According to wikipedia, the Philippines is registering around 20 earthquakes a day, but mostly weak to be felt. This is cause by seismic and volcanic activities being around the Pacific Ring of Fire or tectonic fault lines. Though this earthquakes are not as alarming for residential houses since there are guide maps available in the internet of known fault lines in the cities and other areas.
Safety during earthquake and other calamities is very important for our families. And the first step for securing your family is making sure your house foundation meets standard to avoid accidents or losing your hard earned investments.
Here's an excerpt from Handbook on Good Building Design and Construction In the Philippines by United Nations Office for Risk Reduction.
Example of bad foundations. This house is being built in a swampy, waterlogged area. As the foundations and the foundation trench was dug, it filled with water so the builders dropped dry sand and cement into it and then the first row of blocks were located on top of this mixture. These foundations in permanently wet soil are inadequate and will also be weak when impacted by any external hazard.
Good concrete foundations. The foundations of these houses have been constructed in a dry trench using good materials, and the first row of blocks was laid while the concrete was still wet. Starter bars to reinforce the hollow block walls are inserted while concrete is wet.
Source: Handbook on Good Building Design and Construction in the Philippines by United Nations Office for Risk Reduction, website: www.unisdr.org
In real estate industry, developers specifications are up to standard as they go through the approval of HLURB but not all houses are constructed accordingly because some house are constructed by third party sub-contractors. Some developers give warranty to their house structural foundations which a good sign of quality.
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