This is a massive structure reaching 26 meters deep, adjacent to a resplendent thousand-year-old temple, neighboring 100-meter-tall skyscrapers, and with three metro lines converging here.

But compared to a typical metro construction site, the above-ground part of this fortress station is even smaller than a "snail shell," with a total enclosure width of only 19 meters.

It is also China's first station "pushed out" using rectangular pipe jacking. In the words of all experts and builders, it represents a miracle in world engineering history.

Jing'an Temple Station on Line 14 is located beneath Huashan Road at the intersection of Huashan Road and Yan'an Middle Road, arranged in a north-south direction along Huashan Road. It is about 225 meters long and 20.54 meters wide, forming a three-line interchange with the existing Line 2 and Line 7. The station is in a commercial area with many high-rise buildings and heavy traffic, and underground there are multiple metro lines and utilities crisscrossing, like "holding a ceremony in a snail shell." Because of this, it has become the most difficult and technically complex project in Shanghai's metro system.

What makes it difficult?

Technically first in the country! The first pipe-jacking station. Those in engineering know that pipe jacking is generally used to dig tunnels, but in the Jing'an Temple Station project, we directly "pushed out" a station using pipe jacking!

The north end shaft of Jing'an Temple Station is adjacent to Jing'an Temple Station and the running tunnels of Metro Line 2, and is very close to surrounding structures. Conventional construction methods would be difficult to ensure traffic on Huashan Road and Yan'an Road. Therefore, engineers from Tunnel Engineering Co., Ltd. took a different approach and applied pipe jacking to the construction of the metro station itself—just like tunnel boring, using large-section pipe jacking to "push out" the underground space of Jing'an Temple Station.

During construction, the super-large-section pipe jacking had to enter and exit the shaft multiple times at close range. To address this, the project team of Shanghai Tunnel under Tunnel Engineering Co., Ltd. strictly controlled the quality of entry/exit reinforcement to block soil seepage channels; adopted effective water-stopping measures for entry/exit construction to ensure no leakage during the process; strengthened monitoring of entry/exit sections and reasonably set jacking parameters for entry/exit sections to reduce disturbance to surrounding soil.

In addition, because the pipe jacking in the platform level has an overburden of 15 meters, involving deep overburden and complex strata, the project team also optimized jacking parameters based on the initial jacking situation, used new anti-friction slurry to reduce jacking force and soil adhesion on the cutterhead. A dual correction device was installed on the pipe jacking machine to ensure axis stability; ground monitoring used an automatic measurement system combined with manual verification to ensure timely and accurate settlement data; multiple grouting measures were combined to control ground settlement during and after construction.

Management top in the country! Smallest site, finest management

The construction of Jing'an Temple Station is located in a bustling city center. Compared to a typical metro site, Jing'an Temple Station is even smaller than a snail shell. The total width of the construction enclosure is only 19 meters, and the pipe jacking passes close to pedestrian bridges and elevated bridge piles multiple times, with a minimum clear distance of only 3.6 meters.

To address this, the project teams from Tunnel Engineering Co., Ltd. Urban Construction Design Group and Shanghai Tunnel carefully surveyed the locations and types of bridge piles, set up direct measurement points and strengthened monitoring during crossing; set reasonable jacking parameters for crossing construction to reduce soil disturbance; and promptly carried out grouting to fill the gap between pipe segments and soil. Meanwhile, for the difficulty of side-crossing with ultra-small spacing and large-section pipe jacking, construction parameters were strictly controlled during west line construction to reduce fluctuations; monitoring of the completed tunnel was strengthened during construction to understand the impact of nearby tunnel construction and adjust parameters in time; after tunnel breakthrough, circumferential seams of pipe segments were promptly welded, and secondary grouting and slurry solidification were performed.

In addition to Jing'an Temple Station, on Line 14, a "difficult line," tunnel workers have also created countless "engineering firsts."

Guiqiao Road Station on Shanghai Metro Line 14

The pipe curtain section of Guiqiao Road Station, constructed by Shanghai Tunnel under Tunnel Engineering Co., Ltd., was the first to adopt the pipe curtain + MJS composite method for mined construction of a metro station, innovatively opening a new path for building metro stations in soft soil strata by mined excavation, effectively solving problems such as demolition, traffic diversion, and utility relocation caused by conventional open-cut construction.

Wuding Road Station on Shanghai Metro Line 14

Entrance No. 1 of Wuding Road Station, designed by Tunnel Engineering Co., Ltd. Urban Construction Design Group and constructed by Shanghai Tunnel, was the first to use the U-BIT bundled pipe curtain method. By applying cross-sectional prestress, the integrity of the pipe curtain is improved, offering advantages such as larger cross-sectional dimensions, more flexible cross-sectional forms, and no support during excavation. This is also the first case in China.

Dashijie Station on Shanghai Metro Line 14

Pit B of Dashijie Station is directly above a power tunnel, with a clear distance of only 0.5 meters from the excavation face to the power tunnel. Protection was carried out using in-pit and out-pit reinforcement and freezing reinforcement. The combined wall of inclined diaphragm wall and frozen body was used for the first time in Shanghai. The north side of Lujiazui Station is adjacent to the "century-old Veolia Water Plant," and Xiepu Road Station is close to the piers of Yangpu Bridge, with extremely high environmental protection requirements.

At the same time, during the construction of Line 14, Tunnel Engineering Co., Ltd. Urban Construction Design Group also undertook the design and construction of the tough projects on Line 14—Jing'an Temple Station, Wuning Road Station, Wuding Road Station, Dongxin Road Station, as well as the running tunnel project from Fengbang Station to Jinyuan Wulu Station, etc.

Under the ground of Shanghai

The tunnel vanguard

Benefits the people with core technology

Creates engineering miracles!