Traditional earthquake prevention of earthquake-resistant buildings

Anti-seismic methods of traditional buildings in China

Different from the western masonry structure, the traditional wooden structure in China adopts the thinking of "combining rigidity with flexibility" when resisting earthquake impact. Through various ingenious measures, its goal is to minimize the powerful natural destructive power at the least cost. Many ancient buildings in China have successfully withstood the test of major earthquakes, such as Guanyin Pavilion of Dule Temple in Jixian County, Tianjin, and Wooden Pagoda in Yingxian County, Shanxi Province, which still stand proudly after thousands of earthquakes. Contemporary architectural design aims to resist the 9-degree earthquake, but the traditional wooden buildings in China can basically meet this requirement, and the cost is far less than that in the west, which makes people admire the power of "softness".

Flexible frame structure: The Chinese nation not only wisely chose organic materials such as wood as the main material of the structure from the beginning of civilization, but also developed a flexible frame system with the longest history, the longest duration and the highest technical maturity in the world. The development of wood structure technology in China has a history of at least 7,000 years, if only from Hemudu site in Yuyao, Zhejiang. In contrast, the load-bearing wall system has been used in the west for thousands of years. It was not until the industrial revolution and the development of modern science and technology that we realized the superiority of frame structure and began to popularize it on a large scale. More interestingly, this framework system is still "just as strong". The traditional wood structure in China has all the advantages of the frame structure, such as the effect of "the wall falls but the house does not collapse", but its flexible connection makes it quite elastic and has a certain degree of self-recovery ability. In this Wenchuan earthquake, the walls of many cultural relics buildings were damaged to varying degrees, but the main structure did not collapse, which is the performance of the seismic capacity of this flexible frame structure.

Integral floating raft foundation, bucket arch, tenon and mortise: the key to earthquake resistance In ancient China, there were few buildings with complex planes, and rectangles with aspect ratio less than 2: 1 were mainly used. Regular plane shape and structural layout are beneficial to earthquake resistance. Traditional buildings are often the largest in the middle (the center), and the width between the two rooms and the two sides decreases in turn. This design is very beneficial to resist the torque of earthquake.

Ancient buildings in China are generally composed of abutment, beam frame and roof, and high-grade buildings have a bucket-shaped floor between the roof and beam. The abutment of ancient buildings in China is described by modern structural language, which can be called "integral floating cushion foundation", just like a big ship carrying buildings in the "stormy waves" formed by the earthquake, which can effectively avoid the shear damage of the foundation of the building and reduce the impact of seismic waves on the superstructure. The beam frame of traditional buildings in China generally adopts the lifting beam structure. In the vertical direction of the frame, a structural shape with a big bottom and a small top is formed. Practice has proved that this structure has good seismic performance. Elegant big roof is one of the most prominent image features of ancient Chinese traditional buildings, and it has also made considerable contributions to improving the seismic capacity of buildings. The formation of a large roof (especially the roof of a temple, the rest of the mountain, etc.) ) It needs complex structure and a large number of components, which greatly increases the integrity of the roof and even the whole frame; The huge roof is supported on the column net by its own weight, which also improves the stability of the frame.

Bucket arch is another important force in the earthquake resistance of ancient buildings in China. It acts as a shock absorber of a car to deform and consume energy during an earthquake. Historically, many buildings with one bucket can withstand strong earthquakes. For example, Huayan Temple in Datong, Shanxi, and Daxiong Hall with bucket can still be preserved without damage to the low-rise ancillary buildings, which fully demonstrates the contribution of bucket to earthquake resistance. Buckets can play the role of "shock absorber", and bucket groups connected by various horizontal members can form a "rigid plate" with strong integrity, which transfers seismic force to columns with seismic capacity according to the principle of "those who can do more work", greatly improving the safety of the whole structure.