The advantage of Symmetric Overburden Casing System in anchoring and piling
Symmetric Overburden Casing System are applied to anchoring and foundation piling as it can borehole straight, fast and deeply.
The drilling workflow of symmetric Overburden Casing System
Step One: Installing symmetric casing system. The central pilot bit is connected to the dth hammer and the casing shoe is attached to the casing tube. Powered by the DTH hammer, the central pilot bit drives the ring bit to drill a hole large enough and meantime the casing tube slide down to stabilize the hole.
Step Two: Once drilling the hole into the required depth, unlock the pilot bit by reverse rotation of the drilling string and then pull out the pilot bits through the casing tube. As for the ring bits and casings, they can be left in the hole for the permanent casing system or can be retrieved while pouring concrete.