Grout Through Tech

Ready to Grout: Secant, Micropiles, Pilings, and more

Grout Through technology comes standard in all of our down hole hammers. Traditional check valves in the top are distributed around the bottom of the inner barrel instead. With Holte valving technology, DHHs minimize entry of water and debris into the operating portion, creating extended hammer life. This innovation also facilitates grout pumping into the hole. Grout flows down the evacuation center of the dual wall Drill Pipe, Hammer, and Bit. In overburden conditions, the grout can serve as the casing.

Holte Top Head Drives can be ordered ready to Grout or we can modify many existing drives for Grout Through.

Simply Switch the Valves

When the desired drilling depth is reached, a valve is opened in the Top Head.  Grout is then pumped in while the tooling is retracted back to the surface. Once the hole is complete, the fully rigged mast can be trammed to the next hole to repeat the process.

Using portable grout plants and the ability to use a truck or container as a cutting containment system can further simplify and speed up the process.

Grout Through Schematic

During drilling a pinch valve closes off the grout line such that cuttings properly discharge through the top of the rig (as in RC w/out Grout Through). After drilling is complete, the cuttings discharge pinch valve closes, the grout pinch valve opens, and grout is pumped in as the drilling rig is extracted from the hole. Grout flows through the centers of the top head rotary drive, dual wall drilling pipe, RC down hole hammer, and finally the RC bit.

Shown is Grout Through using a support pipe; most users don’t need any support other than the drill string.  A casing can also be used (either with a casing driver or a drive shoe).