Mechanized Shaft Sinking With VSM: Safe and Resource-Saving Construction of Shafts and Foundations in Urban Surroundings-Paper

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The paper describes the Vertical Shaft Sinking Machine (VSM), a remotely operated technology for building deep shafts in dense urban areas and challenging ground conditions. Since its first deployment in 2006, VSM has been used on more than 111 projects, constructing shafts up to 115 m deep and with internal diameters of 4.5–12 m.<br /><br />VSM excavates underwater while keeping the shaft water level close to the surrounding groundwater level, avoiding groundwater lowering and helping limit settlement and damage to nearby structures. A surface-operated cutting unit removes soil, which is pumped as slurry to a separation plant. Meanwhile, hydraulic strand jacks control the shaft’s descent, and lining—usually precast concrete segments, or sometimes cast-in-place concrete—is installed at the surface. Excavation and lining proceed simultaneously, improving productivity and accuracy. The unmanned operation reduces personnel exposure, while modular equipment can be arranged to suit restricted sites. Grid-powered operation can also reduce noise and emissions; precast lining may require up to 40% less concrete than diaphragm or bored-pile wall methods.<br /><br />Examples include ventilation and emergency shafts for Paris’s Grand Paris Express, where VSM operated in varied ground conditions and tight sites; shafts beneath historic Naples, where compact equipment and low disturbance were important; and Barcelona rail-line shafts through ground ranging from loose soils to very hard rock. The paper also notes applications in Singapore and Nanjing, including shafts for an underground parking system.<br /><br />The authors conclude that VSM offers a safe, accurate, and space-efficient option where conventional shaft construction is technically or economically difficult. They identify potential future uses in underground energy storage, food production, and urban logistics.

Keywords

Vertical Shaft Sinking Machine

VSM

deep shaft construction

urban infrastructure

groundwater control

slurry excavation

precast concrete segments

remote operation

settlement mitigation

tunneling