Blooming to build glass bridges for tourism, safety doubts

The trend of building glass bridges in rugged mountainous areas to attract adventurous tourists is flourishing.

Glass bridge over the mountain, Longjing city, Jilin, China The world in general, and especially in China, is favoring the trend of building glass bridges in rugged mountainous areas to attract tourists who love adventurous experiences. But these glass bridges raise a lot of doubts about the level of safety, especially after the recent glass bridge was severely damaged by wind and storm in China recently. Glass bridge trend blooms, risks go hand in hand There is no organization that has statistics on the number of glass bridges in the world, but one thing is for sure, as tourism develops, the number of new glass bridges, with records of length and sophistication, is built in different places. where the terrain is difficult… more. In the West, there are some names such as Tower Bridge in London (UK), Skywalk Bridge in Grand Canyon (Arizona, USA…). In Asia, China is leading this trend with an estimated 60 glass bridges that have been built across the country of billions of people since 2016, according to the Earth Journal of the China Geological Museum. Even, many Chinese glass bridges entered the Guinness World Records. For example, the glass bridge at Tianmen Mountain, Zhangjiajie, 430m long, spanning two cliffs 300m deep, opened to visitors in 2016. At that time, this was the tallest and longest glass bridge in the world. Recently, this record was broken by the bridge in Qingyuan, Guangdong, China with a length of 526m. Vietnam is also not out of the trend of developing glass bridges with the names of Dragon Cloud Bridge in Sapa and Love Bridge in Moc Chau… However, since this trend has blossomed, China has witnessed a lot of incidents that threaten the lives of tourists, making the people of this country in particular and the world question the level of safety. Recently, on May 7, stormy winds damaged the suspension bridge on Mount Piyan (Longjing City, Jilin Province), many of the bridge’s glass panels were cracked, some were even swept away, causing a tourist stuck, trembling, clinging to the bridge wall in front of winds up to 150km/h. Although the guest in trouble was safely brought down by the rescue team, checked for health and psychology and did not cause any other consequences, local authorities decided to close the bridge and conduct a comprehensive inspection. The entire incident was recorded by nearby tourists and posted on social media, raising concerns about the safety of glass bridges across China. “Too many glass bridges have been built in the last few years to serve tourists, but how can we ensure the safety of these structures?” said a doctor surnamed Li in Sichuan province. question. What are the technical standards and operation of the glass bridge? Photos of tourists stuck on the glass bridge According to Xinhua, many local governments of this country have published guidelines to ensure glass safety since 2018. In particular, Hubei province has published a set of technical standards for bridges and roads for people walk in glass at attractions, clearly stating instructions on materials, location, design, construction as well as operating procedures. For example, glass bridges should not be built in places where earthquakes often occur, must be closed during bad weather or natural disasters, and limit the number of people on the bridge to no more than 3 people/m2. In potentially hazardous locations, the bridge management must provide additional protective equipment, install warning signs in Chinese and at least 1 foreign language. Around the world, according to Paul Bingham, a materials scientist at Sheffield Hallam University (UK), designers and architects always think very carefully before choosing materials. “If using glass as a building material, there will be two weaknesses. The first is glass, which is fragile. The second is that the glass has no crystals, so if there is a crack on the surface, it will quickly spread and be difficult to restore,” said Paul Bingham. Therefore, a lot of research on glass materials has been done focusing on finding ways to limit cracking of the glass surface. “A scratched glass is much weaker than pristine glass when it has not been exposed to dust or air,” says Mr. Bingham. A number of new glass materials manufacturing techniques have been invented to make bridges, which is to add a layer of material such as polymer to the outside, preventing the glass from being cracked or scratched. This technique was used to build bridges in Longjing, China as outlined above. Many other glass manufacturers may put thin layers of flexible polymer in between the glass layers in case one glass breaks, leaving another layer intact to prevent total cracking. In general, the British expert affirmed, if the glass bridge is built by the above methods, it is basically safe. The most important thing is to ensure safety in operation, especially in case of bad weather. Around March 2018, according to China state television (CCTV), Hebei province had to close all 32 glass bridges for safety checks. In 2019, a man in Guangxi, China slipped on a glass bridge due to heavy rain, fell off the bridge and died.