Three technical assessment teams sent by The American Society of Civil Engineers (ASCE) recently visited Chile shortly after the second largest recorded earthquake in history. The teams were interested in learning from the performance of the region’s various infrastructure systems. UNC Coastal Studies Institute’s Coastal Engineering Program Head, Dr. Billy Edge, lead a team that observed the impacts of the earthquake and subsequent tsunami on the region’s seaports. In addition, the team studied effect on inland travel of the tsunami and the location of sediment deposits and scour plus the resulting structural and non-structural damage at the major ports.
The 8.8 magnitude quake caused significant damage to buildings, roads, bridges, water systems, telecommunication, electric power and other lifeline facilities. The tsunami generated by the earthquake also caused extensive damage to the coastline. The team visited nine different locations along the coast of Chile and documented infrastructure damages caused by both the earthquake and tsunami. The engineers made use of multiple transportation methods to observe structures; including foot, truck, boat and by small aircraft.
Chile has a history of earthquakes and a modern attitude to risk management, which created a culture of planning and design that resulted in much less damage than expected. The team observed that port structures built to current building codes performed well during the seismic event, while many structures that had not followed building codes failed. They also found that the rapid evacuation of ports before the tsunami arrived greatly minimized damage. The loss of power immediately after the earthquake created a very significant problem within the ports. The lack of power immobilized the large container cranes that were in the process of loading and unloading. When the ships tried to leave port some became entangled with the container and cable from the crane. Damage to some cranes occurred when ships evacuated rapidly to avoid the oncoming tsunami.
In addition to the structural damage caused by acceleration of the ground, the team also noted that soil failures lead to damage of some ports. Some soils shifted or eroded during the earthquake, which undermined systems and lead to damage of infrastructure.
Throughout the study, the scientists and engineers developed recommendations that could reduce damages in future natural disasters including, plans for vertical evacuations, evacuation assistance for the aged and disabled, and designing flow-through areas within low lying buildings. They also recommended back up of all hospital and research files in locations with less risk of damage from natural disasters.
Port specific recommendations included quick release moorings for faster evacuation of ports before a tsunami, and the development of a uniform port and harbor design code that would lead to infrastructure that can withstand environmental pressures. Key recommendations also included the development of a nationally funded coastal water level monitoring system and seismic monitoring program that can survive flooding, and a long term plan for land uplifting caused by tectonic plate movements.
CSI’s Edge said, “Our investigation of the effects of the earthquake and tsunami on the ports in Chile clearly showed that proper design, planning and construction are very effective in reducing damage and destruction caused by natural disasters. Moreover, we feel that proper planning for emergency response is critical to avoid unexpected damages.”