According to DoSomething.org, the average number of tremors the National Earthquake Information Center (NEIC) records around the world is 20,000. Statista.com estimates that from 2000 to 2012 the total number of casualties due to killer quakes is 812,066.
The figures above should not be treated as mere numbers. It should lead to concrete solutions to prevent tragedy from happening. Of course, we can’t stop an earthquake as it is a natural disaster but Jo Da Silva, head of non-profit design and engineering organization, pinpointed the root cause of the problem during her lecture held at UNOPS (United Nations Office for Project Services) headquarters, she says:
Earthquakes don’t kill people, collapsed buildings do.
Thousands of lives could have been saved if the contractor followed the building code or used above-grade construction material, or avoided the following construction mistakes:
Use of Wrong Materials
Not all building supplies are created equal. Some may even contribute to the structure’s fall. One of the main issues is what type of concrete to use. According to The Constructor, don’t build out of:
- Mud and Adobe – it can’t stand shear, tension and compression. It states that “after the walls fail either due to bending or shearing in combination with the compressive loads, the whole house crashes down.”
- Masonry – houses made of brick and stone attract large inertia forces.
- Reinforced concrete – the weakness of this material was observed at the 1923 Kanto earthquake.
This was the lesson learned during the 2010 Haiti earthquake. Based on a Disasters Emergency Committee report, a 7.0 magnitude earthquake hit Port au Prince and it is estimated that 220,000 have died. Cletus Springer, director of the Department of Sustainable Development at OAS in Washington, said in an interview on CNN last 2010 that Haiti has no building codes in place.
Improper Construction Techniques
In a paper entitled ‘Implications of Design and Construction Decisions on Earthquake Damage of Masonry Buildings,’ the examples of weak construction practices are “improper bonding between walls, unfilled joints between bricks, out of plumb walls, lack of curing, etc.”
Poor Building Design
The paper also states that “complex, asymmetrical, irregular shape, less number of wall or columns, long walls without any cross walls, large or many openings in masonry walls cause more damage because of tensional effects and less shear resisting capacity.” Also, asymmetrical irregularly shaped building units may suffer due to torsion.
Wrong Type of Soil
The foundation where the house or building will be built should be surveyed first. In a checklist by Philippine Institute of Volcanology and Seismology (Phivolcs) and the Japan International Cooperation Agency (JICA) entitled “How Safe is My House? Self-check for Earthquake Safety,” a foundation with soft, muddy or reclaimed soil poses danger. A thorough geotechnical investigation must be conducted.
Wrong Concrete Application
All Mix Concrete enumerates common concrete mistakes as follows:
- Insufficient site preparation
- Getting the mix wrong
- Not preparing for bad weather
- Inadequate finishing work
- Premature removal of forms
It may be a good practice to install seismic gap covers but it should be the least of concerns of contractors and workers. The number one priority is to enforce good workmanship and abide to building codes to be able to make structures withstand earthquakes.
This article is brought to you by: GCK International
