EP0327667A2 - Method and device for taking soil samples - Google Patents

Abstract

The invention starts from a method of taking soil samples, with a boring rod (1) which can be driven into the earth and has a longitudinal groove receiving the sample material, and at least one reamer (7) which engages in the groove and in a sweeping relative reaming movement with regard to the boring rod (1) releases the sample material from the longitudinal groove, at least two depth areas (I, II, III) being established and the sample material which originates from these depth areas being collected in several sample containers (10) allocated to these depth areas. Due to different driving, the boring rod (1) penetrates to varying depths during subsequent boring depending on the nature of the earth. The depth reached is measured and stored. The stored depth value serves as a basis for determining either the initial reaming position which the boring rod (1) assumes with regard to the reamer or reamers (7, 8, 9) or the starting position of an allocation device which alternately connects one of the containers present to the, in this case single, reamer. <IMAGE>

Description

The invention relates to a method for taking soil samples with a borehole which can be driven into the ground and which has a longitudinal groove which receives the sample material, and with at least one reamer which engages in the groove and removes the sample material from the longitudinal groove in a sweeping relative clearing movement with respect to the drill rod , wherein at least two depth ranges are defined and the sample material originating from these depth ranges is collected in a plurality of sample vessels assigned to them.

A device that works according to this method is described for example in DE-GM 86 27 892. The boring machine is driven into the ground by means of a hammer mechanism. The striking mechanism is slidably guided on vertical guide rails. In the ground, the drill stick, which has a U-shaped cross-section, is rotated to shear off the core of the earth located in the longitudinal groove. After pulling it out of the ground, the hammer mechanism moves to the upper end position with the drill stick. Then the clearing fingers are moved in the transverse direction to the drill stick so that they engage in the groove, namely the lowest clearing finger at the tip of the drill stick and two further clearing fingers in the same Distances above. Now the boring bar is moved down by 1/3 of its length, thereby clearing the groove. As usual, the drill rod has a length of 90 cm, each clearing finger clears a section of 30 cm in length. The samples from the various 30 deep areas thus collect in the three connected vessels.

However, the sampling procedure described presupposes that the full length of the drill rod is driven into the earth each time. This is also ensured by the striking mechanism used if the soil is rocky or rocky. The cane is so stable that it pushes the obstacles aside or penetrates them. However, there is a risk that the drill rod will bend. In addition, the striking mechanism represents a considerable effort, which makes such soil sampling devices considerably more expensive.

The invention has for its object to provide a method with which sufficient soil samples for a representative soil analysis can be taken more easily and inexpensively.

Based on a method of the type described in the introduction, this object is achieved according to the invention in that the boring rod penetrates to different degrees depending on the nature of the soil at the extraction point, that the penetration depth is measured and its value is stored and that the relative position which the boring rod on the one hand in Longitudinal direction with respect to the reamer or the reamer on the other hand occupies at the beginning of the broaching movement (broaching position) depending on the stored value of the previous penetration depth.

The invention is based on the knowledge that it is not at all necessary to carry out every puncture in the full length of the drill rod, because usually a large number of soil samples, eg. B. 20 or more, per parcel. Instead of smashing stones on which the cane strikes, it is accepted that when such an obstacle occurs, the depth of penetration remains less than the length of the cane. For this purpose, the drill stick is driven into the ground with much less force. Stony material also does not need to be examined because it does not absorb fertilizers.

However, with changing penetration depths there is the problem that sample material from a certain depth range is located on changing lengths of the pulled out drill rod. If the reamer is always placed in the same place on the drill rod and travels the same way, the sample material will not easily get into the correct container.

The invention therefore allows a variable broaching position and determines this automatically based on the previous depth of penetration, which is therefore measured and stored. The broaching start position is defined as a relative position between the drill stick on the one hand and the broach or cutters on the other hand, it does not matter whether this relative position is brought about by a movement of the drill stick or the broach. The relative clearing movement starts from the clearing position. It is not necessary that the reamer already engages in the drill groove in the broaching position. The broaching start position also includes the case where a reamer is at a distance from the tip of the drill rod and first approaches this tip in the course of the broaching movement and then moves into the groove.

There is also another way to solve the mapping problem without changing the clearing position at different depths of penetration. This approach relates to the case that only one scraper is provided and that an allocation device is attached to it, which determines one of the existing vessels for receiving the extracted sample material and takes the necessary precautions and, depending on the clearing movement, i. H. from the clearing distance covered, which causes the switch to the following vessel. The changeover can be effected, for example, in that the various vessels are arranged such that they can be moved under the pouring channel or the outlet opening of the sample material coming from the scraper by means of a sliding table or a turntable, and in that one vessel replaces the previous one when the changeover takes place. Switching over can also mean readjusting the pouring channel or another conveying device, which also ensures that the cleared sample material falls into a selected vessel.

It is suggested that the boring rod penetrates to different extents depending on the nature of the soil, that the penetration depth is measured and its value is stored, and that the starting position of the allocation device is determined automatically depending on the stored value of the previous penetration depth. The differences in the starting position of the assignment device cause the sample material peeled out of the groove to fall into the correct sample vessel at the beginning or in the course of the broaching movement, the first broaching distance until the switch to the next vessel can be of different lengths. In addition, it may be that the first part of the clearing movement is carried out "empty" if, for example, the clearer always starts on the drill shaft.

The direction of the clearing movement is important. In the known method, for. B. a clearing finger attached to the tip of the drill rod and the latter moves so that the clearing finger moves in the groove towards the drill shaft. However, it can happen, especially as a result of wear and tear, vibrations or the like, that the clearing finger reaches past the tip and is then damaged by the feed movement of the drill stick. A funnel-shaped widened cane groove, which is advantageous for compressing boggy or sandy soils, can trap hard earth or stones.

In order to counter these dangers, it is suggested that the relative clearing movement be directed in such a way that the clearers scrape the drill stick from the shaft to the tip.

Both the adjustment movement to reach the broaching position and the broaching movement itself are generally to be understood as relative movements, i. H. the vise may move with respect to the stationary reamer or these may move with respect to the stationary vise. Movement of both components is also possible. Stationary and moving here refers to the base frame of the device in question, which can also be mounted on a vehicle.

The broaching of the vise in its normally vertical drilling position can result in the vise being pulled very far out of the earth and the corresponding structure must be relatively high. Also with regard to easier accessibility and advantages in broaching itself, it is expedient if the boring bar is pivoted out of its boring position about a horizontal axis. Both a position with a downward sloping tip can be considered, the horizontal position or a position with the tip pointing upwards. Furthermore, depending on the broaching tool and the nature of the ground, it may be advantageous if, in such a pivoted position of the boring stick during broaching, the boring stick assumes a position with respect to its longitudinal central axis in which the longitudinal groove points upwards or assumes another angular position.

The patent also includes all devices which are suitable for carrying out the proposed method. It should be mentioned here that a holder for the reamer (s) can be provided, which is designed to be movable for adjusting the broaching position and / or for broaching in the longitudinal direction of the boring bar. The movement can also be carried out by hand, in particular if display aids obtained and acting according to the invention are provided.

It is particularly expedient if, with such a device, mechanical, hydraulic, optical or electronic aids for measuring and storing the depth of penetration of the drill rod, for bringing about the relative broaching position of the drill stick with respect to the reamer or the reamer and / or for bringing about the start position of the assignment device are provided. Consider z. B. all suitable length measuring devices that work for example with optical markings, friction rollers or the like. Especially in the case of hydraulic actuation of the boring bar, the length values can also be obtained by measuring the flow rate of the hydraulic fluid. Furthermore, all appropriate mechanical and electronic storage and control means are available.

• Fig. 1 die schematische Darstellung einer Vorrichtung zur Entnahme von Bodenproben mit drei Räumern,
• Fig. 2 den Querschnitt des verwendeten Bohrstocks in größerem Maßstab und
• Fig. 3 in grob schematischer Darstellung eine Zuordnungsvorrichtung für eine andere Bodenproben-Entnahmevorrichtung.

An embodiment of the invention is explained below with reference to the drawing. In detail shows.

• 1 is a schematic representation of a device for taking soil samples with three scrapers,
• Fig. 2 shows the cross section of the drill stick used on a larger scale and
• Fig. 3 in a rough schematic representation of an assignment device for another soil sampling device.

The soil shown in section in FIG. 1 is divided by horizontal dashed lines into an approximately 30 cm thick upper depth region I, a subsequent middle depth region II of the same thickness and a lower depth region III of more than 60 cm depth. A 90 cm long drill rod 1, when fully driven, penetrates the two upper depth areas I and II and penetrates 30 cm deep into the third area III. The boring bar 1 is seated on a shaft 2, which is shown in simplified form as an elongated piston which can move up and down in a cylinder 3 under the action of a hydraulic pressure fluid. The cylinder 3 is surrounded by a clamp 4, which is pivotably mounted about a pivot axis 5 perpendicular to the plane of the drawing by means of a suitable bearing and under the influence of a controllable pivot drive, which is not shown. A holding frame 6 has three clearing fingers 7, 8 and 9, which are each at a distance of 30 and whose clearing edges lie on a line which intersects the pivot axis 5. The holding frame 6 as a whole, and / or the clearing fingers 7 to 9 with respect to the holding frame can be resiliently mounted. Laterally below each clearing finger, ie offset perpendicular to the drawing plane against the clearing finger, there is a sample collecting vessel 10 connected to it by means of a chute, it being noted that the lowest collecting vessel receives the samples from the deep region III, the middle one from the deep region II and the upper collecting vessel 10 the samples from the upper deep region I.

In order to make the mode of operation of the device described further clear, the cross section of the boring bar 1 is shown on a larger scale in FIG. The outer contour of the cross section is circular, so that when the drill stick is rotated, the earth core pressed into the groove 11 is sheared off, so that it remains in the groove when the drill stick 1 is pulled out. The flat or spoon-shaped clearing finger, for example 8, corresponds in its outline shape to the cross section of the groove 11.

With the device described, the following course of the method results: First of all, the boring bar 1 together with the piston-cylinder arrangement guiding it is in a vertical position. The groove 11 is empty. The drill tip is just above the surface of the ground. Now the entire length of the drill rod is pressed into the ground, so that the transition point between the drill rod 1 and the shaft 2 is close to the surface of the ground. The core of the earth located in the groove 11 is sheared off by a rotary movement of the drill rod about its axis, the drive means of which are not shown here for the sake of simplicity. The boring bar 1 is then pulled out of the ground and the piston-cylinder arrangement 2, 3 is pivoted into the inclined position (central axis 12) indicated by dash-dotted lines. The cane groove in this example is oriented so that it is in this inclined position at the top. At the end of the swiveling movement, the tip of the drill stick is near the clearing finger 7. Now the drill stick becomes in the direction of the axis 12 shown in broken lines extended to the position that he had previously reached on the ground and that had been measured and saved. The fully extended end position is drawn in dash-dotted lines. In this broaching starting position thus reached, the shaft-side end of the drill stick is in the vicinity of the clearing finger 7 and the drill tip is at a distance of 30 cm from the clearing finger 9.

Now, in order to initiate the broaching process, the piston-cylinder arrangement 2, 3 is again pivoted through a small angle α, so that the broaching fingers 7 to 9 penetrate into the groove 11. Then it is cleared by pulling back the boring stick 1 to its upper end position. The clearing finger 9 covers the lower third of the length of the drill rod, the clearing finger 8 the middle and the clearing finger 7 the upper third of this total length. The respective sample material thus falls into the three sample receptacles 10 in the correct depth assignment. The actual broaching process is already finished after a third of the entire stroke. During the rest of the stroke, the upper clearing fingers 7 and 8 run over already cleared groove sections. After swiveling back into the vertical position, the drill stick can be driven into the ground again to take the next sample.

If the drill stick penetrates less deeply into the ground, for example, as shown in FIG. 1, only in a short section of the depth region III, because, for example, a large stone opposes it, this detects the depth storage device and when it is extended again along the axis 12, the drill stick becomes stopped in the appropriate position. It therefore occupies a different broaching position than in the case described above (full penetration depth). The clearing finger 9 now enters the groove 11 at the location of the drill stick which the drilling stick in the ground in the lowest position reached intersected the interface between depth ranges II and III. Thus, the sample material of the last small piece falls into the lowermost vessel 10 and the two further filled length sections of the groove are properly smeared into the other two vessels. In the same way, the samples are correctly assigned even if there is even less penetration into depth range II or only into depth range I.

When swiveling into the inclined position, the extension of the drill stick can also be started immediately. If the broaching position is reached before the swivel movement is completed, the drill stick can be swiveled all the way to the broaching fingers without stopping.

The device described is expediently mounted on a vehicle, preferably on the rear side of an agricultural tractor, wherein the holding device 6 arranged laterally at a relatively large distance can be designed to be pivotable for road traffic.

If the swiveling of the drill stick is dispensed with, the clearing fingers can, as is known per se, also be moved towards the vertical, pulled out drill stick. In extreme cases, however, the boring bar must then be able to be pulled up to the uppermost clearing finger.

Alternatively, as mentioned, the broaching or the setting of the broaching position can also be carried out by moving the holding frame with respect to the stationary drill rod.

Although a clearing movement of the clearing fingers from the SC-stick to the tip of the drill stick is more advantageous for the reasons described, exceptionally, e.g. B. in sandy soils to prevent trickling out, the opposite clearing direction may be more appropriate.

In the case of the pivotable mounting of the piston-cylinder arrangement about a horizontal axis, as shown in Fig. 1, other pivot angles, e.g. B. a clearing position with a horizontal drill stick or with the drill tip pointing upwards. The cane groove does not have to point upwards, but can assume any angular position with respect to the central axis of the cane, depending on the nature of the ground or the construction of the clearing fingers and their holder during broaching.

The assignment device according to FIG. 3 belongs to a soil sample taking device, not shown, with only one scraper, the sample material detached from it being able to be directed into three different sample vessels via a movable downpipe. The reamer always starts at the tip of the drill rod and travels through the rod groove in the direction of the shaft.

The assignment device comprises a fixed, shown as a triangular mark 15, which cooperates with a rotatably mounted control disc 16. The circumference of the control disk is divided into three arc sections I, II and III of equal size and the arrangement is such that, in the position shown, the sample material falls into the sample vessel which is assigned to the depth region III. If the control disk 16 rotates towards linsk, the downpipe mentioned is converted at the separation point between the bow section III and the bow section I in such a way that the sample material is assigned to the depth area I Vessel falls. Likewise, when the transition to the next bend section takes place, the downpipe is switched over to the vessel for depth range II.

This exemplary embodiment has the following mode of operation: At the beginning, the control disk is in an angular position in which the gripper 15 faces the separation point between the arc regions III and I. The drill tip is on the surface of the ground. If the cane penetrates into the ground, the control disk 16 is driven in counterclockwise direction in exact synchronism. The drive device is designed so that when the tip of the drill bit reaches the depth area II, the pick-up 15 also reaches the bow area II. When the boring stick has run into the ground over its full length of 90 cm, the control disk 16 has rotated exactly once. It remains in the position reached at the end and the drill stick is pulled out and brought into a (always the same) broaching position in which the only reamer at the tip of the drill stick engages in the groove. Now the broaching movement begins, which, as mentioned, can be a movement of the drill rod or the reamer. It is essential in this example that the control disk 16 is in turn driven in exact synchronism in the opposite direction during the broaching. First, the sample material falls from the tip area into the vessel III and then takes place at the right moment, i.e. H. after every 30 cm clearing section, switch over to the other two vessels one after the other.

A maximum draft draft was considered above. For example, if the boring bar only penetrates 20 cm into the ground and then stops, the control slide 16 is still in area I and the area in question Vessel is connected to the reamer. This means that the entire sample material falls into this vessel when broaching. When switching to vessel III, the reamer already enters the empty groove area. It can therefore be provided that the clearing process is interrupted at the transition point from arch area I to arch area III.

The control disk described thus also acts in the example as a measuring and storage device for the depth of penetration.

However, using the same allocation device, the reamer can always carry out its broaching movement on the shaft, i. H. Start at the top of the drill rod, however, the entire length must always be cleared to the tip. In this case, the control disc 16 is driven in the same direction both when the drill rod is moved into the ground and when it is cleared. H. when broaching it moves beyond the end position reached during drilling. After each clearing operation, the control disk 16 must be brought back to its starting position at the transition from sheet I to sheet III.

• 1 Bohrstock
• 2 Kolben / Schaft
• 3 Zylinder
• 4 Schelle
• 5 Schwenkachse
• 6 Haltegestell
• 7 Räumfinger
• 8 Räumfinger
• 9 Räumfinger
• 10 Probensammelgefäß
• 11 Nut
• 12 Ausfahrachse
• 15 Abgreifer
• 16 Steuerscheibe
• I Tiefenbereich
• II Tiefenbereich
• III Tiefenbereich
• α Ausschwenkwinkel

Even if only one reamer is provided, you can work with the broaching position depending on the depth of penetration. The assignment of the vessels can be controlled more simply, namely in such a way that the same sample vessel is always started and after the 30 cm clearing distance, the system switches over to the next vessel in the same order.

• 1 cane
• 2 pistons / shaft
• 3 cylinders
• 4 clamps
• 5 swivel axis
• 6 holding frame
• 7 clearing fingers
• 8 clearing fingers
• 9 clearing fingers
• 10 sample container
• 11 groove
• 12 extension axis
• 15 taps
• 16 control disc
• I depth range
• II depth range
• III depth range
• α swivel angle

Claims (7)

1. A method for taking soil samples with a borehole which can be driven into the ground and which has a longitudinal groove which receives the sample material, and with at least one reamer which engages in the groove and removes the sample material from the longitudinal groove in a sweeping relative clearing movement with respect to the drill rod, wherein at least two depth ranges are defined and the sample material originating from these depth ranges is collected in a number of sample vessels assigned to them, characterized in that the boring stick (1) penetrates to different degrees depending on the nature of the soil at the extraction point, that the penetration depth is measured and its value stored and that the relative position that the boring bar (1) on the one hand in the longitudinal direction with respect to the reamer or the reamer (7, 8, 9) on the other hand at the beginning of the broaching movement (broaching start position) automatically determines depending on the stored value of the previous penetration depth d. 2. A method for taking soil samples with a drivable borehole, which has a longitudinal groove receiving the sample material, and with at least one reamer, which engages in the groove and removes the sample material from the longitudinal groove in a sweeping relative clearing movement with respect to the drill rod, wherein at least two depth ranges are defined and the sample material originating from these depth ranges is collected in a plurality of sample vessels assigned to them, characterized in that only one reamer is provided as well as an allocation device (15, 16) which alternately one of the existing vessels for receiving the detached sample material determines and depending on the clearing movement the switch to the following vessel brings about that the drill rod (1) penetrates to different degrees depending on the nature of the soil at the extraction point, that the penetration depth is measured and its value is stored and that the starting position of the assignment device (15, 16) depends on the stored value of the previous one Penetration depth is determined automatically. 3. The method according to any one of the preceding claims, characterized in that the relative clearing movement is directed so that the clearers (7, 8, 9) the drill stick (1) from the shaft (2) to the tip. 4. The method according to any one of the preceding claims, characterized in that the or the clearers (7, 8, 9) for adjusting the broaching position and / or for clearing with respect to a fixed or mounted on a vehicle base frame moves or move in the longitudinal direction of the boring. 5. The method according to any one of the preceding claims, characterized in that the boring bar (1) is pivoted out of its drilling position for broaching about a horizontal axis (5). 6. The method according to claim 5, characterized in that in a pivoted position of the boring bar (1) assumes a position in broaching the boring bar with respect to its longitudinal central axis, in which the longitudinal groove (11) not only points upwards. 7. Device for carrying out the method according to one of the preceding claims, characterized in that mechanical, hydraulic, optical or electronic aids for measuring and storing the depth of penetration of the drill rod, for bringing about the relative broaching starting position of the drill / reamer and / or to bring about the starting position of the allocation device are provided.

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