EP0346941B1 - Method for producing construction elements in the soil, such as piles, anchors or the like, and apparatus for applying this method - Google Patents

Description

The invention relates to a method for producing components in the building ground, such as piles, anchors, diaphragm walls or the like, with the features of the preamble of claim 1, and a device for carrying out this method with the features of the preamble of claim 9.

From DE-A-21 58 764 it is known to manufacture underground columns by driving an earth auger to the depth of the column base. During the withdrawal of the same, a soil stabilizer under high pressure is continuously introduced via at least one nozzle, which penetrates into the surrounding soil, destroying the soil structure concerned, and mixes with it. An earth auger is used, which is relatively easy to drill due to its small diameter. The introduction of soil stabilizer under high pressure is said to form a column cross-section that is considerably larger than the diameter of the auger. The column cross section then consists essentially of a mixture of soil stabilizer and soil material. The strength and resilience of such columns is not optimal; it is not possible to arrange steel reinforcement.

EP-A-0064663 describes a method and an apparatus for stabilizing slide slopes by attaching piles. Hardening building material is placed in a borehole. A valve pipe is inserted into the bottom of the borehole. This has several outlet openings one above the other. After the building material has hardened in the borehole, a pressure pipe is inserted into the valve tube, which has lateral outlet openings at the lower end. Sealing sleeves are arranged above and below this. With a corresponding height setting, hardening building material is pressed in via this pressure pipe. This emerges through the openings in the valve pipe, blows up the surrounding hardened building material and enters the borehole environment via the cracks. This makes it possible to apply targeted injections at certain altitudes. This allows injections to be injected above and below the sliding layer of a slope. This stabilizes the slope. The injections are applied in layers and not over the entire height of the component. The disadvantage here is that the already hardened building material is blown open again in the area of the injections, for which purpose an increased pressure of the high-pressure source is necessary. It is not possible to create a component that is to be injected over the entire length. The already hardened building material located in the core of the component would be completely broken open, as a result of which the final strength of the component would be adversely affected.

The invention has for its object to provide a method for producing components in the ground, such as piles, anchors or the like. And an apparatus for performing the method, wherein the components are kept largely free of soil material, at least in the core cross section, whereby their load-bearing capacity and Strength is increased considerably. At the same time, it should be possible to insert reinforcement for the components.

The invention solves this problem with the features of the characterizing part of claims 1 and 9.

The features according to the invention ensure that the core cross section of the created component remains essentially free of building ground components, so that the full load-bearing capacity of the hardening building material is fully maintained over this cross-sectional area. In addition, it becomes possible to incorporate reinforcements known per se when manufacturing such components.

Further embodiments of the invention result from the subclaims.

Fig. 1

einen schematischen Vertikalschnitt eines unverrohrten Pfahles mit einer Hochdruckstrahleinrichtung mit Strahlrohr zur Durchführung einer kontinuierlichen Hochdruckinjektion;

Fig. 2

einen Querschnitt nach der Linie X-X in Fig. 1;

Fig. 3

einen schematischen Vertikalschnitt eines bewehrten Pfahles mit teilweise gezogener Bohrlochverrohrung mit Rohrkappe und Strahlrohr;

Fig. 4

einen Querschnitt nach der Linie XII-XII in Fig. 3;

Fig. 5

einen schematischen Vertikalschnitt eines Pfahles mit Bewehrung und Strahlrohr;

Fig. 6

eine Draufsicht auf den Pfahl nach Fig. 5;

Fig. 7

einen schematischen Vertikalschnitt eines verrohrten Pfahles während des Verfüllens des Ringraumes zwischen dem Erdreich und dem eingebauten Strahlrohr mit kiesigem Zuschlagstoff, und

Fig. 8

einen Querschnitt eines Pfahles einer weiteren Ausführungsform mit Schutzrohr und separaten Strahllanzen.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. The drawing shows:

Fig. 1

a schematic vertical section of an uncased pile with a high-pressure jet device with jet pipe for carrying out a continuous high-pressure injection;

Fig. 2

a cross-section along the line XX in Fig. 1;

Fig. 3

a schematic vertical section of a reinforced pile with partially drawn borehole piping with pipe cap and jet pipe;

Fig. 4

a cross section along the line XII-XII in Fig. 3;

Fig. 5

a schematic vertical section of a pile with reinforcement and beam pipe;

Fig. 6

a plan view of the pile of Fig. 5;

Fig. 7

a schematic vertical section of a cased pile during the filling of the annular space between the soil and the built-in jet pipe with gravel aggregate, and

Fig. 8

a cross section of a pile of a further embodiment with protective tube and separate jet lances.

1, a pile hole 2 is created in the ground 1 by drilling, dredging or the like.

The beam tube 3, which is closed at the bottom, is first inserted into the pile hole 2. High-pressure lines 4 are fastened to the inner wall thereof. These end in nozzles 5, which are arranged in the wall of the jet pipe 3 near its lower end, preferably at a large distance.

Preferably, there are two opposing nozzles 5. Each nozzle 5 is fed by its own high-pressure line 4. It would also be possible to supply the two nozzles 5 via only one high-pressure line. In this case, such a single high-pressure line 4 would first have to end in an annular chamber at the lower end of the jet pipe 3, to which the nozzles 5 are then connected.

By using high-pressure lines 4, even a relatively thin-walled, not high-pressure-resistant tube can be used as the supporting structure as the jet pipe 3. Several nozzles 5 located opposite one another allow the jet pipe 3 to be self-centered in the pile hole 2. The jet pipe 3 protects the pile core against contamination by soil material.

A carrier device (not shown) holds the jet pipe 3. It is used for lowering, lifting and rotating or pivoting the jet pipe 3.

Concrete, e.g. Flow concrete, pump concrete or bulk concrete or cement suspension, starting from the bottom of the pile, introduced. The annular space 6 between the jet pipe 3 and the pile hole wall 7 is completely filled with concrete 8.

By means of two pumps 9, liquid building material is then continuously pressed under high pressure into the high-pressure lines 4 located in the jet pipe 3 and introduced into the immediate building ground 1 via the side nozzles 5 on the jet pipe 3 through the concrete annular space 6. The carrier device sets the jet pipe 3 and thus the nozzles 5 in a rotational movement while simultaneously lifting the jet pipe 3. The introduction of the liquid building material over the Nozzles 5 in the subsoil 1 take place on the length of the intended force application area of the pile.

Advantageously, the rotary movement is not constantly rotating, but there is a back and forth movement of the jet pipe 3, that is, a pivoting movement, so that the high pressure lines 4 do not have to be fed via a special feed head.

The jet pipe 3 is centered in the pile hole 2 by the arrangement of at least two opposing nozzles 5, each of which is fed by an independent pump 9 with the same amount of compression at the same pressure. The diameter of the jet pipe 3 is matched to the local soil conditions and pile dimensions so that excess grouting material is largely compensated for by the volume released when the jet pipe 3 is pulled up.

2 shows the treatment of the entire pile circumference by pulling up and constantly pivoting the jet pipe 3 and the nozzles 5 by a pivoting angle α of at least ∓ 90 °.

According to the modified version shown in FIG. 3, a pile hole 2 is created in the subsoil 1, which was drilled with pipes. In this Figure 3, the piping 10 is shown partially drawn. Before the piping 10 was pulled, the jet pipe 3, the reinforcement 11 and the concrete 8 were introduced. The borehole piping 10 has a pipe cap 12 in which the jet pipe 3 is movably and sealingly guided. In addition, this cap 12 also has two valves 13, 14 for the inlet and outlet of a pressure medium. The pressure medium, consisting for example of cement milk, water or air, prevents or at least prevents the liquid building material which is continuously supplied by the jet nozzle 5 from breaking out through the concrete column upwards. Thereby the liquid building material is increasingly caused to penetrate into the soil of the building ground 1. The pile concrete is kept free from mixing with soil.

4 shows the treatment of a part of the pile circumference over circumferential segments lying opposite one another. Such pile elements result in overlapping walls that, in addition to other functions, e.g. Tightness, thanks to the reinforced core pile can also have a high load capacity or bending stiffness.

According to Fig. 5, an uncased pile hole 2 is e.g. by bentonite rinsing.

The reinforcement 11 is within a modified beam pipe 3 '. This is now open below. It also fulfills a protective function and certainly keeps the reinforced core cross section of the pile free of ground inclusions.

The high pressure lines 4 with the nozzles 5 can also be arranged on the outside of the jet pipe 3 '.

The outer annular space 2 between the jet pipe 3 'and building ground 1 can be kept tight. The mouths of the jet nozzles 5 are then immediately in front of the pile hole wall 7. The continuous high-pressure jet can accordingly have an optimal effect.

The pile hole 2 is first uncased, possibly drilled with cement or bentonite flushing. The jet pipe 3 'including the associated jet pressing device is lowered to the bottom of the borehole. The reinforcement 11 is then introduced. Within the jet pipe 3 'is now concrete from bottom to top by means of a backfill pipe introduced until the drilling fluid is completely displaced and flowed away at the top.

The outer annular space 15 is filled with pumpable cement or cement-sand mortar at low pressure from the bottom upwards via the blasting device until the drilling fluid, e.g. the bentonite suspension, completely displaced and flowed away at the top. Now the continuous high-pressure jet supply takes place with constant turning back and forth and pulling up, so that the area assigned to one jet nozzle 5 is exposed to the high-pressure jet. The pressing process is carried out until the end of the desired force transmission path of the pile.

In a modified embodiment, not shown, drilling can be carried out directly with the jet pipe 3 with the drill bit attached. For this purpose, the jet pipe 3 can be double-walled, so that the high-pressure lines 4 can be guided in the protection of this double wall.

From Fig. 6 it can be seen that four high-pressure lines 4 with nozzles 5 are fed by four high-pressure pumps 9. With a swivel angle of the jet pipe 3 'of 90 °, a total circumference of 360 ° is then covered.

7, a borehole with tubing 10 has been made in the ground. The reinforcement 11 is located within the beam tube 3 'open at the bottom, which also has a protective function. The annular space 15 between the subsoil 1 and the jet pipe 3 'is filled up to the top with gritty concrete aggregates (Fig. 7 shows the operation in the backfilling).

The gritty concrete aggregate is penetrated by the liquid building material ejected through the jet nozzle 5 and thereby becomes part of the pile concrete. The jet nozzle 5 expelled building material then penetrates into the surrounding building ground.

The gritty concrete aggregate is on the one hand extremely suitable for preventing or hindering the breaking up of the building material expelled by the jet nozzle 5 and on the other hand fulfills a protective filter function to keep the pile core cross section clean.

In this embodiment, the holes are first drilled with piping. The jet pipe 3 'including the associated jet pressing device is installed projecting up to the bottom of the borehole. The reinforcement 11 is then inserted. Then concrete is introduced within the jet pipe 3 '. The borehole piping 10 is pulled and, in the process, filler material is added to the outer annular space. The supply of the high-pressure jet now takes place continuously while rotating and pulling up the jet pipe 3 'and the piping 10. The jet pipe 3' is moved back and forth by a swivel angle of 90 °.

The pressing process is carried out until the end of the desired force transmission path of the pile.

As can be seen from FIG. 8, separate lance-shaped jet pipes 3˝ can also be used. In order to secure the pile core cross section against mixing with the soil, a protective tube 16 separate therefrom can be used.

Claims (15)

1. Process of manufacturing assembly elements in a construction base, such as poles, anchors or the like,
   in which a hole (2) is produced in a construction base (1),
   a jet pipe (3) comprising one or more lateral nozzles (5) is introduced into the hole the diameter of which is smaller relative to the hole in the construction base,
   the annular space (6) between the jet pipe (3) and the perforated wall (7) is filled with a material (8) which forms a hardened annular layer, and
   a hardening liquid is pressed through the annular space (6) via jet pipe (3) comprising one or more nozzles in the form of a high-pressure jet whilst drawing the jet pipe into the construction base which surrounds the hole,
   characterised in that
   prior to hardening of the annular layer, the high-pressure jet (8) is, whilst being drawn, continuously pressed whilst rotating or pivoting the jet pipe (3) to and fro .
2. Process according to claim 1,
   characterised in that
   the annular space (6) between jet pipe (3) and hole wall (7) is filled with a hardening material, such as wet concrete, pumped concrete or bulk concrete.
3. Process according to claim 1,
   characterised in that
   the annular space (6) between jet pipe (3) and hole wall (7) is filled with concrete additives containing gravel.
4. Process according to claim 1,
   characterised in that
   the hole (2) in the construction base (1) is fitted with pipes, and the annular space (6) between jet pipe (3) and hole wall (7) is filled with concrete whilst drawing the tube (10).
5. Process according to claim 1,
   characterised in that
   a reinforcement (11) is fitted into the annular space (6) between jet pipe (3) and the tube (1) prior to being filled with a hardening material.
6. Process according to claim 1,
   characterised in that
   a downwardly open jet pipe (3') is used, and that the inner space of this jet pipe is, like the annular space (15), filled with a hardening material.
7. Process according to claim 6,
   characterised in that
   a reinforcement (11) is fitted into the inner space of a downwardly open jet pipe (3') prior to being filled with a hardening material.
8. Process according to claim 1,
   characterised in that
   the hole (2) in the construction base (1) is tubed whilst being drilled, that the annular space between jet pipe (3') and tube (10), which is sealed towards the air, is filled with a hydraulic medium which impedes or prevents break-out in an upward direction of the hardening material which has been delivered via the jet nozzle (5) of the jet pipe (3).
9. Device for carrying out the process according to one or more of claims 1 to 8, comprising a drilling device for a pole hole (2) in the construction base (1) and at least one high-pressure source, which is suitable for continuous operation and to which is connected a jet pipe (3), which is entered into the pole hole in the construction base, with at least one lateral outlet nozzle (5) at the end of the jet pipe for hardening wet construction material, and which can be lowered or raised, and that the jet pipe (3) has a smaller cross-section relative to the drill for the pole hole (2) in the construction base (1) or relative to a pole hole tube,
   characterised in that
   the jet pipe (3) is also rotatable around its longitudinal axis or pivotable around its longitudinal axis.
10. Device according to claim 9,
    characterised in that
    the jet pipe (3, 3') comprises internally or externally at least one pressure-resistant high-pressure pipe (4) which terminates in a lateral jet nozzle (5).
11. Device according to claims 9 and 10,
    characterised in that
    the jet pipe (3) is sealed at the bottom.
12. Device according to claims 9 and 10,
    characterised in that
    the jet pipe (3') is open at the bottom.
13. Device according to claim 9,
    characterised in that
    a reinforcement (11) is provided either inside or outside the jet pipe (3, 3').
14. Device according to claim 9,
    characterised in that
    the tubing (10) for the hole (2) drilled into the construction base (1) is upwardly sealed by a cover (12), which seals against the inner jet pipe (3, 3') and which comprises valves (12, 13) by means of which a pressure medium is delivered to the inside of the tubing (10).
15. Device according to claim 9,
    characterised in that
    the jet pipe is composed of an inner protective pipe (16) and a plurality of separate and peripherally spaced lances (3'').

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