|
 - Directionally controlled drilling assisted by pilot pipes in displaceable soil
 - Drilling of casings leaded by the pilot pipes
 - Jacking of the product piping
 - Expanding from pilot to product pipe, with steel jacking pipes and augers as inner piping
 - Drilling of steel pipes leaded by the pilot pipes
|
|
Basic requirements for guided auger boring are displaceable soils with SPT values ≤ 35 and stones ≤ 80 mm. The ground water table must
be ≤ 3 m.
Guided auger boring will be done with the help of pilot rods with optical path, pilot head, theodolite with CCD camera and monitor in displaceable soil. The pilot rods are jacked through the ground into the target shaft. During the drilling direction and slope are permanently surveyed. Torque problems could occur in cohesive grounds depending on ground conditions and drilling length. As a solution for this and also for the use in ground-water, Bohrtec has developed a double wall pilot rod for which the control head can be turned by means of the inner pipe. The augers and casings then precisely follow the pilot rods, followed by follow-up insertion of the product pipes.
Extension step
After finishing the guided step there are different opportunities for the extension step for different diameters:
- 3 step method for jacking pipes up to OD 419 mm
- 3 step method for jacking pipes up to OD 1000 mm
- 2 step method for jacking pipes up to OD 1000 mm
- 2 step method for welded steel pipes up to OD 1200 mm
[top]
[top]
2 step method for jacking pipes up to OD 1000 mm
 - 1. Directionally controlled drilling assisted by pilot pipes in displaceable soil
 - 2. Expanding from pilot to product pipe, with steel jacking pipes and augers as inner piping
[top]
2 step method for welded steel pipes up to OD 1200 mm
 - 1. Directionally controlled drilling assisted by pilot pipes in displaceable soil
 - 2. Drilling of steel pipes leaded by the pilot pipes
[top]
|
|
Measuring technology
The measuring technology basically consists of three elements: the LED target in the pilot head, a theodolite with a special camera, and a monitor. By means of the theodolite, it is possible to continuously monitor the position of the diode target. When a deviation from the required alignment is seen on the monitor, it is possible to correct by means of the pilot head, which has a slanted plane.
|
 |
Requirements:
- Displaceable soil SPT ≤ 35
- No stones > 80 mm
- Ground water max. 3 m
Machines:
BM 150D, BM 400, BM 400LS, BM 500, BM 600LS,
BM 600LSC and BM 800L
|
