Description of horizontal driling technology

Horizontal, steered drilling machines are used to execute precise horizontal drillings with desired direction and slope. In the first stage of the works, from starting trench (starting chamber), with use of hydraulic steered machine, pilots are being provided into the soil. Pilots are made out of steel pipes 1m length and diameter of 88 or 114mm, that are being thread and twisted. In front of the first pilot pipe, angle cut ending has been provided that allows drilling direction adjustment due to its rotation and pushing. Strait line of the drilling has been assured by the teleoptical system composed of the LED target shield located in the front of the pilot, electronically controlled leveling machine equipped with camera and LCD monitor. Leveling machine is being placed in the starting chamber, and its optical axis indicates the axis of the drilling. Picture from leveling machine is being transferred via digital camera to the monitor. On the monitor, LED target shield located in the front of the pilot has been indicated as well as cross of the leveling machine. The aim of the operator is to push the pilot so that LED target shield is covered by the cross of the leveling machine.

When pilot reaches desired trench (receiving chamber) second stage of works begins – final drilling. Steel cover pipes, together with helix shaped soil carriers are being pushed into the soil. In the meantime pilot is being dismantled in the receiving chamber. Soil surplus that is being produced during the final drilling is being transported with use of helix shaped carriers back to the starting chamber. When drilling is finished (steel pipes are located underground, between starting and receiving chamber) third stage of works begins. Steel pipes are being pushed out to the receiving chamber with use of technological pipes. Diameters of the steel pipes are being adjusted dependently to the diameters of the designed technological pipes. Work is finished, when technological pipes are being placed between starting and finishing chambers.