| 摘要 |
<p>The process buries a pipe in the bed of a watercourse etc. by moving a fluidising unit along it, and injecting fluid at low speed and pressure via the openings in the unit so as to fluidise the non-cohesive material adjacent to the pipe. The pipe with fluidising unit then sinks into the fluidised material. On encountering cohesive material, this is eroded by fluid at high speed and pressure via injection openings at the front of the device. As this is being done, these openings are moved in a direction other than that in which the unit is travelling, so that the jets from them cut a wide opening in the cohesive material. This movement can be a rotary one.</p> |
