Brilliant Modular Engineering, How China Built Anti Earthquake Palaces that Survived Centuries

Brilliant modular engineering. How China built anti-earthquake palaces that survived centuries. Architects have long turned to the past for inspiration. In this age of glass and steel, however, they're more likely to be looking for aesthetic influence than technical know-how. But an ancient Chinese construction technique called dougong is a notable exception. Consisting of a series of interlocking brackets, this building innovation may be more than 2,500 years old. From Beijing's Forbidden City to Sichuan Province's Bao'an Temple, it has helped many of China's oldest buildings withstand earthquakes and natural disasters. Forbidden City is the world's largest palace complex, covering more than 720,000 square meters and separated from the rest of Beijing by a 52-meter moat and a 10-meter wall, with gate towers guarding the entrances. The fortress-like design was intended to protect the emperor, but also to emphasize his preeminence. The emperor was, after all, heaven's representative on earth, and in its scale, majesty and separateness, his palace was built to ensure that neither his subjects nor foreign visitors ever forgot that. The built-to-last dougong, or translate as cap-and-block, even with the addition of modern technology, the earthquake-resistance level of many buildings is still not comparable to the Forbidden City. As early as 2,500 years ago, builders in China developed disaster-resistant structures with interlocking flower-shaped brackets called dagong that reduce the impact of earthquakes on buildings. These joints are so effective, they have helped the Forbidden City in Beijing withstand 200 earthquakes without any major destruction. Specialist carpenters decided to find out how the Forbidden City has survived so many earthquakes, including the 20th century's deadliest quake. They constructed a scale model of a structure on shake floor. To strive for accuracy, they drew on traditional techniques and tools. They then put the structure, a fifth of the size of buildings in the Forbidden City, through simulated earthquakes. In reality, the largest earthquake the earth has ever recorded is about 9.5 in magnitude, but these scaled models withstood up to 10.1 magnitude simulated earthquakes. Dagong are often found nestled beneath the eaves and roof, and in case of a quake, the brackets don't shake apart easily, but also aren't so stiff they'll shatter under pressure. Multiple joints help them remain stable. The model shown was freestanding, meaning unlike those in the Forbidden City, these models weren't even anchored into the ground for strong foundations. The buildings wobbled at 10.1 magnitude simulated earthquake, but stood as if nothing has happened. Between tradition and modernity, engineering has come a long way since Dagong was last in fashion, but modern-day designers are now adopting the technique to produce stunning and sturdy works of architecture. Among them is celebrated Japanese architect Kengo Kuma, who used Dagong-inspired methods for two of his recent buildings, Yusuhara Wooden Bridge Museum and Cafe Curion, a 2,120-square-foot restaurant in Toyama Prefecture. Also, during the 2010 World Exposition in Shanghai, the China Pavilion designed by the Chinese architect He Jing-Tang was constructed to showcase the spirit of the traditional Chinese culture. Dagong was also selected for its feature of simple prefabrication and fast on-site assembly. Most pavilions at the 2010 World Expo are temporary. Thus, the materials and construction need to be socially and environmentally sustainable. In this aspect, Dagong, with its modular design strategy, not only represents the wisdom of ancient Chinese architecture, but also meets the contemporary standards of sustainability. Modern Modular Construction In recent years, as the concept of green architecture is being promoted worldwide, more and more modular design has emerged and grown in popularity, such as the shipping container architecture. Furthermore, the use of prefabricated materials and modular design is also being celebrated for its feature of shortening the construction cycle, saving construction materials, reducing energy consumption, and adding to diverse sites. Some examples, also featured in videos of our channel, are The Ark Hotel in Changsha, constructed in six days. A replacement of a 1,300-ton bridge, where the entire process of dismantling, reconstruction, signage, and paving took just 43 hours. The construction of Wuhan Hospital, built in 10 days. Nevertheless, we should always be cautious about how the modules can adapt to different environments. The ancient treatise has taught us the principles of how to calculate the optimal ratio between each component. We should not be merely memorizing the numbers. Instead, it is crucial for us to embed modular thinking into our contemporary construction and materials.