Structural analysis

DEFINITION: Evaluation of the engineering and construction of buildings and other structures.

SIGNIFICANCE: When structures fail or are deliberately damaged, forensic scientists are often involved in conducting analyses to determine exactly what occurred. Structural analyses can reveal whether structural failures were caused by design flaws, properties of the physical components used, or other factors. In cases of deliberate destruction by explosive or mechanical means, structural analyses can determine the nature of the criminal acts and provide investigators with information about possible suspects.

The analysis of architectural structures such as buildings, bridges, and highways involves the evaluation of the physical and chemical properties of their material components and the engineering theory behind the ways in which these components are put together, which includes the mechanics of the components’ elasticity and their response to natural laws such as the law of gravity. Construction design involves applied theoretical frameworks of physics, chemistry, and mathematics. Generally, when structural deformations and design failures occur, engineers and physicists perform structural analyses; when catastrophic structural failures take place that may have been caused deliberately, forensic engineers become involved in such analyses. Forensic engineers are also sometimes involved in examining structural failures that have led to property damage or personal injury lawsuits; they may be called upon to determine whether such failures resulted from poor design, problems with construction, or lack of maintenance.

Architectural Design and Construction

The designs of structures begin with architects and engineers. Architects provide the artistic designs, and engineers detail the construction elements required to achieve those designs. Construction engineers determine the types and amounts of materials needed for structural projects. Typically, they use computer models to conduct extensive tests and determine how much of each material will be required. They examine the spatial relationships among the components to be used, the amount of weight or pressure each beam or other part can hold, and how the completed structure will function. Usually, engineers construct computer models of each design component and test each virtually under all potential conditions and stresses, such as varying structural loads, earthquakes, and strong winds. These tests serve to identify any potential weaknesses that need to be eliminated in structural designs.

Forensic Engineering

Forensic engineering is a highly specialized branch of forensic science that is involved in the analysis of buildings and other constructed artifacts in legal cases of property damage, injury, and death. Most often, forensic engineers are called upon in cases concerned with liability issues resulting from property damage. In such cases, they help to determine the causes of structural failures.

The first task of a forensic engineer in a case of structural failure is to determine whether the structure of interest met all local, state, and federal building regulations, where applicable. To begin this process, an investigator must first determine the safety of any remaining parts of a structure. If a section of a building survives, then he or she must map out a safe route through the remaining parts of the structure. After saving any perishable or potentially unstable evidence, the investigator can then preserve samples, document conditions, and conduct interviews. 

If the case concerns a house or business, the engineer must find out whether the structure met all building codes specified by the planning and zoning regulations of the town in which it was located. The engineer then goes on to examine systematically the individual components of the structure and how they related to one another.

One of the most common applications of forensic science in cases of structural failure is the analysis of damaged structures in which fires of suspicious origin are implicated. In such cases, forensic experts—both engineers and fire investigators—examine the remains of the structures to determine the fires’ origins. They look at burn patterns and gather for chemical analyses to identify the possible presence of accelerants, which can point to arson.

Forensic engineers are also involved in maintaining safe structures by conducting materials tests and analyses of building codes and reconstruction costs. By analyzing completed existing structures, forensic engineers can provide those responsible for maintaining the structures with recommendations for repairs and improvements that can help the structures remain safe while performing in an efficient manner.

Legal Issues

Legal cases that involve structural or architectural failures are decided under the laws of product liability, which are based in the legal concept that consumers must be protected from harm caused by dangerous or unreasonably unsafe products. Under product liability laws, manufacturers and distributors are responsible for injuries or property damage resulting from poor design of their products (including buildings and components of buildings such as doors and windows). For example, if a bridge was designed to withstand certain load specifications but forensic engineers determine that it failed under lesser pressure, the construction company that built the bridge would be deemed responsible under product liability laws and would be liable to pay compensation for damages and injuries resulting from the structural failure.

Bibliography

Bosela, Paul A., and Norbert J. Delatte, eds. Forensic Engineering: Proceedings of the Fourth Congress. Reston, Va.: American Society of Civil Engineers, 2007.

Brown, Sam, ed. Forensic Engineering: Part 1; An Introduction to the Investigation, Analysis, Reconstruction, Causality, Prevention, Risk, Consequence and Legal Aspects of the Failure of Engineered Products. Humble, Tex.: ISI, 1995.

Day, Robert W. Forensic Geotechnical and Foundation Engineering. 2d ed. New York: McGraw-Hill, 2011.

Goudarzi, Kevin. "The Forensic Engineering Process for Structural Failures." Structure Magazine, Mar. 2023, www.structuremag.org/?p=23031. Accessed 19 Aug. 2024.

Hibbeler, Russell C. Structural Analysis. 10th ed. Upper Saddle River, N.J.: Prentice Hall, 2017.

Noon, Randall K. Forensic Engineering Investigation. Boca Raton, Fla.: CRC Press, 2001.

Petty, Stephen E., ed. Forensic Engineering: Damage Assessments for Residential and Commercial Structures. Boca Raton, Fla.: CRC Press, 2013.