Tunnelling projects require shafts, either as start and reception shafts for the tunnelling process or for inspection, ventilation and rescue purpose. The current trend towards installations in growing depths is driven by deep sewers to avoid pumping stations and the need to build new installations below existing infrastructure.Inner-city shaft structures demand safe working principles for surrounding buildings and environment, especially regarding potential settlements. In addition, deep shafts need special attention for the safety of the operating personnel. The VSM method procures safety for the surrounding environment and for all personnel. As the water level in the shaft equals the groundwater level outside the shaft, there is no water flow which can cause ground movement. All installations including the lining erection are completed from the surface. No personnel have to enter the shaft until it has reached the final depth and is fully secured. The lining consists of either precast segments or cast in place concrete. As the lining installation is completed on the surface, a high quality installation can be reached. In most cases, a secondary lining is not required.The first VSM equipment was put into operation more than 15 years ago. Today, nearly 80 shafts of up to 85 m depth have been sunk worldwide using VSM. This paper will describe the role of shaft sinking in tunnelling projects along with all necessary safety and planning aspects when VSM is being discussed.
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