China builds “record-breaking” high-speed rail tunnel under Great Wall

The nerves are tight in China about the structural integrity of the Great Wall in Badaling while the engineers exploding deep tunnels below records high-speed and cavernous stations.

The 12-kilometer tunnel extends at a maximum depth of 432m below the most visited part of the China’s Great Wall, which was completed in 1504. To carry trains from 350 km/h between Beijing and Zhangjiakou City to two winning cities in the wake of the Winter 2022 Winter Olympics.

The engineers use the technology "precision micro-blasting" to dig a tunnel so as not to damage the world-famous monument, according to the state newspaper Global Times.

Chief engineer Duhao Luo's project said precision micro-blasting had a speed of 0.2 cm per second and produced a smaller tremor than traditional blasting.

Since February there have been 4500 blasts.

“I myself once stood on the Great Wall and I could not feel the blast at all,” Dai Longzhen, deputy manager of the Beijing-Zhangjiakou High-Speed Railway Line, told the Global Times.

It took months for Chinese engineers to "choreograph" the best point 174km railway to intersect the Great Wall, the Global Times reported.

When completed in 2019, the railway is expected to reduce driving time between two cities within 3 hours for about 1 hour.

In addition to the tunnel, engineers build a large station at 102m below the Great Wall. The station should be 36,000 square meters.

Longzhen Dai said the construction area and depth of the station is a "record-breaking".

The Great Wall is Badaling surrounded by parks and scenic locations, with the completion of the station due to avoid environmental damage, said Dai and show the railway capacity building in China.