The justice system and messy construction sites – Seeing is believing

There’s an argument for the justice system to go on site and see what it’s really like for the expert.  See what he’s got to deal with, and describe and explain to them later.  That means judges, juries, and counsel for all parties, also insurance claims managers.  It’s messy out there and not at all clean, tidy and precise as might be gathered from the text books.

I’ve seen the justice system on site less than half a dozen times in the years I’ve been investigating engineering failures and accidents.

I thought of this recently when I was examining and measuring conditions on a construction site.  I was knee deep in messy, wet pits in the ground and cramped in tiny, grubby crawl spaces.  And it was raining off and on too.  I was happy though, I was collecting valuable data.

But how to tell the justice system later that conditions were different from what I expected and more difficult and expensive to quantify?  In this case, less accurate for one element of the problem but more informative for a second.

How to describe this in words?  I got pictures and this will help.  But, seeing is believing.  It’s easier if the justice system has seen the conditions.  It’s easier then for the expert to explain the technical issues arising from the conditions associated with the failure or accident.  Most of our knowledge is acquired visually – about 80 to 85 percent, so come out and see and understand better what the expert is saying.

Bibliography

  1. An expert’s “dirty hands and muddy boots”.  Posted December 20, 2013
  2. The messiness of some forensic engineering and insurance investigations is illustrated by messy snow banks.   Posted April 14, 2015
  3. More about messy, lumpy Mother Nature and how we deal with her effect on our forensic engineering and insurance investigations.  Posted April 23, 2015

 

 

 

“Expensive” experts are not so expensive compared to the cost of key technical issues going undetected

This is particularly the case when counsel is assessing the merits of a case.  There’s a strong argument for consulting an “expensive” expert then.

This is echoed in the remarks of no less an authority than John Sopinka, former judge, Supreme Court of Canada (Refs 1 and 2) and in the text by the quite respected David Stockwood, Q.C., Ontario. (Ref. 3)

A key technical issue missed by counsel could render a case untenable.  Or be too expensive to investigate relative to damages thought due the Party and to the worth of the file to counsel.  Best to spend some money on an expert at the case-assessment stage than possibly lose a lot of money later.

I blogged last year on the importance of retaining an expert “…early in the life of a case”. (Ref. 2)  I was reminded of its importance to a Party seeking justice and the money involved on reading the following in an engineering case study:

“As a wise man once said about “expensive” experts, “When you have to hire one to undo the work of an amateur, they don’t seem so expensive after all.” ” (Ref. 4).

The case study was of inadequate renovation of a building that cost the owner $300,000 a few years ago. (Ref. 4)  The expert’s fees are certain to have paled by comparison.  I also recently investigated an inadequate renovation that is likely to cost a lot of money to fix.

Counsel almost always recognizes that the cause of a failure or accident must be determined – a key technical issue for sure.  But there are often other issues – key ones and subordinate ones – that are beyond counsel’s technical expertise to identify.  Some of these might need to be investigated in determining cause, at unexpected expense.

I’ve had the occasional investigation stopped because of mounting cost to the worth of the file.  Counsel’s costs are cut but I wonder to what extent justice for the Party is compromised by an incomplete forensic investigation?

The cases likely will be argued still but without benefit of complete technical input.  One case is certain to be argued and likely cost the law firm much more compared to the cost of an “expensive” expert.  In this case, for want of a simple, one line, 2″ long, high school, arithmetic calculation that would quickly resolve an important technical issue in counsel’s favour.  Without the calculation three parties will keep arguing their respective subjective assessment of the size of a feature in the landscape – on and on and dollar after dollar.  I offered to report verbally but senior management declined.

What happened in these cases was that non-technical people – counsel, with all due respect, estimated the cost of technical services unrealistically low when the merit of the cases were being assessed.  Yet in these cases – three come to mind, the awards would be well into six figures.

Consulting with an “expensive” expert before a case is taken will ensure most if not all technical issues are identified.  And the need recognized to investigate these at some cost if the case has merit.  The expert might cost in the very low 1,000s, the possible need for forensic investigation in the low 10,000s won’t be a surprise, and awards in the 100,000s won’t be compromised by investigations stopped in mid-task.

Reference

  1. Sopinka, John, Judge, Supreme Court of Canada, The Use of Experts, Chap 1, The Expert: A Practitioner’s Guide, Volume 1 by Matthews, Kenneth M., Pink, Joel E., Tupper, Allison D., and Wells, Alvin E. Carswell 1995
  2. Please, Counsel, retain an expert “early in the life of the case”.  Posted March 27, 2014
  3. Stockwood, Q.C., David, Civil Litigation, A Practical Handbook, 5th ed, 2004, Thompson Carswell
  4. Reference Advocates Principles
  5. Nicastro, David H., editor, Failure Mechanisms in Building Construction.  ASCE Press, 1997 page 26

Bibliography

  1. The role of a professional engineer in counsel’s decision to take a case – Update Posted May 21, 2014
  2. A bundle of blogs: A civil litigation resource list on how to use forensic engineering experts, Posted November 20, 2013
  3. Lewis, Gary L., editor, Guidelines for Forensic Engineering Practice, American Society of Civil Engineers (ASCE), 2003

 

“Slow”, thorough engineering investigation solves flooding problems

Going slow – like many months for a simple investigation, longer still for complex ones, ensures the cause of the problem is determined.  And the investigator doesn’t succumb to the tyranny of the obvious – as I almost did. (Ref. 1)  You’ve got to have time to think and reflect.  Going slow also helps the owner adjust to seeing his property taken apart during the work.

I investigated the cause of two wet basements in the past 1.5 years.  More than just wet, a flood in one case, 3 inches deep, and very wet in the other.

There was also water in depressions on the properties that sloped down to nearby lakes.  That meant poor surface drainage and probably high water tables – evidence of a possible cause of the wet basements..

The homeowners helped in both cases.  One used a novel method for determining the correct cause of her wet basement.  I’ll use her simple technique in future.  The other was in the right place at the right time to see the actual cause of their wet basement, and in a very striking way.

Both Houses

Both basements were finished including the floors.  But you could see water flowing from under the finished floors and across the exposed concrete floor in adjacent furnace rooms.  The water came from the direction of the basement walls on the up-slope side of the properties.

We cut small holes in the gyproc at the bottom of the walls and gradually added other holes and enlarged them – in a sense, we chased the wet basement problem.  This exposed the wood sill at the bottom of the walls and the area where the concrete floor abuts the concrete wall.  We also took up part of the finished floor in one house.

The owners helped and we went slowly so they could get their heads around the dismantling and the mess.  These were well-appointed, $350,000 plus homes, one about 30 years old and the other 40.

The exposed wood sills were water stained at both properties.  The stain gradually faded along the length of the wood sills from a dark area in the middle.  The stain indicated the wall was leaking, and the dark area suggested the location of the leak.

Just to be sure, we cut small holes in another wall in each house well away from where the water was seen in the houses.  We saw clean, unstained wood sill indicating no leaks.  There was a leak along one of these adjacent walls 20 years earlier that was fixed by constructing a new, perimeter footing drain.  Fine soil clogs these drains often enough after a few decades.

I concluded a clogged footing drain was the cause of the flooding at both houses, a good initial hypothesis as to cause.  But, I was in for a surprise.

(You can imagine there was quite a mess in both houses now with dismantled wall debris everywhere.  But we were going slowly – weeks now, and soon months)

Where was the leak?  How was water getting from a clogged footing drain into the basement – if that was the source?  The concrete wall was stained a little at the location of a hairline crack in one house.  But this crack was so fine I quickly dismissed it as the source of the leak, and it was above the suspect footing drain.  Surely such a tiny crack was not the cause.  Surely.

Where was the leak then?  I thought about the construction joint where the concrete floor abuts the concrete basement wall in both houses.  It measured 1 to 1.5 mm wide and ran the length of the walls.  The construction joint was also down near the suspect footing drains on the outside of the basement wall.

I concluded that the footing drain at both homes was clogged after 30 and 40 years, water was backing up in the drains and getting into the basement through the construction joints.  We would dig up the footing drains at both houses and fix them.

It took me a while to conclude that construction joints could admit so much water.  The penny dropped, so I thought, when I realized that not much water would flow through a 1.5 mm hole but a lot would flow through 100s of 1.5 mm holes joined together.  Like a line of holes in a sieve or the holes in a garden hose used for irrigation.

House #1

But, again, just to be sure, we uncovered a greater height of wall in House #1 – more time more debris, and saw that an area of the wall was honeycombed a few feet above the wood sill.  There were small holes in the wall between the pieces of gravel in the concrete.  The inside wall was porous.  This happens when the concrete is not well mixed during construction.  It doesn’t usually cause a problem because it’s localized and above the footing drain.

Fortunately, we had a very heavy rain a few hours after work.  My client called to say water was flowing from the honeycombed area like water from a tap.  It stopped shortly after the rain stopped.  He videotaped and I saw that it was so.  My client was in the right place at the right time.

We uncovered more wall later and found that a large area was honeycombed.  We also uncovered the outside of the wall and saw that the honeycombing – the porous area, continued through the wall.  We also saw that the water table was at the level of the honeycombing.

There was a source of water and a means for the water to get through the wall, through the porous honeycombing.  The honeycombing and the high water table were the cause of the wet basement in this house, not the footing drain.

We fixed the leak by patching the outside of the wall well above the footing drain that we had considered digging up, and at much lower cost.

(The patching details are not so important to my message here about the advantages of a “slow”, thorough engineering investigation)

House #2

Also, again to be sure, my other client, House #2, decided to investigate the innocent-looking, fine crack in their wall when I was away.  She simply took a garden hose and let it run for some time at different locations against the wall starting at the fine crack.

She saw that water flowed through the crack and stopped when she removed the hose.  She also saw that less water flowed when the hose was at increasing distances from the fine crack.  The fine crack and a water filled depression in the sloping ground were the cause of the wet basement, not the footing drain. 

We fixed it too by patching the outside of the wall at the location of the crack, also at a much lower cost than digging up the footing drain.  We did expose the top of the footing drain over a short distance during the patching.  It appeared to be well constructed.

(We are going to monitor the effectiveness of this repair over the next couple of years)

***

So, four or five months later in both cases after a “slow”, thorough investigation – and a lot of gradually accepted mess, we determined the correct cause of the wet basements.  And we fixed them for a lower cost than might have been the case if I had remained in the grip of the obvious.

References

  1. “Getting seduced by the tyranny of the obvious”  Posted December 9, 2013 at www.ericjorden.com/blog

 

 

U.S. civil litigation lawyer on using air photos in environmental litigation

You might be interested in an article by a U.S. civil litigation lawyer on the use of aerial photographs in environmental litigation – see Appendix.  I came across it while researching material for a forensic engineering investigation that I was carrying out.

References at the end of the article in the Appendix might be of interest to civil litigation lawyers in eastern Canada.

The article is quite descriptive and detailed.  It possibly claims a bit more potential for these types of high altitude aerial photographs taken from 1,000s of feet than is actually the case, but the claim is close to reality.

For certain, all the claims for high level aerial photographs do apply to the low level aerial photographs taken with drones at 10s to 100s of feet that I noted recently. (Refs 1 to 4)  I’ve used both high and low level aerial photographs in my civil, geotechnical and forensic engineering work for years.

Following are a few non-technical comments on aerial photographs to help you know if the method is applicable to your case:

High level aerial photography

This type of high altitude aerial photography is readily available everywhere in north America.

The ground is photographed from aircraft flying at altitudes of several 1,000s of feet.  You get photographs of quite extensive areas – 1,000s of feet across.  However, you can sometimes identify quite small objects as mentioned in the article in the Appendix.  You can also view a site in 3D with overlapping pairs of photographs.

The civil engineer/former land surveyor in me does not usually go on the site of an engineering failure or problem without first getting this type of photography.  I got it most recently for a site in Cape Breton, N.S.

The high altitude photography has particular application to tracking changing conditions on the ground over time or the conditions at a site at some point in the past.  Like the activity on a site as noted in the article.

On one occasion, I relied on high level photography during the forensic investigation of the inadequate underpinning of a structure – to confirm what was not there.

Lidar

Lidar (Light, Radar), another form of high level remote sensing from an aeroplane, is not so readily available but invaluable when it is.  It measures distance by illuminating a target – e.g., a point on the ground, with a laser and analysing the reflected light.  Radar measures the location of the point.  A gazillion points are illuminated and measured and a contoured topographic map produced.

It was very valuable during my investigation of a failure in Sydney.  The site had flooded, a building had settled and the foundations cracked, and a swimming pool had settled a lot – catastrophically.  Lidar imagery clearly showed the probable cause of the flooding and settlement – from an altitude of several 1,000s of feet.  This was one of the most satisfying experiences I’ve had using remote sensing technology to investigate the cause of a failure.

Low level photography with drones

This type of low altitude photography is readily available in eastern Canada and at reasonable cost.  The drones consist of rotorcraft – mini helicopters, and small, fixed wing aircraft fitted with a camera.  The craft are a few feet in size.  They are flown remotely by a pilot on the ground.  The investigating engineer directs the pilot on the photographs and video to take.  That is, the altitude above the site, the distance from the site and the angle with respect to the horizon, also whether still or video.

Photographs taken from drones flying at metres to 10s of metres are able to record existing conditions in considerable detail – almost minute, at the time of the flight.  It is easy to see an object six inches across – even a toonie, in such photographs.  Low level photography produces images of very compact sites – 10s to 100s of metres across.

It can also be used today to start building a photographic record of changing site conditions for study and analysis in the future.

Low level aerial photographs taken from drones would have been quite useful in the forensic investigation of the bridge that failed while under construction in Edmonton earlier this year. (Refs 5 and 6)

Before drones fitted with cameras were available, I occasionally hired small planes to fly over a site and take photographs at quite low levels – several 100s of metres.  I occasionally went aloft in the plane myself.

This technique was quite valuable to me in solving problems with a sewage lagoon in the Annapolis Valley in Nova Scotia one time.  From above, you could easily see the line of seepage where the lagoon was leaking.

In both low and high altitude photography, and the study, analysis, and interpretation of the images of what’s on the ground – known as ‘terrain analysis’ – ground proofing is essential. (Ref. 7) This involves going on the site and checking at selected locations that what you thought you saw in the photographs is actually on the ground.

***

There’s a lot of sophisticated aerial photographic techniques being used in forensic investigation today.  I’m using them in eastern Canada, and they are getting good use in the U.S. as indicated in the article in the Appendix.

But, at the end of the day, an expert has to get on site and “get his hands dirty and mud on his boots” examining the site in detail – something more than the ground proofing noted above. (Ref. 8)

References

  1. A picture is worth a 1,000 words, possibly many 1,000s in forensic engineering with a new aerial photographic technique.  Posted January 15, 2014
  2. New forensic aerial photographic method proving extremely valuable.  Posted  January 30, 2015
  3. Forensic photography – the expertise available in eastern Canada.  Posted February 26, 2015
  4. Fixed wing drones – another tool in forensic engineering investigation.  Posted November 4, 2015
  5. Globe and Mail page A8 Tuesday March 17, 2015, “Buckled girders may delay Edmonton bridge a year”
  6. Wind, construction crane and inadequate cross-bracing caused Edmonton bridge failure: An initial hypothesis.  Posted March 27, 2015
  7. Way, Douglas S., Terrain Analysis: A guide to site selection using aerial photographic interpretation, 2nd edition, 1978, McGraw Hill, New York
  8. An expert’s “dirty hands and muddy boots”.  Posted December 20, 2013

Appendix

Using Aerial Photography to Win Environmental Cases by Kim K. Burke

June 7, 2011

Most environmental lawyers and consultants are first introduced to aerial photographs when reviewing Phase I Environmental Site Assessments (ESA) prepared in accordance with ASTM E-1527-05.  However, the use of aerial imagery in Phase I ESA reports to determine historical site conditions barely scratches the surface of the effective use of aerial photography.

Aerial photography, also referred to as aerial imagery (as a component of remote sensing), is a potent tool for environmental trial lawyers.  Databases of aerial photographs from 1938 are readily available through aerial photography clearinghouses.

The photos are usually taken with a high resolution camera using overlapping images.  The overlapping images are called “stereo pairs” and when viewed as “diapositives” through a stereoscope on a light table produce a three dimensional image of the surface features: buildings, drainage patterns, ravines, containers, tanks, vehicles, mounds, etc.  Vertical and horizontal surface features can be measured, depending on the quality of the photographs.

Aerial photography interpretation can be used in conjunction with geographic information systems (GIS) to develop trial exhibits recreating site conditions at the time of important historic environmental events.

Accurate aerial photography interpretation is a critical component of environmental forensics.  The stereo pairs should be interpreted by a seasoned imagery analyst trained in environmental remote sensing.  Many analysts are former employees of the military or the U.S. government.

Finding a qualified environmental imagery analyst is difficult, because the telltale signs or marks on the aerial photographs of ground level activity, referred to as “signatures,” are different for 55 gallon drums or former burial pits than, for example, intermediate range ballistic missiles.

Stereo pairs are usually shot by aircraft when cloud and vegetative cover are at a minimum (excepting aerial imagery by agencies analyzing crop growth).

Some aerial photos are taken using cameras that detect ranges of the electromagnetic spectrum not visible to the human eye, such as infrared signatures.

The detail can be stunning: some aerial images permit identification of features as small as six inches, and in some cases permit license numbers to be read on vehicles when taken from low-altitude oblique angles.

Collecting and analyzing the historical library of aerial imagery is not a task for most environmental consultants.  Specialists can call upon not only the more widely used public sources of aerial photographs, but also upon databases of lesser-known aerial photography companies that operate on a regional basis.

Because of the incredible detail and information that can be extracted from stereo positives viewed through a stereoscope on a light table (a table that projects diffuse light from underneath the positive images into the stereoscope), it is usually a mistake to order “prints” from the public resources offering to sell historical aerial photos.

To say that aerial photography can be a game changer in environmental cases is an understatement: in one case handled by this firm, the historical aerial photographs showed trucks tipped to dump waste into a ravine…a fact denied by the prior owner of the real property.1   The case settled shortly after sharing these photos with the responsible party.

Juries are intrigued and persuaded by visual and scientific evidence…sometimes known as the “CSI effect.”2   This law firm has used the testimony of experts interpreting environmental signatures on historic aerial photographs.3   The impact on jurors (and judges)4 can be profound.

Environmental attorneys and consultants not trained in aerial photography signature interpretation can miss important clues about past uses of the property.5

The photographs can also be used during, or after, witness interviews to test the accuracy of a person’s memory.

Of course, aerial photographs provide an excellent means of impeaching the credibility of opposing witnesses who testify with professed certainty about different historic site features.

For more information about the effective use of aerial photographs in environmental cases, please contact Kim Burke or any member of the Taft Environmental Practice Group.

References

1Burke, Kim K., The Use of Experts in Environmental Litigation: A Practitioner’s Guide, 25 N.Ky.Law Rev. 111 (1997).

2Lawson, Tamara F., Before The Verdict and Beyond the Verdict: The CSI Infection Within Modern Criminal Jury Trials, 41 Loy.U.Chi.L.J. 119 (Fall 2009).

3Stout, Kristen K. and Hickerson, Glen H., Environmental Research, Inc., The Use of Aerial Photography to Determine Contamination Events at Agricultural Chemical Facilities, Proceedings before the American Academy of Forensic Sciences, Colorado Springs, CO (Feb. 2003).

4Nutrasweet Company v. X-L Engineering Company, 227 F.3d 776, 788 (7th Cir. 2000)(expert testimony interpreting aerial photographs admissible to show history of site contamination).

5Burke, Kim K., 1999 Annual Meeting, American Academy of Forensic Sciences: Experts and Attorneys in Environmental Litigation: Avoiding Common Mistakes, Coronado Springs Resort, Orlando, FL.

Falls have overtaken motor-vehicle accidents as the major cause of serious injury in Canada – and many are preventable including the litigation that sometimes results

It`s so easy to do stupid things.  I know this from experience.

I thought this when I read the front page of today`s National Post about the increase in accidents when people fall from ladders, porch railings and roofs trying to hang Christmas lights.

The item reports studies documenting the increase in accidents seen by Canadian hospitals to people putting up their lights.  Many are severe some are deadly.

One hospital reported an average of four severe accidents per year at Christmas in the past decade.  Another indicates 14 times as many check in at Christmas for less serious Christmas-light injuries.

We forget when we are on a ladder that we are one to three stories above the ground.  I forgot.

I investigated the cause of a fatal step ladder accident a few years ago.  A chap was one story up checking services above a hung ceiling when he fell, struck his head and died.

Three months later I was one story up nailing a board in place on a storage shed on my property, leaned too far and fell.  The fall knocked me out for long seconds.  I was lucky though because there were cobbles and small boulders exposed at the ground surface and my head missed every one.

Decoration-installing falls are only a sub-set of a much larger, generally overlooked problem.

The National Post reports that falls in general have overtaken motor-vehicle accidents as the major cause of serious injury in Canada.

It`s no different in the U.S. where more than one million people suffer from a slip, trip or fall each year.  In 2005, 17,700 died as a result of falls (U. S. National Safety Council, 2007).  In public places, falls are far and away the leading cause of injury.

I`ve read some of the engineering literature on the investigation of slip, trip and fall accidents, and the slip and fall legal practice handbooks.  Many falls are preventable.  This is far cheaper than pressing or defending a claim for damages.

Last evening I went for a swim in a rec centre.  As per my routine, I bake a little in the sauna before and after my swim – also soak in the hot tub.  The sauna floor has a very good skid resistant mat.  The pool deck is also highly skid resistance.  The shower room floor just outside the sauna and the dressing room floor beyond are as slippery as any I’ve seen.  A preventable slip and fall accident waiting to happen.

 

Fixed wing drones – another tool in forensic engineering investigation

As I mentioned in earlier blogs, low level aerial photographs taken from small helicopters – rotorcraft drones, are invaluable in forensic engineering investigation.  (Refs 1 to 3)  Using a small helicopter to take pictures a few 10s of metres above the ground could also be fun – if it weren`t for the seriousness of the issues in an engineering failure or personal injury accident.

Google ‘You Tube Wetthetent7’ and view a fun video of scenes on Prince Edward Island taken from a rotorcraft drone fitted with a camera.  The potential for serious forensic photography with these mini aircraft is obvious.

Fixed wing dronesaircraft drones, are also valuable in forensic work.  I learned about these earlier this year.  Servant Dunbrack McKenzie MacDonald, (SDMM), Halifax, a land surveying and engineering firm own one.  They demonstrated it’s uses to me.

Where rotorcraft drones hover over a site taking low level, aerial photographs, fixed wing drones fly across the site taking low level photographs.  They do much the same as the aircraft flying1,000s of metres above the ground taking the aerial photographs relied on by civil engineers for years.  Except the photographs are of what you want, taken on the day you want, from the height and angle you want, and more detailed and cheaper.

SDMM are using fixed wing drones to map open pit mines.  The low level aerial photographs can also be used to make topographic and infrastructure maps – maps of the built environment and the ground we walk on.

I haven’t used fixed wing drones yet.  I will when I see that it will help me determine the cause of an engineering failure or a personal injury accident.

References

  1. A picture is worth a 1,000 words, possibly many 1,000s in forensic engineering with a new aerial photographic technique.  Posted January 15, 2014
  2. New forensic aerial photographic method proving extremely valuable.  Posted January 30, 2015
  3. Forensic photography – the expertise available in eastern Canada.  Posted February 26, 2015

 

 

Don’t take the ground for granted

Expect the unexpected.  This is relevant when designing foundations to support a structure.  Also, when investigating the cause of a failure in the built environment – a forensic engineering investigation.

I sometimes wonder how often the designer does this – takes the ground for granted, and gets away with it because the foundation soils in Nova Scotia are often very strong.  That includes well constructed, man-made filled ground.

I thought of this when an experienced structural engineering friend of mine exclaimed recently, “There’s sand everywhere in Moscow..!!”.  He was describing his trip to the Scandinavian countries and Russia this summer.  He went on to describe the size of the grains, the expanse of the deposit and the level terrain.  It was like he was seeing a natural, undisturbed deposit of sand for the first time.

That might be understandable.  My friend has practised structural engineering in Nova Scotia since the 1970s.  Much of the province is covered by dense mixtures of gravel, sand, silt and clay – natural, undisturbed glacial soils.  This is what my friend probably expects to find beneath a site when he’s designing the foundations, and the steel, concrete or timber supporting the structure above.

(Everything in the built environment can be thought to have three major components:

  • the Structure above the ground surface,
  • the Foundations at or near the ground surface, and,
  • the Foundation Soils below.

The lower you go the less glamour there is, and too often the less attention paid to what’s below.  “There’s no glamour in the ground”. Ref. 1)

Such an expectation by my friend would be dangerous.  The comfort we feel in Nova Scotia about what is below the ground surface can get you in trouble.  It’s better to “expect the unexpected” as I learned practising geotechnical engineering – a civil engineering specialty, in the U.K., Australia and eastern Canada.

We have loose sand and silt in Nova Scotia and also soft clay – poor foundation soils.  Not a lot but it’s out there.  We also have poorly constructed fills – “un-natural, disturbed“ mixtures of different materials.  Fill is material brought from elsewhere and placed on the ground to raise the level.

Poorly constructed fill can cause problems for low-rise structures like one and two story buildings.  In fact, when I investigate the cause of a foundation failure, as an initial hypothesis, I “expect” to find a poorly constructed fill beneath the foundations.  Or one of the other poor foundation soils that occasionally show up on our construction sites.  This expectation is reasonable because I would have evidence suggesting something is wrong down below when most of the time in Nova Scotia all’s good there.

Appendix

Good fill in engineering usually consists of well compacted mixtures of soil – gravel, sand, silt and clay, placed on undisturbed, natural soil.

Poor fill can consist of these materials plus varying amounts of topsoil, peat, roots, boulders and/or debris.

Geotechnical engineering is a civil engineering specialty that identifies the types of soils and rocks below the ground surface –  below proposed foundations, measures and tests their physical properties, and analyses and calculates how they will perform when used as engineering materials by design engineers.

Reference

1. A quite well known comment by Karl Terzaghi, considered the father of soil mechanics, the science underlying geotechnical engineering.

 

How to use an expert at short notice

I had a good talk with a client recently about investigating the cause of three personal injury accidents.  And what’s possible, in the case of one, when there’s not enough time to thoroughly investigate the accident to the standards of civil procedure rules governing experts.  We both learned something.

I was reminded that an experienced tradesman can look at a structure and report if construction is similar to what he has seen on other sites.  He would not comment on the adequacy of design and construction, which would be outside his area of expertise, just what he saw and it’s similarity.  This would be valuable.

Also, that an expert could be retained as a consulting expert and do a scaled back investigation consistent with the time available rather than as a testifying expert who must meet the requirements of civil procedure rules. (Ref. 1)

An initial hypothesis as to cause can be based on the data available, as limited as that might be.  That’s how science works.  For example, counsel’s description of what happened, reading some documents, and/or a cursory site examination.  It’s important to remember, however, that an initial idea about cause is not necessarily conclusive and could change with a detailed investigation. (Ref. 1)  Sometimes quite significantly.  The tyranny of the obvious can cause grief.

It’s the same in many applied scientific fields.  For example, in medicine where the final diagnosis and successful treatment plan – following the SOAP process, might be quite different from the initial diagnosis and plan. (Subjective gathering of data/evidence, Objective gathering, Assessment of data, Plan)  (Ref. 2)

(Remembering is important because too often experts are retained after a case has been taken and the final technical conclusion might not support counsel’s assessed merit of the case)

My client learned that a forensic investigation takes time if it’s to meet the strict requirements of civil procedure rules governing experts, like Rule 55 in Nova Scotia.

***

I was asked by my client if I could investigate a catastrophic failure resulting in personal injury and issue an expert’s report a few days later.  It would be difficult to examine the property after that.

I couldn’t, of course, and meet the requirements of Rule 55.  A few days might be just enough time to do preliminary work like read documents on the case and visually examine the site.

There is time to investigate the other two accidents discussed with my client.  I know the expertise needed for the major accident.  It appears clear cut.  That for the more minor accident – still serious and painful, is less clear but will possibly involve four areas of expertise: Design, construction, a trade and construction inspection.

References

  1. How experts are retained in civil litigation is changing – and the changes are good for counsel and the justice system.  Posted May 1, 2014
  2. Using SOAP notes in forensic engineering investigation.  Posted February 6, 2014

 

 

Civil litigation, forensic engineering and motor vehicle accident reconstruction

You might be interested in CATAIR, the Canadian Association of Technical Accident Investigators and Reconstructionists.

It’s quite a mouthful but members of this national group do exactly that – figure out why and how a traffic accident happened, reconstruct it.  Not too much different than figuring out why a building, bridge or mall collapsed or a person slipped and fell.  The objectives are the same, the techniques are different.

This type of person – a reconstructionist, could show up in your civil case, engineering investigation or insurance claim’s file. One did on an engineering investigation of mine.

I attended the first session Sunday evening of CATAIR’s annual, week long AGM at the Holiday Inn, Halifax.  The meeting is held in conjunction with a five day advanced collision reconstruction course.  Getting familiar with new technology – a “silver box” in this case, to collect data on a collision from a vehicle’s black box.

An estimated 22 people will take the course.  They come from across Canada and several U.S. states.  I spoke with fellows from South Carolina, British Columbia, Alberta, Ontario and New Brunswick. Another is up from Missouri.  The course is being given by a well regarded chap from Maryland.

Similar groups exist in the U.S. but they are not national in scope – and a bit international, like CATAIR.

Many of the people taking the course are police officers or were at one time.  Some others are private consultants – engineers and technologists of various stripes. Almost all investigate and reconstruct motor vehicle collisions.  One, the chap in N.B., has gone on to educate truck fleet owners on avoiding collisions.

These people are very busy.  The officers from Alberta and Ontario reconstruct collisions full time – no foot or car patrols for them.  Not surprisingly, considering that there are approximately 3,000 motor vehicle fatalities in Canada each year and 15 times that in the U.S. Then there are the serious injury accidents that are investigated and reconstructed.

I was introduced to the group by engineering colleagues of mine, private consultants Dr. Stu Smith, Cliff Tyner and Al Tupper who reconstruct motor vehicle accidents.  Ken Zwicker, President of the Atlantic provinces chapter of CATAIR, also a private consultant and former RCMP officer, has been quite supportive of my interest in the group.

My interest in CATAIR and accident reconstruction stems from my interest in different engineering and scientific investigative procedures and techniques and their application to forensic engineering.  I was quite impressed a couple of years ago when I learned from Stu and Al of the quite rigid testing and analysing carried out in motor vehicle accident (MVA) reconstruction.

I investigated the cause of the John Morris Rankin fatal MVA a few years ago for the RCMP.  I realize now that the police at the time gave me the results of a collision reconstruction by one of their own.  Basically a description of the accident and the vehicle speed at the time.  I was asked to establish if the pile of salt on the highway contributed to the accident.

I did this with full scale field testing – similar to that done in speed bump design, using the same type of vehicle driven by Mr. Rankin, a Toyota 4-Runner.  I filmed the testing and this filming was key to demonstrating the contribution.

There are different types of accident investigation – police, insurance and workman’s compensation to name three.  The results of collision reconstruction could contribute to any one of them:  And show up in your civil litigation case or insurance claim’s file, as one did in mine.

 

 

Counsel, tell your expert about the Rule governing expert opinion. It’s important

Make sure your expert knows about this Rule before he starts his investigation. Particularly the sub-section on the content of an expert’s report. (Ref. 1)  Abiding by the Rule, as required by the judicial system, may increase the time spent gathering data – the forensic engineering investigation, and also the time spent analysing the data and writing the report.  Increased time means increased cost.

This is possible – higher costs, for the small to medium size forensic investigations typical in Atlantic Canada and I suspect across the country.  Certainly when these investigations are complex.

Experts are unlikely familiar with the Rules in the same way that lawyers are unlikely familiar with the expert’s field of practice.

Engineers sometimes investigate a failure or an accident and report the cause but stop short of a detailed description of what they did.  Particularly the technical analysing and reasoning lest counsel’s eyes glaze over.  Many lawyers just want an answer – “and spare me the details”.  This might be the case when the engineer is retained as a consulting expert rather than a testifying expert.

Knowing about the Rule and that it requires more comprehensive reporting doesn’t mean estimating the cost of the forensic investigation is any easier. (Ref. 2)  It just alerts counsel and the expert to the information that must be reported and that costs may be higher.

1. Things leading to the opinion

The expert’s report, according to the Rule, must include everything the expert regards as relevant to the expressed opinion.  This approximates a full engineering report.

Everything means that the report contains all of the following information to support the opinion (I have expanded and added to the statements in the Rule according to how engineers investigate failures and accidents):

  1. Identify and describe in detail the steps and tasks carried out during the investigation and the purpose of each.
  2. Describe any research carried out.
  3. List and describe the data obtained from each task.
  4. Analyse the data from each task and any research – its nature, what it means, how the data from the different tasks are related to each other, and how each is related to the failure or the accident.
  5. Fully explain the reasoning leading to the opinion.
  6. Describe a test(s) to formulate or confirm the opinion.
  7. State the degree of certainty with which the opinion is held.
  8. State any qualification put on the opinion because of the need for further investigation or for any other reason.
  9. Reference all the literature and other material consulted in arriving at the opinion.
  10. List the documents and other information acquired to prepare the opinion.

This is comprehensive reporting.  It takes time and it can be expensive particularly in a complex case.

2. Things leading to a different opinion

But the Rule also requires that the expert’s report draw attention to anything that could reasonably lead to a different conclusion.  If “drawing attention” to “anything” means identifying and investigating other interpretations of the data, or follow-up investigations, then including the listed information on these things takes time.  It may not mean exhaustive investigating and reporting but even a little more adds to the cost of an expert’s opinion..

Experts may not expect such comprehensive report requirements. It’s important to give an expert a heads-up at the time he is being retained and before he starts his investigation.  I was given a copy of this rule by counsel shortly after it was published – after I had carried out a forensic engineering investigation but before I had written my report.  It turned out okay but we like to know about such requirements before we start an investigation.

References

  1. Nova Scotia Civil Procedure Rule 55, sub-section 55.04
  2. A bundle of blogs: A civil litigation resource list on how to use forensic engineering experts.  Posted November 20, 2013 (Contains blogs on estimating the cost of forensic investigations)