Advanced earthquake simulations reveal vulnerabilities in Panama's century-old Gatun Dam

As one of the critical infrastructures of Panama, the Gatun Dam plays a vital role in the functioning of the Panama Canal and the surrounding environment. Constructed between 1907 and 1913 by the U.S. Army Corps of Engineers, our estimates of seismic risks to the structure have undergone significant revisions. Today, research led by Antonio Bobet, the Edgar B. and Hedwig M. Olson Professor in Civil Engineering, and PhD student Daniel Muschett sheds light on the potential vulnerabilities of the dam and emphasizes the urgent need for proactive measures in engineering and safety.

One of the primary concerns in seismic safety is the phenomenon of liquefaction. During an earthquake, certain soil types can lose their strength and behave like a liquid, a process that poses a grave risk to structures built with such materials. For the Gatun Dam, liquefaction could lead to severe deformations, settlements and even catastrophic failure. The dam’s original design did not account for earthquake loads, largely due to a historical belief that Panama was a seismically inactive area.

However, modern seismological studies have revealed that Gatun Dam is situated within an active seismic zone, exposing it to moderate to strong earthquakes. The implications of potential liquefaction and subsequent dam failure cannot be overstated. Besides the threat to the dam itself, a catastrophic failure could lead to the loss of the Panama Canal, extensive flooding and damage to the surrounding environment and infrastructure.

In response to these challenges, Bobet and Muschett are employing advanced 3D computer models to simulate earthquake conditions and predict the dam’s behavior under stress. These models recreate the dam’s complex geometry — given that it sits on top of two very deep paleochannels carved by the Chagres river — and the seismic response of the surrounding soil, providing crucial insights into potential failure modes. By estimating how the dam might deform during an earthquake, researchers can develop effective mitigation strategies aimed at protecting this vital infrastructure.

Muschett, a Panamanian graduate student researcher in geotechnical engineering, outlines two primary paths for future research: analyzing the 3D effects on seismic response in various dams and continuing work on Gatun Dam with new mitigation strategies.

“This analysis is crucial for helping engineers determine when a simpler and less costly 2D analysis is sufficient, and when full 3D seismic models are necessary,” Muschett said. “This research combines aspects of geotechnical engineering, earthquake engineering and advanced computational modeling.”

In an era of increasing natural disasters related to climate variability and tectonic activity, the need for proactive infrastructure assessments has never been more pressing. The research conducted by Bobet and his team is a crucial step toward ensuring the safety and longevity of the Gatun Dam.

“As we continue to learn more about the seismic dangers it faces, it is imperative that we act decisively to address these vulnerabilities,” Bobet said. “By investing in modern engineering techniques and comprehensive risk assessments, we can safeguard this important structure for future generations.”