The Cancer Hospital Station of Tianjin Metro Line 7 is under construction. The connecting wall has a depth of 69.45m, which is the deepest wall constructed by the Tianjin Metro. It is also the most difficult and risky bid section of the Tianjin Metro.

The air shaft between Cancer Hospital Station and Lijiang Road Station of Tianjin Metro Line 7 is located in the ramp in the northeast quadrant of the China Petroleum Overpass at the intersection of Weijin South Road and Heiniucheng Road. It is relatively close to the Cancer Hospital Station. In order to ensure the cancer hospital ultra-deep wall project The project team of Tianjin Cancer Hospital Station, the general contractor, after various demonstrations and investigations, decided to test excavate an 80m deep and ultra-deep trough section in the ventilation shaft construction site of this interval, which is a choice for the construction of the ground wall of the tumor hospital station in the future. Optimal construction plan. Zhongrui Heavy Industry ZG70 groove forming machine is very honored to have this opportunity to complete the deepest 80-meter ultra-deep groove trial groove task in the history of Tianjin ground wall construction.

The experimental tank has a design depth of 80 meters, a wall thickness of 1 meter, and a total earthwork of 225m?. According to the on-site geological survey report, the main geological conditions are mainly silty clay and silty sand (iron plate sand) with a high iron content, and the highest standard penetration number is more than 100. On the other hand, the on-site mud has a large sand content and low viscosity, which brings great challenges to the construction of ultra-deep troughs. With the great help of the general contractor’s project team, after more than 19 hours of hard work, finally at one o'clock in the morning on July 21, 2020, the ZG70 slot machine successfully dug to 80.25m, completed the project test, and handed over the order. The project team answered the paper satisfactorily and was unanimously approved by leaders and experts, providing solid and reliable first-hand information for the smooth construction of the cancer hospital station in the later stage.

The construction information of ZG70 equipment is as follows:

Construction efficiency (equipment engine working time totals 16 hours):

Equipment fuel consumption:

The hourly fuel consumption of the ZG70 slotting machine is 48.5 liters, and the square fuel consumption is 3.67 liters

Grooving accuracy:

The first inspection; time: 11:25-12:25; inspection depth: 35m

The second inspection; time: 15:40-16:40; inspection depth: 55m

Final slot inspection; time: 01:30-2:50; inspection depth: 80.23m