As part of a study unit about Forces and Motion, a group of Form 3 (Year 9) Science students at St Margaret College Secondary School, Verdala, Cospicua, recently took part in a school project to learn about China’s ancient science of constructing earthquake-resistant buildings.
Earthquakes are experienced in many parts of the world, but China has experienced the world’s 10 deadliest earthquakes throughout history. The country is particularly susceptible to earthquakes due to the structure and position of the globe’s tectonic plates. As a consequence, earthquakes have always been taken seriously in China, and 2,500 years ago Chinese builders developed earthquake-resistant structures using interlocking flower-shaped brackets called ‘dougong’ in the Chinese language.
The ‘dougong’ system consists of a series of interlocking beams cut to precise measurements, that when compressed under the weight of the buildings’ heavy timber roofs, enable the buildings to be flexible yet strong enough to withstand earthquakes.
The pieces are fitted together without using nails or glue. Formidable skill and precision is needed to make each timber piece. By using a large number of pieces in the design, the weight is shared, and so individual elements are not prone to splitting or cracking.
What is also interesting is the fact that the pillars of buildings that use this system are not sunk deep below the ground on a foundation, but rather they sit lightly on the surface of the ground.
China adopted the ‘dougong’ system in architecture to build temples and palaces, such as those at the Forbidden City in Beijing, during the Spring and Autumn period (770-476BC). Many of these ancient buildings have survived intact despite experiencing many earthquakes.
In 2008, China was hit by a massive earthquake in the Sichuan province, killing an estimated 69,000 people and injuriung over 300,000. Since then, massive changes in regulations have been introduced to ensure that rebuilt buildings are able to withstand earthquakes and many Chinese architects are trying to imitate the old ‘dougong’ system when designing new building structures.
During the project, the students also watched a short video (available at the link below) of a modern-day science test showing a scale model of a building being constructed using the ‘dougong’ system and then being subjected to, and surviving, a shake test simulating a massive earthquake.
The project was coordinated by senior science teacher Martin Azzopardi with the support of the Malta-China Cultural Centre and the China Embassy in Malta.
The authors are students at St Margaret College Secondary School, Verdala, Cospicua.
https://www.youtube.com/watch?v=w78yb_aoth0