A NEW high-efficiency tunnel digging method will be promoted in more projects to develop Shanghai’s underground spaces.

Compared with traditional digging by a shield, the rectangle pipe jacking method can shorten schedules, reduce land subsidence and assist digging besides subways and other underground projects, the Shanghai Tunnel Engineering Co Road and Bridge Group, the city’s major road and bridge constructor, said yesterday.

The world’s largest rectangle pipe jacking machine, 9.9 meters long and 8.15 meters tall, dug through the Luxiang and Qilianshan roads tunnel in Baoshan District on Tuesday.

Using the method, the machine placed concrete rectangle frameworks into the soil to cut a rectangle-shape tunnel.

The machine known as “Baoshan Pioneer” dug for 445 meters beneath the Gucun and Dachang towns of Baoshan, setting a new world record for tunnel digging distance.

Part of the tunnels is only 4 meters beneath the earth and 7.8 meters away from the operating Metro Line 7, and the under-construction Line 15.

“The successful application of the innovative method will create broader possibilities to Shanghai’s future underground space development,” said Zhen Liang, the chief engineer of the project.

The method will also offer more solutions, for instance, on comprehensive pipelines, “sponge city” construction, underground express road and buildings, Zhen added.

The Luxiang and Qilianshan Road Tunnel and Bridge project, stretching for 2.3 kilometers, will create a major thoroughfare connecting Baoshan, Putuo and Changning districts. Upon its opening, the project will become a major channel for the Luodian and Gucun residential regions and the Nanda area, which is being transformed into an environment-friendly business and residential zone from the former notorious polluted industrial parks.

The Luxiang and Qilianshan roads are currently diverted by Gucun Park and Wenzaobang River, forcing vehicles to detour via Hutai Road.