Caijing’s investigation of five schools that collapsed showed that none of the building sites had undergone a geological survey prior to construction. From day one, a combination of problematic design and poor construction, coupled with geological peril, meant these schools were time bombs waiting to be triggered by a natural disaster.
Strong shaking can cause buildings to tumble in one of two ways – in a brittle or ductile collapse, said Wang Bangjin, an engineer at the Ministry of Transportation. In a brittle collapse, a building can crumble to dust in a few seconds. In a ductile collapse, a damaged building can stand for a short while, allowing time for an evacuation.
All of Sichuan’s quake-wrecked schools experienced brittle collapse, according to Wang’s definition. They lacked the reinforced concrete that allows for a ductile collapse, often saving lives.