Among the natural disasters that we are familiar with, earthquakes are perhaps the most difficult to prepare for. They strike by surprise, and the casualties and structural damage that we see are mostly because many are just caught off-guard by this calamity.
There are places like Japan that experience earthquakes more frequently because of their location. Most likely, they are near or are actually on the so called Pacific Ring of Fire, or that string of volcanoes that seem to outline the vastness of the Pacific. Earthquakes have long been linked to volcanic activity, yet the predictive utility of such an association is still not as precise as we would want it to be.
Because earthquakes can happen at any time, residents in such places have needed to adapt in order for their structures to survive the tremors. Through time, they’ve innovated. They also receive help from partner nations that take part in the effort to ensure sustainability in places frequented by quakes. The knowledge that they’ve accumulated will surely be of good use to everyone, and some of them are presented here.
China’s Rammed-Earth Structures
After a 2014 earthquake flattened several earthen structures in Guangming Village in China’s Yunnan Province, a lot of people lost confidence in their traditional building methods. Many rebuilt their homes using bricks and concrete, an alien way that unwittingly exposed them to new structural threats because of gross cases of misapplication and/or misuse of materials.
A team or architects from the Chinese University of Hong Kong endeavoured to reinvigorate the traditional building methods by infusing them with modern knowledge and research. Specifically, they reinforced the earthen structures with concrete belts and steel rebars. The aim was to create homes that are not only sustainable and earthquake-resistant but also sensitive to their social and environmental contexts.
“The architects succeeded in translating ‘four walls and a roof’ into something which, through architectural commitment, becomes a project that is much more profound,” Paul Finch, World Architecture Festival program director, said in a press release. Finch’s program recognized the prototype of this structure as the World Building of the Year in 2017.
Stanford’s (USA) Seismic Isolators
Having learned the lessons of the Loma Prieta earthquake more than two decades ago, a team of Stanford engineers set out to discover and apply earthquake-resistant structural principles. They came up with seismic isolators, which are basically sliders that are made of plastic and steel. Under these sliders are bowl-shaped dishes made of galvanized steel. The earthquake-resistant structure is conceptualized to rest on at least a dozen isolators instead of the usual firm and stationary foundation.
“The idea of seismic isolation is to isolate the house from the vibration of the ground,” said Eduardo Miranda, a Stanford professor who co-leads the team. “When the ground is moving, the house will just slide.”
When tested, the isolators were able to keep a box-like structure on top of them intact, even after it had been subjected to rumblings that are three times more forceful than what was experienced in Loma Prieta. “Under the isolators, the house basically saw no damage,” project co-leader Gregory Deierlein said. He continued that isolators should be able to protect homes even during strong earthquakes, like the one that happened in Northridge in 1994 which registered 6.7 on the Richter scale.
It is important to note that the box-like structure on top of the isolators was also made extra strong. Instead of just screwing the drywall to the wood frames, it is glued securely to it. The white stucco on the exteriors are attached with the help of more screws and a strong mesh. These made the structure into a ‘unibody,’ which was expected to have a better response to sideways shakes.
Given all these breakthroughs, it makes sense if you consider a structure’s earthquake resistance when buying a new home. Remember, buying a house is more than just writing a house offer letter. It’s an investment around which your life will significantly revolve and eventually depend on.