DE4430874C2 - Process for obtaining samples for soil tests - Google Patents

Description

The invention relates to a method for extraction of samples for soil tests, such as z. B. for the extraction of geological Soil samples, in soil investigations etc., use Find.

Very different drilling methods are used to explore soils. DIN 4021, exploration by digging and drilling, summarizes the procedures in Tables 1-3. The method according to the invention falls under small-bore methods DIN 4021, Table 3, line 2 .

Small drilling processes generally work according to the following principle: Ram probes 1 m long and 30 mm-80 mm in diameter are rammed into the ground. After every meter the Probes pulled, emptied and back into the borehole introduced to ram another meter. Of the The main disadvantage of the small drilling method is in addition to shallow digestion depth mainly in the restricted Possible application. Soils by this method unlocked must meet the following criteria: Cohesion, low coarse grain, no groundwater,  low storage density. That said, the procedure is only under previously well known soil conditions and there can only be used at shallow depths.

Drilling processes of larger borehole diameters (from 80 mm Diameter) pipe the borehole, that is, it is around the inner linkage concentrically driven in an outer tube, to prevent the borehole from collapsing to after the soil sampling again at the point drill on which was dropped. For bringing one However, piping is a major technical effort necessary. You need drills with big ones Dead loads, their outer tubes, usually one on the front Have drill bit, hydraulically with slow turning used or "screwed".

In order to prepare building site reports, i.a. Digestion depths of up to 20 m required. For properties of the soil in To bring experience, they will a. through holes explored. In the Munich area it is assumed that it will happen it all comes down to the boundary line between the quaternaries Gravel (coarse-grained gravel) and tertiary soil layers (Fine sand, toning) to be proven with sufficient accuracy and furthermore classify the tertiary soils with sufficient accuracy.

From the prospectus "Explore and probe with the RKS core probe RKS "from Nordmeyer GmbH und Co. KG, 31206 Peine is a process for a "small drill system" Collection of samples in the wide range of Soil investigations known. With this is im Diameter small sized slot probes (up to 32 mm) or Ram core probes (up to a diameter of 80 mm) and one Drive unit (internal force hammer or electric hammer) worked. Here, for. B. at the top of one Rammkernson an insertion impact tool by screws attached. The top end of the plug-in striking tool will  in turn in a corresponding tool holder of the Impact hammer priced. Then the ram core probe is opened a depth of about 1 m. Then the Hammer removed and the probe using a mechanical or hydraulic traction device from the ground drawn. Then the ram core probe becomes the sample removed, the plug-in impact tool unscrewed and a ram link between this and the ram core probe Solid material inserted by screwing. This extended rod is in the existing borehole inserted, on the insertion of the plug-in impact tool the percussion hammer is firmly attached, d. H. fixed what after is rammed another meter. This way of working repeats itself according to the desired drilling depth several times, each time to insert another Ramming rod to be unscrewed got to. In addition, the borehole can also collapse here or pour drilling material or through groundwater material be flushed in so that on the one hand imprecise soil samples pulled, which falsifies the results can and on the other hand the drilling must be stopped.  

Finally, EP 0 305 178 A1 describes a Method and device for taking soil samples the one inner probe and one arranged concentrically to this neat outer tube always together over one on the inner sun de or its extension rod or via a connector screwed-in drive head is driven in, after which the inner probe is pulled and the sample is taken. The inner probe is then reinserted into the outer tube leads and both parts come with appropriate extensions provided elements. In doing so, a Extension rod screwed while on the outer tube an extension tube is placed in an axial extension is that against a side or a collar or a clamp is secured. Then both are extended parts together via the input head into the Soil rammed in, and the process becomes necessary repeated several times. After reaching the final depth only pulled the inner probe one last time while that Outer pipe remains in the ground, ie a "lost" part is. If necessary, however, the last outer tube Extension part can be pulled from the ground. The other outer tube parts cannot be pulled because no fixed axial connection between the individual outside pipe parts is available. Only in the case of a penetration / ramming attempt the inner probe alone, with the outer tube still, is driven ben. However, if further samples are taken afterwards, the inner probe and the outer tube are again driven together ben. Thus, the inner probe and the outside are used for taking samples tube rammed together. For this there are inside and outside dimensionally matched pipe so that between they only have a minimal gap between the rings. Here are also the outer tube and the corresponding outer tube Extensions are designed relatively thin-walled and are like already mentioned, axially not attached to each other, son they just stand on each other at the front and are  secured against radial slipping via an outer sleeve chert. The arrangement of an outer cuff should be Impeding drive, d. H. additional driving force need. Also by the simultaneous ramming both parts need a slightly higher driving force, as if the two parts each separately one after the other would be rammed in. Finally there are inner probe and outer tube arranged with a minimal space between what only if the parts and their design are very thin-walled ramming at the same time makes sense, otherwise the first a large frictional force arises between the parts and on the other hand, when rammed separately, the strength which parts would not be enough.

The object of the invention is a method for the extraction of Samples for soil tests, to indicate that a quick, easy and safe Work on taking samples in different soils as well Ensures provision of optimal samples, in particular a collapse of the borehole in the course of the different Work steps should be avoided.

This task is accomplished using a procedure solved the features of claim 1. Beneficial Refinements are in the subclaims  described.

Accordingly, the ram core probe Piling linkage alternating in external piping Steps with their introduction. It will thus every time after ramming the inner rod External piping driven in by a further pipe length. Instead of the conventional plug-in impact tool a ram core probe used, the lower end of which has hood-shaped expansion. This ram hood remains during the whole ramming or driving or Sampling time set in the hammer. With everyone The new hammering process will make the impact hammer work on it attached ram hood to the respective upper outer tube or End of inner rod placed like a hood or lid or put on and then hammered in the corresponding part, after which the hammer with ram hood simply from that part can be lifted off and put away to put on the drawing tool. It will therefore always be the Process of unscrewing and screwing on the plug-in impact tool saved.

To ensure accurate hammering, especially around Make sure the hammer over the ram hood too as centrally as possible on the inner rod or the External piping strikes between Ram hood and respective driving-in part, that is Inner rods or outer piping in the shape of the corresponding, upper drives of the adapted adapter put this on. This adapter could do it be designed differently, depending on the dimensions and after forming the upper tube or rod ends. So can  the adapter has the shape of a sleeve, the wall thickness of the cylinder part is designed so that the respective remaining clear cylinder width the outer diameter of the Part to be driven so that it is easy on this can be put on or pulled up.

The adapter can, especially for thicker rods and pipes be designed as a hood adapter, that is, its lower one Part can, similar to that attached in the hammer Ramming hood, designed to accommodate additional sleeve adapters his. For this purpose, it has a recording at its upper end Guide pin on which the ram hood when Drive process is simply pushed over. These diverse Adapters can be loose parts or already Wrapping the inner rod or outer tube in corresponding set must be firmly assembled.

Take special care when driving in the outer linkage be proceeded as this is known to be at the Input top side each has a thread. This can namely at least by opening on the front The beginning of the thread must be destroyed so that the next outer tube can no longer be screwed on properly. Therefor is opened before driving in the outer tube a sleeve adapter is attached to the upper end or screwed on, its inner blind hole has the appropriate thread. By screwing this on Threaded sleeve adapter except that the Blind hole bottom on the front ring of the outer tube, it will Protected the front end of the outer tube from bruises, see above that the thread remains in optimal screwing condition, too after a large number of driving processes.

To make sure that when driving in between the two essentially concentric driving parts, that is  this constancy between the inner rods and the outer piping or concentricity at least at the upper end of each stationary part is preserved, before each or placing the part to be rammed into the at the process stationary part top end an introductory or Spacer inserted or attached. This leadership or Spacers can be made of metal or firmer, crushed and tear-resistant plastic. However, they all point a cylindrical part (socket), which in the Clearance between the parts to be kept at a distance being pushed in while at their respective Working position upper end either an outer flange Insert and support on the outside of the outer tube or one Inner flange or even a closed bottom part have to be pushed onto the internal piping. There on the parts which are essentially horizontal in the working position, So the flange or bottom part here as good as these parts can simply be designed be, for example, instead of a full, in essential annular flange also only two to three outward-facing webs or one cross-connection Floor bridge for the inner linkage can remain, which e.g. B. material and thereby weight is saved.

When penetrating the coarse-grained Soil layers become one instead of the front ram core probe Rammspitze with front conical input tip from full Material used. Is this bottom layer that in the Munich area can be up to 10m thick, drilled through, then a ram core probe is used again instead of the ram tip at the bottom used to take soil samples from the underneath to remove existing floors.

In the case of stratified or groundwater occurrences is conventional Drilling process reaches the final drilling depth because of the water  Soil material and the borehole again and again clogged. This is prevented by the method according to the invention. Because through the external piping that continues is driven as long as the inner linkage is driven, the insertion depth of both parts is before Pulling up the inner rod always about the same, that is Drill hole depth is approximately equal to the drive depth of the Outer tube when the inner rod is pulled so the borehole is open. This means that no water can flow through the external piping flow into the borehole after pulling the inner rod.

It is advantageous if the hammer is a hydraulic hammer that has a stronger punch. This is particularly important for driving in the outer tubes, since the conventional internal combustion or electric impact hammers generate less impact and are therefore less efficient.  

As before are exchangeable depending on the part to be driven Adapter, as a sleeve adapter, threaded sleeve adapter or Hood adapter and finally designed as a second adapter and / or be usable.  

It should also be pointed out that, of course, at Impact on coarse grain layers that, as before described in the Munich area up to 10m thickness can have when ramming the coarse grain layer with the Rammspitze, i.e. without a Rammkernsonde, after driving in the no samples are taken in the respective outer tube section, so that the inner rod after driving in the outer piping is not pulled or lifted. It always gets straight alternating inner rods-outer piping-inner rods- External piping etc., preferably driven in meters, by always the on the part to be driven Drive extension is put on and always the appropriate on the upper parts Spacer on the stationary and the corresponding Adapter parts are placed on the part to be driven. Of course, this continues until the coarse grain layer is permeated and samples from the underlying floors must be removed. So it has to be done again Inner rods pulled after driving in the outer tube and then reintroduced and driven in, as previously described for sampling.

The method according to the invention is described below with the aid of the drawing described in more detail.

Show it:  

Fig. 1 is a schematic representation of a Kleinbohrsystems used during the driving of the first outer pipe,

Fig. 2 is a view in partial section of a driving cap of the system,

Fig. 3 is a view with a partial axial section of a hood adapter for driving cap,

Fig. 4 is an axial section through a sleeve adapter for the Rammgestänge, including that of the prior art

Fig. 5 is an axial section through a sleeve adapter for the gouge,

Fig. 6 is a plan view with a partial axial section of pipework of a threaded adapter for the tubes of Außenver,

Fig. 7 is an axial section through a guiding and spacer ring for the inner rod,

Fig. 8 is an axial section through a guiding and spacer ring for the outer rod,

Fig. 9 is a view in partial section of a Rammstabes, the beetle-Tangen be attached at its upper end,

Fig. 10 is a view in partial section of a Rammwechselspitze,

Fig. 11 is an axial section a casing tip,

Fig. 12 is a schematic representation of the driving-in steps when ramming in soils with a low coarse grain fraction, and

Fig. 13 shows the most important driving steps when ramming in soils with a high proportion of coarse grains (Munich gravel).

The small drilling device system shown schematically in Fig. 1 in driving action consists of a hammer 1 , a ram hood 2 , a hood adapter 3 and / or a sleeve adapter 4 , an outer tube 5 , which is driven in and a ram core probe 6 , which already is driven into the ground and still protrudes slightly above the upper edge 7 . The ram hood 2 is removably fastened in the percussion hammer, but is firmly held for the entire working time, while the sleeve adapter 4 is placed on the upper end of the outer tube 5 by hand before driving starts. Then the hood adapter 3 is placed on the sleeve adapter 4 by hand, after which the hammer is finally placed on the hood adapter 3 or partially slipped over it via its ram hood 2 . As can be seen, it is a real "modular system", which is assembled or assembled depending on the parts to be driven in relation to adapters and spacers.

The driving cap 2 shown in Fig. 2 comprises a matched at the tool holder of the hammer shank 1 8, a stop or attachment shoulder 9 is provided on its bottom. A pot-shaped hood 10 which is open at the bottom is arranged below the shoulder 9 via an intermediate piece 11 . In the hood opening 12 , an interchangeable sleeve adapter 13 is arranged for small drilling diameter parts. The ram hood 2 provided with the adapter 13 is slipped directly onto the outer tube 5 via its attachment opening 14 without the adapters 3 and 4 shown in FIG. 1 being used. The sleeve adapter 13 corresponds to the sleeve adapter 4 , but designed for smaller diameters.

The hood adapter shown in FIG. 3 3, has at its upper end an insertion pin 41 for insertion into the cover opening 12 of the driving cap 2 while 15 of larger diameter is provided at its lower part a hood. In the hood opening 16 of the hood adapter 3 z. B. introduced the sleeve adapter 4 shown in Fig. 4 to 6, or the hood adapter 3 translated over this sleeve adapter 4 .

The sleeve adapter shown in FIG. 4 4 has a stepped attachment hole 17 z. B. also for ramming poles according to the prior art.

The sleeve adapter 4 shown in FIG. 5 has an unstaged, smooth attachment opening 18 .

The sleeve adapter 4 according to FIG. 6 has a threaded mounting opening 19 , and is thus a threaded adapter for screwing on the upper screwing end of the outer tube 5 to be driven .

The guide spacers 20 , 21 shown in FIGS. 7 and 8, i.e. the spacer 20 for insertion and placement on the linkage 6 , 40 and 21 for the outer tube 5 , both have a guide bush 22 as the main component, which is also for both Parts, of course with respect to the same bore diameter system, have essentially identical dimensions. The difference is that in the spacer 20 for the inner linkage 6 , 40 , a bottom 23 is arranged on the top, while the spacer 21 for the outer tube 5 has a flange 24 , which each serve as an axial support or stop. It makes sense if these parts 20 , 21 are made of highly abrasion-resistant material.

In FIGS. 9 and 10, a 25 and a Rammstab Rammwechselspitze 26 are illustrated in function belonging together, which are connected to each other via an unillustrated threaded nipple. For this nipple connection, both parts each have threaded holes 27 on the end face. The ramming bar 25 has at its upper section a bar part 28 which has a smaller diameter than the rest of the bar part 29 . The rod part 28 corresponds in diameter to the ramming rods, not shown, which are attached in pieces above it during ramming via nipples, not shown, which are mentioned below in connection with FIG. 13.

The ram changing tip 26 has at its lower end a tip 30 which has a cone angle of z. B. 65% or 60%, depending on the material. Rammwechselspitze 26 and ramming rod 25 together form a unit (ram tip), the diameter of the respective rod part 29 corresponds to the diameter of the ram core probe 6 , which must be passed through the borehole after ramming. As already mentioned, the rod part 28 has essentially identical outer diameter dimensions to the elongated ramming rods, which are thus passed through the rammed hole essentially smoothly.

The piping tip 31 shown in FIG. 11 has different sections when viewed in the axial direction. In the upper section it has a threaded section 32 for axially screwing an outer tube 5 over its inner threaded part. Each of the outer tubes 5 also has such an upper threaded section 32 . On this threaded portion 32 is z. B. the sleeve adapter 4 shown in Fig. 6 screwed over its threaded attachment opening 19 . The threaded section 32 is followed by a smooth pipe section 33 which , in a radial section, has essentially the same dimensions as the outer pipes 5 to be attached above it. The last section is followed by a cutting section 34 , which consists of two counter-conical sections, namely a tip cone 35 and a counter cone 36 , which meet to form an annular diameter widening 37 . The tip cone 35 is arranged in relation to the lower, somewhat smaller diameter of the inner guide section 38 for the ramming core probe or the ramming rod, so that a narrow cutting ring 39 remains at the end. It can be seen from Fig. 11 that the piping tip 31 , in particular by the diameter extension 37 ; pushes the soil a little further apart, so that the pipe section 33 and the subsequent outer pipes 5 can be driven without great frictional resistance.

Fig. 12 shows the situation states a to h or the arrangement of the collectible or the driven parts of the system during driving in soils with low coarse fraction to substantially sequential steps.

Thus, in a) the state at the beginning of the first method step is shown, namely the placement of a ram core probe 6 on the ground surface 7 , while only a hood adapter 3 is shown as power transmission devices, instead of for all adapters and the hammer, so as not to obscure the drawings complicate.

In b) the ram core probes are in the fully rammed condition shown reaching into the ground to a depth of approx. 1 m.

In c) the initial state when "ramming" the ram core probe 6 with an outer tube 5 can be seen, while in d) the state is recorded after the ramming has taken place.

The next method step shown in e) represents the pulling or lifting of the ram core probe 6. After removing the sample from the probe, a ramming rod 40 made of solid material is placed on its upper end, after which the combined rod 6 , 40 into the cased borehole introduced and the ram core probe 6 is driven by a further meter. This final state can be seen in f). A further outer tube is then screwed onto the top of the outer tube 5 , after which this tubing is also driven in by a further one-meter step. This state is shown in g). Then, the inner rod is pulled again with the gouge 6, is placed the sample located on the top of the drive rod 40 a further drive rod 40, after which the stages f to to to achieve the desired depth of the well be wierderholt h.

In Fig. 13 for specific situations or states process steps during driving in soils with a high proportion of coarse particles (Munich gravel) are shown. Consequently, the coarse-grain layers are simply rammed through with the help of the ramming rod 25 , without taking a sample. Only after the coarse layer up to 10 m in the Munich area has been rammed through is the transition to the sampling steps shown in FIG. 12 under f to h carried out using the ram core probe 6 .

Thus, a) in Fig. 13, a Rammstab 25 shown with a hood adapter 3 and prior to the beginning of the Einrammens. In state b), the ramming bar 25 is already rammed into the ground, while in state c) the start of driving over the ramming bar with an outer tube 5 is shown, while in d) the driving over of the ramming bar has ended.

State e) shows the ramming bar 25 , to which a ramming rod 40 is fastened, driven in one step further, while state f) shows the completed ramming process with a further outer tube. Subsequently, the last process steps are repeated with the states e) and f), that is to say the ramming rod 25 is driven in, of course, always by adding a further ramming rod 40 above, after which, of course also after unscrewing another outer pipe 5 , the outer piping is driven in becomes. When ramming through, no parts are pulled, so that this method of operation proceeds very quickly using the system according to the invention, especially since only screwing-on operations always take place and no unscrewing operations need to be carried out, since the hammer is no longer screwed on via its ramming hood, but is only put over.

Claims (5)

1. A method for obtaining samples for soil tests, with the following steps:

• a) fastening a plug-in percussion tool designed as a ram hood ( 2 ), with a hood-shaped widening at the lower end, in a percussion hammer ( 1 ), in which it remains until the end of work,
• b) Placing the percussion hammer ( 1 ) with the ram hood ( 2 ) on a hollow ram core probe ( 6 ) which is open at the bottom or on a closed ramming rod ( 25 ) made of solid material and driving in or ramming in the ramming core probe ( 6 ) or the ramming rod ( 25 ) with the help of the hammer ( 1 ), between the ram hood ( 2 ) and the part to be driven ( 6 , 25 ) one or more, adapted to the shape of the upper end of each part to be driven ( 6 , 25 ) hood or sleeve adapter ( 3 , 4 ) are arranged,
• c) driving in an outer tube ( 5 ) at a concentric, narrow distance from the ram core probe ( 6 ) or the ramming rod ( 25 ), one or more of the shape of the upper end of the outer tube ( 5 ) between the ram hood ( 2 ) and the outer tube ( 5 ) 5 ) adapted hood or sleeve adapters ( 3 , 4 ) are arranged,
• d) pulling or lifting the ram core probe ( 6 ), after removing the impact hammer ( 1 ), using a mechanical or hydraulic lifting or pulling device and taking the soil sample from the ramming core probe ( 6 ) or leaving the ramming rod ( 25 ) in the driven-in state,
• e) attaching an extension ramming rod ( 40 ) made of solid material to the upper end of the ramming core probe ( 6 ) or to the upper end of the ramming rod ( 25 ), the parts ( 6 , 25 , 40 ) each being screwed on the end face,
• f) inserting the ram core probe ( 6 ) extended with a ram rod ( 40 ) into the borehole and driving in the extended ram core probe rod ( 6 , 40 ) or driving in the extended ramming rod linkage ( 25 , 40 ) using one or more of the hood or sleeve adapter ( 3 , 4 ),
• g) Repeat the previous steps b) - f) several times, if necessary, an additional ram bar ( 40 ) being attached to the upper end of the upper ram bar ( 40 ) each time.

2. The method according to claim 1, wherein a guide and spacer ( 21 ) is inserted before inserting the ram probe rod ( 6 , 40 ) or the ram rod rod ( 25 , 40 ) into the outer tube ( 5 ) located in the borehole. 3. The method according to claim 1 or 2, wherein a guide and spacer ( 20 ) is placed before driving the outer tube ( 5 ) onto the upper end of the ram core rod assembly ( 6 , 40 ) or the ramming rod assembly ( 25 , 40 ). 4. The method according to any one of claims 1 to 3, wherein a hydraulic hammer is used as a hammer ( 1 ). 5. The method according to any one of claims 1 to 4, wherein an adapter ( 4 ) for the outer tube ( 5 ) is used, which has an internal thread ( 19 ) for an external thread ( 32 ) of the outer tube ( 5 ) in its receiving opening as thread protection.