By Eng. Vaughn I. Lezama, B.Sc., FAPETT, M.ASCE, R.Eng.
Registrar, Board of Engineering of Trinidad and Tobago (BOETT)
CEO and Principal Engineer, Consulting Engineers Associates 2005 Ltd (CEAL)
The devastation witnessed following the recent Venezuela earthquake was not caused solely by the immense forces released beneath the Earth’s surface. Rather, it was the interaction between those forces and the built environment that determined the extent of the human tragedy. This distinction is fundamental to understanding the role of engineers in disaster risk reduction.
The Objective of Earthquake-Resistant Design
Modern earthquake engineering is founded on a simple but profound principle: Buildings are not expected to remain completely undamaged during a major earthquake; they are expected to protect human life.
No structure can be designed to resist every conceivable earthquake without damage. Such an objective would be technically impractical and economically prohibitive. Instead, internationally accepted seismic design standards seek to achieve a hierarchy of performance objectives. Under minor earthquakes, buildings should experience little or no structural damage. Under moderate earthquakes, damage may occur but should be repairable. Under severe earthquakes, buildings may sustain significant structural distress, but they should not collapse in a manner that endangers occupants.
When buildings collapse catastrophically, it is often not because the earthquake exceeded all reasonable design expectations, but because one or more fundamental engineering principles were ignored during planning, design, construction, inspection or maintenance.
Why Buildings Collapse During Earthquakes
Experience from major earthquakes throughout the world—including Chile (2010), New Zealand (2011), Japan (2011), Nepal (2015), Türkiye and Syria (2023), Morocco (2023), and now Venezuela—demonstrates that structural failures generally arise from a limited number of recurring deficiencies.
One of the most common causes is the presence of soft-storey buildings, where the ground floor contains large open spaces for parking, retail activity or public access, while the upper floors are enclosed by stiff masonry walls. During strong ground shaking, the relatively weak ground storey attracts large horizontal deformations, often leading to progressive collapse of the entire structure.
Another frequent cause is poor reinforcement detailing in reinforced concrete structures. Reinforcing steel provides the ductility necessary for buildings to deform during an earthquake without sudden failure. Where reinforcement is inadequately anchored, improperly spliced, insufficiently confined, or incorrectly placed, structural members may lose their ability to carry loads once cracking begins. The result is brittle failure with little warning.
Equally significant is the quality of construction itself. Even the most sophisticated engineering design can be rendered ineffective if concrete is poorly mixed, improperly placed, inadequately compacted or insufficiently cured. Inferior construction materials, inadequate quality control, and poor workmanship can significantly reduce the strength and durability of structural components, leaving buildings incapable of performing as intended during seismic events.
Structural irregularities also contribute to poor earthquake performance. Buildings with abrupt changes in stiffness, large cantilevers, discontinuous load paths, re-entrant corners or unsymmetrical layouts tend to experience complex torsional movements during earthquakes. These dynamic effects can generate localized concentrations of stress that were never adequately considered during design.
Foundation performance is another critical factor. Earthquakes do not only affect buildings; they also affect the soils supporting them. Soft or saturated soils may undergo liquefaction, temporarily losing their ability to support structural loads. Differential settlement, lateral spreading and slope instability can severely damage otherwise well-designed structures if appropriate geotechnical investigations have not been undertaken and incorporated into the design.
Many earthquake failures are therefore not failures of structural analysis but failures of the engineering process itself.
Earthquake Performance Depends on the Entire Engineering Process
Competent engineering requires much more than preparing structural calculations. It involves a comprehensive understanding of geology, geotechnical engineering, structural dynamics, materials science, construction methods, inspection procedures and quality assurance. Every stage of a project’s life cycle—from site investigation through design, construction, commissioning, operation, maintenance and eventual rehabilitation—must contribute to achieving the intended level of structural safety.
Perhaps the most important lesson emerging from earthquake investigations worldwide is that catastrophic failures are rarely attributable to a single error. They usually result from the cumulative effect of multiple deficiencies: inadequate site investigation, incomplete engineering analysis, poor detailing, design changes during construction, deficient supervision, substitution of materials, inadequate inspection and insufficient regulatory oversight.
When these weaknesses occur simultaneously, the margin of safety that engineers deliberately incorporate into their designs can be progressively eroded until failure becomes inevitable under extreme loading. These recurring failures share a common characteristic—they are preventable through competent engineering.”
Engineering Competence Saves Lives
This reality reinforces the importance of engineering competence. Earthquake-resistant design is a specialised discipline requiring education, training and practical experience. The application of seismic provisions within modern design codes demands sound engineering judgement, not simply compliance with prescriptive rules. Every project presents unique challenges arising from its location, occupancy, structural configuration, foundation conditions and intended service life.
For this reason, engineering decisions that affect public safety must be undertaken only by appropriately qualified and registered professional engineers who possess the competence and experience necessary to assume responsibility for those decisions. Equally important is ensuring that construction activities are carried out under appropriate engineering supervision so that the completed structure faithfully reflects the approved design.
Protecting Existing Buildings and Critical Infrastructure
The Venezuela earthquake also highlights the importance of protecting existing infrastructure. Many buildings currently in service were designed under earlier standards that did not incorporate modern seismic provisions or were constructed before present-day understanding of earthquake behaviour became available. As infrastructure ages and urban populations grow, the need for systematic structural assessments, condition evaluations and, where necessary, seismic retrofitting becomes increasingly important.
Investing in the strengthening of vulnerable buildings—particularly schools, hospitals, emergency operations centres, bridges and other critical facilities—is often considerably more economical than rebuilding after a disaster.
The Lessons for Trinidad and Tobago
For Trinidad and Tobago, these engineering lessons are directly relevant. The country continues to experience substantial investment in residential, commercial, industrial and public infrastructure. Every new building constructed today will likely remain in service for fifty years or more, during which time it may experience one or more significant seismic events.
The engineering decisions made during its planning, design and construction will therefore influence not only its structural performance but also the safety of future generations. Ultimately, the most important lesson from Venezuela is that earthquake resilience cannot be achieved through emergency response alone. It begins long before the ground starts to shake—with competent engineering, rigorous design, effective construction supervision, quality assurance, regulatory compliance, and a professional commitment to protecting the public.
These are not optional components of good practice; they are the essential foundations of a safe, resilient and sustainable built environment.