Delicate soil environment means 90% of project was built on bridges or in tunnels

The new high-speed railway running through the Loess Plateau was opened on Sunday, the last piece in the puzzle linking the less-developed northwest region to the rest of the country.

The 401-kilometer line links Baoji in Shaanxi province and Lanzhou in Gansu province, connecting the northwestern region to the national high-speed rail network.

To the west, the line connects to the Lanzhou-Xinjiang high-speed railway, China's westernmost high-speed rail track. To the east, it links the Xuzhou-Zhengzhou high-speed railway to the country's farthest east coastal area.

The Baoji-Lanzhou line has eight stops, including Baoji South, Tianshui South and Qin'an stations. With trains traveling up to 250 km per hour, it cuts the travel time between the two cities from seven hours to just two, according to China Railway Corp, the nation's rail operator.

The new line has reshaped the map of China's bullet train operations. Lanzhou, the capital of Gansu, is now connected to many metropolises, including Beijing, Shanghai, Guangzhou, Hangzhou, Wuhan and Changsha.

The travel time from Lanzhou to Beijing has been cut from 17 hours to nine; to Shanghai, from 23 hours to 10; and to Guangzhou, from 30 hours to 12.

"The Baoji-Lanzhou high-speed railway is the main rail channel linking China's eastern, central and western regions," said Zhang Tao, chief engineer of Lanzhou railway bureau's passenger transport department.

"It has further improved China's high-speed rail network, cutting rail travel times, boosting people-to-people communications, as well as greatly enhancing social and economic development," he said.

"It has also increased the rail transport capability of the New Eurasian Continental Bridge, playing an important role in linking China with countries in Central Asia, and promoting economic development along the new Silk Road," he added.

Building a high-speed railway along the Loess Plateau was not an easy task. The new line runs through the erodible soil of the plateau, with more than 90 percent of the tracks being built on bridges or in tunnels.

"Building a high-speed railway here is like building a high-speed railway on tofu," said Yuan Tao, project manager of the Gansu section of the Baoji-Lanzhou high-speed rail project from the China Railway Construction Corp.

Zhu Yaozhang, chief engineer of the Gansu section, said, "It was a big challenge to build a high-speed railway on the Loess Plateau due to the complicated geological environment.

"The erodible soil is fragile, and can subside when saturated," Zhu said, adding that such soil can cause geological hazards such as landslides.

Because the soil is prone to subsidence, a simultaneous observation system has been built to closely monitor the state of the soil.

"The system collects data, which is monitored by technicians to prevent damage and ensure safety," he said.

luowangshu@chinadaily.com.cn