ABSTRACT
Pipe jacking method is an economically rational and environmentally safe technique for installing underground pipelines. Hydraulic jacks are used to push pipes and TBM through the ground from a launching shaft at the same time as excavation is taking place with the TBM. The main factor influencing jack force is the frictional resistance between pipes and ground. To reduce the friction resistance, the excavation radius by a TBM is larger than the outer radius of the pipes, that is, the over-cutting area between pipes and ground exists, which is a significant factor giving influence to jack force.
