DD221221A1 - METHOD AND DEVICE FOR OBTAINING SOIL SAMPLES - Google Patents

Abstract

The invention relates to the recovery of soil samples (cores) from substantially non-cohesive, aquiferous soil layers. The invention makes it possible, with relatively simple means, to obtain soil samples in the form of cores using economically favorable drilling by means of endless hollow screws. The essence of the invention consists in a two-stage drilling process, wherein for core production with high pressure, high torque and a speed of 20 min 1 and to promote the located on the helices of the endless hollow screw compacted earth with speeds of 60 min 1 is working. To carry out the process, a core tube 1 is suspended with the interposition of a rope vortex 3 on a cable 4 and mounted on a Hülse 8 preferably on PTFE whose length corresponds to the length of the core tube 1 14, a non-closed film tube 7, the mounted position about 13 of his Length over the free edge of Huelse is deducted. Fig. 1

Description

For this 2 pages drawings \ _: '

Field of application of the invention

The invention relates to a method and apparatus for obtaining soil samples from substantially non-binding, aquiferous soil layers. , '. ::

Characteristic of the known technical solutions

Hollow screw boring processes have already been used successfully for soil analysis and the production of cores. In order to obtain as undisturbed soil samples as cores, endless hollow screws are used with an inner core extraction tube, in which the core extraction tube does not rotate.

The core removal tube is advantageously equipped with a flexible receiving tube closed at least at one end, in which the drill core slides during the drilling process - DE-AS1634543; DE-AS 2617551; DD-PS141069. ; '.' v ... ';:'-..;;''.'' .. W "'' \ '' /

Undrilled core cores of 0.8 to 1.0 m in length can be obtained by means of the internal core extraction tube, whereby the process is performed depending on the physical-mechanical rock properties, the drill depth, the drive power and other factors with speeds between 100 and 100 mm. 200min 'is worked.

BM Rebrik indicates in its publication that core mining auger drilling requires a special auger core tube and that the rotational speed must be 60-250 min ^-1 .

High torques at low speeds are required in a company brochure from the Acker Drill Company, Inc. for auger drilling with non-core continuous screws and for hollow augers. Depending on the rock and the borehole diameter, rotational speeds of 50-225min ~ ^{1 are} suggested.

In the series of publications Bohrtechnik-Bohrverfahren (auger drilling / impact drilling) of the VEB Geological Research and Exploration Hall; Operation section of the KDT is in addition to the speeds of 100-200 min " ¹ for soft rock pointed out that in auger drilling speeds of 400-600 min" ^{1 are} required to reach in heavily aquiferous sands a discharge of the cuttings. On the basis of investigations, it has also been found that, when drilling with endless hollow screws, there is a certain critical speed at which only a delivery of the soil occurs. This critical speed is crucial for determining the rotational speeds of drilling rigs and certainly the cause of the fact that internationally at worm and hollow screw drilling at high speeds is used.

With the hitherto known, above-mentioned hollow screw equipment and the instructions given in the relevant literature references for carrying out the method excellent results can be achieved only in dry soil layers. In aquiferous soil layers, the application of this technology is indeed possible, but there is only a poor nuclear production. The drilling of cores by means of hollow augers from water-bearing earth layers previously failed because of the Erdstoffeintrieb and falling cuttings the core tube system is not to lock and the drilling process can not be continued with nuclear production.

Although it is possible to continue drilling with a hollow worm tool in these layers, the material in the crown segment must be obtained by valve boring. With the help of a valve drill again only mixed and segregated drill samples can be obtained.

For the most part, boreholes are drilled by piping and valve drills in water-bearing sand and gravel layers. A nuclear extraction is not possible in any case. Minor interlayers are over-drilled and misinterpretation is common. ,

Object of the invention

By the invention, the identified deficiencies are eliminated and proposed an extremely economical solution, with the help of non-entrained water-bearing soil layers won a non-segregated core sample and low-power intermediate layers can be detected quantitatively and qualitatively.

Explanation of the essence of the invention.

The invention is based on the object, using a Hohlschneckenbohrwerkzeuaes with Seilkerneinririhtiinn

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According to the invention, this object is achieved in that after installation of the cable core device in the endless hollow screw by repeated, short-term tightening and dropping the rope core device it is latched to the endless hollow screw and worked in a two-stage drilling regime, in the first stage drilling the Bohrmarschlänge with nuclear production under high pressure, a high torque and a rotational speed of <20min ~ ¹ is carried out and in the second stage of the spirals of the Hohlbohrschnecke located, highly compacted material with speeds> 60 min " ^{1 is} promoted and during the drawing process of the cable core device with the drilled core additional water is supplied for the purpose of pressure equalization.

For carrying out the method, a cable vortex is arranged above the catching device. In the core unit or the core tube, an open casing tube is mounted for receiving the soil sample on one, advantageously coated with PTFE sleeve, wherein approximately ^1/3 of the length of the Hüllschlauches over the free upper edge of the sleeve deducted

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According to a further feature of the invention, the length of the coated sleeve corresponds approximately to ¹ A of the length of the core tube. , / ^: ":; · ,, ... -., '-'. ''. '. · _; Μ · 1''- ^ v,' / ^;

Execution Example '

The invention will be explained in more detail with reference to an embodiment, (n show the accompanying drawings: · '' .. '·''·' V ¹ '/.·.· .; ^1.....' V. '. ,

Fig. 1: the cable core device according to the invention in the phase of the setting process and Figure 2: the drawing of the drilled drill sample.

The core tube 1 is so far introduced via the locking part 2 and the rope vertebrae 3 with the help of the rope 4 in the interior of the crown segment of the endless hollow screw 13 with screw flights 14 until the blade 5 is seated on the ground 6. During the inlet, the water can flow through the open film tube 7, which is mounted on the sleeve 8 to approximately Va its length, without removing the tube. This means at the same time that the film tube must be mounted with sufficient adhesion to the sleeve 8. In order to deposit the core tube system on the support ring 9, an up and down movement is performed on the rope, which causes the soil penetrates into the core tube and the locking part 2 touches the support ring 9. During the now beginning drilling process, the pawls 10 wedged into the groove 11, so that the whole system is taken through the crown segment and the core 6 passes through the crown, the cutting edge 5 and the sleeve 8 in the open top film tube 7. In this case, the core 6 slides along the film tube 7 until the friction between the material and the film is greater than the friction between the film tube 7 and the PTFE-coated sleeve 8. This state is achieved within the deducted length of the film tube, which is above the free Top edge of the sleeve 8 protrudes. After that, the core automatically pulls the film off until the end of the drilling process. The speeds must be <20min " ¹ during this drilling step.

After completion of the drilling process, the cable 4 is tightened, the pawls 10 slip into the old position, the valve plate 12 slides up to the core tube head and seals the core tube.

If the cuttings are nonbinding soils, the part located in the sleeve 8 falls out and the foil tube sags somewhat, forming a constriction of the film tube 7 at the free edge of the sleeve 8, which prevents the earth from falling out further , '

Is the cuttings in the sleeve 8 made of cohesive soil, no falling out is possible. -

In order to avoid in each case a passage of the earth through the film tube 7 into the core tube, it is advantageous to also insert a plastic sleeve in the open end of the film tube 7. This additional sleeve simultaneously supports the removal of the shirred film tube 7 of the sleeve 8 upon entry of the soil in the tube 7. The core production can also be improved if around the, reefed on the sleeve 8 film tube ring springs at intervals of about 5cm are attached. These ring springs are deducted when entering the soil together with the film tube 7 of the sleeve 8 and lacing film tube 7 at regular intervals. As a result, the slipping out of the soil when pulling the core tube can be advantageously counteracted.

Claims (7)

   :._;· ·,. =; . --- .; . ·^: '' ^: -2- 25 ^ 718 3 Invention claims: A method for obtaining soil samples from substantially non-binding, aquiferous soil layers by means of endless hollow screw drilling and a Seilkerneinrichtung located in the endless hollow screw auger, which is equipped with a mounted on a sleeve, folded film tube, characterized characterized in that «after lowering and locking the rope core device with the endless hollow screw auger is operated by repeated, short - term tightening and dropping the rope core device with a two - stage drilling process, wherein in the first stage drilling the Bohrmarschlänge with high pressure, a high torque and a rotational speed of <20min " ¹ takes place and in the second stage of the helical Hohlbohrschnecke located, highly compressed soil with speeds> 60 min, ¹ promoted and additional water is supplied during the drawing process of the drill sample. 2. Apparatus for carrying out the method, characterized in that between the capture device (2) and the cable (4) a cable vertebra (3) is arranged, while on the sleeve (8) in the core device (1) wound up hose (7 ) is open at the end and approximately ^: / 3 its length over the free upper edge of the sleeve (8) is deducted. 3. Device according to item 2, characterized in that the length of the sleeve (8) approximately ¹ A of the length of the core tube     equivalent. '·'. '' · '', '-'. ^^ v -'- 'P: v; 4. The device according to item 2, characterized in that the sleeve is coated with PTFE. ' 5. Device according to item 2, characterized in that the sleeve (8) consists of PTFE 6. Apparatus according to item 2 to 5, characterized in that at constant intervals annular springs on the, on the sleeve (8) mounted, shirred film tube (7) are arranged. 7. The device according to item 2, characterized in that at the open end of the film tube (7) also a sleeve is arranged. -