EP0758699B1 - Method for installing tapered piles, tapered piles, and foundation structures made with these piles - Google Patents

Abstract

The piles (1) decrease in size in direction of setting. They are subjected to vibrations (9), to and fro in longitudinal pile direction, and in this way are driven into the ground (2) until they reach a position, which is slightly short of their final position. The vibrations are stopped, and a pressure or traction force (10), free of vibrations, and acting in direction of insertion, is applied to the pile, until it is held in the ground with a certain prestress. Initially, each pile is drawn or pressed into the ground over part (5) of its length, without vibrations, which are applied after this process. The piles consist of concrete and decrease in size conically or in an arch-shape.

Description

The invention initially relates to a method for introduction of piles tapering in the direction of insertion the ground, which is used to support or support buildings or building parts, in particular building foundations serve (preamble of claim 1). Such, in the Piles also called "nails" by experts are from DE-PS 194 125 in the form of hollow ramming piles tapering downwards known from reinforced concrete. According to the title cited above In this patent, these piles are said to be in the ground be rammed in. Hereby presumably at that time usual ramming of piles, sheet piling and the like referred to by steam-driven battering rams. With like this driven piles have the disadvantages that after every ram and thus also after the last ram the pile in question moves up a short distance (spring back, so to speak) and thus a certain amount of slip to the adjacent earth. This will, however in the event of subsequent loading by the attached building a certain disadvantageous settlement (sinking into the ground) of the piles and thus the building. Settlement of the Such dormant buildings are to be avoided, however they can lead to construction damage and complaints. The the latter disadvantages also arise with the subject from CH-PS 622.570, which is a set of prefabricated concrete pile elements and a concrete pile made with them concerns. They are frustoconical pile elements provided that put together in alignment with other pile elements and result in the concrete pile to be driven. This composition of the pile to be driven in from several Elements has the further disadvantage that the elements shift at their junctures can, or that the junction from the flight of the Elements to the side, so that the entire pile in has one or more kinks. Hereby receives an unstable foundation. In addition, the aforementioned are often Shifts or kinks after insertion of the concrete pile can no longer be determined and therefore a permanent threat to the structure supported by it represent.

WO 94/17252 discloses piles and methods which should contribute to an improvement of the foundation. To do this, use a slightly tapered pile Hammering or vibration driven into the ground. The created hole is either directly with cement or similar poured out or struts first inserted and then poured cement into it.

To create foundations for larger and therefore accordingly heavy structures, e.g. is about 40 m high Warehouse, it is currently common in practice drilling relatively deep, cylindrical holes in the ground, then insert reinforcement into the hole and finally pour this hole in concrete. The holes must be long enough to reach a stable layer of earth on which the cylindrical created by the pouring The concrete pile can support itself with the building load.

The friction between the cylindrical outer wall of the concrete pile and the hole wall is not sufficient to the later to take up a load resting on this concrete pile. Out The above often results in a relatively large hole length, e.g. of 20 m until the stable soil layer is reached. The cost of manufacturing such concrete piles is extremely high. On top of that comes from the ground outstanding top ends with a jackhammer leveled and brought to the same level have to be, since usually several concrete piles with each other form a foundation. Despite this great manufacturing effort it can be considered viable if the estimated soil layer that happen on such Pile dormant buildings sit down. This can be too Cracks in the building and further damage. So at the warehouse building cited above as an example Height of storage areas in relation to other areas to change. Since in such warehouse buildings computer-controlled Mobile devices can be operated for loading and unloading and an exact adherence to the respective altitude of the pallets or the like to be recorded is absolutely necessary the entire building can be or essential areas of it become inoperable.

The task or problem of the invention is in contrast, initially in a procedure for collecting of piles according to the preamble of claim 1 in to create the earth with a relatively small Work and material expenditure is feasible, the so driven piles under the one resting on them No or practically no longer set the building load, i.e. not penetrate further into the ground, which is a corresponding lowering (settlement) of the building in question would result.

To solve this task or problem is therefore initially provided according to the characterizing part of claim 1, that the piles reciprocate in their longitudinal direction Vibrations and in this way initially in the Earth can be driven to a position that is short before reaching its intended final depth it is convenient that the vibrations are then switched off and then a final phase of driving in by application a vibration-free force acting in the driving direction on the pile until it is pre-tensioned is firmly held in the ground. This bias can also be seen as a wedging or bracing of the pile be understood with the adjacent soil. The bringing in such piles by means of in their longitudinal direction and vibrations are compared to the known Ramming cheaper because it is essential with a less equipment expenditure and also one essential less noise can occur. It must but take into account that after turning off the vibration generator concerned, e.g. a vibrator, this still swings back and forth a little, which makes one slight indentation and moving up again Pile relative to the ground. The person concerned thus receives Pile or receive the piles in question some degree of slip relative to the ground. So it would in principle then the same disadvantages as with the rams explained at the beginning with the risk of a later, disadvantageous settlement of the piles and thus the building. Around now both the advantages of a light and fast, with relatively small amount of equipment can be carried out on the construction site Introduction of such piles using vibrations or To have vibrations as well as the explained disadvantageous Avoiding settlements is according to the second half of the Characteristic of claim 1 provided that the vibration generation shortly before reaching the end position of the pile stops and then the last piece of the driving process due to a vibration-free pull acting on the pile or pressure force. This burden drives him full and without slipping into the ground. It is the above preload reached. So settlements are avoided or they only have still such a small amount that this affects the building does not affect afterwards. Another advantage comes added that the load on such a prestressed pile electronically recorded and as the basis of soil mechanics Calculations can be used.

A preferred embodiment of the method according to the invention is the subject of claim 2 the pile is not under the longitudinal vibrations or -vibrations set, but by means of an appropriate Tensile or compressive force over a portion of its length in depressed the ground. It is therefore relative to the earth firmly held so that the on it in its longitudinal direction acting vibrations can not lead to it moved aside or even damaged.

The invention further relates to the configurations from Concrete or reinforced concrete existing piles for the implementation of the method according to the invention can be used can. For this purpose, reference is made to claims 3 to 11.

According to claim 3, the concrete piles are over their entire Length with a tapered or arched downward Provide taper. In addition, the surfaces roughened the outside of the piles or there are there deepenings. Thus, the piles take on their diameter viewed from the bottom up constantly. this has a constant displacement of the soil with the introduction of the piles. It will also hold the Piles in the ground with the pretension explained in claim 1 further consolidated. The further in such piles provided roughening or deepening support the The piles in question stop in or on the side of the ground. The advantages explained above are with the state of the Technology according to US Pat. No. 3,820,347 not achieved. For one are the piles provided there are not along their entire length tapered or arched, but only on the lower half of their length. In contrast, the diameter is the top half (the terms "bottom" and "top" are always based on their position after their introduction in the Soil) of these piles. So there not according to the claim for holding the pile in the ground 1 preload to be created. Finally this reference does not show the subject of claim 3 belonging roughening or depressions. Especially in the case of a relatively soft soil, soil can be in these roughening or depressions penetrate, causing the The stake is improved accordingly. So it is missing the subject of this reference is synergistic Interaction of those extending over the entire length Rejuvenation and the roughening or depressions around the Piles, including the load they carry, in the Keep insertion position and avoid further settlement. The holding force exerted by the piles with the invention is so big that it is no longer necessary for the piles with their lower one to be driven into the ground first End on a stable layer of earth for support and support have to come.

The subjects of claims 4 and 5 deal with the advantageous slope or slope of the outer sides of the Piles to their central longitudinal axis. Claim 5 gives the Possibility of inclining or tapering the piles in Dependence on the consistency of the respective soil choose. This tendency can be around 2-6%.

By the "trumpet-like" expansion of the concrete piles in its upper end portion according to claim 6 is an additional Displacement of the soil in the upper area of the concrete piles reached. Hereby the load capacity of such Concrete piles additionally raised.

Claim 7 includes a preferred embodiment of the Invention for creating outer surfaces or sides of the Concrete pile, which have roughening and / or depressions.

Regarding the subject of claim 8 it should be noted that the aforementioned US Pat. No. 3,820,347 piles with an approximately shows square cross section; but not piles round or elliptical cross sections.

The claims 9 and 10 allow the attachment both a vibrator as well as a foundation, e.g. one Support plate.

Fig. 1 bis 4 :

verschiedene Stadien des Eintreibvorganges gemäß dem-erfindungsgemäßen Verfahren, mit Darstellung von Pfählen nach der Erfindung,

Fig. 5 :

eine erste Ausführungsmöglichkeit eines Gerätes zur Durchführung des Eintreibvorganges,

Fig. 6 :

eine zweite Ausführungsmöglichkeit eines Gerätes zur Durchführung des Eintreibvorganges,

Fig. 7 :

einen Pfahl nach der Erfindung in perspektivischer Ansicht,

Fig. 8, 9 :

in Teilansichten die Erfindung im Zusammenhang mit einer Gründung für ein Einzelfundament, mit Darstellung von Pfählen nach der Erfindung,

Fig. 10, 11 :

eine Ausführungsmöglichkeit der Erfindung im Zusammenhang mit einer Gründung in Form eines plattenförmigen Fundamentes, mit Darstellung von Pfählen nach der Erfindung. Dabei ist Fig. 11 ein Schnitt gemäß der Linie XI-XI in Fig. 10.

Further advantages and features of the invention can be found both in the subclaims explained above, the content of which is hereby expressly incorporated by reference, and in the following description and the associated drawing of possible embodiments of the invention. The drawing shows:

1 to 4:

different stages of the driving-in process according to the method according to the invention, showing piles according to the invention,

Fig. 5:

a first possibility of executing a device for carrying out the driving-in process,

Fig. 6:

a second embodiment of a device for carrying out the driving-in process,

Fig. 7:

a pile according to the invention in a perspective view,

8, 9:

in partial views the invention in connection with a foundation for a single foundation, showing piles according to the invention,

10, 11:

an embodiment of the invention in connection with a foundation in the form of a plate-shaped foundation, showing piles according to the invention. 11 is a section along the line XI-XI in FIG. 10.

The principle of driving the piles 1 into the ground 2 is shown in Figs. 1-4. The stake in question 1 is with a only schematically indicated bracket 3 in placed vertically on the ground 2 and then by a pushing or pulling force according to arrow 4 over a Section 5 of its total length L pressed into the ground. This indentation is vibration-free or vibration-free. Then the upper end face 6 of the Pile 1 a vibrator, here only schematically indicated vibrator 7, placed in the, not shown Way connected to the upper portion 8 of the pile 1 and this in its longitudinal direction A-B according to the Arrows 9 swings up and down until it is the one shown in FIG Has reached the driving position. After that, the vibrator 7 removed or switched off and it is according to arrow 10 the pile by a further amount 11 vibration or pressed vibration-free into its end position shown in FIG. 4. In this position he has the one described for the invention Preload. This explains the disadvantageous slip avoided between pile 1 and ground 2, the one after completion the vibration according to the position of FIG. 3 occur can. The pile is stuck in the ground.

In summary, it follows that this is initially done by pulling or pressing on post 1 was done by the amount 5 holds it in the ground so that the vibrations that then occur which bring the pole 1 around the main part of its length, Do not move or damage the pile to the side can. The last phase of the transition, already described from Fig. 3 to Fig. 4 by the force 10 creates the final, fixed driving position and preload, in the case of the intended load practically no setting of the pile more into the ground.

As shown in FIGS. 1-4 and in particular in FIG. 7, the pile 1 is tapered downwards. He can any cross-sectional shape, e.g. square or rectangular 7 have. He could also use an oval instead or have a circular cross-section. Furthermore, the Post 1 "trumpet-like" towards its upper end face expand as it is by the dash-dotted lines Lines 12 in Fig. 1 is indicated above.

Instead of tapering the piles downwards such a taper is also arched. The In a preferred embodiment, piles have one Design of the taper of its outer sides in such a way that after driving in and final impressions in stick the earth to it. The rejuvenation of the Piles depending on the consistency of each Soil can be chosen, in such a way that with harder The inclination of the outside of the concrete pile whose longitudinal central axis A-B is smaller and a softer one In contrast, soil is larger. For example, the Inclination of each of the outer sides of the pile 1 in question its longitudinal central axis A-B is about 2 to 6%. Finally, in terms of the task of Invention roughened the surfaces of the outside of the piles or be provided with depressions. This will further their liability or friction on the surrounding Soil increased. For this it is recommended to use the concrete piles to produce from a porous concrete material, the the aforementioned porosity the roughening or indentation forms.

The conical taper of the pile jams its side surfaces when driving in with the adjacent one Soil. In contrast to the explained state of the Technique in which cylindrical cast in the ground Concrete piles are supported on a load-bearing layer of soil, it is not necessary here for the lower end face 13 of the pile a fixed abutment in the form of a load-bearing one Soil layer finds. While the previously known cylindrical Concrete piles must be very long, e.g. 20 m, are enough for adequate foundation with piles according to the invention trained and driven, one against it smaller pile length of e.g. 8 - 12 m. It is understood that the invention is not limited to piles of this length.

It should also be mentioned that in principle the impression of the Pile from the position of FIG. 1 to the position of FIG. 2 not necessarily by applying a tensile or compressive force 4 necessary is. You could instead go to the 1 already with the Application of the vertical vibrations using a Vibrators 7 or the like start for so long continue until the post reaches the position of Fig. 3 Has. Then the driving-in process continues as above explained.

The piles 1 are made of concrete or reinforced concrete. You can also hollow and be made from a porous concrete, so that through its hollow interior (not shown) about the porous concrete in the ground is sucked off can be. This reduces the on very damp floors Risk of excessive slipperiness on the outside of the pile on Ground.

FIGS. 5 and 6 schematically show arrangements and Devices shown to the piles according to the invention in the Bring in soil. 5 is a smaller one, off-road vehicle 14 at the construction site by means of Common, hydraulically operated supports 15 supported and possibly held firmly by a ballast 16. It carries a via only schematically indicated struts 17 likewise only schematically indicated bracket 18, in the a hydraulic system 19 is attached. The movable part 19 ' this hydraulic is fixed in a manner not shown the upper region of the vibrator 7 connected via a only indicated connection 20 at the upper area 8 of the pile 1 attacks. The hydraulics 19 ensures the so-called Preload, i.e. the last vibrationless impression of the Pile 1 into the ground from the position shown in FIG. 3 in that of Fig. 4. It can also with appropriate training for indenting the area 5 of the pile 1 from the 1 position in that of FIG. 2 serve. The stress results The hydraulic system 19 explained can be electronic be recorded and evaluated. The exact vertical position of the bracket 18 can by hydraulic Adjustment of the supports 15 of the device 14 reached become.

6 is a mobile tractor 21 provided a scaffold via a strut arrangement 22 23 carries, which is only indicated schematically here. The Scaffold 23 is supported on the ground at 24. There are two Cable pulls 25 and 26 are provided in the form of cable winches. This Cable pulls bring about the scaffold 23, also called leader and attached to them, explained in more detail below The following pulleys:

The rope 25, which from the roller 27 of the tractor on and can be moved, runs via an intermediate roller 28 ' a deflection roller 28 of the leader 23. The vibrator hangs on this 7 and on this the pile 1. FIG. 6 shows the Post 1 before it is placed in the ground. This matches with 1. The second cable 26 is moved by the roller 29 of the tractor and overflows another pulley 30 of leader 23, which as well the aforementioned pulley 28 in the upper area is appropriate. The cable 26 runs from the deflection roller 30 to a lower guide roller 31 of the leader and from there back up to the vibrator 7. This cable serves at corresponding drive via the roller 29, via which then not operated vibrator the pole 1 from the position 3 to the end position shown in FIG. 4, i.e. to give him the pretension already explained.

It is understood that the above-mentioned remarks after 5 and 6 are only exemplary and that the teaching of Claims 1 - 3 also realized with other device versions can be. The adjustment of the vertical position of the Bracket or leader 23 can by in the drawing hydraulic supports of this leader, not shown respectively.

Both the device 14 and the tractor 21 are because of required off-road capability with a caterpillar drive Mistake.

Fig. 7 shows the possibility of executing one of the piles 1 in perspective. From this is both the Taper the pile from its top face 6 to to its lower end face 13 as well as a rectangular one or square cross-sectional shape. It could but also an oval or circular cross-sectional shape be provided. The cast-on pin 35 can be gripped of the pile by a crane or to connect to the Serve vibrator.

Figures 8, 9 show the creation of a single foundation or a single foundation with the invention. Fig. 8 shows in this example a top view of part of the bottom 2 with a total of nine piles 1, each of which is the upper one End faces are recognizable. What to apply to this The foundation is for the sake of simplifying the drawing only indicated by dash-dotted lines in FIG. 8.

9 shows a view in the direction of arrow 32 with cast foundation 33. The foundation 33 is on the top end faces 6 of the piles 1, which are in are on a common level. You can do this in Pour the material of the piles 1 embedded iron rods 34 his. These iron struts 34 are in one of the piles 1 in Fig. 8 indicated. You can stop the piles at her Set down on the ground and also to transfer the Vibrations from vibrator 7 serve on the piles. So is a foundation 33 created in Fig. 8 by a group this single foundation of piles 1, here of eight Piles in the square and one in the middle of the square arranged pile is formed. Brackets 35 and 34 are firmly connected to the upper end faces of the piles 1. You can use it to attach and hold the vibrator, as well as a foundation plate according to number 33 in Fig. 9 serve. It goes without saying that for the establishment of a Building whose weight and size absorbing number of such individual foundations are to be provided. A compression of the soil between the individual foundations not to be provided here. But leave a certain one Soil of the building and is between the Pile existing soil compressed, so it can also be used for Load transfer from the building can also be used. To Soil examinations are appropriate after stake setting.

An arrangement of the piles according to FIGS. 10, 11 may be provided, which, like the piles after the Embodiment of Figures 8, 9 according to the teaching of Invention are introduced into the ground. It is a Area 36 shown, in which a number of support posts 1 in several rows next to or on top of each other C-D and E-F is driven into the soil 2. The distances a between the support piles (see Fig. 10) are relative low. They are chosen, for example 0.5 m, that according to the respective load and the soil value areas 37 with the driving of the supporting piles between them compacted earth, which is cross-hatched in Fig. 11 are shown. Here, too, the support piles taper 1 from above, i.e. from their end faces 6 downwards their end faces 13, as well as in the rest Embodiments in a preferably conical shape Rejuvenation. In this embodiment as well Embodiment previously discussed with reference to FIGS. 8, 9 the piles can be configured as previously explained. This creates a total area between the piles compacted soil. They also serve here as well as in the other embodiments, the side walls 38 of the soil as contact and support areas for the tapered side walls 39 of the support piles 1. The load of the structure indicated by the arrows 40 presses on the supporting piles 1. In the present embodiment the length L of the piles is in the range of 8 - 12 m, while the dimension of the upper end face 6 50 x 50 cm and the lower end face 13 is 15 x 15 cm. admission and support of the load 40 takes place, as explained, in the same way as in the previous embodiments. In addition, here is the above Given effect that due to the small distances a between the supporting piles 1 overall a compacted earth plate is created. A such a plate can be produced with much less effort as a base plate otherwise to be cast from reinforced concrete. The arrangement according to Figures 10, 11 is recommended especially in the presence of soft and therefore hardly load-bearing floors. The building can with a foundation analogous to part 33 in FIG. 9 on the individual piles shown, here twelve pieces, laid on or with outstanding ones Reinforcement (see number 34 in Fig. 8, 9) cast become.

Claims (11)

1. A method of inserting piles (1) into the ground (2), the piles (1) tapering in the insertion direction and serving to support or carry structures or structural members, in particular building foundations, characterised in that the piles (1) are set into vibration (9) in their longitudinal direction (A - B) and in this way are first driven into the ground (2) into a position just short of their final depth, in that thereafter the vibrations are stopped and then a final phase of the driving process is carried out by exerting a vibration-free tensile or compressive force (10) on the pile in the driving direction (4) until the pile is firmly held in the ground with a certain prestress.
2. A method according to claim 1, characterised in that the respective pile (1) is first drawn or pushed into the ground (2) vibrationlessly over a portion (5) of its length (L) and in that only then are the vibrations (9) transmitted to the pile.
3. Concrete piles for carrying out the method according to claim 1 or 2, wherein the concrete piles taper downwards in a conical or curved manner over their entire length, characterised in that the surfaces of the outsides (1') of the concrete piles (1) are roughened or provided with recesses.
4. Concrete piles according to claim 3, characterised by an inclination of the outsides (1') of the piles (1) relative to their longitudinal central axis (A - B) such that, after the piles have been driven and finally pushed into the ground (2), they adhere thereto.
5. Concrete piles according to claim 4, characterised in that, for harder ground, the inclination of the outsides (1') of the concrete pile relative to its longitudinal central axis (A - B) is less than for softer ground.
6. Concrete piles according to one or more of claims 3 to 5, characterised in that the concrete piles (1) expand upwards and outwards in a trumpet-like manner in the region of their upper ends (8).
7. Concrete piles according to one or more of claims 3 to 6, characterised in that the concrete piles (1) comprise a porous concrete for producing the roughening or recesses.
8. Concrete piles according to one or more of claims 3 to 7, characterised in that the piles (1) have an approximately square or round or approximately elliptical cross-section.
9. Concrete piles for carrying out the method according to claim 1 or 2, and according to one or more of claims 3 to 8, characterised in that the piles (1) have, in their upper region (8), a mounting (35; 34) accessible from the upper end surface (6) and provided for attaching a vibrator.
10. Concrete piles according to claim 9, characterised in that the mountings (35; 34) are formed for securing a foundation block (33).
11. Concrete piles according to claim 10, characterised in that the foundation block (33) is cast with iron supports (34) which project upwards from the upper regions (8) of the piles (1) beyond the upper end surfaces (6) thereof.

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