Since more than 240,000 people were killed in the 1976 Tangshan earthquake, Beijing has adopted building codes that analysts say are no less stringent than those in place in California and Japan.
But what's on the books here, and what gets followed and enforced, are sometimes two different matters, especially in poor rural areas.
Engineers who have worked in the mountainous region of the quake's epicenter, in Wenchuan County, say a lot of unregulated construction has taken place over the years. And that may help explain the horrific damage caused by Monday's magnitude 7.9 temblor, which has resulted in more than 12,000 deaths.
At least eight schools were flattened in the quake, including the three-story Juyuan Middle School in nearby Dujiangyan where hundreds of students were buried. It was unclear whether the schools collapsed because they were too old, had faulty design or were constructed poorly or with cheap materials. Some of the schools may have been built before current seismic codes were enacted.
Many buildings in remote areas are low-rise structures that have drawn little attention from inspectors. The older buildings don't have substantial piers, experts said, and walls are still made of brick.
"Bigger cities are following and complying more seriously" with building codes, said James Yeh, the Shanghai manager for Gateway Engineering & Construction, a St. Louis-based company.
China's current seismic regulations contain detailed requirements for practically every type of structure, from one-story playhouses to multi-level apartments made of mud, wood and stone.
The nation's building codes don't have separate earthquake mandates for schools. Instead, structures are grouped into four classes, with each adhering to a certain intensity of seismic reinforcement, according to rules approved in 1999. Class 1 facilities include airports and nuclear reactors. The second highest class includes some hospitals, low-rise kindergarten buildings and elementary schools with large enrollments. Buildings that fall into Class 3, requiring ordinary seismic requirements, are most schools and apartment complexes.
"Schools should have more safety investments because students are more vulnerable," said Gao Jianguo, a geologist with China Earthquake Administration, a government institute in Beijing.
Apart from the code, money is a problem, Gao said. "Unfortunately, right now, the education fund is not enough and many areas have more students but only a few old schools," he said.
