China Railway No.3 Engineering Group Co., Ltd. has successively undertaken the construction of more than one hundred metro projects in such major cities as Beijing, Shanghai, Guangzhou, Shenzhen, Tianjin, Nanjing, Shenyang, Xi'an, Chengdu, Chongqing, Hangzhou, Suzhou, Wuhan, Zhengzhou, Changsha & Wuxi.Its construction covers almost all domestic cities having metros. Having undergone the construction under various formation conditions of sandy gravel, upper softness & lower hardness, loess & karst development, metro shield construction obtained the progress & innovation of construction technology for open & concealed excavation of metro stations under various complex geological conditions, totally forming 39 scientific & technological achievements, of which 5 reached international advanced level, 11 won the science & technology awards at / above the provincial / ministerial level, developing 102 construction methods (including 3 national construction methods) & licensing 69 patents (including 16 patents for invention).

Construction technologies for metro stations lead the industry. By studying & applying the key technology of HPE construction method of hydraulic vertical insertion into AM pile of steel pipe column, China Railway No.3 Engineering Group Co., Ltd. developed the construction technology system of metro station with top-down covered excavation & deep large foundation pit excavation & support, successfully solved the technical problems of enclosure & excavation of deep foundation pits of urban metros & formed 2 provincial construction methods. Its overall technology reached the international advanced level. In the field of station construction technology, it developed 2 national construction methods, i.e. "construction method of underground excavation of center drift in three-arch & two-column structures" & "comprehensive construction method of metro top-down covered excavation foundation". They filled the technical gap of the industry & were widely applied in metro projects in Beijing, Guangzhou & other cities, gaining favorable applying effects & generating significant economic & social benefits.

Comprehensive shield construction technology is at the forefront of the industry. By introduction, digestion & innovation, China Railway No.3 Engineering Group Co., Ltd. successfully studied & applied the key technologies for group piles in slurry shield full-cross-section sand-layer underneath building foundation & muddy shallow earthing burial deep underneath surface river, the slurry shield excavation in upper-soft & lower-hard formation, slurry shield open operation in water-permeable formation, mud mold production as well as other leading construction technologies of slurry shield, which solved the problem of slurry shield construction under complex geological & working conditions, having its key technologies reaching the international advanced level. It developed & used a series of shield construction technologies such as shield starting in loess area, shield under ancient city walls & rivers as well as shield empty-propulsion over station, successfully achieving rapid & safe construction of the shield under complex conditions in loess area. Overall technologies reached the industry's leading level. Besides, it initially developed & used vertical isolation pile protection, inner tamping curtain of small pilot heading, sleeve valve pipe grouting advance reinforcement technology as well as automatic monitoring technology of rational shield excavation parameter & real-time settlement, which solved technical difficulties for safe construction that upper-soft & lower-hard formation shield went underneath high-speed railways in case of high-speed rail without rail girder at unlimited speed.

Build the new normal of green construction & promote low-carbon development of enterprises via green concept.China Railway No.3 Engineering Group Co., Ltd. adheres to problem-oriented approach, starts from details of the construction process as well as daily management, builds a new normal of green construction, creates a new landscape of green construction & uses the green construction concept to promote the sustainable development of enterprises.