DH-Series Automatic Drop Hammer

The days when you had to choose a machine based on whether you wanted to do environmental or geotechnical work are fading fast. Now you can do both.

Need SPT blow counts for your customer? Use a Geoprobe® DH-Series Automatic Drop Hammer with your hollow stem augers or with the specially designed dual tube system by Geoprobe Systems®. Going to a job where you won't need the automatic hammer? No problem. A couple of minutes is all it takes to remove it from your machine, or you can swing and secure the drop hammer away from your work spaces.

Features & Options

• Easy on / Easy off design!
• Conforms to ASTM Standards D1586-99.
• Operates from auxiliary hydraulics.
• Consistent results with no human error.
• No cables or ropes needed for operation.
• All moving hammer components are enclosed for operator safety.
• Hammer swings over hollow stem augers... no need to reposition the whole machine.
• Operates at up to 60 blows per minute.
• Throw height can be adjusted within seconds.
• Use your Geoprobe® track machine for both environmental AND geotechnical projects.
• Used to perform Standard Penetration Test (SPT) which is the most common in situ geotechnical test in the U.S.
• SPT blow count results are used by engineers for obtaining strength and density properties of soil, designing foundations, and defining earthquake sensitive soils.
• Use the Geoprobe® SPT dual tube system with the automatic hammer for SPT testing.

Applications

The Geoprobe^® DH-Series Automatic Drop Hammers are an effective tool to collect Standard Penetration Test (SPT) blow counts with your Geoprobe^® machine.

SPT BLOW COUNT consists of:

• Using a 140 lb. (64 kg) driving mass falling free from a height of 30 in. (762 mm)...
• Driving the standard split spoon sampler a distance of 18 in. (457 mm) into the soil, and...
• Counting the number of blows (N) to drive the sampler 12 in. (6 in. plus 6 in.) [152 mm plus 152 mm].

The hammer is powered through the auxiliary hydraulics on 66 and 77 Series Machines and is lifted into position using the probing cylinder. The inconsistency that has historically been a problem for the SPT test is minimized with the repeatable, accurate function of this hammer. The 140-pound weight has a 30-inch free fall before making contact with the anvil so every test is performed the same. And safety was a prime consideration during the development of this tool, so all moving parts and impact surfaces are enclosed in a steel housing.

Specifications