Summary:
No damage reported from Monday morning's earthquake, but concerns remain about infrastructure readiness.
April 25 Bridge designed to withstand 4.5 times seismic forces, while Vasco da Gama Bridge has slightly lesser resilience.
Older bridges may not meet current seismic standards due to past design limitations.
Sines’ industrial facilities face significant risks in the event of seismic activity, particularly regarding pipeline ruptures.
The shallow nature of the recent quake could have led to high casualties if it had struck directly under Sines.
The ground shook early Monday morning, but fortunately, no damage was reported. However, experts are questioning whether the country’s infrastructure is truly prepared for a more intense earthquake event.
Structural Resilience of Key Bridges
According to engineer Armando Rito, the April 25 Bridge must withstand 4.5 times the forces generated by a seismic event. He emphasized that this bridge is a critical link between the north and south of Portugal, stating, "I do not believe that a violent earthquake could put it at risk. Damage may occur, but collapse is unlikely."
On the other hand, the Vasco da Gama Bridge is designed with slightly lesser resilience due to its structural differences. It features a semi-suspended deck that utilizes dampening devices to minimize movement during seismic activity.
Rito noted that regulations are constantly being updated based on new knowledge, but he cautioned against overhauling all older bridges at once, referencing the Douro bridges, which were not originally designed with seismic events in mind.
Potential Risks in Sines
The epicenter of the recent quake was offshore, but concerns were raised regarding Sines, a town with a refinery and industrial facilities. Rodrigo Falcão Moreira, an expert in seismic safety, explained that these infrastructures are generally built to withstand higher seismic intensities than residential buildings, ensuring structures do not collapse and that people can escape.
However, he warned of a cascade of events that could occur if a pipeline ruptured, leading to flammable fluid leaks and potential fires, reminiscent of the disasters following the 1755 earthquake.
In Lisbon, there are also concerns regarding integrated gas networks and how infrastructure failures could hinder access to emergency services, highlighting the importance of not only focusing on building integrity but also on transportation routes.
The recent quake was relatively shallow, but Moreira expressed that if it had occurred directly beneath Sines, the consequences could have been dire, potentially resulting in significant casualties.
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