>> Back to Tools Menu

Geoprobe® direct push machines outfitted with the DH100 Automatic Drop Hammer can be used to perform the Standard Penetration Test (SPT).

SPT BLOW COUNT consists of:

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

Use either a hollow stem auger setup or our 3.25 in. probe rod system.

During a recent Kansas Field Demonstration event, the DH100 Automatic Drop Hammer was used to perform SPT tests and collect soil samples.  The drop hammer is mounted on a Geoprobe 6600 machine.

Split-Barrel Soil Sampling Systems

Hollow Stem Augers Hollow stem augers are turned to the desired depth with a pilot bit blocking the rod ID. The pilot bit is pulled and a split barrel sampler (split spoon) is lowered. The drop hammer is then placed on top of the rod string and the number of blows to advance the sampler is counted. The pilot bit can then be placed back in the augers and the auger string advanced to the next testing depth.

Geoprobe® 3.25 in. Probe Rods 3.25 in. probe rods are driven to the desired testing depth. The solid drive tip is pulled and a split barrel sampler is lowered. The drop hammer is then placed on top of the rod string and the number of blows to advance the sampler is counted. The solid drive tip can then be placed back in the cutting shoe and the rod string advanced to the next testing depth.

Split Barrel Soil Sampler
20739
This sampler is commonly referred to as a split spoon sampler. Used for sampling with the DH66 Automatic Drop Hammer and SPT Systems. The SPT blow count is the number of blows of the automatic hammer required to advance the split barrel sampler 12 inches (305 mm).

• 2.0 in. (51 mm) OD x 24 in. (610 mm) length
• AW Box at top.
• Requires Adapter (17320) if used with 1.5 in. probe rods.

Drive Cap, Centering 16914 The Centering Drive Cap centers the 1.5 in. probe rods during driving. The dirve cap is placed on the top 1.5 in. probe rod and fits the ID of the 3.25 in. outer probe rods.	Adapter 17320 1.5 in. Pin x AW Pin. Used to adapt AW thread to Geoprobe® 1.5 in. probe rod thread. The Split Barrel Sampler (20739) has an AW box at the top. Adapter is required if 1.5 in. probe rods are used.
Drive Cap, Threaded 15590 Threaded Drive Cap for 1.5 in. Probe Rods. For use with GH40 Series Hammers and with the DH66 Automatic Drop Hammer.	SPT Cutting Shoe 20737 2.38 in. (60.5 mm) ID. This Cutting Shoe threads into the leading 3.25 in. probe rod and provides an opening for the Split Barrel Sampler (20739) during the SPT test. Requires a 21114 SPT Solid Drive Tip to seal tool string while advancing outer casing to SPT interval.
SPT Solid Drive Tip Assembly 21114 2.37 in. (60.2 mm) OD. Seated in the 3.25 in. SPT Cutting Shoe Assembly (20737) as the 3.25 in. probe rods are driven to testing depth. 1.5 in. rods hold the point in place. Requires O-rings.	O-rings for SPT Solid Drive Tip Assembly 19744 Replacement O-rings for Solid Drive Tip Assembly (21114). Pkg. of 25.