The first underground diaphragm wall of the 2nd bid of Shanghai Daming Drainage System Upgrading Project has been smoothly inserted into the trough

On April 9, 2023, Shanghai Daimyo drainage system upgrading project 2 ushered in the first underground diaphragm wall construction, marking the project on a new journey to a new level!

A new confluence pump station was built in the 2nd bid of Daiming Drainage System Upgrading project, including a rainwater pump house with a scale of 18m³/s, a sewage pump house with a scale of 0.97m³/s, and an initial rainwater storage tank with an effective volume of 12600m³. The main projects include: confluence pump station, inlet and outlet water tank culverts, flood control wall restoration, pipe jacking project, sewage throttling pipe project, reserved branch pipe project and equipment procurement, installation, commissioning, trial operation and handover in the pump station.

The foundation pit supporting form of the new combined pump station is the underground continuous wall, a total of 32 pieces. The thickness of the ground joint wall is 1200mm, the depth is 54/51m, the cross steel plate joint is adopted, the depth of the foundation pit is 28.8 meters, six reinforced concrete supports and one steel support are set, and the construction is carried out by open excavation.

The construction is faced with three difficulties: poor geological conditions: the project is near the Hongkou Port of the North Bund, and there are many sundry objects in the underground dark creek and backfill soil, and the adverse geological conditions have a great influence on the stability of the trouging. The lifting risk of steel cage is large: the deepest underground wall reaches 54m, and the weight of the steel cage including the lifting gear reaches 81T in the advance width, and the construction site is close to high-rise buildings and municipal roads, so the lifting risk is large. Heavy workload of coordination: The project is located in a busy area, and earth-moving vehicles and concrete vehicles cannot enter and exit normally during morning and evening peak hours, so the continuous operation coordination of the ground wall is heavy.