ABSTRACT
The dimensions of shafts relate to the type of equipment being used. The width is in direct relationship to the diameter of the pipe being driven, plus an allowance for working space. External diameter of pipe plus 2000 mm is typical. The length is determined by the length of pipe sections to be installed and the space needed for the jacking equipment. Attention also needs to be paid to the longest shield section which has to be handled in the pit, as this can be greater than the pipe lengths. The most compact microtunnelling equipment will work in a shaft the length of the pipe section plus 1000 mm. Some Japanese equipment may require anything up to 5000 mm. For pipejacking in diameters up to DN 1500, the minimum additional length to be added to the pipe length increases from 1500 mm to 2000 mm. Shaft dimensions for drives in larger diameters tend to be site specific. Manufacturers provide information on dimensions of shafts required for their equipment.
