The Guided Boring Method is used to install underground pipes with high accuracy. It involves creating a small, precisely guided pilot hole that follows a planned path beneath the surface. After the pilot hole is completed, the bore is expanded to the size needed for the pipe, which is then pushed through the enlarged space. This process allows pipes to be installed without digging trenches, reducing surface disruption and maintaining precise alignment and slope
Applications of the Guided Boring Method:
- Installing underground utility pipelines in urban infrastructure projects
- Laying sewer and drainage systems beneath roads and highways
- Installing water supply lines in residential and commercial construction
- Creating conduits for electrical and telecommunication cables in infrastructure development
- Constructing stormwater management systems in city planning
- Installing pipelines beneath bridges and tunnels without disrupting surface traffic
- Utility installations in industrial and commercial infrastructure projects
- Expanding existing infrastructure with minimal surface impact
- Enabling precise pipe alignment for large-scale municipal infrastructure networks
How Guided Boring Method Works:
- Excavate launch and receiving shafts at pipeline start and end points
- Place GBM in the launch shaft to begin pilot bore drilling
- Steer the pilot boring head using laser or optical guidance for accurate alignment
- Complete the pilot bore by reaching the receiving shaft
- Enlarge the borehole by reaming to the required pipe diameter
- Jack or push the pipe through the enlarged borehole from launch to receiving shaft
- Backfill and restore the shafts after pipe installation is complete
Advantages of the Guided Boring Method:
- High precision in achieving accurate line and grade, essential for gravity-based pipelines.
- Trenchless installation reduces surface disruption, preserving roads, pavements, and landscapes.
- Minimizes traffic disruption by eliminating the need for open-cut trenches in busy areas.
- Suitable for urban areas where space is limited and excavation is impractical.
- Environmentally friendly due to low noise, vibration, and minimal surface impact.
- Improves safety by reducing the risks associated with deep trench excavation.
- Faster project completion with fewer delays caused by surface restoration.
- Effective in various soil types, including soft ground and mixed conditions.
- Reduces utility relocation costs by avoiding interference with existing underground services.
- Cost-efficient for long-distance or deep installations requiring precision and minimal surface access.
Equipment types used in the Guided Boring Method
1. Guided Boring Machine (GBM) Jacking Frame
The GBM jacking frame is the central machine in the guided boring process, responsible for applying the necessary hydraulic force to push pilot tubes, casing pipes, or product pipes through the ground. Installed within a launch shaft, this frame is anchored securely to withstand the reactive forces generated during jacking. The frame includes guide rails to maintain alignment and a push-block or clamping system to grip and advance each pipe segment. Its modular design allows it to be adapted to various pipe diameters and ground conditions, ensuring precision and repeatability throughout the boring process.
2. Pilot Tube Jacking Rig
This rig is used for the first phase of the GBM method, where pilot tubes are advanced along the intended bore path with high accuracy. The rig includes a hydraulic push/pull system capable of fine control, ensuring that the pilot tubes follow a predetermined alignment. The front-end of the pilot tube assembly features a steering head with a reflective target, allowing operators to make real-time directional adjustments. This rig sets the foundation for the subsequent pipe installation, and its performance directly affects the overall alignment and success of the bore.
3. Auger Boring Machine
In some GBM applications, particularly where larger diameter pipes are installed or soil conditions necessitate mechanical excavation, an auger boring machine is integrated with the GBM setup. This machine uses a rotating auger inside a casing to excavate soil and transport spoil back to the launch shaft. It allows for a dry, controlled removal of material without the need for slurry or vacuum systems. Though optional, the auger boring machine enhances the GBM’s versatility, especially in mixed ground or extended drives where pilot tube methods alone may not be sufficient.
4. Casing Jacking System
Once the pilot bore is complete, and in cases where pipe reaming is needed, a casing jacking system is employed to push larger steel or concrete casing pipes along the bore path. This system works in tandem with the GBM frame and includes additional hydraulic jacks capable of delivering higher thrust. The casings often serve as a conduit through which the final product pipe may be installed, or they may act as the permanent pipeline in utility applications. This system must be precisely aligned with the pilot bore to maintain the correct grade and line.
5. Cranes or Hoists
Heavy-duty cranes or excavator-mounted lifting systems are required for handling and positioning the product pipes during installation. These lifting devices ensure safe and precise alignment of each pipe section with the jacking frame. Depending on the site constraints, mobile cranes, crawler cranes, or hydraulic hoists may be used. These machines also assist in lowering GBM components into the launch shaft and retrieving them from the reception pit, playing a vital logistical role in the overall construction process.
Conclusion:
The Guided Boring Method offers a precise, efficient, and minimally disruptive solution for underground pipeline installations in modern infrastructure projects. Its trenchless nature, combined with high accuracy and adaptability, makes it especially suitable for urban environments, congested corridors, and sensitive surface areas. With its broad range of applications and operational advantages, GBM continues to play a key role in advancing smart, sustainable construction practices.
