Trenchless Training FR
Courses Down-the-hole hammer (DTH)

ST01G-MFT FREN

Down-the-Hole Hammer

The most versatile steel casing boring method: mixed soils, till and rock, compressed air constraints and lessons learned.

Down-the-hole hammer head emerging from a casing

Module preview

4 of 30 slides, as they appear in the module.

  • Slide 1 Down-the-hole hammer

  • Slide 6 Horizontal boring specifications

  • Slide 14 Additional equipment

  • Slide 23 Ring bit assemblies

The down-the-hole hammer has taken on an important role in the industry in recent years: it bores equally well through mixed soils with cobbles and boulders and through hard rock.

The module presents the method, the equipment and the constraints, notably the large volumes of high-pressure air, and reviews the challenges met on site.

Objectives

By the end of the module, you will be able to:

  • Describe the down-the-hole hammer method
  • Identify the soils and rocks where it is appropriate
  • Assess its constraints: compressed air, equipment, weight in the hole
  • Learn from recent field experience

Outline

  1. The three steel casing boring methods
  2. The DTH hammer, step by step
  3. Versatility and constraints
  4. Lessons learned: equipment and ring bit
  5. Deviation, breakdowns and other hazards

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