Source: Science and Technology Daily
A 6-story house built with thin-walled steel of only 1.2-1.8 mm still stands in the magnitude 8 "earthquake".
htmlOn June 8, the reporter learned from Chongqing University that the first vibration table test of a full-size solid 6-layer cold-bending thin-walled steel structure house in my country was successfully completed in the vibration table laboratory of Chongqing University. This experiment proves the safety and reliability of multi-layer cold-bending thin-walled steel structure houses, laying the foundation for the construction of high-rise buildings in my country's cold-bending thin-walled steel structures." prefabricated steel structure building is a green building with wide application prospects that the country is vigorously developing." Professor Shi Yu from the School of Civil Engineering, Chongqing University, introduced, "Cold-bending thin-walled steel structure houses have the advantages of low steel use, light self-weight, high assembly efficiency, small dust and construction waste emissions, and superior seismic resistance. They have been widely used in the post-disaster reconstruction of Sichuan Wenchuan earthquake ."
model without covering the wall panel. Chongqing University/Photo provided
However, Shi Yu said that the thin-walled steel structure has poor stiffness and stability. Due to technical limitations in wind, earthquake and fire resistance, most of the cold-bent thin-walled steel structure houses at home and abroad are 1-3 low-rise buildings. The promulgation and implementation of the industry standard "Technical Standard for Cold-Bent Thin-Walled Steel Multi-Story Housing" compiled by Academician Zhou Xuhong has promoted the promotion and application of multi-layer cold-bent thin-walled steel structure houses in China, but at present, there are only 10 five-story cold-bent thin-walled steel structure houses built in China. Whether the safety of buildings above 6 floors is sufficient, they decided to use vibration experiments equivalent to the intensity of an earthquake of magnitude 8 to verify this time.
Chongqing University Vibrating Bench Laboratory has a net height of 25.5 meters, a countertop size of 6.1 meters×6.1 meters, a load capacity of 60 tons, and can input earthquakes in 3 directions and 6 degrees of freedom. It is one of the vibration tables with the largest countertop size, load capacity and anti-capsulse moment in China. This time, they built a 6-story solid cold-bending thin-walled steel structure house on the vibration table, with a total height of 16.2 meters, a length of 5.6 meters and a width of 4.2 meters. Two new side force-resistant systems are adopted, steel pipe end columns - double-sided skinned steel plate shear wall and clamped single-layer thin steel plate shear wall. Compared with the vibration table test of cold-bending thin-walled steel structures that have been completed at home and abroad, this cold-bending thin-walled steel structure vibration table test has a series of characteristics, such as new structural system, large structural height and aspect ratio, rare conditions of up to 8 degrees of loading intensity, and two stages of testing for construction stage and normal use.
Academician Zhou Xuhong was in front of the wall-covered panel model. Chongqing University/Photo provided by
"This experiment is the world's first test of a 6-story, foot-bent cold-bending thin-walled steel structure house vibration table input from two-way earthquakes." Academician Zhou Xuhong introduced that this experiment is the building with the largest height-to-wide ratio in the world. The seismic waves are in both horizontal and vertical directions, which can simulate more complex real earthquake situations. After more than 100 earthquakes before and after, the building is tested, and the building is still standing. After stopping the test, they conducted a comprehensive observation of the building and found that some of the plates inside were cracked and some of the screws were loose, but they were all normal test phenomena, and there was no problem with the main structure of the building.
Academician Zhou Xuhong (first from left) was at the test site. Chongqing University/Photo provided
This experimental project originated from the National Key R&D Program Project "Research and Demonstration Application of High-Performance Steel Structure System" chaired by Academician Zhou Xuhong and Professor Shi Yu and the National Natural Science Foundation's major project "Research on the High-Efficiency Seismic System of Steel Structures" hosted by Academician Zhou Xuhong and Professor Shi Yu.
The vibration table test results of the construction phase on May 22 and the normal use phase from June 3 to 4 show that cold-bending thin-walled steel structure multi-story houses are safe and reliable, and also lays the foundation for the development of cold-bending thin-walled steel structure houses to higher levels. The team will continue to study the cold-bent thin-walled steel structure system, and use experiments to verify the safety and reliability of the structure, laying the foundation for practical applications.
