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Counsel benefits when they have some knowledge of the forensic engineering investigative process that is followed by an expert.\u00a0 The process determines why a structure failed\u00a0or an accident happened.\u00a0\u00a0The process\u00a0results in a thorough investigation leading to an objective opinion rendered with considerable certainty.<\/p>\n
This item identifies and describes the steps in the process. The process is followed regardless as to whether the professional engineer is retained as a consulting expert\u00a0or a\u00a0testifying expert.<\/p>\n
A structure is anything in the built environment, including alterations of the natural environment like highway embankments and earth and rock slopes.\u00a0 A failure can involve total collapse of a structure or its inadequate performance.<\/p>\n
There are three fundamental components to the forensic engineering investigative process:<\/p>\n
Rigid formulae for investigating failures and accidents do not exist.\u00a0 But all forensic engineering investigations contain the following steps to a greater or lesser degree.<\/p>\n
Field investigations can be broken down further:<\/p>\n
Most of the investigation involves gathering data and most of the report – more than 3\/4, involves presenting and analysing the data.\u00a0\u00a0This points to the importance of the data gathering.\u00a0 The degree of certainty in the final opinion of the cause of the failure is often a function of the amount of data gathered and the budget for this.<\/p>\n
Following is a brief description of each step in the investigative process:<\/p>\n
Documents provided by counsel during the initial briefing are important in a forensic\u00a0engineering investigation.\u00a0 They sometimes provide the only data available to an engineer investigating a failure.\u00a0<\/em>Documents include items like the following:<\/p>\n Additional published documents almost always\u00a0researched by a professional engineer include:<\/p>\n Documents like these are often studied a number of times during the different stages of an investigation.<\/p>\n Information from the documents along with an initial site visit and visual assessment enables the engineer to plan the different investigations based on what he thinks caused the failure or accident \u2013 his initial hypothesis.\u00a0 Investigations are designed to confirm, revise, or refute the initial hypothesis.<\/p>\n In checking the hypothesis, engineering investigations determine:<\/p>\n This step involves visiting the site as soon as possible after the failure or accident, walking and poking around the site\u00a0to get\u00a0a feel\u00a0for where things are and the nature and extent of the damage, and\u00a0examining exposed surfaces.\u00a0 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 Measuring in a number of different ways characterizes the investigation carried out by professional engineers.<\/p>\n Describe the Failure or Accident<\/em><\/strong><\/p>\n This step involves learning what happened – getting a description of the failure\u00a0or accident by interviewing witnesses.\u00a0 This discription may be gleamed from the documents but talking with people who were there and\u00a0saw or experienced the failure – particularly if it\u00a0was a sudden collapse of a structure, or an accident, is\u00a0much better.<\/p>\n Survey and Document the Damage to the Structure<\/em><\/strong><\/p>\n This step involves recording the damaged condition of the structure that has collapsed or\u00a0does not\u00a0perform properly.\u00a0 The condition is recorded\u00a0by means of tasks such as the following:<\/p>\n This should be done as soon as possible after the\u00a0failure before data and evidence are altered or lost.\u00a0 The information enables a before-after comparision to be made after the next step is completed.\u00a0 This type of comparison is\u00a0often helpful.<\/p>\n Determine how the Structure is Built<\/em><\/strong><\/p>\n How the structure is built, whether or not it comforms to the design, and the adequacy of\u00a0the design is determined in this step.\u00a0 Also, whether\u00a0or not\u00a0the design\u00a0reflects the standards of the day.\u00a0 This information is\u00a0obtained from various\u00a0plans and\u00a0research of standards and checking these against the structure on site.\u00a0 Tasks involved in this step include the following:<\/p>\n How many of these tasks are carried\u00a0out and in what detail depends on the situation, the structure,\u00a0and the failure.\u00a0 Sometimes very little of the above is done.\u00a0 Sometimes it’s enough just to measure and prepare sketches of\u00a0the damage and view and study the structure with these sketches in hand.<\/p>\n Determine the Site Conditions<\/em><\/strong><\/p>\n The site is the area the structure is on\u00a0and the terrain beyond the site including other structures.<\/p>\n The site conditions of interest\u00a0at this stage of the investigation include:<\/p>\n Investigation of site conditions includes:<\/p>\n Detailed topographic and elevation\u00a0surveys 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 Drainage studies (hydrology) are made when surface or groundwater may have been a factor in a failure or an accident.<\/p>\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 Full scale field tests and accident reconstruction may be carried out.\u00a0 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 It is often necessary to carry out laboratory tests to determine the chemical, physical, mechanical, strength, and\/or drainage properties of materials used in construction at the site of a failure or an accident.\u00a0 It might be necessary to measure the toxic fumes emitted by a compound or product used in construction.<\/p>\n Typical materials used in construction are soil, rock, steel, concrete, wood, plastic, adhesives, asphalt, and masonry products.<\/p>\n Composite materials like asphalt or reinforced concrete can be taken apart in a laboratory to determine how the material was formed.\u00a0 For example, the location, type, and size of reinforcing steel in a reinforced concrete slab that failed.<\/p>\n To some extent, research studies and investigations \u2013 desk studies in some disciplines, are on-going like document review during a forensic\u00a0engineering investigation.<\/p>\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 It also involves research and study of aspects of the engineering investigation that have assumed some relevance.\u00a0 For example, past mining activity in an area, the standard of care at the time the structure was designed and constructed, the shrinkage properties of a fill material, and the different modes of failure of a soil-steel bridge.<\/p>\n Research\u00a0also identifies and gathers together all information in appropriate categories relevant to the investigation of the failure (see Document Review above).\u00a0 This would be information usually not contained in the documents provided by counsel during the initial briefing.\u00a0 Information like original construction and as-built drawings, geotechnical and environmental reports, and published mapping of the area<\/p>\n This task of carrying out one or more follow-up investigations results from the need to “follow the evidence”.\u00a0 This concept hardly needs explaining to counsel.\u00a0 It is equally important in a forensic investigation.\u00a0 Data will be gathered and evidence uncovered during\u00a0a previous investigation that suggests another\u00a0line of enquiry should be followed up or another area\u00a0investigated.\u00a0 This is like cross-examination during discovery\u00a0uncovering evidence that suggests a new line of questioning.<\/p>\n Implicit in\u00a0the fact that there\u00a0might be\u00a0evidence that should be followed\u00a0up is\u00a0the possibility that the initial hypothesis on the cause might need to be revised or rejected completely.<\/p>\n The possibility of the need for follow-up investigations is a fact of life\u00a0during\u00a0forensic engineering investigations.<\/p>\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 their interaction examined.<\/p>\n The data is also looked at closely to see if it is characteristic of or associated with a mode of failure or a cause based on past experience and\/or mathematical calculation.\u00a0 Professional engineers\u00a0have identified and published typical modes of failure\u00a0for the various structures in the built environment.\u00a0 These are available for review and guidance to the forensic engineer during a forensic investigation.<\/p>\n The data from other stages of the\u00a0forensic investigation\u00a0are similarly looked at, and also studied to see if there is corroboration of conclusions between stages.\u00a0 Pattern is looked for within individual data and amongst different sets of data.\u00a0 And\u00a0if there is a pattern, considering if it is typical of a known cause of failure.<\/p>\n At some point, when engineering judgment dictates, conclusions are drawn from the analysis and the hypothesis confirmed, revised, or refuted.\u00a0 If revised or refuted then a new hypothsis is formed and this investigated with follow-up forensic investigaions.<\/p>\n If the initial hypothesis is confirmed then\u00a0the cause of a failure has been identified and an opinion can stated.<\/p>\n Sometimes the data analysis and development of an opinion is quite easy.\u00a0 For example, when field work uncovers a concrete floor slab that is supported by irregularly spaced columns and the type of slab that should be\u00a0beneath the structure is required to be uniformly supported.\u00a0 Then it\u2019s easy to hold the opinion that the floor slab is inadequately supported.<\/p>\n At other times it\u2019s complex. \u00a0For example, when there are more than 20 possible modes of failure for the collapse of a soil-steel bridge.\u00a0 When\u00a0the collapsed bridge is not available to examine, then the data must be analysed for each mode and the cause identified by a process of elimination.<\/p>\n Sometimes it\u2019s mysterious.\u00a0 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?\u00a0 A chance remark about timber structures “breathing” \u2013 are more pervious, in a sense, in engineering terms, solves the mystery as to cause.\u00a0 The fumes in the upper levels diffuse through the exterior timber walls to the outside of the structure.<\/p>\n The report, in particular, the written\u00a0report,\u00a0is an important step in a professional \u00a0engineer\u2019s investigation of a failure or an accident.\u00a0 It is an objective\u00a0documentation for the judicial system of the methods used during the investigation, the data gathered, the analysis of the data, and the reasoning to an opinion on cause.\u00a0 It’s importance is highlighted by the fact that civil litigation rule changes in some provinces are resulting in the report often replacing the discovery stage.<\/p>\n The results of an engineer\u2019s investigation of a failure or an accident are presented in:<\/p>\n If possible, an oral report is given to\u00a0counsel as soon after the documents are read, an initial site visit and visual assessment\u00a0completed, and an initial hypothesis formed as to cause.\u00a0 The report will indicate the direction the investigation appears to be leading.\u00a0 This will\u00a0give counsel an\u00a0early indication as to whether the\u00a0professional engineer will serve as a consulting expert or as a testifying expert.<\/p>\n A written report is provided at completion of the investigation.\u00a0 It is prepared on instruction of counsel for the court and judge and submitted to counsel.<\/p>\n The need for supplementary reports\u00a0might depend on whether or not new evidence is\u00a0found during discovery, in follow-up investigations, or presented in rebuttal reports.<\/p>\n The outline of a report will vary depending on the nature of the failure or accident\u00a0and the extent of the investigation.\u00a0 Many will be in chronological order, generally the order of the steps in the forensic engineering investigative process.\u00a0 The process is a series of investigations and follow-up investigations.\u00a0 My reports generally:<\/p>\n References<\/strong><\/strong><\/p>\n The foregoing is based on several sources.\u00a0 The citations are not complete:<\/p>\n Copyright 2012, Eric E. Jorden. All rights reserved<\/p>\n <\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Counsel benefits when they have some knowledge of the forensic engineering investigative process that is followed by an expert.\u00a0 The process determines why a structure failed\u00a0or an accident happened.\u00a0\u00a0The process\u00a0results in a thorough investigation leading to an objective … Continue reading \n
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2. Visual Assessment<\/strong><\/h1>\n
3. Field\u00a0Investigations<\/h1>\n
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4. Laboratory\u00a0Investigations<\/h1>\n
5. Research<\/h1>\n
6. Follow-up Investigations<\/h1>\n
7. Data\u00a0Analysis and Formulation of\u00a0Opinion<\/h1>\n
8. Report<\/h1>\n
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