Experts analyzed how to prevent a glass curtain wall from bursting on the 38th floor of Pudong Lujiazui national gold center. Fortunately, no casualties were caused. It was revealed that four glass curtain walls of the building had burst in the past six months. It was also reported that a similar accident occurred in the Times financial center, also located in Lujiazui, two months ago
many friends call the Lujiazui area with high-rise buildings a high-risk area of "glass rain". In this area, there are many glass curtain wall buildings with a height of more than 100 meters
why do bursts often occur on the 30th and 40th floors
the broken glass curtain wall of the national financial center is located on the 38th floor, while the two glass curtain walls of the Times financial center burst earlier, which occurred on the 43rd and 46th floors of the building respectively
aixiaoqiu, deputy director of the wind and Disaster Prevention Research Office of the Shanghai Institute of disaster prevention and relief at Tongji University, said that there had been several glass curtain wall accidents in Lujiazui area, most of which were on the 30th and 40th floors of buildings
dozens of glass curtain wall buildings in Lujiazui area are a scientific research topic of AI Xiaoqiu. She said that the reasons for the bursting and even falling of the glass curtain wall of the building are very main: the loading process is complex, with internal and external causes. Internal factors mainly include glass curtain wall material, frame structure design, installation and operation level, etc; The external causes are mainly induced by strong winds, rainstorms and other factors
another incentive worthy of special attention is "building group wind". The high-rise and super high-rise business buildings in Lujiazui are close to each other, and most of them are "all inclusive structures", that is, the whole body is covered by glass curtain walls, and "the combination of these two factors is easy to produce" building group wind "
assuming that the measured wind force at the bottom of the building is level 3, that is, the wind speed is 3 to 4 meters per second, then at the height of the building, due to the complex effect of the air flow between the buildings, "building wind" can sometimes reach level 10 instantaneously, which is the level of a typhoon
theoretically, the higher the floor, the greater the wind force, but why are the glass curtain walls that are easy to burst not on the top floor of the building, but in the middle and high areas of the thirtyand fortieth floors? AI Xiaoqiu explained that this is related to the market image of the "building group wind" which has a protective polyurethane insulation material different from the voltage test principle. The average height of many buildings in Lujiazui area is more than 200 meters, and some, such as the world financial center and Jinmao Tower, are more than 400 meters. Because the height of the super high-rise building is one end higher than the surrounding buildings, it is less affected by the "building wind", while the middle and high floors are greatly affected
AI Xiaoqiu judged that the internal cause was significantly greater than the external cause of several glass curtain wall accidents in the national financial center. "It may be because the outdoor temperature is very high, and the air conditioner is turned on in the building, which causes the frame to deform due to thermal expansion and cold contraction, resulting in glass bursting. It may also be that there is a material problem with the glass." As for the "building wind", even if it works in these cases, "it is only the last straw to crush the camel"
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