Forensics in Various Engineering Disciplines

Forensics in Structural Engineering

Columbia University describes structural forensic engineering in the following terms, [21]: "Engineering investigation and determination of the causes of structural failures of buildings, bridges and other constructed facilities, as well as rendering opinions and giving testimony in judicial proceedings, often referred to as Forensic Structural Engineering, has become a field of professional practice of its own in the US.

Fig. 22. 3 by 3 risk matrix used to assess risk

“With rapid economic development, increased design sophistication, more-and-more daring construction technology and accelerated project delivery came the proliferation of structural failures throughout the world. Several countries are reviewing and/or streamlining technical, business, and legal procedures modeled on US practices - with both their advantages and faults - which require expert consultants/witnesses in both the forensic investigation and in the ensuing dispute resolution."

Structures are the most common civil engineering products which fail in accidents.

Mechanics and structural engineering, and more recently biomechanics, are my forte, and I try to accept assignments primarily in that area, computer graphics running a close second. I have found that tools of the trade here should include:

• Strength and properties of materials, and structural testing;
• Mechanics and structures analysis tools, both classical and digital;
• Fair degree of familiarity with biomechanics analysis;
• Strong fundamentals of various factors that make structures and components stand up or fall down - not ignoring very basic statics and dynamics; and,
• Associated skills like computer spreadsheets and graphics. 

Carper  lists the common causes of structural failures, as follows:

• Site selection and site development errors;
• Planning  deficiencies - high client expectations;
• Design and/or construction errors;
• Material deficiencies; and,
• Operational errors, such as alterations, use change, inadequate maintenance, etc.

Non-destructive testing (NDT) at the site and destructive testing in the lab are the common investigative test methods in structures.

In particular, concrete is quite amenable to NDT [23], as shown in Table 3.

Table 3. Non-destructive testing methods

Forensics in Transportation Engineering

On this, Hochstein [24] states, "Forensic engineering in transportation matters requires the application of basic Traffic and Transportation Engineering principles in investigating, analyzing, reporting and testifying with regard to an incident on, or the design, operation, and maintenance of, a transportation facility, a building, commercial, residential and other public sites, pedestrian areas, etc. It may require services such as accident reconstruction, right-of-way appropriation, pedestrian fall down, driver behaviour, design defects, signing, seat belts, code reinforcement, vehicle mechanics, maintenance practices, etc."

 As traffic injuries and fatalities are the most common around the world, forensic analysis of traffic accidents is a very essential professional service, and many companies and experts thrive from it. Re-creation and simulation constitute a very large part of the investigation.

Forensics in Geotechnical Engineering

Saxena [25] opines: "Forensics in the geo-domain encompasses an extensive array of topics with general emphasis in civil engineering and specific emphasis in geotechnical and related fields having geological, geophysical, geo-environmental, and structural applications. Mostly, it applies to failures after they occur when their application has prevented and/or identified failures prior to their occurrence. Furthermore, cases of analyses and evaluation of selected remedial measures, along with their effectiveness and economy, are normally subjected to judicial scrutiny."

As geo-technical engineering deals with properties of soil and other natural materials of which we can find only limited data from which we must extrapolate to the rest of the domain, and as these natural materials are susceptible to wide variations with complicated interactions with structures built in and on them, any accident which involves natural earth can get highly complex in its investigation. Experts here should be really experienced in their work and be willing to face a lot of argument in their testimony. Singapore, induced by the Nicoll Highway collapse discussed earlier, has in recent years highlighted the importance of sound geo-technical analysis and design, and emphasised its role in accident prevention.