Humans have constructed magnificent structures and civilizations throughout history to help us protect ourselves from crimes and the elements of Mother Nature. However, natural disasters such as earthquakes are among the most devastating forces on our planet. The seismic waves that travel down the ground may demolish buildings and kill people while also causing billions of dollars in damage and restoration.
In the United States, there are around 20,000 earthquakes recorded every year, with 16 of them considered catastrophic. These natural phenomena have cost thousands of lives worldwide. In the course of history, one of the strongest quakes that hit the United States cost 316,000 fatalities. Moreover, destructions are not due to the earthquake solely but to the failure of structures killing more people inside them.
Thus, making it imperative to earthquake-proof buildings, structures, and residentials is essential to add protection, especially since this natural disaster is primarily abrupt and can’t be easily predicted. Luckily, engineering has advanced in recent decades, with different innovations and building materials being developed to better equip structures to resist earthquakes.
Building materials capable of withstanding high levels of stress and vibration should have excellent corrosion resistance, which refers to their capacity to withstand massive deformations and strain. Modern structures are frequently constructed and supplied with structural steel, which is available in various forms and sizes and allows buildings to flex without cracking or breaking. Moreover, wood is a fantastic ductile material because of its robust and flexible structure.
One method of defending against ground pressures is to elevate the foundation of the structure above the surface of the earth. For example, a base isolation structure is built on top of adjustable pads comprising metals, rubbers, and lead. When the foundation of the building moves during an earthquake, the isolators tremble, but the structure itself does not. This efficiently aids in the absorption and prevention of seismic waves from progressing through the system.
You may be familiar with automobiles equipped with shock absorbers. But you may not realize that engineers also use them to design quake-resistant structures. These dampers lessen the amplitude of shockwaves and aid in the slowing down of movements for buildings.
Two types of equipment are used to do this. The first is vibration control, a device installed in dampers between a pillar and a beam for each level in a structure. Each absorber is made up of piston heads contained within a cylinder loaded with silicone oil. The structure converts the tremor and force into the pistons, which press on the oil during an earthquake. The energy is then turned into heat, which allows the power of the vibrations to be dissipated.
The second technique is the pendulum power, which is commonly found in skyscrapers. An engineering team uses hydraulics to suspend a big ball from metal bars. A pendulum effect occurs when the structure begins to wobble, and the ball starts moving toward the opposite direction to balance the motion.
Shield from vibration
Instead of simply mitigating earthquake pressure, experts are exploring techniques to entirely divert and redirect the energy generated by earthquakes. Also known as the “seismic invisibility cloak,” it is made of 100 concentric plastics and concrete circles buried at least 3 feet underneath the base of a structure to provide seismic invisibility.
When seismic waves reach the rings, they pass through the outer circle, where they may travel more efficiently. Consequently, they have effectively diverted away from the source and dispersed into the bottom plates as part of the design.
Strengthening the structure of the building
A building’s ability to survive a catastrophic downfall depends on its ability to disperse the forces that go through it during a significant earthquake. Therefore, reinforcing a structure is vital to shear barriers, cross-braces, diaphragms, and momentary frameworks. In earthquake-prone areas, shear walls are a valuable building innovation because they help to distribute seismic stresses.
These walls, which are made of panels, assist a structure in maintaining its shape as it is being moved. In addition, they are frequently reinforced by diagonal cross bracing that run diagonally across the wall. As a result, they can sustain tension and compression, which counterbalance the stress and transmit forces back to the base.
The strategies used to design earthquake-resistant structures have been developed over time by engineers and scientists. But while modern technologies and methods are still not feasible for buildings to totally endure a strong earthquake without being damaged, we should consider building structures using innovation capable of providing a safe escape for its people while also saving lives and communities to be a significant achievement.