Recently, small-diameter shallow tunnels have often been built using pipe-jacking. This is the sewage tunnel drivage method. This system involves the pushing or thrusting of a drivage machine through concrete pipes ahead of jacks. This method utilizes mud slurry which is formed around the pipes in order to stabilize the surrounding soil. However, the behavior of the soil and the mud slurry around the pipes is not clearly understood. From this point of view, this paper discusses the performance of mud slurry around drivage pipes by means of two-dimensional Eulerian-Lagragian seepage analysis and field data.
The use of small-diameter tunneling and micro-tunneling in Japan to date has been extremely limited (Matsumoto, 1997). However, in order to protect workers' safety during construction, as well as for environmental and cost reasons, efficient small-diameter shallow tunneling methods have recently become increasingly important in regards to outside plant engineering such as for water supplies, electricity, telecommunications and gas. The effects of the above project in overcrowded urban areas are significant and often result in substantial impact and traffic delays with associated loss of travel time. Clearly the solution to these utility placement problems, if the full impact of trench excavation is to be avoided, is trenchless technology (McFeat-Smith and Herath, 1994). In particular, for construction work near existing facilities, an underground tunnel that is excavated by pipe-jacking is being increasingly used in order to avoid the above problems. Pipe-jacking is firmly established as a special method for the non-disruptive construction of the underground pipelines of sewage systems. Pipe-jacking, in its traditional form, has occasionally been used for short railways, roads, rivers, and other projects (Hunt, 1978). Basically, it involves the pushing or thrusting of a drivage machine through concrete pipes ahead of jacks.