Direct Pipe Tunnelling
Definition - What does Direct Pipe Tunnelling mean?
Direct pipe tunnelling is a trenchless technology combining the strengths of Horizontal Directional Drilling (HDD) and microtunnelling. Pipe is laid in a single operation with steerable equipment thus saving time and money. Combining these methods, piping can be installed in a shallower route than HDD and entry and exit pits can be shorter due to the due to the curve routing possibilities of this technique.
Trenchlesspedia explains Direct Pipe Tunnelling
Earth excavation is done through a micro-tunneling machine which uses a flushing circuit to remove the excavated earth to the surface. The machine is steerable, allowing good control of the installation along the intended route. A pipe thruster provides the force necessary to push the pipe into the bore and supply pressure to the cutting head. The tunnel is fully supported by the pipe as it is installed. This trenchless technology is fairly new, but the advantages over HDD and micro-tunneling alone make it well suited to specific applications.