Buderus Manual on Trenchless Installation of Ductile Cast ... - Duktus
Buderus Manual on Trenchless Installation of Ductile Cast ... - Duktus
Buderus Manual on Trenchless Installation of Ductile Cast ... - Duktus
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
8. Installati<strong>on</strong> with steered pilot bore<br />
An interesting variant technique for the trenchless installati<strong>on</strong> <strong>of</strong> new ductile cast ir<strong>on</strong><br />
pipelines was seen for the first time in 200 at the Berlin Water Exhibiti<strong>on</strong> [8.1]: a steered<br />
pilot bore was run to the arrival pit over a distance <strong>of</strong> approximately 70 metres using a<br />
tunnelling machine for microtunneling. As a sec<strong>on</strong>d step, this pilot bore was upsized to a<br />
diameter <strong>of</strong> 80 millimetres by soil removal through auxiliary pipes c<strong>on</strong>taining an auger<br />
feeder. The third step was to withdraw the auxiliary pipes while at the same time pulling<br />
in individual ductile cast ir<strong>on</strong> pipes. The accuracy which can be achieved with this variant<br />
technique is so great that even the stringent requirements <strong>of</strong> draft DWA Arbeitsblatt A<br />
12 [8.2] for gravity pipes can be met.<br />
8.2 A descripti<strong>on</strong> <strong>of</strong> the technique<br />
The first step is to make the pilot bore. Starting from the launch pit, the pilot pipe is<br />
pressed through the displaceable soil to the arrival pit. An optical system, a steering<br />
head, a theodolite fitted with a CCD camera and a display are used to enable the target<br />
point to be homed in <strong>on</strong> exactly while directi<strong>on</strong> and inclinati<strong>on</strong> are c<strong>on</strong>stantly m<strong>on</strong>itored<br />
(Fig. 8.1).<br />
Fig 8.1 Step 1: Pilot bore<br />
8<br />
The steered pilot bore technique<br />
8.1 General<br />
1. Pilot bore<br />
Bohrtec<br />
BM 00<br />
Launch pit<br />
Surface <strong>of</strong> ground<br />
Drive <strong>of</strong> pilot bore<br />
Arrival pit