voda schreef op 29 december 2013 15:04:
Experts warns on fake steel bars in Manila
Experts on disaster management have already warned that if Metro Manila is hit by a major earthquake with a 7.2 magnitude on the Richter scale, similar to what devastated Bohol and Cebu, it would cause unprecedented and unimaginable havoc.
The head of the Emergency Service branch of the UN’s Office for the Coordination of Humanitarian Affairs Arjun Kartoch estimates that such an earthquake would destroy 16,000 buildings and injure or kill at least 150,000 people.
Some studies predict even greater devastation. There are studies that say up to 35,000 residents of Metro Manila would die and up to three million others would need to be evacuated. In addition, some 175,000 buildings would be damaged. The pressure from collapsed buildings and the inability to rescue those who would be trapped inside would cause most of the deaths.
While science does not have the capability to stop earthquakes, there are ways to reduce the damage to properties and human lives. For example, the building code and the regulation of the use of substandard or fake construction materials must be strictly implemented.
The earthquake that struck Cebu last October destroyed or damaged more than 50,000 homes and buildings.
According to reports, engineers inspecting damaged structures recovered substandard building materials. The most usual cause for the structures collapsing is the use of inferior reinforcement steel bars. Many of the reinforcement bars recovered from the debris of concrete houses in the quake zone weighed at least 11% less than the required product specification. It is likely that many of these inferior steel products were fabricated from wire rods instead of billets, causing them to have less tensile strength.
The building code specifies that structures should be able to survive intensity 9 quakes. The quake that hit Bohol was measured at Intensity 7.2. Had the building code been scrupulously observed, most of the damaged structures whould have been able to withstand the tremor.
The building code bans the use of reinforcement bars from wire rods since such material has significantly less tensile strength than bars made from steel billets.
The proliferation of substandard and fake building materials has been a long-standing controversy particularly in Bohol and Cebu where rampant smuggling of steel products has been virtually uncontrolled.
Source – Manila Standard Today