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As summer heat subsides, so does the rain phobia that has afflicted Beijing residents since the July 21 downpour that claimed 79 lives. But residents still have to deal with an irksome aftermath of the torrential rain—road cave-ins.
Ninety-nine cave-ins on Beijing’s roads were reported in the 20 days after the city’s most severe rainstorm in 61 years, leaving pits of different sizes. The largest one was 30 square meters large and 3 meters deep in Haidian District.
The number of road cave-ins in Beijing is nearly two thirds more than those in the same period last year, according to official statistics.
At around 5 p.m. on August 12, part of the road surface on Baiwanzhuang Street in Xicheng District caved in 1 meter below. After seeing a 2-square-meter pit appearing on the road, a middle-aged man parked his electric bike near it to alert people and directed passing vehicles away from the cavity until police officers arrived.
Road maintenance workers arrived at around 7 p.m., filling the pit and repaving the road. Fortunately, the accident did not result in any injuries despite heavy traffic.
On thin ice
Road cave-ins have recently been reported in major Chinese cities, including Harbin in Heilongjiang Province and Dalian in Liaoning Province in the northeast, Yangzhou in eastern Jiangsu Province and Changsha in central Hunan Province
In Harbin, seven cave-ins occurred from August 9 to 17. The accident that took place at 4 p.m. on August 14 in front of a store on Liaoyang Street, Nangang District, resulted in two deaths and two injuries. The collapsed area was around 20 square meters.
Jin Zhenshu, a victim around 60 years old, recalled she was sitting in front of the store, watching her school-age granddaughter playing. Then a woman carrying a baby passed by the store.
“Without any warning, the road beneath buckled. It became dark in front of me. My granddaughter, the woman carrying the baby and I fell off. After hearing a loud thundering sound, I lost consciousness,” Jin said.
After a while, Jin woke up and found most of her body buried in mud. It was dark and cold around her. She could not move or utter a sound. She struggled to get out, but fainted again. When she woke up again, she was in hospital, being treated for bone fractures.
The baby, 14-month-old Guo Xiaoyu, also survived, leaving scars on her face and a 2-cm cut on the back of her head.
On the same day the pit on Harbin’s road victimized four pedestrians, a man in Dalian suffered burns across 65 percent of his body after he fell into hot water leaking from underground heating pipes.
Netizen Diudiu said when she and her husband were strolling that day, they noticed a man walking nearby had suddenly disappeared. Then they saw steam rising from the road. It dawned on the husband that the man might have fallen into a manhole connected to a heating pipe. The husband dashed to the collapsed area, and saw the man raising two hands, yelling for help. He dragged the man up. The victim was rushed to hospital.
The accident in Dalian is reminiscent of a similar one in Beijing on April 1 that killed a young woman named Yang Erjing. Yang was walking on a road near Chegongzhuang in Xicheng District when the ground underneath her suddenly collapsed. Yang fell into a pool of hot water formed by water leaking from a pipeline operated by the Beijing District Heating Group. Scalded by 90-degree water, Yang died several days later in a hospital.
The frequent road cave-ins have unnerved residents. Chen Zhejiao, a 25-year-old saleswoman in Beijing, was quoted by Metro Beijing as saying that now she worries about her safety while walking on the street.
A netizen surnamed Yu said that if heavy rain continues to fall on Beijing, the city will probably become a sieve, and every step will be startlingly dangerous.
Soil damage
The road cave-ins suggest structural damage to underground soil, said Sun Jichao, a researcher with the Institute of Hydrogeology and Environmental Geology under the Chinese Academy of Geological Sciences.
“Although road cave-in may happen because of excessive extraction of groundwater, a serious problem in China, nonetheless, recent accidents in Beijing have little to do with that,” Sun said. He blamed poorly planned underground infrastructure projects for causing the damage.
Sun’s idea is echoed by Zhang Jianguo, an official with the Beijing Municipal Bureau of Land and Resources. Zhang said that Beijing’s roads caved in mainly because soil loosened during underground infrastructure construction and water leaked from ruptured underground pipelines.
The earth under Beijing’s roads is crisscrossed with public utility networks supplying electricity, telecommunications services, heating and for drainage. Large underground projects such as subways, shops and tunnels are also intensifying.
“The roads are often dug open to install or repair various utility networks, which are managed by different utility providers. Sometimes, the same section of a road is repeatedly dug up and repaved by different departments,” said Shan Jingjing, an associate research fellow with the Institute for Urban and Environment Studies under the Chinese Academy of Social Sciences.
If refilled soil has not been sufficiently compacted, loosened soil under the road will be easily washed away by heavy rain, resulting in cavities and road collapses, according to Zhang.
“Road cave-ins used to occur only on automotive lanes, whereas in the last two years they also affected bicycle lanes and pedestrian walks,” said Qian Xiaojun, Deputy Director of the Beijing Urban Road Maintenance Management Center.
Sewage pipes and rainwater drainage pipes usually run underneath bicycle lanes and pedestrian walks, which are more likely to cave in after heavy rainfall, said Qiao. He suggested that in the future, these pipelines should be moved beneath lawns to avoid injuries to passers-by.
“If there is no other underground construction project, usually, the road depression will not be very deep,” Qiao said.
The roadbed collapse that claimed two lives in Harbin was caused by cracks in an old sewage pipe above an obsolete airraid shelter. According to the local government, the city had recently been pounded by a series of heavy rains; waters burst an old drainage pipe and flowed into part of an old tunnel built more than four decades ago. Soil was washed into the crumbled ceiling of the shelter, leaving a huge cavity under the pavement. Eventually, the pavement fell apart. The victims plummeted into the accumulated mud in the shelter.
Sun said that underground projects should be monitored and maintained to prevent cavities, and the public should be alerted of safety hazards.
“The government should not just focus on above-ground infrastructure such as railroads, highways and airports while neglecting those underground,” said Li Xiaoxi, Deputy Director of the Academic Council of Beijing Normal University.
Ninety-nine cave-ins on Beijing’s roads were reported in the 20 days after the city’s most severe rainstorm in 61 years, leaving pits of different sizes. The largest one was 30 square meters large and 3 meters deep in Haidian District.
The number of road cave-ins in Beijing is nearly two thirds more than those in the same period last year, according to official statistics.
At around 5 p.m. on August 12, part of the road surface on Baiwanzhuang Street in Xicheng District caved in 1 meter below. After seeing a 2-square-meter pit appearing on the road, a middle-aged man parked his electric bike near it to alert people and directed passing vehicles away from the cavity until police officers arrived.
Road maintenance workers arrived at around 7 p.m., filling the pit and repaving the road. Fortunately, the accident did not result in any injuries despite heavy traffic.
On thin ice
Road cave-ins have recently been reported in major Chinese cities, including Harbin in Heilongjiang Province and Dalian in Liaoning Province in the northeast, Yangzhou in eastern Jiangsu Province and Changsha in central Hunan Province
In Harbin, seven cave-ins occurred from August 9 to 17. The accident that took place at 4 p.m. on August 14 in front of a store on Liaoyang Street, Nangang District, resulted in two deaths and two injuries. The collapsed area was around 20 square meters.
Jin Zhenshu, a victim around 60 years old, recalled she was sitting in front of the store, watching her school-age granddaughter playing. Then a woman carrying a baby passed by the store.
“Without any warning, the road beneath buckled. It became dark in front of me. My granddaughter, the woman carrying the baby and I fell off. After hearing a loud thundering sound, I lost consciousness,” Jin said.
After a while, Jin woke up and found most of her body buried in mud. It was dark and cold around her. She could not move or utter a sound. She struggled to get out, but fainted again. When she woke up again, she was in hospital, being treated for bone fractures.
The baby, 14-month-old Guo Xiaoyu, also survived, leaving scars on her face and a 2-cm cut on the back of her head.
On the same day the pit on Harbin’s road victimized four pedestrians, a man in Dalian suffered burns across 65 percent of his body after he fell into hot water leaking from underground heating pipes.
Netizen Diudiu said when she and her husband were strolling that day, they noticed a man walking nearby had suddenly disappeared. Then they saw steam rising from the road. It dawned on the husband that the man might have fallen into a manhole connected to a heating pipe. The husband dashed to the collapsed area, and saw the man raising two hands, yelling for help. He dragged the man up. The victim was rushed to hospital.
The accident in Dalian is reminiscent of a similar one in Beijing on April 1 that killed a young woman named Yang Erjing. Yang was walking on a road near Chegongzhuang in Xicheng District when the ground underneath her suddenly collapsed. Yang fell into a pool of hot water formed by water leaking from a pipeline operated by the Beijing District Heating Group. Scalded by 90-degree water, Yang died several days later in a hospital.
The frequent road cave-ins have unnerved residents. Chen Zhejiao, a 25-year-old saleswoman in Beijing, was quoted by Metro Beijing as saying that now she worries about her safety while walking on the street.
A netizen surnamed Yu said that if heavy rain continues to fall on Beijing, the city will probably become a sieve, and every step will be startlingly dangerous.
Soil damage
The road cave-ins suggest structural damage to underground soil, said Sun Jichao, a researcher with the Institute of Hydrogeology and Environmental Geology under the Chinese Academy of Geological Sciences.
“Although road cave-in may happen because of excessive extraction of groundwater, a serious problem in China, nonetheless, recent accidents in Beijing have little to do with that,” Sun said. He blamed poorly planned underground infrastructure projects for causing the damage.
Sun’s idea is echoed by Zhang Jianguo, an official with the Beijing Municipal Bureau of Land and Resources. Zhang said that Beijing’s roads caved in mainly because soil loosened during underground infrastructure construction and water leaked from ruptured underground pipelines.
The earth under Beijing’s roads is crisscrossed with public utility networks supplying electricity, telecommunications services, heating and for drainage. Large underground projects such as subways, shops and tunnels are also intensifying.
“The roads are often dug open to install or repair various utility networks, which are managed by different utility providers. Sometimes, the same section of a road is repeatedly dug up and repaved by different departments,” said Shan Jingjing, an associate research fellow with the Institute for Urban and Environment Studies under the Chinese Academy of Social Sciences.
If refilled soil has not been sufficiently compacted, loosened soil under the road will be easily washed away by heavy rain, resulting in cavities and road collapses, according to Zhang.
“Road cave-ins used to occur only on automotive lanes, whereas in the last two years they also affected bicycle lanes and pedestrian walks,” said Qian Xiaojun, Deputy Director of the Beijing Urban Road Maintenance Management Center.
Sewage pipes and rainwater drainage pipes usually run underneath bicycle lanes and pedestrian walks, which are more likely to cave in after heavy rainfall, said Qiao. He suggested that in the future, these pipelines should be moved beneath lawns to avoid injuries to passers-by.
“If there is no other underground construction project, usually, the road depression will not be very deep,” Qiao said.
The roadbed collapse that claimed two lives in Harbin was caused by cracks in an old sewage pipe above an obsolete airraid shelter. According to the local government, the city had recently been pounded by a series of heavy rains; waters burst an old drainage pipe and flowed into part of an old tunnel built more than four decades ago. Soil was washed into the crumbled ceiling of the shelter, leaving a huge cavity under the pavement. Eventually, the pavement fell apart. The victims plummeted into the accumulated mud in the shelter.
Sun said that underground projects should be monitored and maintained to prevent cavities, and the public should be alerted of safety hazards.
“The government should not just focus on above-ground infrastructure such as railroads, highways and airports while neglecting those underground,” said Li Xiaoxi, Deputy Director of the Academic Council of Beijing Normal University.