久久精品30_一本色道久久精品_激情综合视频_欧美日韩一区二区高清_好看的av在线不卡观看_国产自产精品_91久久黄色_午夜亚洲福利_欧美黄在线观看_国内自拍一区

Measures to deal with any difficulties relating to cracking and heaving caused by permafrost along the Qinghai-Tibet Railway will be taken by China's Ministry of Railways, said Vice Minister Sun Yongfu Wednesday.

Speaking at the Asian International Permafrost Conference in Lanzhou, capital of northwest China's Gansu Province, Sun Yongfu said the Ministry of Railways would further study the effect of temperature increases and train loads on the permafrost-ground that is permanently frozen and is prone to movement as temperatures fluctuate.

"We've already established a long-term inspection system of the permafrost and will solve problems in a timely fashion," the official said. Around 550 kilometers of the world's highest railway is built on permafrost.  

China's Ministry of Railways spokesman, Wang Yongping, said earlier there had been foundation movement on sections of the track and that some railway structures had been affected. 

Cheng Guodong, of the China Academy of Sciences, said starting to run trains on the line was not the final hurdle. "There remain some problems to solve such as issues relating to permafrost," Cheng said. He said the major problems were partial foundation cracking, water accumulation and that cracking occurred when cooling techniques were not applied.

"Current problems are merely on the surface which can be solved with normal maintenance and the stability of the railway foundation is not affected," he said at the Asian International Permafrost Conference held from August 7 to 9.

"The railway represents the latest development of permafrost engineering," said Jerry Brown, president of the International Permafrost Association. "Other countries can learn from China's achievements in this field."

Yet international experts agreed that permafrost engineering, including the Qinghai-Tibet Railway, is a complicated business and needs further examination. 

"The Siberian Railway has been running for over 100 years yet stability problems remain," said Professor Valentin Kondratiev from Russia. "It's little wonder the magnificent Qinghai-Tibet Railway will suffer some problems."

American permafrost engineering expert Max Brewer said that the Alaska Railway, which also runs on permafrost, was built in 1923. "It's naive to expect such a long railway not to encounter problems," he said.

Security measures have already been put in place to protect the line. "We've installed a long-term permafrost monitoring system in order to settle new problems," said Sun Yongfu in a written speech.

"As for movement of the permafrost foundation we'll take timely measures to repair them," Sun said. "As for the impact of global warming and repeated loading we'll conduct further research."

Chinese engineers are carrying out detailed examinations and maintenance along the line and will develop effective measures to deal with emerging issues.  

"The opening of the Qinghai-Tibet Railway doesn't mean an ultimate success nor will the permafrost problems be solved once and for all," said Cheng Guodong. "Measures will be continuously taken and we're confident we can ensure the safety and stability of the line.”

(Xinhua News Agency August 10, 2006)