed, the technical cause.
• The distress to the structure is manifested as unwanted movement and distortion.
• The materials and systems affected by this movement are the structural systems and foundations.
• A case history in Nicastro’s book is the differential settlement of the temporary foundation support of a bridge deck during construction.

Example #2, A client’s structure experiences:

• Corrosion – the way in which a component failed, the technical cause.
• The corrosive distress to the structure manifests itself as an unsightly appearance
• Affecting the component’s materials, the metals.
• Case histories in the book include a steel masonry shelf, and reinforcing steel in a concrete wall façade.  Both corroded with the infiltration of rain water.

Brief Summary

This is the kind of published data – 

• exhaustive categorizing of failures, like 209 for a building 
  
• good evidence on the primary causes of failure
• the percentage distribution during the life cycle of a structure, and
• the percentage distribution of errors professional engineers make –

that allows an expert,

• based on your briefing and his experience,
  

to orally report during the merit assessment stage on the cause of a failure or accident or the basis of a claim.  It’s a preliminary oral report, that’s for sure, but more than a hypothesis, a guess.  The expert’s initial oral report comes from good evidence.- your briefing, his experience and published data.

References

1. Merriam-Webster dictionary, on-line, February 2019
2. Cost management of expert services. Posted January 31, 2019
3. What’s wrong with this (sink hole) picture near Vancouver? Posted February 20, 2019
4. Petroski, Henry, To Engineer is Human; The Role of Failure in Successful Design, Random House, New York, April 1992
5. American Society of Civil Engineers (ASCE) Guidelines on Forensic Engineering Practice
6. How many ways can a building fail, and possibly result in civil litigation or an insurance claim? Posted July 10, 2014
7. Nicastro, David H., ed., Failure Mechanisms in Building Construction, ASCE Press, American Society of Civil Engineers, Reston, Virginia 1997 (Readily available by interlibrary loan from Memorial University, Newfoundland)
8. Janney, Jack R., ed., Guide to Investigation of Structural Failures, American Society of Civil Engineers (ASCE) 1979 and 1986
9. Built Expressions, Vol. 1, Issue 12, December 2012, Argus Media PVT Ltd., Bangalore, E: info@builtexpressions.com, info@argusmediaindia.com
10. Swinton, Michael C. and Kesik, Ted, Performace Guidelines for Basement Envelope Systems and Materials, National Research Council of Canada Research Report 199, pp 185 October 2005

I was surprised at the news last week about the evacuation of 14 homes in Sechelt, on the Sunshine Coast near Vancouver because of sink holes and unstable ground.

How a party engages a forensic expert affects how well costs are managed.  The best way is easy.  It involves starting early and reporting often.  It also involves learning about the forensic investigative process the same as experts are expected to learn about the judicial process.  Do this and you and your expert will understand one another.  Frequent reporting is essential to effective cost management..

The following summarizes the best way to manage costs:

• Engage an expert early,
• on a simple fee basis,
• with frequent oral reporting
• on the evidence-to-date,
• the cost-to-date,
• the estimated-cost-to-complete, and,
• if required, a written report.

You’ll go through some tasks several times until you’re done.  It’s easy, and cost management proceeds nicely when you follow this routine. The process is commented on as follows:

1. Engaging an expert early can be as simple as talking with one at the merit assessment stage.  You can’t benefit from an expert’s knowledge until you talk with an expert, and the sooner the better.  If nothing else, brief him on the issue and get his off-the-record thoughts.  Most experts don’t mind giving a bit of time to something like this.

Perhaps engage him more formally to read some documents and/or visit the site.  Do this if the two of you perceive technical issues that could impact the dispute or forensic work and would need to be investigated.

Engage early: You really don’t want to take a case or pay out on a policy if the technical issues don’t support the position of the parties involved, or the parties can’t afford the cost of an investigation.  Experts sometimes see embarrassing situations when we’re engaged late.

(You can engage an expert in about eight different ways.  All the way from getting one to briefly give some factual data without analyzing it to retaining an expert to peer review and analyse the work and written report of another expert you retained earlier. (Ref. 1))

An expert can give a preliminary estimate of the cost to investigate the issues based on other forensic work he’s done – a rough order of magnitude of costs if nothing else.

During your initial briefing and talk with an expert you might also get a feel for the evidence that could be found during an investigation and where it might lead..

In a sense, at the merit assessment stage you’ll get your first oral report on

• the evidence-to-date – the experts initial thoughts on this,
• the cost-to-date – the expert’s charges for reading some documents, and
• the estimated-cost-to-complete – the expert’s preliminary estimate of cost to investigate the issue.

before you’ve even decided to get involved in the issue.

While this is going on, you will gain some understanding of the dispute resolution and forensic engineering investigative processes.  There’s more information in the references on the nature of forensic engineering (Ref.2), the steps in the forensic engineering process (Ref. 3) and the difficulty estimating the cost of forensic investigation (Ref. 4).

At the end of the day, engaging an expert early will enable you to engage with him or her only as long as required by the judicial process and the needs of the parties involved in an issue.  And this decision will be based on good evidence.

2. Engaging an expert on a fee basis is the most effective way of managing the cost of dispute resolution and forensic work.  This is because it’s very difficult to estimate the total cost of this work at the merit assessment stage and should not form the basis for retaining an expert. (Ref. 4) The difficulty estimating costs is handled with frequent oral reporting on cost.

Nor should you pay too much attention to dollar-differences between the hourly fees of the experts you might consider engaging.  The fees of experts in Atlantic Canada are similar as they are elsewhere in Canada and in the New England states. (Ref. 5)  The qualifications and experience of the expert are far more important.

3. Get frequent oral reports on everything found at each stage of the dispute resolution or forensic investigation.  There are many stages in these processes and many opportunities to review evidence and cost. (Refs 3 and 6)

Get your expert’s thoughts

• after you brief him at the merit assessment stage,
• then again after he reads some of the documentation,
• after he takes a look at the site,
• studies all of the documentation,
• does some work at the site
• does some laboratory testing,
• after he does some research,
• after he … well, etc., etc.

and on and on for as many of the stages of a forensic investigation or dispute resolution justified by the evidence..

You’ll talk a lot but you’ll manage the cost of the issue well, based on the evidence-found-to-date, the cost-to-date and the estimated-cost-to-complete the investigative process.  When these line up with the requirements of the judicial process and your party’s interests you’ll bring the forensic investigation to a close based on hard evidence – lots of data plus costs.

4. Evidence-to-date

An expert is collecting hard and soft evidence all the time.  He’s

• carrying out standard investigative tasks,
• following leads,
• journalizing and thinking-on-paper,
• developing a time-line of tasks carried out, why he did them and the data and evidence he got, and,
• ever alert to promising side-lines to the time-line,
• analysing the data and evidence,
• drawing tentative conclusions,
• tweaking his hypothesis as to cause and
• inching closer all the time to formulation of an opinion as to cause or the way forward in a dispute.

You can get the expert’s thoughts and the evidence-to-date at many and minute stages of an investigation.

As well, it may not be well known but the probable cause of quite a few different types of failure and accident in the built environment have been identified and published.   Tell an engineering expert what happened and the damage and, based on published material and experience, we can tell you possible causes. (Ref. 7 for example)

5. Cost-to-date

Experts book their time and expenses daily.  You can get cost-to-date whenever you like and as often as you like.

You can get costs at each stage and task of the forensic investigation and dispute resolution, and each stage of the judicial process.  The expert may not have updated evidence at all stages but he’ll have updated costs and expenses on a daily basis.

6. Estimated-cost-to-complete .

You can also get increasingly accurate estimated-cost-to-complete the forensic work whenever you like and as often as you like.

It’s well understood in project and cost management that the further along you are in a process the more accurate the estimated-final-cost.  This is because the more stages of a project or investigation you complete the more information you have for estimating cost and the more accurate the estimate.

7. Get a written report, if required

At this stage of the process, you’ll have lots of information on which to base a decision about getting a written report.  The sooner you decide the easier it is for the expert to estimate the cost of a written report, and the lower the cost .

Leave it for a year and the expert has gone onto other cases and disputes.  He must come back to your file and review the evidence and everything that took place during the investigation before he can plan and write the report.

I solve this problem to some extent by keeping a detailed time-line on What i did, Why I did it, and The data and evidence I got.

***

There is a very simple and effective procedure for managing the cost of dispute resolution and forensic expert services.  The simple, stepped procedure is easy to follow and not high tech by any stretch.  Some of us are engaged in it now and we like it, and our clients do too.

It starts by

• engaging an expert early,
• going through the simple steps as itemized and commented on in this blog, and
• frequent oral reporting.

It ends when you decide, based on good evidence and the cost-to-date, that the requirements of the judicial process and the parties involved have been met.

The procedure is based on well developed, decades old project management methods..  These methods can be applied to dispute resolution and expert services as shown in this blog.

References

1. How to retain an expert in a cost effective way. Posted November 30, 2018
2. What is forensic engineering? Posted November 30, 2012
3. Steps in the forensic engineering investigative process with an appendix on costs.  Posted July 15, 2013
4. Why the difficulty estimating the cost of forensic engineering investigation?  Posted September 1, 2013
5. An expert’s fees and forensic engineering investigation.  Posted July 5, 2016
6. A bundle of blogs: A civil litigation resource list on how to use forensic engineering experts.  Posted November 20, 2013
7. How many ways can a building fail, and possibly result in civil litigation or an insurance claim?  Posted July 10, 2014