Trenchless Alternatives 2

Pipe Bursting

The static pipe bursting method is an installation system used by Cro-Bar Construction Ltd. for the trenchless renewal of gas and water lines in sensitive soil conditions, where other external lines and buildings are within the immediate vicinity.

When replacing pipes with the static bursting technique, a bursting rod is pushed from a start pit (shaft) through the old pipe into a target pit (shaft). On arrival in the target pit the bursting blade with the new pipe connected is attached to the rod string.

Guided Auger Boring

Guided Auger Boring is a trenchless method of installing pipe by Cro-Bar Construction Ltd. in situations of limited access, such as beneath a busy road or railway crossing, where no surface heave or settlement is acceptable.

Installation is a three-step operation:

1. Pilot rods are accurately guided through the ground using a theodolite-camera and laser target.
2. Steel casings containing auger drills are attached to the last pilot rod and pushed through the ground. Excavated material is conveyed back to the launch pit as the pilot rods are pushed into the reception pit.
3. The steel casing can be left as sacrificial duct, or the product pipe is installed behind the steel casings that are pushed into the reception pit.

Pipe Ramming

For the dynamic pipe installation according to the ramming technique pneumatically driven pipe ramming machines are used. These machines enable the economic installation of open steel pipes as casing or product pipes up to 4000 mm diameter over lengths up to 80 m.

Steel casings with a cutting edge are driven horizontally using compressed air, leaving displaced soil inside the casing.

This is later removed by either:
1. Compressed air or water
2. Manually, depending upon size of bore