{"id":10448,"date":"2022-11-27T23:09:38","date_gmt":"2022-11-28T03:09:38","guid":{"rendered":"http:\/\/www.ericjorden.com\/blog\/?p=10448"},"modified":"2022-11-27T23:09:38","modified_gmt":"2022-11-28T03:09:38","slug":"what-happens-during-a-forensic-engineering-investigation","status":"publish","type":"post","link":"http:\/\/www.ericjorden.com\/blog\/2022\/11\/27\/what-happens-during-a-forensic-engineering-investigation\/","title":{"rendered":"What happens during a forensic engineering investigation?"},"content":{"rendered":"\n

(Abstract: <\/span><\/strong>The following is a detailed description of the tasks that an engineer carries out during a forensic investigation. This type of investigation determines the cause of a failure or accident as a means of assisting the resolution of disputes. <\/p>\n\n\n\n

(The description is based on my engineering experience in eastern and western Canada, the Yukon, off-shore Nova Scotia and the Beaufort Sea, and overseas. I also relied on 11 well regarded references on forensic and engineering investigation. My description is characterized by a list of tasks as well as 19 sub-lists that help the reader easily understand what’s involved.<\/p>\n\n\n\n

(Understanding the tasks is easy, estimating the cost of the tasks can be difficult. An Appendix <\/span><\/strong>on costs helps the reader understand this difficulty. <\/p>\n\n\n\n

(This blog was originally posted on July 15, 2013. There is little change in forensic investigation in 10 years. What has improved even more is encouraging: <\/p>\n\n\n\n

  1. Increased reliance on visual and virtual site assessments by an experienced engineer<\/li>
  2. Using drones to take low level aerial video of failure and accident sites both indoors and out<\/li>
  3. Strict guidelines for objective expert reports<\/li>
  4. Interest in peer review<\/li>
  5. Amicable dispute resolution well before the court house steps have been reached<\/li><\/ol>\n\n\n\n

    (It’s interesting that a list like the above has proved useful in this Abstract<\/span><\/strong> as was found to be the case 10 years ago in the following updated blog)<\/p>\n\n\n\n

    ***<\/p>\n\n\n\n

    Introduction<\/span><\/h1>\n\n\n\n

    How do clients benefit?<\/strong><\/span><\/p>\n\n\n\n

    Counsel benefits, as well as insurance claim managers, when they have some understanding of forensic engineering investigation.  An investigation determines why – the cause – a structure failed or did not perform properly, or why an accident happened.<\/strong><\/span><\/em>  <\/strong>Included are environmental accidents, fuel oil spills, and slips, trips and falls. Structures are anything in the built environment.<\/p>\n\n\n\n

    The process followed by experienced engineers results in a <\/strong>thorough <\/strong><\/span>investigation that leads to an objective<\/span> <\/strong>opinion on cause.  The results can be given in a well written report to standards like civil procedure Rule 55 in Nova Scotia.<\/p>\n\n\n\n

    What does this blog set out to do?<\/strong><\/span><\/p>\n\n\n\n

    The following identifies and describes the typical steps, the tasks in a forensic engineering investigation. <\/p>\n\n\n\n

    Investigations can be complex and time consuming involving all the steps in the process.  Or simple and quick, particularly when some steps are not needed because of the nature of the failure or accident, or there’s interest in focusing on one key element in the problem. <\/em><\/p>\n\n\n\n

    The engineer’s experience can also simplify an investigation.  For example, I saw the reason ice was falling from a roof – from across the street with binoculars.  And another time, the reason for a trip and fall accident in a couple of photographs sent me.  Still another, the reason for a fatal motor vehicle accident – even the standard field tests I had to carry out were dangerous.<\/p>\n\n\n\n

    The process is followed regardless of whether the professional engineer is retained by the plaintiff or the defendant, a claims manager or the property owner, and whether retained as a consulting expert or a testifying expert.<\/p>\n\n\n\n

    The process is also followed in spite of the fact that the great majority of disputes are settled out of court – many quite amicably after the evidence is in.<\/p>\n\n\n\n

    The word \u201cforensic\u201d from the Latin forum<\/em> indicates that the investigative findings assist the justice system resolve a dispute. That\u2019s certainly the case if the thoroughness of a forensic investigation keeps a dispute out of court.<\/p>\n\n\n\n

    What is a structure and how many ways can it fail?<\/strong><\/span><\/p>\n\n\n\n

    A structure is anything in the built environment. Look around you – the built environment comprises many 100s of different structures that could go wrong in some way. And 100s of ways an accident can happen.<\/p>\n\n\n\n

    A structure also includes alterations of the natural environment like highway embankments, earth and rock slopes, land drainage and tunnels driven through soil or rock to carry highways or water.  <\/p>\n\n\n\n

    A failure can involve total or partial collapse of a structure or inadequate performance of it’s components.<\/p>\n\n\n\n

    A blog I posted in 2020 is informative as to the number of structures in the built environment and the many ways they can fail. Scary to be truthful. See, What’s in “…the built environment” and how many ways it can fail? <\/em>Posted July 8, 2020. Look at some of the references too.<\/p>\n\n\n\n

    Fundamental tasks in all forensic investigations<\/strong><\/span><\/p>\n\n\n\n

    There are four basic steps in a forensic engineering investigation:<\/p>\n\n\n\n

    1. Gather data<\/strong><\/li>
    2. Analyse data<\/strong><\/li>
    3. Draw conclusions <\/strong><\/li>
    4. Form opinion<\/strong><\/li><\/ol>\n\n\n\n

      Before and after the failure or accident<\/span><\/strong><\/p>\n\n\n\n

      At some point during an investigation we are interested in establishing a before-after scenario:<\/p>\n\n\n\n

      1. What were the conditions existing before the failure or accident?<\/li>
      2. What took place during the incident?<\/li>
      3. What are the conditions existing afterwards \u2013 the property damage, the injuries?<\/li>
      4. What caused the incident?<\/li><\/ol>\n\n\n\n

        Standard tasks in a forensic engineering investigation<\/strong><\/span><\/p>\n\n\n\n

        Rigid formulae for investigating failures and accidents do not exist.  But all forensic engineering investigations contain the following steps to a greater or lesser degree.<\/p>\n\n\n\n

        1. Review documents<\/strong><\/li>
        2. Visually assess the failure or accident site<\/strong><\/li>
        3. Video the site from the air with a drone mounted camera<\/strong><\/li>
        4. Field investigations<\/strong><\/li>
        5. Laboratory investigations<\/strong><\/li>
        6. Research<\/strong><\/li>
        7. Follow-up investigations<\/strong><\/li>
        8. Analyse data <\/strong><\/li>
        9. Draw conclusions<\/strong><\/li>
        10. Form opinion<\/strong><\/li>
        11. Assess<\/strong> repair and remediation<\/strong><\/li>
        12. Write<\/strong> report<\/strong><\/li><\/ol>\n\n\n\n

          A visual assessment can be broken down further:<\/span><\/strong><\/p>\n\n\n\n

          1. Visit and visually assess the site<\/li>
          2. Take low level aerial video with a drone mounted camera<\/li>
          3. Take terrestrial photographs with hand-held and dash cameras <\/li>
          4. Interview witnesses<\/li><\/ol>\n\n\n\n

            Field investigations can also be broken down:<\/span><\/strong><\/p>\n\n\n\n

            1. Describe the failure or <\/strong>accident<\/li>
            2. Survey and document the damage to the structure<\/li>
            3. Determine how the structure was built<\/li>
            4. Determine the site conditions<\/li><\/ol>\n\n\n\n

              Research too:<\/span><\/strong><\/p>\n\n\n\n

              1. Desk studies <\/strong><\/li>
              2. Leg work<\/strong><\/li>
              3. Identify building codes and industry guidelines<\/strong><\/li>
              4. Assess the standard of care<\/strong><\/li><\/ol>\n\n\n\n

                Most of an investigation involves gathering data and most of the report – more than 3\/4 – involves analysing and presenting the data.  This points to the importance of the data gathering.  The degree of certainty in the opinion on the cause of the failure or accident is often a function of the amount of data gathered.<\/p>\n\n\n\n

                In fact, guidelines on failure investigation and forensic engineering issued by national engineering associations (see the References) have strong advice for professional engineers: – “Take only those cases where you can carry out a thorough investigation and gather enough data to be able to give an objective and reliable opinion<\/em>“<\/span><\/strong>.<\/p>\n\n\n\n

                Following is a brief description of each task in the investigative process:<\/p>\n\n\n\n

                1.<\/strong> Document Review<\/strong><\/span><\/h1>\n\n\n\n

                Review documents<\/span><\/em><\/strong><\/p>\n\n\n\n

                Reviewing documents provided by the client is an important first step in a forensic engineering investigation.  These documents sometimes provide the only data available to an engineer investigating a failure or accident. Documents include material like the following:<\/p>\n\n\n\n

                1. Client narrative<\/li>
                2. Discovery transcripts<\/li>
                3. Text material<\/li>
                4. Geotechnical reports<\/li>
                5. Structural design reports<\/li>
                6. Environmental assessment reports<\/li>
                7. Drawings and site plans<\/li>
                8. Construction and site photographs<\/li>
                9. Damage photographs<\/li>
                10. Maintenance records<\/li>
                11. Weather reports – usually rainfall<\/li><\/ol>\n\n\n\n

                  Additional published documents often researched by a professional engineer include:<\/p>\n\n\n\n

                  1. Legal surveys and descriptions<\/li>
                  2. Land development and drainage plans<\/li>
                  3. Aerial photography of the area of the site<\/li>
                  4. Topographic and contour maps<\/li>
                  5. Surficial and bedrock geology maps<\/li>
                  6. Agricultural soil maps<\/li>
                  7. Hydrological maps and studies<\/li>
                  8. Hydrogeological maps and studies<\/li>
                  9. Flood plain mapping<\/li>
                  10. Mining activity mapping<\/li><\/ol>\n\n\n\n

                    Documents like these are often studied a number of times during the different stages of an investigation.<\/p>\n\n\n\n

                    Form hypothesis and plan investigation<\/span><\/em><\/strong><\/p>\n\n\n\n

                    Information from the documents along with an initial site visit and visual assessment enables the professional engineer to plan the investigation based on what he thinks caused the failure or accident \u2013 his initial hypothesis.  Investigations are designed to confirm, revise, or refute the initial hypothesis.<\/p>\n\n\n\n

                    The assumptions made underlying the professional engineer\u2019s initial thoughts on the incident are identified and documented. <\/p>\n\n\n\n

                    Implicit in the most thorough investigations is an effort to also prove a failure or accident did not occur in some way different from the forensic engineer’s initial hypothesis.<\/p>\n\n\n\n

                    Format of some forensic investigations<\/strong><\/span><\/em><\/p>\n\n\n\n

                    Well planned investigations are sometimes set out as follows:<\/p>\n\n\n\n

                    1. Task.<\/strong> Identify and describe each task.<\/li>
                    2. Purpose.<\/strong>  State the purpose of each task – what is hoped to be learned.<\/li>
                    3. Data.<\/strong>  Describe what is actually learned, the data gathered.<\/li><\/ol>\n\n\n\n

                      This simple format enables the investigation to be easily described in detail in a report later, and more easily understood by the reader.  It also enables development of a timeline for the forensic investigation. My forensic reports follow this format.<\/p>\n\n\n\n

                      The format is much the same as a \u201cwork breakdown structure<\/em>\u201d<\/span> in the field of project management.  The \u201cwork\u201d in this case is the forensic engineering investigation that has been \u201cbroken down\u201d into different tasks.<\/p>\n\n\n\n

                      Determine the before-after scenario<\/span><\/em><\/strong><\/p>\n\n\n\n

                      In checking the hypothesis, engineering investigations determine the before-after scenario (see Introduction):<\/p>\n\n\n\n

                      1. The nature of the area the structure is in and the ground beneath the structure – the terrain, geomorphology and surficial geology of the area<\/li>
                      2. How the structure was built initially, and its conformance to the design and construction plans<\/li>
                      3. What took place during the failure or the accident, and,<\/li>
                      4. The nature and extent of the damage, inadequate performance, or injuries<\/li><\/ol>\n\n\n\n

                        2.<\/strong> Visual Assessment<\/strong><\/span><\/h1>\n\n\n\n

                        Visit and visually assess site<\/span><\/em><\/strong><\/p>\n\n\n\n

                        This step involves visiting the site as soon as possible after the failure or accident.  The professional engineer walks and pokes around the site \u2013 kicks the tires in a sense <\/em>– to get a feel for where things are and the nature and extent of the damage. He visually examines exposed surfaces.  It’s a very simple task, not very technical at all, but invaluable in getting a feel for the scene and bringing the documents to life.<\/p>\n\n\n\n

                        It helps to dictate to a smartphone what is being seen and done during the visual assessment.<\/p>\n\n\n\n

                        Sketching and measuring what seems to be relevant is started at this early stage.  Measuring, testing, and quantifying in a number of different ways often characterizes an investigation carried out by a professional engineer.<\/p>\n\n\n\n

                        Photograph and videotape site<\/span><\/em><\/strong><\/p>\n\n\n\n

                        Photographing and videoing the failure or accident site and the collapsed structure is an important initial step. The sooner the better before remedial work alters conditions.<\/p>\n\n\n\n

                        Equally important is a caption or descriptive note for each photograph stating:<\/p>\n\n\n\n

                        1. What was photographed and videoed<\/li>
                        2. The position of the camera and the view captured<\/li>
                        3. Why the object was photographed<\/li>
                        4. What to look for in studying the photographs and video, and,<\/li>
                        5. The date and time.<\/li><\/ol>\n\n\n\n

                          Interview witnesses<\/span><\/em><\/strong><\/p>\n\n\n\n

                          Interviewing witnesses to the failure or accident and the conditions existing beforehand is also an important initial step.  It should be done as soon as possible after the incident while memories are fresh and site conditions unchanged.  Record names and addresses in the event the witness must be called to testify at a hearing later.<\/p>\n\n\n\n

                          3.<\/strong> Drone Photography<\/strong><\/span><\/h1>\n\n\n\n

                          Describe the failure or accident<\/em><\/strong> from the air<\/em><\/strong><\/span><\/p>\n\n\n\n

                          This task involves taking low level aerial video of the failure or accident site with a camera fixed to a drone. Video is taken from eye level to a few 10s of metres above the site. Screen grabs or stills can be taken off the video and inserted in the report. Site plans can be easily generated from the stills.<\/p>\n\n\n\n

                          Re-enactments of slip and fall and traffic accidents can also be photographed from different heights above the site, and also from different directions and distances. Traffic accidents or their re-enactment can also be captured with video cameras mounted on the dashboard of vehicles – dash<\/em> cameras.<\/p>\n\n\n\n

                          Copies of the video can be distributed to parties interested in the failure or accident to facilitate discussion on the telephone or via Zoom or Microsoft Teams meetings.<\/p>\n\n\n\n

                          We can get high resolution video of sites in urban areas from Google Earth today; we can get even better from drone video.<\/p>\n\n\n\n

                          Apps are available to plan drone video of a site several days in advance of a site visit that is several hours driving away.<\/p>\n\n\n\n

                          I’ve taken drone video of all my sites in recent years and the coverage has proved invaluable. For example: <\/p>\n\n\n\n

                          1. It solved a road re-aligment problem: Drone video demonstrated what went wrong during design and construction, <\/li>
                          2. Aerial video enabled me to identify the cause of a retaining wall failure, <\/li>
                          3. Drone video helped me assess the depth of the water table beneath a fuel oil contaminated site – I was surprised at what I saw, <\/li>
                          4. Low level video pointed the finger at the likely cause of a nail gun accident, and,<\/li>
                          5. Drone video showed how poor land drainage is causing a dangerous situation for kids in the winter time.<\/li><\/ol>\n\n\n\n

                            4.<\/strong> Field Investigations<\/strong><\/span><\/h1>\n\n\n\n

                            Describe the failure or accident<\/span><\/em><\/strong><\/p>\n\n\n\n

                            This task records what happened during the failure or accident based on the comments of the witnesses interviewed and information from the documents.  Interviewing people who were there, and saw or experienced the failure if it was a sudden collapse of a structure, or an accident, is particularly valuable to the description.<\/p>\n\n\n\n

                            Survey and document the damage to the structure<\/span><\/em><\/strong><\/p>\n\n\n\n

                            This stage involves recording the damaged condition of the structure that has collapsed or does not perform properly.  This is done with tasks such as the following:<\/p>\n\n\n\n

                            1. A visual examination and description of the structure’s condition,<\/li>
                            2. Measuring the extent and location of the damage, and,<\/li>
                            3. Photographing and videoing the damage.<\/li><\/ol>\n\n\n\n

                              These tasks should be carried out as soon as possible after the failure before data and evidence are altered or lost.  The information enables a before-after comparison to be made after the next task is completed.  This type of comparison is often helpful as noted.<\/p>\n\n\n\n

                              Determine how the structure was built<\/span><\/em><\/strong><\/p>\n\n\n\n

                              This stage determines how the structure was built and whether or not it conformed to the design.  Also, whether or not the design and construction conformed to the standards of the day.  This information is obtained from the design and construction plans.  Also from research of building codes and industry guidelines existing at the time and checking these against the structure on site.  Tasks involved in this step include the following:<\/p>\n\n\n\n

                              1. Obtaining copies of the design and construction drawings – often quite similar<\/li>
                              2. Checking that the design conforms to the building code and good engineering practice<\/li>
                              3. Checking that the construction drawings conform to the design<\/li>
                              4. Obtaining a copy of the as-built <\/em>drawings – drawings that record changes made during construction for various reasons<\/li>
                              5. Checking that the existing structure conforms to the as-built <\/em>drawings.  This involves examining and measuring the different components of the structure.  It often involves taking things apart or using remote sensing techniques to detect what is below the surface.  To facilitate this examination, drawings of the damage might be superimposed on the as-built<\/em> drawings.  This superimposing would eventually be done during the data analysis (see below)<\/li>
                              6. In the absence of drawings – often the case for older structures – measure the structure and prepare drawings, and then superimpose sketches of the damage<\/li><\/ol>\n\n\n\n

                                How many of these tasks are carried out and in what detail depends on the situation, the structure, and the failure.  Sometimes very little of the above is done.  Sometimes it’s enough just to measure and prepare sketches of the damage and view and study the structure with these sketches in hand.<\/p>\n\n\n\n

                                Determine the site conditions<\/span><\/em><\/strong><\/p>\n\n\n\n

                                The site <\/em>is the area where the structure is located including other structures nearby.<\/p>\n\n\n\n

                                The site conditions of interest at this stage of the forensic engineering investigation include:<\/p>\n\n\n\n

                                1. The lay of the land, the terrain, the topography<\/li>
                                2. Surface features like bedrock exposures, sinkholes, and wet land<\/li>
                                3. Drainage features like ponds, lakes, and water courses (hydrology)<\/li>
                                4. Subsurface and foundation soil and rock conditions (geotechnology)<\/li>
                                5. Groundwater conditions (hydrogeology)<\/li><\/ol>\n\n\n\n

                                  Investigating and determining site conditions includes:<\/p>\n\n\n\n

                                  1. Photographing and videoing the site<\/li>
                                  2. Aerial photography, drone video and map making<\/li>
                                  3. Topographic and contour surveys<\/li>
                                  4. Drainage and groundwater studies<\/li>
                                  5. Geotechnical and foundation soil and rock investigations<\/li>
                                  6. Environmental assessments<\/li>
                                  7. Field tests like skid resistance tests, plate load tests and pile load tests<\/li>
                                  8. Accident reconstruction<\/li><\/ol>\n\n\n\n

                                    Detailed topographic and elevation surveys are usually made when the failure of a building or a civil engineering structure, or the cause of an accident, is thought to involve the terrain in which the site is located.<\/p>\n\n\n\n

                                    Drainage studies (hydrology, hydrogeology) are made when surface or groundwater may have been a factor in a failure or an accident.<\/p>\n\n\n\n

                                    Geotechnical and foundation investigations may be necessary if the cause of the failure of a structure appears to be in the foundations or the subsurface soils.<\/p>\n\n\n\n

                                    Full scale field tests and accident reconstruction may be carried out.  This is done when these methods are assessed as the most reliable means of gathering data on the effects of the terrain, and features in it, on the failure or the accident.<\/p>\n\n\n\n

                                    Slip, trip and fall accidents<\/span><\/em><\/strong><\/p>\n\n\n\n

                                    Almost all of what is done and described above at the site of a structure’s failure: <\/p>\n\n\n\n

                                    1. Document review<\/li>
                                    2. Visual assessment<\/li>
                                    3. Drone video<\/li>
                                    4. Field investigations<\/li><\/ol>\n\n\n\n

                                      is carried out at the sites of slip, trip and fall accidents. The structure<\/em> in this case is the person’s body<\/em> that collapsed in every sense of the word – was caused to fall down, often by something at the site. <\/p>\n\n\n\n

                                      I tripped one time because of a 1″ to 2″ difference in the height of a curb – not my fault. Another time I stood on my dog’s lease so she couldn’t run off. However, she had a mind of her own and dashed off jerking the lease from under me and causing me to fall down\/collapse\/fail, hard – my fault.<\/p>\n\n\n\n

                                      In addition to the usual field and site investigations, the skid resistance of the surface where a person slipped and fell is measured – the coefficient of friction in high school physics. There is a standard of care for the procedure that is reflected in a basic field investigation as outlined above – going from the simple to the more accurate.<\/p>\n\n\n\n

                                      5.<\/strong> Laboratory Investigations<\/strong><\/span><\/h1>\n\n\n\n

                                      At this stage in the investigation, it is sometimes necessary to carry out laboratory tests.  These would determine the chemical, physical, mechanical, strength, and\/or drainage properties of materials used in construction at the site of a failure or an accident.  It might be necessary to analyse the toxic fumes emitted by a compound or product used in construction.<\/p>\n\n\n\n

                                      Typical materials used in construction are soil, rock, steel, concrete, wood, plastic, adhesives, asphalt, and masonry products.<\/p>\n\n\n\n

                                      Composite materials like asphalt or reinforced concrete can be taken apart in a laboratory to determine how the material was formed.  For example, the location, type, and size of reinforcing steel in a reinforced concrete slab that failed.<\/p>\n\n\n\n

                                      6. Research<\/span><\/h1>\n\n\n\n

                                      Desk studies and leg work<\/span><\/em><\/strong><\/p>\n\n\n\n

                                      To some extent, research studies during a forensic engineering investigation \u2013 desk studies in some engineering disciplines – are on-going like document review.<\/p>\n\n\n\n

                                      The work often involves literature searches, telephone and internet work, and leg work to sources outside the office like libraries and the offices of persons to interview and consult with.<\/p>\n\n\n\n

                                      It also involves research and study of aspects of the engineering investigation that have assumed some relevance.  For example, <\/p>\n\n\n\n

                                      1. Past mining activity in an area, <\/li>
                                      2. The standard of care at the time the structure was designed and constructed, <\/li>
                                      3. The shrinkage and compressive properties of a fill material, and, <\/li>
                                      4. The different modes of failure of a soil-steel bridge.<\/li><\/ol>\n\n\n\n

                                        Research also identifies and gathers together all information in appropriate categories relevant to the investigation (see Document Review above).  This would be information missing from the documents provided by counsel or the claims manager.  Information like original construction and as-built<\/em> drawings, geotechnical and environmental reports, and published mapping of the area.  Availability of the material would be determined and copies obtained if possible.<\/p>\n\n\n\n

                                        Also during this step in the forensic investigation the need is identified for additional engineering and scientific specialists to investigate some aspect of the failure, and to study relevant findings.  Specialists would be identified, contacted, and conferred with about their possible contribution, and retained if necessary.<\/p>\n\n\n\n

                                        Identify building codes and industry guidelines<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        Of particular importance during the research stage would be the identification of building codes and industry guidelines.  Also the standard of care followed at some period relevant to the design and construction of the failed structure, or the structure involved in the personal injury accident.<\/p>\n\n\n\n

                                        Identify applicable government and industry codes, standards, regulations, and guidelines.  Include national and international codes that are relevant to the failure or accident and relied on locally.  Search and identify technical papers and state-of-the-art reports that relate to the problem and review this material.<\/p>\n\n\n\n

                                        Identify standard of care<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        This could be an important task during a forensic engineering investigation if the findings might be presented during a more formal dispute resolution process or at trial.<\/p>\n\n\n\n

                                        The standard of care is the standard commonly applied by professionals or other workers practicing the same discipline or trade in the same area at the time the structure(s) was designed and constructed that was involved in the failure or accident.<\/p>\n\n\n\n

                                        Identifying the standard can be quite simple or very involved and time consuming.  It involves interviewing other professional engineers and\/or workers practicing in the area at the time the structure was designed and constructed to determine the procedures they followed and the standards they employed.  If there is wide variance you would speak with more people until you feel satisfied you know the average.<\/p>\n\n\n\n

                                        If there were two small firms practicing in the area at the time then it’s easy. For example, a soil-steel bridge failure that I investigated.<\/p>\n\n\n\n

                                        On the other hand, as in another case of mine, if there are 11 different types of firms and associations playing a part in the design and construction process associated with a failure or accident \u2013 providing different products and services – then it\u2019s difficult and time consuming.  You would need to identify and speak with a number of representatives of each type of firm and association \u2013 potentially dozens of people – to be satisfied you understand the standard followed at the time.<\/p>\n\n\n\n

                                        7.<\/strong> Follow-up Investigations<\/strong><\/span><\/h1>\n\n\n\n

                                        This task of carrying out one or more follow-up investigations<\/em> results from the need to “follow the evidence”<\/em>.  This concept hardly needs explaining to counsel and claims managers.  It is equally important in a forensic investigation.  <\/p>\n\n\n\n

                                        Data will be gathered and evidence uncovered during a previous investigation that suggests other things should be investigated.  This would be like cross-examination during discovery uncovering evidence that suggests a new line of questioning.<\/p>\n\n\n\n

                                        Implicit in the fact that there might be evidence that should be followed up is the possibility that the initial hypothesis on the cause of the failure or accident might need to be revised or rejected completely.<\/p>\n\n\n\n

                                        The possibility of the need for follow-up investigations is a fact of life during forensic engineering investigations.<\/p>\n\n\n\n

                                        8.<\/strong> Data Analysis <\/strong><\/span><\/h1>\n\n\n\n

                                        Lots of data is good but you\u2019ve got to do something with the data – draw meaning from it as to the cause of the failure or accident. This is what the dispute resolution process or a claim manager wants.<\/p>\n\n\n\n

                                        Data from one stage looked at critically<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        In analysing and reasoning to a conclusion, the data from any one stage of the investigation is looked at critically – taken apart, in a sense – and each part looked at carefully and how they are related and interact.<\/p>\n\n\n\n

                                        Identify typical modes of failure?<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        The data is also studied to see if it is characteristic of a mode of failure or a cause based on past experience or a mathematical calculation.  Professional engineers have identified and published typical modes of failure for the various structures in the built environment.  These are available for review and guidance to the forensic engineer during a forensic investigation.<\/p>\n\n\n\n

                                        Data from other stages looked at critically and for corroboration<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        The data from other stages of the forensic investigation are similarly looked at, and also studied to see if there is corroboration of conclusions between stages.  Pattern is looked for within individual data and amongst different sets of data.  And if there is a pattern, considering if it is typical of a known cause\/mode of failure.<\/p>\n\n\n\n

                                        Draw conclusions and confirm, revise, or refute hypothesis<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        At some point, conclusions are drawn from the analysis and the hypothesis confirmed, revised, or refuted.  If revised or refuted then a new hypothesis is formed and this investigated with follow-up forensic investigations.<\/p>\n\n\n\n

                                        If the initial hypothesis is confirmed then the cause of a failure or accident has been identified and an opinion can be formed.<\/p>\n\n\n\n

                                        Document reasoning<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        At all points in the analysis the reasoning followed is documented and the basis of the conclusions recorded.<\/p>\n\n\n\n

                                        Easy analysis<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        Sometimes the data analysis and development of an opinion is quite easy.  For example, in one of my investigations when field work uncovered a concrete floor slab that was supported by irregularly spaced columns. This type of slab beneath a structure was meant to be uniformly supported.  In this case it was easy to hold the opinion that the floor slab was inadequately supported.<\/p>\n\n\n\n

                                        Complex analysis<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        At other times it\u2019s complex.  For example, when there are more than 20 possible modes of failure for the collapse of a soil-steel bridge.  When the collapsed bridge is not available to examine, then the available data must be analysed for each mode and the cause identified by a process of elimination.<\/p>\n\n\n\n

                                        Mysterious analysis<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        Sometimes it\u2019s mysterious.  Why is there a toxic odour in the concrete enclosed lower level of a structure and the lighter-than-air fumes are not detected in the timber-framed upper levels?  A chance remark about timber structures “breathing” \u2013 are more pervious in engineering terms – solves the mystery as to cause.  The fumes in the upper levels diffuse through the exterior timber walls to the outside of the structure, and also through open doors and windows.<\/p>\n\n\n\n

                                        9.<\/strong> Draw Conclusions<\/span><\/h1>\n\n\n\n

                                        In some ways this is the easy part. You look and see if data collected from an investigative task points to the cause of the failure or accident. You then check the data from another task for an indication of cause. And still another. Etc. You cross-check causes. Is there agreement amongest the causes – a little a lot? Does the cause from one set of data support the cause from another? Is a common cause emerging? Are conflicting causes emerging? What is the preponderance of the causes pointing to as the cause of the structure’s failure or the person’s injury? How does this conclusion fit with published findings of cause of similar failures or accidents? At some point you stop – when you’re comfortable with your findings.<\/p>\n\n\n\n

                                        10.<\/strong> Form Opinion<\/span><\/h1>\n\n\n\n

                                        At this stage in a forensic engineering investigation, your view of cause forms in your mind. It slowly appears in your head as you analyse the data, reason and draw conclusions. You then tell the listener or the reader your opinion of cause and the basis for your view.<\/p>\n\n\n\n

                                        11. Repair and remediation<\/strong><\/span><\/h1>\n\n\n\n

                                        Often times near the completion of a forensic engineering investigation there is a need to plan and design repair of the damaged or failed structure, and then estimate the cost of the repair.  This repair cost contributes to an evaluation of the damages claimed in a lawsuit or by an insurance policy holder.  Occasionally the repair is constructed involving engineering supervision and inspection costs, which also contribute to the damages claimed.<\/p>\n\n\n\n

                                        12.<\/strong> Write Report<\/span><\/h1>\n\n\n\n

                                        Types of reports<\/span><\/em><\/strong><\/p>\n\n\n\n

                                        The report, in particular, the written report, is an important step in a professional engineer\u2019s investigation of a failure or accident.  It ‘s a documentation for the client and the dispute resolution process:<\/p>\n\n\n\n