EP0151389A1 - Method and apparatus for constructing building elements in the soil like piles, injection anchorages, cut-off walls or similar - Google Patents

Abstract

1. A method for constructing building elements (1) in the soil (5) such as piles, injection anchorages, cut-off walls or the like, comprising the steps of feeding liquid material under high pressure through at least one outlet nozzle (7) from the surface (4) of the soil into an opening (2) in the soil filled with hardened building material (3) and driving said liquid material against the surrounding wall (8) of the opening in the soil, characterized in that said liquid material is introduced by impulse shocks and said building material (3) acts as insulating mass for the liquid material supplied through said outlet nozzle (7) due to the inertia of its mass.

Description

The invention relates to a method for producing components in the subsoil, such as piles, injection anchors, diaphragm walls or the like. With the features of the preamble of claim 1, and an apparatus for performing this method.

In a known method, liquid building material is moved in a pulse-like manner against the wall of the building site opening by a pulse pressure source. The pulse pressure source is formed by a device working with an explosive charge. Since the pulse pressure source directly moves the liquid building material for the component in a pulse-like manner, the pulse pressure source must be arranged in the opening in the ground, which can be disadvantageous.

From DE-AS 21 58 764 it is known to manufacture underground columns by driving an earth auger to the depth of the column. During the withdrawal of the same, a soil stabilizer under high pressure is continuously introduced through at least one nozzle, which penetrates into the surrounding soil, destroying the soil structure concerned, and mixes with it. Here, 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 The strength and resilience of such columns is not optimal; it is not possible to arrange steel reinforcement.

The invention has for its object to provide a method and an apparatus for producing reinforced and unreinforced components in the ground, which are free of soil material at least in the core cross-section, the load-bearing capacity and strength is considerably increased, and wherein the pressure source are attached outside the ground opening can.

The invention solves this problem with the features of the characterizing part of claims 1 and 7.

The invention provides the advantage that the pulse pressure on the liquid construction material in the building opening through an intermediate medium, _- 8th liquid material is applied. This material can be acted upon by a pulse pressure source, for example a pile driver of a high pressure pump or the like, which can be accommodated above the ground without restricting space conditions. The liquid material that is recurrently introduced into the still liquid building material for the component displaces the liquid building material in all directions into the surrounding contact zone with the building ground. As a result, the building ground is compacted and expanded, with building material interspersed, and a "cracking" can take place if the building ground is of a suitable nature. The strength, the number of repetitions and the altitude of the pulse-like pressure can be adapted to the building ground properties and / or the shape of the component. Finally, the pulse pressure application can be kept the same or changed over the height of the component. A pulse pressure application can also be carried out only at different heights of the component, such as for connecting components arranged next to one another in the form of disks or the like.

However, liquid, hardenable building material can also be introduced continuously under high pressure, which interlocks the contact zone between the component and the building ground, so that there is an increased frictional connection between the building ground and the building component. The core of the component formed by hardenable building material remains essentially unmixed.

Further refinements of the invention result from the subclaims.

• Fig. 1 einen schematischen Vertikalschnitt eines zu erstellenden Pfahles;
• Fig. 2 einen Querschnitt nach der Linie II-II in Fig. 1;
• Fig. 3 einen Vertikalschnitt wie in Fig. 1, mit einer geänderten Impulsdruckvorrichtung;
• Fig. 4 einen Vertikalschnitt eines Pfahles nach Fig. 1 mit erweitertem Pfahlfuß;
• Fig. 5 u. 6 schematische Vertikal- bzw. Teilvertikalschnitte eines Pfahles mit zusätzlichen Vorrichtungen;
• Fig. 7 einen schematischen Vertikalschnitt einer Fundamentunterfangung,
• Fig. 8 einen Horizontalschnitt nach der Linie VIII-VIII in Fig. 7;
• Fig. 9 einen schematischen Vertikalschnitt eines unverrohrten Pfahles mit einer Hochdruckstrahleinrichtung mit Strahlrohr zur Durchführung einer kontinuierlichen Hochdruckinjektion;
• ; Fig. 10 einen Querschnitt nach der Linie X-X in Fig. 9;
• Fig. 11 einen schematischen Vertikalschnitt eines bewehrten Pfahles mit teilweise gezogener Bohrlochverrohrung mit Rohrkappe und Strahlrohr;
• Fig. 12 einen Querschnitt nach der Linie XII-XII in Fig. 11;
• Fig. 13 einen schematischen Vertikalschnitt eines Pfahles mit Bewehrung und Strahlrohr;
• Fig. 14 eine Draufsicht auf den Pfahl nach Fig. 13;
• Fig. 15 einen schematischen Vertikalschnitt eines verrohrten Pfahles während des Verfüllens des Ringraumes zwischen dem Erdreich und dem eingebauten Strahlrohr mit kiesigem Zuschlagstoff, und
• Fig. 16 einen Querschnitt eines Pfahles einer weiteren Ausführungsform mit Schutzrohr und separaten Strahllanzen.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawing. The drawing shows:

• Figure 1 is a schematic vertical section of a pile to be created.
• 2 shows a cross section along the line II-II in Fig. 1.
• 3 shows a vertical section as in FIG. 1, with a modified pulse printing device;
• 4 shows a vertical section of a pile according to FIG. 1 with an enlarged pile foot;
• Fig. 5 u. 6 schematic vertical or partial vertical sections of a pile with additional devices;
• 7 shows a schematic vertical section of an underpinning of the foundation,
• Fig. 8 is a horizontal section along the line VIII-VIII in Fig. 7;
• 9 shows a schematic vertical section of an uncased pile with a high-pressure jet device with a jet pipe for carrying out a continuous high-pressure injection;
• ; Fig. 10 is a cross section along the line XX in Fig. 9;
• 11 shows a schematic vertical section of a reinforced pile with partially drawn borehole piping with pipe cap and jet pipe;
• Figure 12 is a cross section along the line XII-XII in Fig. 11 .;
• 13 shows a schematic vertical section of a pile with reinforcement and beam pipe;
• Fig. 14 is a top view of the pile of Fig. 13;
• Fig. 15 is 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
• 16 shows a cross section of a pile of a further embodiment with a protective tube and separate jet lances.

For the production of a component 1, e.g. of a pile, a hole 2 is made in a known manner, e.g. drilled.

As can be seen from Fig. 1, the borehole 2 is then filled with liquid, hardenable building material 3, e.g. Cement milk or cement mortar, if necessary filled with additives.

Before or after filling the hole 2 with building material 3, a lance 6 is introduced centrally into the hole 2. The end 7 of the lance 6 is moved from bottom to top according to the desired purpose using pulse pressure injections. In the present case, a friction pile is to be created according to FIG. 1 by compaction and expansion 8 of the contact zone in the ground 5.

The lance 6 is connected to a device, not shown, which can generate recurring pulse pressures with pauses in between in the direction of the arrow I. Such a device can be of a type known per se and can work with explosive propellant charges, sudden discharges of a bladder accumulator or with dynamic forces of a ram, etc.

A certain quantity of a medium, preferably a liquid, hardenable building material, e.g. Plastic, cement milk or cement mortar, optionally with additives, is injected into hole 2 at high speed. A pulse pressure injection occurs at the outlet end 7 of the lance 6. The pressure continues, as indicated schematically in FIGS. 1 and 2, from the lance 6 in all directions, downwards and radially. It causes the still liquid building material 3 in the hole 2, which is practically incompressible, to transmit the pulse pressure surge almost undamped into the surrounding ground 5. The column of liquid building material 3 located above the lance end 7 acts as an insulation abutment due to the inertia. By appropriate dimensioning of the strength of the pulse pressure surge, the length of the pauses, the composition of the pulse pressure mass and the building material 3 forming the component, the surrounding building ground can be compacted and thereby expanded, depending on the given ground properties. At the same time, the adjoining building ground 5 can be penetrated with hardenable building material 3 and / or "cracking" takes place.

This expanded and compacted area of the subsoil 5 is indicated by dashed lines in FIGS. 1 and 2.

The pulse pressure injection mass can be replaced by displacing the component 1, e.g. Pile, forming building material 3 indirectly exert pressure on the building site 5 and compact and expand it. Here, the impulse pressure injection mass can be released by thickening a part of its liquid phase to the building material 3 forming the component, and this in turn can instantaneously and in a corresponding quantity hardenable liquid phase with e.g. forward suspended solid particles to the subsoil 5, whereby compaction and infiltration and / or "cracking" can be effected.

A complete separation of the pulse pressure mass from the building material 3 forming the component can take place in that the pulse pressure surges take place within an expandable hose which is immersed in the building material of the component. This eliminates the otherwise applicable condition that the pulse pressure mass must be hardenable and compatible with the building material 3 forming the component. Any liquid or gaseous mass, e.g. the propellant gas of a powder charge can be used, which can be of importance for the machine for generating the pulse pressure surges; In order to obtain an insulation abutment here, too, the expandable hose, if it is not closed above, must be filled with liquid mass, provided that it is not already compressed by the specifically heavier building material 3 forming the component 1.

The pulse pressure surge can also be transmitted directly to the building site 5 by a part of the pulse pressure injection mass passing through the still liquid building material 3 forming the component 1 and thus compressing, expanding and possibly penetrating the building site 5.

The pulse pressure can be transferred directly or indirectly to the building ground 5 directly or indirectly without any significant reduction.

It is therefore important to produce and maintain a liquid state of this building material 3 despite the unavoidable filtering off of the liquid phase. If the hardening building material 3 is concrete or cement mortar, then due to the thixotropic property of the building material 3, a liquid state can also be obtained by a vibrating bottle or by a vibrating effect due to a certain series of successive pulse pressure surges.

As can be seen from FIG. 3, a deflection device 9 can be arranged at a corresponding height in the hole 2 filled with building material 3. This deflection device 9 is connected via a pipe 10 to the pulse pressure source, not shown. It preferably has nozzle-like outlet openings 11 at circumferential points opposite one another. Its height adjustment means that the wall of the hole 2 can be compressed, widened and / or cracked at any point. The reaction forces are balanced in the case of outlet nozzles 11 lying opposite one another. The pulse pressure injection can be directed in one or more specific directions by such outlet nozzles 11.

As can be seen from FIG. 4, a pile 1 can also be created using a pullable tube 12. The lance 6 and the pipe 12 are set back in relation to the bottom of the borehole. An expanded pile foot 13 of height h can be generated by means of a pulse pressure injection, with the subsoil 5 being expanded downwards and laterally.

If the pulse pressure lance 6 or nozzle 11 and the tube _{12 are} changed in height while performing a large number of pulse pressure injections, the subsoil 5 is compacted and expanded along this route. In this way, for example, a grouting anchor can be produced, the tensile force of which is to be transferred into the building ground along this predetermined distance.

A residual tension of the finished component 1 with the building site 5, which goes beyond the hydrostatic pressure of a liquid building material column after pulse pressure injection, is achieved by arching action in the building site, arching effect in the grain structure of the aggregates of building material 3 and especially when "cracking" occurs and the building material 3 loses in the resulting roots 16 by filtering off the liquid phase. With the building material 3 thickened in this way, hydrostatic pressure compensation can then no longer occur.

The residual tension can be increased further in that a perforated tube 14 is installed in the hole 2 filled with liquid building material 3 and then 14 pulse pressure injections are carried out within this tube. This tube 14 can be smooth or shaped as shown in Figure 5. The shaped tube 14 forms openings 15 to which, as shown, adjoin outwardly widening nozzle-shaped walls. It is also possible to have the walls tapered in the opposite direction to the opening 15. It can be designed as an expanded metal or plastic tube.

When pulse pressure injections are carried out, the liquid building material is shot through these openings 15. If the building site 5 is now such that it can absorb something from the liquid phase of the building material 3, the building material 3 is in the annular space between the pipe 14 and the building site 5 thickened. The openings 15 in the tube 14 then act approximately like check valves with respect to the thickened building material 3, so that the building material 3 pressed into the annular space by the pulse pressure injection can no longer fully compensate for itself hydrostatically, as a result of which a zone of remaining excess pressure is created.

If "cracking" is additionally achieved with the pulse pressure injection in the building site 5, the thickened building material located in the roots 16 can be supported on this zone, as a result of which a two-stage pressure build-up and thus an increased residual tension between component 1 and building site 5 is retained. The tube 14 can also support the cavity wall if necessary and at the same time act as reinforcement.

In all embodiments, e.g. a hole 2, a slot or the like, reinforcement elements, e.g. Reinforcement cages and the like, are installed. The pulse pressure injection can take place inside or outside such reinforcement. Since the building material 3 is always kept liquid in the cavity 2 during the pulse pressure injection, it is also possible to subsequently install reinforcements. The pulse pressure lance 6 can also itself be a remaining reinforcement element if the pulse pressure injection is progressively carried out from the air-side to the earth-side end into the cavity 2 filled with hardening building material 3, or if the pulse pressure lance 6 is only installed beforehand, an end node on the component 1 is important , e.g. to achieve a pile foot extension.

By means of pulse pressure injection, form-fitting points can be reliably produced by expanding the cavity and / or "cracking".

It is also possible to combine components 1 produced using the pulse pressure injection point by point in nodes or disks, but also entirely with one another, in order to produce space lattice constructions in the ground.

In this way e.g. Underpinnings, as shown in FIGS. 7 and 8, are carried out. Under the foundation 20 to be underpinned, holes 21 are radially graduated at a certain distance from one another and from approximately the same starting point. By pulse pressure injections extending over the length of the bore, e.g. with cement milk, these bores 21 grow together to form vertical disks 22 from the cement ground and thus form underpinning elements.

These disks 22 can then be connected and anchored by means of so-called nails 23, which are provided with steel rods and are also produced using pulse pressure injection. The nails 23 can have end anchoring nodes 24 both individually and together with a plurality of nails 23.

It is particularly advantageous that the pulse pressure injection with cement can replace conventional chemical injections, but at the same time avoids environmental damage or pollution.

The pulse pressure source can also be accommodated in the ground opening. Instead of a pump, a pressure source working with explosive charge can also be used as the pressure source.

In the exemplary embodiment according to FIG. 9, a pile hole 2 is created in the ground 5 by drilling, dredging or the like.

In the pile hole 2, the beam tube 30 closed at the bottom is first inserted. On the inner wall of the same high-pressure lines 31 are attached. These end in DL'en 32, which are arranged in the wall of the jet pipe 30 near its lower end, preferably at a large distance.

There are preferably two opposing nozzles 32. Each nozzle 32 is fed by its own high pressure line 31. It would also be possible to supply the two nozzles 32 via only one high-pressure line. In this case, such a single high-pressure line 31 would first have to end in an annular chamber at the lower end of the jet pipe 30, to which the nozzles 32 are then connected.

By using high-pressure lines 31, even a relatively thin-walled, not high-pressure-resistant tube can be used as the supporting structure as the jet pipe 30. A plurality of nozzles 32 located opposite one another allow the jet pipe 30 to be self-centered in the pile hole 2. The jet pipe 30 protects the pile core against contamination by soil material.

A carrier device (not shown) holds the jet pipe 30. It serves to lower, raise and rotate or pivot the jet pipe 30 back and forth.

Concrete, e.g. Flow concrete, pump concrete or bulk concrete or cement suspension, starting from the bottom of the pile hole. The annular space 33 between the jet pipe 30 and the pile hole wall 34 is completely filled with concrete 35.

Subsequently, by means of two pumps 36, liquid building material is continuously pressed under high pressure into the high-pressure lines 31 located in the jet pipe 30 and via the lateral nozzles 32 on the jet pipe 30 through the concrete annular space 33 into the surrounding building ground 5 initiated. The carrier device sets the jet pipe 30 and thus the nozzles 32 in a rotational movement while simultaneously lifting the jet pipe 30. The liquid building material is introduced into the ground 5 via the nozzles 32 in each case over 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 30, that is to say a pivoting movement, so that the high-pressure lines 31 do not have to be fed via a special feed head.

The jet pipe 30 is centered in the pile hole 2 by the arrangement of at least two opposite nozzles 32, each of which is fed by an independent pump 36 with the same amount of compression at the same pressure. The diameter of the jet pipe 30 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 30 is pulled up.

10 shows the treatment of the entire pile circumference by pulling up and constantly swiveling the jet pipe 30 and the nozzles 32 by a swivel angle of at least + 90 °.

According to the modified embodiment shown in FIG. 11, a pile hole 2 is created in the ground 5, which was drilled with the pipes. 11, the piping 40 is shown partially drawn. Before the piping 40 was pulled, the jet pipe 30, the reinforcement 41 and the concrete 35 were introduced. The borehole piping 40 has a pipe cap 42, in which the jet pipe 30 is guided in a movable and sealing manner. In addition, this cap 42 still has two valves 43, 44 for 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 continuously supplied by the jet nozzles 32 from breaking out through the concrete column upwards. As a result, the liquid building material is increasingly caused to penetrate into the soil of the building site 5. The pile concrete is kept free from mixing with the soil.

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

13 According to Fig. 13, a piped pile hole 2 is e.g. by bentonite rinsing.

The reinforcement 41 is located within a modified beam pipe 30 '. 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 31 with the nozzles 32 can also be arranged on the outside of the jet pipe 30 '.

The outer annular space 45 between the jet pipe 30 'and building ground 5 can be kept tight. The orifices of the jet nozzles 32 are then immediately in front of the pile hole wall 47. 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 30 'turns on finally the associated jet compression device is installed down to the bottom of the borehole. The reinforcement 41 is then introduced. Concrete is now poured from the bottom upwards within the jet pipe 30 'by means of a filling pipe until the drilling fluid is completely displaced and has flowed away at the top.

The outer annular space 45 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 back and forth turning and pulling up, so that the area assigned to a jet nozzle 32 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 30 'with the drill bit attached. For this purpose, the jet pipe 30 'can be double-walled so that the high-pressure lines 4 can be guided in the protection of this double wall.

14 that four high-pressure lines 31 with nozzles 32 are fed by four high-pressure pumps 36. With a swivel angle of the jet pipe 30 'of 90 °, a total circumference of 360 ° is then covered.

15, a borehole with piping 40 has been made in the ground 5. The reinforcement 41 is located within the beam tube 30 'which is open at the bottom and which at the same time has a protective function. The annular space 45 between the subsoil 5 and the jet pipe 30 'is filled up to the top with gritty concrete aggregates (FIG. 15 shows the work step during the backfilling).

The gritty concrete aggregate is penetrated by the liquid building material ejected through the jet nozzle 32 and thereby becomes part of the pile concrete. The building material ejected from the jet nozzle 32 then penetrates into the surrounding building ground.

The gritty concrete aggregate is, on the one hand, ideally suited to prevent or hinder the breaking up of the building material expelled through the jet nozzle 32 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 30 'including the jet pressing device connected to it is installed protruding up to the bottom of the borehole. Reinforcement 41 is then inserted. Concrete is then placed inside the jet pipe 30 '. The borehole piping 40 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 by rotating and pulling up the jet pipe 30 'and the piping 40. The jet pipe 30' is moved back and forth by a swivel angle of 90 °.

The pressing process, which acts in the surrounding ground, is carried out up to the end of the desired force transmission path of the pile.

16, separate, lance-shaped jet pipe 30 "can also be used. In order to secure the pile core cross section against mixing with the earth region, a protective pipe 46 separate therefrom can be used.

In the exemplary embodiments according to FIGS. 9 to 16, pulse pressure sources can also be used instead of continuous pressure sources.

Claims (18)

1. A method for producing components in the ground, such as piles, injection anchors, diaphragm walls or the like, in which an opening in the ground is filled with hardenable liquid building material, whereupon pressure is applied and liquid building material is driven against the surrounding contact zone in order to close it Compress and expand, characterized in that liquid material is repeatedly introduced into the still liquid building material (3) for the component in a pulsed manner or as a continuous high-pressure jet. 2. The method according to claim 1, characterized in that the hole (2) in the ground (5) is filled with prayers, such as flow concrete, pumped or poured concrete or with cement suspension. 3. The method according to claim 1, characterized in that the pulse-like supplied material is introduced axially into the cavity (2) for the component (1). 4. The method according to claims 1 and 3, characterized in that the pulse-like material is introduced radially to the longitudinal axis of the cavity (2) for the component (1) via at least one nozzle (9). 5. The method according to claims 1 to 3, characterized in that the pressure strength, the pulse duration, the pulse pause and the nature of the supplied material, the properties of the ground (5) is selected accordingly. 6. The method according to claim 1, characterized in that the high pressure jet is supplied over a peripheral segment. 7. Device for carrying out the method according to claims 1 to 6, characterized in that at least one pulsed or continuously operating high-pressure pump (9) for supplying a hardenable, liquid building material with at least one outlet nozzle (11; 32) having jet pipe (30, 30 ', 30 ") is connected, which is rotatably and vertically movable or additionally longitudinally displaceable in a hole (2) or slot in the ground (1). 8. The device according to claim 7, characterized in that in the cavity (2) for the component (1) projecting jet tube is an axial lance (6). 9. The device according to claim 7, characterized in that the jet tube projecting into the cavity (2) has at least one laterally directed outlet opening (11). 10. The device according to claim 7, characterized in that the in the cavity (2) projecting jet pipe (6, 10) is arranged centrally to a tube (14) with passage openings (15). 11. The device according to claim 10, characterized in that the tube (14) over the circumference side by side and one above the other, forming outwardly or inwardly tapering nozzles (15). 12. The apparatus according to claim 6, characterized in that the lance (6) remains as reinforcement in the component (1). ₁ 3. Device according to one or more of the preceding claims, characterized in that reinforcement cages or d ^g l. are present and the lance (6) for introducing liquid material is arranged inside or outside these reinforcement cages. 14. Component in the form of a chimney lattice structure, characterized in that impulse pressure injections are carried out in bores (21, 23) filled with liquid, hardening building material, so that these bores are entirely connected to one another or point by point in nodes (24) or disks. 15. The apparatus according to claim 7, characterized in that the jet pipe (30, 30 ') on the inside or outside has at least one pressure-resistant high-pressure line (31) which ends in a side nozzle (32). 16. The device according to claims 7 to 15, characterized in that the jet pipe (30, 30 ') is closed or open at the bottom. 17. The apparatus according to claim 7, characterized in that i a reinforcement (41) inside or outside of a jet pipe (30, 30 ') in the hole (2) in the ground (5) is arranged. 18. The apparatus according to claim 7, characterized in that the jet pipe (30) passes longitudinally through an outer tube (40) which can be locked at the top by a cover (42) which seals against the jet pipe and has valves (42, 43) which a pressure medium can be fed into the interior of the outer tube.

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