The Group started to undertake the construction of metros of the new century since 2002 and successively built a total of 32 projects such as some stations of Metro Line 1, Metro Line 3, Metro Line 5 and Metro Line 6, Tianjin West Railway Station, Transportation Hub Project of Yujiapu Station, Transportation Hub of Tianjin Railway Station, transportation hub project affiliated to the expansion of Tianjin Binhai International Airport, metro shield construction of two sections among three stations between Meijiang Scenic Area Station and Exhibition and Convention Center Station, and between South Jiefang Road and Meilin Road, and the metro shield construction of the one section between two stations from Meijiang Scenic Area Station to Exhibition and Convention Center Station of Tianjin Metro Line 6. The section from Meijiang Scenic Area Station to Exhibition and Convention Center Station of Tianjin Metro Line 6 is a single-tube single-way/two-way tunnel. The section tunnel starts at the mileage of DK37+186.836 and ends at the design mileage of DK37+775.266. The main line (right line) is 588.430m long, and the left line with a surplus of 0.011m is 588.441m long. The radius R of the curve is 1,000m. The maximum longitudinal grade of the line is 25‰. The vertical profile of this section is a “V” shaped slope. A connecting aisle and a pump station are set up at the design mileage of DK37+446.226. This section starts from Meijiang Scenic Area Station in the north to the south. The section line runs along South Youyi Road and mostly passes through under the South Youyi Road. Left and right lines of the line enter the greenbelt on the west side of Youyi South Road by a reverse curve of 1,000m near the Exhibition and Convention Center Station and go straight into the Exhibition and Convention Center Station. The section structure is covered with soil on the top by about 13-20m. The section from South Jiefang Road Station to Dongting Road Station is a single-tube single-way/two-way tunnel. The section tunnel starts at the mileage of DK39+905.916 and ends at the design mileage of DK40+720.864. The main line (right line) is 814.948m long, and the left line is 814.948m long. The maximum longitudinal grade of the line is 25‰. The section between Dongting Road Station and Meilin Road Station is a single-tube single-way/two-way tunnel. The section tunnel starts at the mileage of DK40+917.864 and ends at the design mileage of DK41+543.666. The main line (right line) is 625.802m long, and the left line with a surplus of 3.874m is 629.676m long. The maximum longitudinal grade of the line is 5.35‰. Tianjin Metro Line 1 extends eastward to the 3rd contract section for civil construction of National Exhibition and Convention Center. The Exhibition and Convention Center Station is a two-story underground island station with a building area of 35,510m2. The external lateral structure is a continuous underground wall with width of 0.8m. The total length of the structure is 530.7m. The end well section is 26.5m wide and 16.86m deep. The standard section is 22.7m wide and 15.16m deep. Weisan Road Station is a two-story underground island station with a building area of 15,783m2. The external lateral structure is a continuous underground wall with width of 0.8m. The total length of the structure is 217.7m. The shield shaft section is 27.4m wide and 15.99m deep. The standard section is 22.9m wide and 14.29m deep. Transportation Hub Project of Tianjin Railway Station covering an area of 140,000m2 is applied with the construction technique of covered excavation reverse construction method. With the deepest excavation depth of 32.5m, it is the deepest foundation pit in Tianjin up to now. The project has formed comprehensive construction techniques like large-scale ultra-deep continuous underground wall construction, large-diameter ultra-deep cast-in-situ bored pile construction, ultra-deep foundation pit dewatering, and reverse construction of main structure, awarded with national engineering method: reversed positioning, installation and placing of steel pipe columns for an underground transportation hub.