Pipe jacking method for long curve construction

The D301 pipe jacking method is the first to accomplish long spans, curves and high speed construction in the field of small diameter (300 mm) tunneling. The design of the system components are described: tunneling machine with directional control ability, jacking machine, power unit, and control unit which contains a microprocessor. As a result of field tests in about 100 m in length with a 200 curvature radius, the following capabilities are confirmed: the span length is up to 100 m, the curvature radius is down to 200 m, it is useable in either cohesive or sandy soils having N-curves up to 10, and the construction speed is up to 3 m/h.