Earthquakes and Construction

Safety, Earthquakes, and Construction

According to the United States Geological Survey(USGS), there are several million earthquakes happen every year around the globe. Most of them are undetectable and about 500,000 are detectable but only 100,000 of these are felt by us. However, what concerns us the most is the number of earthquakes that can cause damage and that’s roughly a hundred in a year.

Apparently, our species have been in the world for more than 200,000 years and we’ve come a long way in our attempt in conquering nature. Nature is both a preserver and a destroyer; most of our development is actually focused on trying to harness its power and use it to remove nature’s negative attribute.

Earthquakes and the construction industry is no doubt connected to each other. The concept of an earthquake is always visualized with buildings crumbling down, ceilings falling off, and roads cracking. Seeing such images makes us realize and hope at the same time that we had better infrastructures and there are several methods that could reinforce a structure other than bars and concretes.

Earthquake Engineering

Earthquake engineering is an interdisciplinary branch of engineering that designs and analyzes structures but specifically focused on functions that are earthquake related. Its main purpose is concerned with protecting society, natural environment and man-made environment from the destructive force of an earthquake. It doesn’t necessarily mean that they have to invent buildings that are completely invulnerable but structures that can withstand the seismic effects while sustaining minimal or acceptable amount of damage. Take note, a properly engineered structure doesn’t necessarily have to be extremely strong or expensive.

 

Here are three processes or methods on how the construction industry improves modern buildings’ resilience on earthquakes.

1. Seismic Design

CCTV Building, Beijing, China

Above: Aside from exterior forces – it can resist an earthquake of up to 8 — the CCTV Building in Beijing has a cantilevered shape that puts enormous pressure on the building from gravity and other lateral forces.

This is probably the most common requirement before a construction entity can raise a building in a certain place. The design is based on a sanctioned engineering principles and procedures meant to strengthen buildings against earthquakes. Seismic designs are only based on up-to-date knowledge and experiments of trial and error so it can never guarantee a hundred percent fortification against collapse or serious damage. They are are solely based on understanding the imaginable course of failure during such disasters, therefore, the main purpose of this method is to minimize casualties or loss of life.

 

 

 

2. Tuned Mass Dampers

Construction Details of Taipei 101

Taipei 101 Earthquake Engineering

Obviously, the higher the building the complex its structure becomes and the greater risk for safety. For skyscrapers, it’s not only earthquakes that they have to think about but also typhoons and strong winds. One of the famous skyscrapers that has this feature of controlling seismic vibrations is Tapei 101, formerly known as Taipei World Financial Center.

The tall building stands on the Asia-pacific where typhoons and tremors are common. The tuned mass damper in this building is a pendulum weighing approximately 600 metric tons is suspended at the top through several floors and sways to decrease movements that are caused by earthquakes.

 

3. Base Isolation

This kind of method is founded on the idea that the whole base of the building should not be directly constructed on the ground. Isolating the base through different techniques aims to prevent the kinetic energy of the earthquake to the building. The principle of separating the structure from the ground is to enable it to move somewhat independently and that can minimize the movement during earthquakes. However, the degree to how massive and minimal the energy from the ground that’s going to be transferred to the building depends on the technology that’s used.