When a construction project or a completed structure encounters a sudden failure that leads to loss, injury, or inability to perform as intended, a licensed and experienced forensic engineer (or a team of forensic engineers) are often brought in to investigate.
Forensic building investigations are conducted using tested scientific methodologies and in accordance with accepted engineering standards. The forensic engineer’s goal is to determine why a failure happened, who was responsible, and how to prevent it from occurring again. Furthermore, the findings produced by a forensic building investigation can be used as evidence in litigation (expert testimony).
Needless to say, to a contractor, investor, property owner, or another party affected by a given failure, prevention is always better than remediation. In this article, the expert construction & engineering consultants from VERTEX will discuss some of the more common causes of structural failures and provide suggestions on how to avoid a collapse. Read on to learn more.
Why do structural components fail?
Structural components are designed for use in specific setting and environments. They fail due to problems with design, material, environmental conditions, type of use, and construction methods. Major causes include bad designs, substandard materials, faulty construction, unexpected failure modes, and unusual loads.
Failures can also occur as a result of natural catastrophes such as floods, fire, earthquakes, cyclones, and hurricanes. In some unfortunate cases, they may also be caused by deliberate criminal action. And finally, there’s the simple fact that not all things last forever.
What are the most common faults in structural design?
Every structure is ultimately designed to support certain loads without deforming excessively. These loads typically include the weight of the structure itself (dead or static load), and the weight of the objects and the people in it (live load).
Broadly speaking, design faults fall into three categories:
- Human errors/internal factors. In addition to computational errors, these include erroneous theories, inaccurate data, failure to take the expected loads into consideration, suboptimal choice of materials, an ignorance of the effect of repeated stresses, and so on. Typically, these faults are attributed to human error or negligence of the structural engineers and/or architects.
- External factors. These include things such as heavy rain, earthquakes, hurricanes, floods, fire, unusual conditions at the construction site (swampland, sinkholes, etc.). Of course, a structure that’s expected to stand for a prolonged period of time should be able to withstand such stresses.
- Insufficient awareness. Some failures are a consequence of lacking technical knowledge and research. However, as technical awareness improves, errors are becoming the most common reason behind structural collapses in technologically advanced countries.
Other reasons for structural failure include:
- Improper construction. This includes the weakening of the building’s structural reliability due to overloading, or the failure of a contractor to follow the agreed-upon specifications and drawings.
- Inferior workmanship. Even top-quality materials and designs, if implemented poorly, can fail to serve the intended function. This can result in problems that range from repairable (shedding paint, cracked floor tiles, pollutants, etc.), to serious structural infirmities and even collapses.
- Inferior materials. Excessive corner-cutting and insufficient understanding of the realities of the project can cause one or more components of a structure to be built using materials that are unable to withstand the expected stresses. This can lead to a breadth of different problems, up to and including structural collapse.
- Foundation failure occurs when a structure is constructed on soil that’s not strong enough (or otherwise unable) to bear the structure’s weight. Inadequate drainage, vegetation, evaporation, and plumbing leakage can all cause soil variation.