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.
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.