Recently, as the 230-ton main unit was lowered to the bottom of the foundation pit, the world's largest shaft boring machine, "Dream," was safely lowered into the pit at the underground smart parking garage project in Jing'an District, Shanghai, laying a solid foundation for its smooth launch.

"Dream" being lowered into the pit

Jointly developed by CRCHI (China Railway Construction Heavy Industry Corporation) and China Railway 15th Bureau, "Dream" integrates excavation, mucking, support, and guidance functions, and is suitable for the construction of super-large-diameter shaft projects in soft soil and soft rock strata. The equipment's overall technology has reached the international advanced level, and it is currently the world's largest-diameter shaft boring machine.

The above-ground footprint of the smart parking garage in Jing'an District, Shanghai is only 286 square meters

In recent years, localities have been accelerating the construction of livelihood projects such as sponge cities and underground smart parking garages, resulting in an increasing number of super-large-diameter and ultra-deep shaft projects. Previously, domestic and foreign enterprises had developed shaft boring machines with excavation diameters of 13 to 14 meters for mechanized caisson engineering, but the development of a super-large-diameter shaft boring machine with an excavation diameter of 15 meters or more is the first of its kind in the world.

To meet the project's super-large-diameter excavation requirements while ensuring shaft excavation efficiency, the CRCHI R&D team overcame the design technology for complete sets of super-large-diameter mechanical caisson equipment, strengthened the reliability of the equipment for underwater construction, and solved the difficulty of controlling the sinking posture in traditional caisson construction. Compared with traditional manual-excavation caisson construction methods, "Dream" uses mechanized caisson operations to achieve unmanned underground work and minimal personnel on the surface, fulfilling the goal of shaft builders "digging shafts without going down the shaft," saving more than 50% of construction costs and effectively improving construction safety.

"Dream" at the rollout ceremony

It is reported that the underground smart parking garage in Jing'an District, Shanghai has a surface footprint of 286 square meters and an underground area of 1,408 square meters, with a total of 19 levels. It is planned to build two deep foundation pit shafts with a diameter of 23 meters and a burial depth of 53 meters, each equipped with 152 mechanical parking spaces. The surface level will serve as the garage entrance/exit level and equipment rooms. Once completed, it will become the world's largest-diameter vertical-excavation underground smart parking garage.