Special Coring

Special Coring – Detailed Overview



What Is Special Coring?



Special coring refers to non-standard or complex core drilling techniques that go beyond vertical, horizontal, or angled coring. These methods are used when precision, access, or structural complexity requires customized drilling solutions, typically involving unique angles, shapes, depths, or confined-space access. Special coring may also involve advanced tools, robotics, or remote-controlled equipment.





Primary Uses of Special Coring



1. Confined-Space Coring





  • Used in tight, restricted, or hard-to-reach areas such as utility tunnels, shafts, tanks, and crawlspaces.




  • Often requires compact or handheld coring equipment or remote-controlled rigs.





2. Deep and Long-Distance Coring





  • Special rigs are used to core several meters into structural elements, such as thick walls or deep foundations.




  • Ideal for anchor bolt installations, grouting operations, or geotechnical sampling.





3. Large-Diameter Coring





  • Coring holes larger than standard diameters (e.g., 600 mm – 1500 mm) for:





    • Ventilation ducts




    • Elevator shafts




    • Utility vaults







4. Overhead and Inverted Coring





  • Drilling upward into ceilings or soffits, often in parking structures, bridges, or overhead beams.




  • Requires secure rig anchoring and water control to manage slurry from above.





5. Multiple-Angle or Complex Path Coring





  • Combines horizontal, angled, and vertical drilling in a single operation.




  • Used in retrofit scenarios where elements are embedded at unique geometries.





6. Coring Through Reinforced or Post-Tensioned Concrete





  • Specialized scanning and drilling methods are required to avoid damaging post-tension cables or dense reinforcement.




  • May use low-vibration tools or custom-designed core barrels.





7. Marine and Submerged Coring





  • Involves underwater or splash-zone drilling for:





    • Pile inspection




    • Corrosion sampling




    • Structural testing in marine environments







8. Asphalt and Composite Surface Coring





  • Combines concrete with layers of asphalt, epoxy, fiber mesh, or polymer overlays.







Tools and Equipment for Special Coring





  • Hydraulic or electric coring rigs




  • Robotic/remote-controlled drilling systems




  • Custom-angle rigs and adjustable stands




  • Vacuum-mounted rigs for non-anchor surfaces




  • Wet and dry coring systems




  • Advanced scanning tools (GPR, X-ray)