Whatever drilling method is used, there are several considerations which must be taken into account:

  • The amount of energy required to drill is governed by the rock type. Unconsolidated formations such as sand, silt or clay are weak and much easier to drill than consolidated rocks such as granite, basalt or slate which are hard, strong and dense.
  • For hard rocks, cutting tools will need cooling and lubrication.
  • Rock cuttings and debris must be removed.
  • Unconsolidated formations will require support to prevent the hole from collapse.

More over the drilling techniques can be found in the following paragraph.

Turned drilling by hand/stir at depth sample

The technique where a device is operated by hand and operated and by turning driven deeper into the ground. During the drilling there is an open hole. To maintain the drilled hole. In order to maintain the drilled hole during further drilling tubes can be placed. Examples of devices used are the various types of Edelman augers, the gravel auger, the spoon auger, the riverside auger, the spiral auger and the boulder catcher. This sample is remotely dry.

Pressed drilling by hand/cores at depth sample

The technique where a device is operated by hand and by turning which drives the drill deeper into the ground. The devices used are usually called coring devices and examples are the gouge auger, the VanderHorst coring device, the Dachnovsky device, the profile cutter, the peat profile cutter, the sample ring cutter, the foil sampler, the core sampler, the Beeker sampler and the soil column cylinder.

Piston pressed drilling by hand/push sample

The technique where a device is operated by hand and the drill is driven by a piston. The drill is turned and pushed to advance further into the ground. Examples of devices that are used are the Livingstone device, the piston sampler and the VanderStaay drill.

Hammering by hand/hammer sample

The technique where a device is operated by hand and a hammer is used to drive it deeper into the ground; the hammer can be operated by hand or electrically driven. Examples of devices used are the gouge auger and certain coring devices (Dachnovsky device, sample ring cutter, foil sampler, the core sampler and soil column cylinder).

Pulse drilling by hand/sticking out at depth

The technique where a device is operated by hand and a tube with a check valve is driven deeper into the ground by repeatedly getting tilled and falling back to the ground. The tube with the check valve is called: the pulse. During pulse drilling the drilled trajectory is only open for a small part. The rest of the hole is protected by a tube that is pushed downward during the drilling. Additional measures to maintain the drilled hole in order to continue drilling are not necessary.

Mechanically untubed turned drilling/stir at depth sample

The technique where the drill is turned and driven into the ground mechanically. During drilling there is an open borehole with the exception that one part of the trajectory has a tube due to the preparation of the hole. In order to maintain the position of the borehole during further drilling (Additional) casing tubes or flushing may be used. Examples are drilling with an auger, the bucket system, the airlift system, the rotary drilling system, the straightflush system and the piston drill. This sample is remotely dry unless flushing is used.

Mechanically tubed drilling/sticking out at depth sample

The technique where a device is mechanically driven and by turning driven deeper into the ground. The rotating drill head sits at the bottom of a tube that fits exactly into the hole. The tube ensures that the hole is maintained during drilling. The example is counterflush drilling.

Mechanically pressed drilling/push sample

The technique where a device is mechanically driven and driven deeper into the ground. by continuous pushing. Examples of devices that are used are the Ackerman device, the Begemann stabbing device, the DLDS, the MOSTAP and the rush hour sampler. Also a gouge auger is used when the nature of the subsurface permits. T

Mechanically gripping/gripping at depth sample

The technique where a mechanically operated gripper is used to make the hole deeper. During the drilling, there is a completely open hole. In order to maintain the borehole flushing or tubing is used. When only a shallow hole is made, this is not considered to be a form of drilling. An example is the gripper drilling system.

Mechanically hammering/hammer sample

The technique where a device is mechanically driven and a hammer is used to drive it into the ground. Examples include the ram gouge auger, the window sampler and the Ackerman device; a gouge auger is hammered when the nature of the soil is required. This sample is remotely dry.

Mechanically tubed hammering and flushing/hammer sample

The technique where a device is driven mechanically and driven deeper into the ground by hammering and loosening the soil. The drill head sits at the bottom of a tube that ensures that the hole is maintained is maintained. The example is ro-flush drilling.

Mechanically pulse drilling/sticking at depth sample

The technique where a device is driven mechanically and a tube with a check valve is driven deeper into the ground by repeatedly dropping. The tube with check valve is called the pulse and this technique is most widely used in the world of geotechnical engineering. With pulses, the drilled trajectory is always only open for a small part of the hole and most of the hole is protected by a tube that pushed down during the drilling process. Additional measures to maintain to allow for deeper drilling are not necessary.

Mechanically rotating flush drilling/stir at depth sample

The technique where a device is mechanically driven and driven deeper into the ground by a combination of spraying and rotation. During the drilling, there is a completely open hole. In order to maintain the drilled hole tubes are applied. The example is drilling with use of the Sherbrooke sampler. This sample is remotely wet.

Mechanically untubed flush drilling

The technique where a mechanically operated device is used to make a hole by loosening the soil with spraying. During the drilling there is a completely open hole. In order to maintain the position of the drilled hole tubes can be applied. Examples of devices used are a hose connected to a compressor and a spray lance.

Mechanically vibrating drilling

The technique by which a device is mechanically driven deeper into the ground by a high-frequency vibration. The vibration can be combined with with pressure or turning drill. Examples are (rotary) sonic drilling, vibrocoring and drilling with the vibratory flip, geodoff, the Zenkovitch drill and the Aqualock sampler.

Mechanically drop drilling

The technique where the device is mechanically driven and a tube is driven into the into the ground by inserting it at once into the water bottom from a low height. Examples are the dropcorer and the pistoncorer.

Mechanically rotating drilling

The technique where a device is mechanically driven into the ground by turning, hammering, pressing or vibration without actually material to bring up. The example is displacing (rotary) sonic drilling. No samples are taken.

Push hammer drilling/ hammer or push sample

There is a technique used which involves a hammer or continue pushing into the ground. This technique is operated by hand.

Hand drilling unidentified

Use this option when there is known a hand drill type is used, but there can't be specified which one.

Mechanically untubed rotating drilling with partly push hammer drilling

Two techniques were used: the technique where a device is driven mechanically by turning advances deeper into the ground and a technique in which a device is driven deeper into the ground mechanically with the use of a hammer or by continuous pressure. Covers, among other things the use of a hollow auger in combination with some kind of coring device.

Unknown partly mechanically press or hammer drilling

Two techniques were used: a technique where a device is driven mechanically, in not specified manner, deeper into the ground and a technique where a device is mechanically driven into the ground with a hammer or by continuous pressure.

Unknown

It is not known which technique is used.

Unknown partly push hammer drilling

Two techniques are used. On the first technique there is no information available and with the second technique a device is hammered or pressed into the ground.

Unknown pulse drilling

The technique where a pulse is driven into the ground using gravity.

References

  • Catalogus geotechische boormonsterbeschrijving en analyse v1 by the BRO
 
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