| 20090078464 | MICROTUNNELING METHOD - A microtunneling method includes: (a) forming a working well; (b) boring a tunnel from the working well through waterjet techniques which use at least one waterjet cutter including a jet seat and a jet nozzle mounted rotatably on the jet seat, the tunnel being bored by moving progressively the jet seat along a circular path and by rotating the jet nozzle relative to the jet seat; (c) removing excavated soil, rocks or gravel from the tunnel; and (d) advancing the waterjet cutter along an axis of the circular path. | 03-26-2009 |
