Record Horizontal Anchor Holes on Turkish Highway Project
Two Sandvik Top Hammer drills have recently completed record horizontal anchor holes on an elevated highway project in Turkey using techniques generally associated with down the hole (DTH) rigs.
The highway, the Artvin-Erzurum State Road Stage II in Turkey’s Eastern Black Sea region features a number of bridges.
Soil conditions determined that horizontal anchors were needed to stabilize the embankment supporting the elevated highway.
Kolin opted for the non-traditional tophammer technique for drilling on this project due to the abrasive ground conditions causing considerable wear on both hammers and bits.
Under subsequent trials with a Sandvik DX 700 Top Hammer rig fitted with Sandvik T51 drilling tools and the smaller Sandvik 115 mm diameter retrac drill bits, Kolín was able to drill horizontally record breaking 24 m long, and in some cases even 30 m, anchor holes on the remaining six levels.
The Sandvik performance, using the smaller diameter drill bits and Top Hammer rigs was, according to a spokesman for Kolín, outstanding being “quicker and more cost effective using the lower cost tophammer tools, compared with DTH.”
The nine levels cover an area of 101 m x 72 m with individual anchor holes spaced 3,5 m apart.
The Sandvik DX 700 is a hydraulic, self-propelled, self-contained and crawler – based surface rig powered by a Cat C7 diesel engine rated at 202 hp @ 2200 rpm.
Sandvik Drill Rig sales manager, Ergun Sokulluoglu, also confirmed that the contractor was also using a DX 680 rig on the highway project; forming part of its fleet of 7 Sandvik drill rigs.
Work is shortly to start on the second bridge, once again using both drilling techniques in a repeat performance over nine levels.
Source: Sandvik Mining and Construction
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