Reverse Circulation Drilling with Patented Grout Through Hammer

The manufacturer was an early pioneer of reverse circulation technology. From the beginning, almost 30 years ago, the manufacturer recognized the significant advantages of this style of drilling, particularly large diameter, and has remained dedicated to developing a complete line of drilling tools specifically designed around reverse circulation technology.

The manufacturer's patented technologies allow the most efficient use of air flow in the industry, allowing your hammer to hit harder, in turn removing rock faster through our down hole hammer and bit, while their accessories are designed to work most efficiently with your rig and ground conditions.

Available Sizes: 14" to 30" diameter. Custom sizes also available.

Benefits: Ultimate control of cutting removal and containment. Reduces air loss into formation. Less impact in sensitive areas. Energy efficient. Drill and grout in one pass.

	Hardened Steel Discharge Elbow
	Open Spindle Top Head
	Grout Inlet with Hydraulically Operated Ball Valve
	Flexible Hose Contains Discharge
	System Allows Grout to Pump Through Drill Rod
	and DHH

			Secant wall made with grout through drill system
FIRST
SET		SECOND
		SET
		drills
		through
		hardened
		concrete

One Specific Job Example

Tooling

• 14" Reverse Circulation (RC) Down Hole Hammers with patented Grout Through Technology and Quick Change Bit System
• Custom 14.6" Reverse Circulation down hole bits
• 13 5/8" threaded joint dual wall Reverse Circulation drill pipe in 5', 15', and 32' lengths
• Reverse Circulation shock syncs
• Reverse Circulation top head conversion on Bauer BG28 drill rig

The site, located on the banks of the Mississippi River, presented numerous challenges for drilling that were overcome through a collaborative design process. Reverse Circulation was critical in keeping the site free of debris and preventing any runoff from infiltrating into the adjacent grounds or the Mississippi River. Having to drill 800+ piles to a depth of 45 +/- feet below grade, the drilling contractor needed a system that would allow them to quickly complete the multiple holes in each cap and quickly move to another part of the site, all the while mitigating any unwanted pressurization to the surrounding soils that might degrade the integrity of an adjoining pile or the existing foundation of the current hospital.

An innovative design and manufacturing process allowed the conversion of the existing head to accommodate RC and marry it with a custom system that utilized dual wall reverse circulation drill pipe, a grout through hammer and bit, and a heavy weight shock sync placed directly above the DHH. The drill pipe took the place of traditional casing and was critical in allowing the rig to drill through the glacial overburden that was littered with boulders, while not having to take the time to monitor and work with a separate casing. In fact, the entire drill string was assembled at the beginning of the job, and after 800+ holes the string was only disassembled several times for maintenance of seals and the inspection of tooling.

During drilling operation the 14" RC Hammer penetrates to the desired depth of the pile, at which point a hydraulic valve is repositioned in the top head conversion to direct grout from the portable batch mixing system. As grout passes the valve it is directed into the center of the dual wall pipe, flowing directly through the center of the DHH and out the face of the bit. Patented check valves in the bottom of the hammer prevent grout and debris from flowing back into the hammer's working parts.

Monitoring systems allow retraction speed of the tooling to the calculated to ensure that grout is applied properly, while also giving awareness to anything happening below the surface that might jeopardize final pile integrity.

After the bit reaches the surface the rig moves to another hole, remaining fully rigged, while rebar and caging assemblies are inserted into the grouted pile through the use of an adjacent crane. Production rates averaged 30 minutes to drill and grout each 14'' hole to an average depth of 45 ft.