The Role of Pipe Jacking in the process of Horizontal Directional Drilling

The Role of Pipe Jacking in the process of Horizontal Directional Drilling

Horizontal Directional Drilling (HDD) has become a popular trenchless technology for installing underground pipes and utilities with minimal disruption to the surface. But what many people don't realize is that HDD often relies on a silent partner: pipe jacking.

While HDD focuses on creating the underground pathway, pipe jacking takes center stage when it comes to safely and efficiently installing the pipe itself. Here's how these two methods work together to create a winning team:

The HDD Side of the Story:

  • The Drill Does the Dirty Work: HDD utilizes a powerful drill rig equipped with a specialized drill head to bore a precise tunnel through the ground. The drill head may employ various techniques like earth augering, fluid jetting, or a combination of both, depending on the soil conditions.
  • Keeping it Clear: Throughout the drilling process, a mud circulation system continuously removes cuttings (excavated soil) from the tunnel. This mud also helps stabilize the borehole walls and cools the drill head.
  • Preparation for the Main Event: Once the HDD has completed the pilot bore and potentially reamed it to the desired diameter, the stage is set for pipe jacking.

Pipe Jacking Takes the Lead:

  • The Jacking Force: A pipe jacking machine, positioned at the entry pit, takes over. This powerful machine uses hydraulic rams to push the prefabricated pipe sections into the pre-drilled HDD tunnel.
  • One Piece at a Time: The pipe sections are typically made of steel, concrete, or high-density polyethylene (HDPE) and are specifically designed for this purpose. The jacking machine pushes each section forward, connecting it securely to the previous one.
  • Continuous Monitoring: Throughout the jacking process, engineers closely monitor the alignment, pressure, and overall stability of both the pipe and the surrounding soil. This ensures a smooth and safe installation.

The Benefits of the Pipe Jacking & HDD Teamwork:

  • Minimized Surface Disruption: HDD and pipe jacking work together to eliminate the need for extensive trenching, significantly reducing disruption to traffic, landscaping, and existing infrastructure.
  • Environmental Advantages: This trenchless technique minimizes environmental impact by disturbing less soil and vegetation. Additionally, controlled mud circulation in HDD helps prevent soil contamination.
  • Increased Accuracy and Efficiency: Pipe jacking allows for precise pipe installation within the pre-drilled HDD tunnel, reducing the risk of damage to existing utilities or unforeseen obstacles.
  • Versatility for Various Projects: The combined power of HDD and pipe jacking can be applied to a wide range of underground pipe installations, from sewer lines and water mains to gas pipelines and telecommunication cables.

Pipe jacking, though often overshadowed by HDD, plays a crucial role in the success of trenchless pipeline installations. It's a powerful and precise technique that ensures the safe and efficient placement of pipes underground.

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