The pain of fire protection in skyscrapers

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★The city’s security department conducted an experiment in which a strong firefighter was asked to run from the 33rd floor to the 1st floor, taking 35 minutes to do so. And fueled by the wind, it can reach from the 1st floor to the 33rd floor in just 30 seconds. By this calculation, the possibility of a panicked crowd rushing outside to escape in the event of a fire is almost zero. ★The CCTV Television Culture Center, known as the \"Transformers in the television station,\" failed to fully demonstrate its concept of \"architecture as a source of enjoyment\" before being destroyed in the fire that broke out on the Lantern Festival in 2009. Just as the indestructible Titanic sank after hitting an iceberg. ★“High-rise buildings—especially those with unusual appearances—are generally steel-frame structures or partially made of steel. ”Qin Youguo, a professor at the School of Architecture at Tsinghua University, said, “This is because concrete structures are too heavy, whereas steel structures can be made very tall and large.” ”Nevertheless, its fatal weakness is its sensitivity to fire—although steel itself does not burn, ordinary steel loses much of its strength at 600 degrees Celsius, becoming as weak as noodles. Therefore, after the installation of the steel structure, a thick layer of fire-resistant coating is applied to its surface; such coatings typically provide a fire resistance period of 2 to 3 hours, allowing people inside the building to escape. Regarding the fate of the building he helped design, architect Wu Zhaohui said, “It burned for five or six hours, and by then the main structure of the building was largely intact.” ” ★It is understood that this building makes extensive use of glass curtain walls. And this has sparked considerable controversy in the architectural community both at home and abroad. Among them, countries such as Japan and Germany **explicitly prohibit its use. The reason is that although glass curtain walls do not burn on their own, they can become a pathway for the spread of fire due to ventilation effects. Moreover, these curtain walls are prone to reaching their fire resistance limit and falling down, posing a serious threat to public safety. ★Due to the numerous vertical shafts for various services in high-rise buildings, these shafts act like tall chimneys during a fire, serving as the main pathways for the spread of flames. Tests have shown that in a super-tall building of 100 meters, it takes only about 25 to 35 seconds for smoke to spread from the ground floor to the top floor through the vertical shafts, and the fire will also spread as a result. ★Currently, the tallest ladders available in global fire protection systems reach about 130 meters, whereas the tallest ladders in Beijing’s fire protection system do not exceed 100 meters. Typically, a fire ladder truck can only rise to about 80% of its maximum height. If the ground wind speed reaches level 4 to 5, the scissor lift cannot be raised for operation. If a burning skyscraper is taller than the height of a ladder, it is impossible to extinguish the fire from the outside—making fire rescue in high-rise buildings a global challenge. ★In the international community, the fire safety performance of skyscrapers has always been a subject of doubt. China has the most skyscrapers in the world. Shanghai has over 400 skyscrapers that are more than 100 meters tall, making it the city with the highest number of high-rises in the world. How to ensure their safety will be the challenge we face. (According to Wang Jing et al. of China News Weekly) This post was last edited by Lailai on 2009-3-10 at 13:19]