Seeing the severe damage and massive loss of life from earthquakes led Jenny Ram铆rez into the field of geotechnical earthquake engineering. Ramirez, who was born in Guayaquil, Ecuador, is a doctoral student in听. She now is doing numerical simulations of soil deposits subjected to earthquakes.
Two earthquakes occurred in Japan that same month and Ram铆rez had the opportunity to be part of a scientific reconnaissance team that traveled to Japan to study the geotechnical damage there. The goal is to recommend changes in how geotechnical structures, such as foundations, tunnels, pipelines, dams and slopes, are built in order to better withstand natural disasters.听
鈥淲e can learn a lot about the type of structures that are successful after an earthquake,鈥� said Ram铆rez.
Shideh Dashti, assistant professor of geotechnical engineering and geomechanics at 抖阴旅行射-Boulder, co-led a scientific reconnaissance team mobilized by the Geotechnical Extreme Events Reconnaissance (GEER) Association to travel to Kumamoto-shi, Japan, after the two earthquakes that occurred on April 14 and 16.听
In the days after the magnitude 6.2 and 7.0 earthquakes, geotechnical engineers investigated the damage to see how well the infrastructure that was built to withstand earthquake loading had performed. Extreme-events engineering is an experience-driven field in which perishable data that can be used to advance understanding of the effects of earthquakes needs to be collected as soon as possible.
鈥淩ight after a disaster the affected area becomes a giant laboratory,鈥� said Dashti. 鈥淕eotechnical engineers rush to learn what causes damage to structures, foundations and pipelines. The important thing about a reconnaissance project is that we go with an open mind. We don鈥檛 go in with a hypothesis in mind and then try to prove it.鈥�
Sponsored by the National Science Foundation, GEER is an organization of geotechnical engineers who are mobilized into teams and sent to study a variety of disasters.
Accompanying Dashti, Ram铆rez and other team members from the United States was Samantha Gullies, a senior majoring in civil engineering at 抖阴旅行射-Boulder. Gullies found the experience to be educational and inspirational.
鈥淏eing out in the field was great,鈥� said Gullies. 鈥淚t was an incredible experience to get to learn from the people on the trip. I followed them around and asked questions all day. If I could do this as a career, I absolutely would in a heartbeat.鈥�
Impacts of earthquakes include liquefaction, a phenomenon that makes the soil behave like a liquid while the ground is being shaken; landslides; site and basin effects and surface faulting. Liquefaction can cause major damage to structures and lifelines that cause buildings to tilt or even sink into the liquid-like soil or the pipelines to float.
The U.S. team of engineers and engineering students collaborated with Japanese engineers and scientists to document the damage. They focused on mapping the occurrence and effects of soil liquefaction as well as how well structures, slopes, and sewer and water networks held up.
Dashti said the science team鈥檚 hypothesis is that the soil contained a lot of plastic soils鈥攎ainly clays鈥攚hich likely prevented extensive soil liquefaction to the extent they expected given the amount of sand present in the area, a high water table and the extreme level of ground shaking. Earthquake shaking.
鈥淪urprisingly, there was not a lot of damage,鈥� said Dashti. 鈥淲hat we learned was the type of soil and the type of movement of the earthquake did not lead to as much damage as we expected for such strong earthquakes. While the shaking level was greater than what the code recommended for building design, we think we have an explanation that will be explored as we do more detailed investigations in collaboration with our Japanese colleagues.鈥�
After the field investigation is complete, observations and findings will be posted on the听.听
