Ian Watt: Chilean seismic culture in general is something that can be exported, but with humility

Ian Watt, former president of the Association of Structural Civil Engineers of Chile (AICE) and representative of the Model Seismic Code for Latin America and the Caribbean, has emphasized that Chile's seismic culture can be exported, albeit with humility. Speaking on La Tercera’s streaming program Desde la Redacción, Watt discussed his experiences traveling to countries affected by earthquakes and observing their aftermaths. He noted that while Chilean buildings have a certain level of stability due to its seismic culture, this does not automatically translate into confidence in other regions. Watt described his initial impressions upon seeing collapsed structures in Colombia following a magnitude 7.4 earthquake. He stated that every earthquake provides lessons, and professionals must approach such events with humility because they always work under uncertainty. The damage observed in Colombia aligns with structures designed for seismic resistance, which differ from practices in Chile. In Chile, buildings are constructed with higher density walls, and facades are integrated into the structural design rather than being non-structural elements. This approach began in Chile after the 1939 earthquake. The method used in Colombia involves constructing columns and beams and then filling them in, a technique validated globally. However, it is crucial to ensure that the fill material is carefully separated from the structure so it doesn't affect it during an earthquake. Watt referred to this as a filled frame structure with masonry, emphasizing that the masonry should be well detailed and separated from the main structure to minimize impact during seismic activity. This type of construction is not unique to Colombia. Watt mentioned the term "Chilean building," referring to residential buildings with eight to twenty floors where touching the wall against a neighbor feels solid not because of masonry but because it is a structural wall. This distinction is recognized in literature and contrasts with the common housing structures found throughout South America, including Colombia and Venezuela, as well as Central America. Watt highlighted that Chile's frequent and large earthquakes present both challenges and advantages. These conditions have fostered a seismic culture present not only among engineers but also architects, builders, regulators, and buyers. The regular tremors mean that mistakes made in construction are quickly identified and corrected, unlike in some countries where older, vulnerable structures still exist and collapse during major events. Watt pointed out that even though some buildings may collapse, the design philosophy aims to allow occupants to evacuate before complete failure. Globally, the approach to designing for earthquakes includes ensuring that frequent smaller quakes cause no damage, moderate quakes result in controlled, repairable damage, and major quakes prevent total collapse. This philosophy is also applied in Chile, where controlled damage allows people to survive and evacuate, although significant repairs or demolition might be necessary afterward. Watt stressed the importance of learning from each seismic event and applying these lessons with humility. While Chile's seismic culture offers valuable insights, it is essential to recognize that different regions face unique challenges and require tailored solutions. His comments reflect a broader understanding of how seismic resilience can be adapted and shared internationally, acknowledging the need for careful consideration and respect for local contexts.