EP0788572A1

EP0788572A1 - Building underpinning process

Info

Publication number: EP0788572A1
Application number: EP96938908A
Authority: EP
Inventors: Roland Beck
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-08-17
Filing date: 1996-08-16
Publication date: 1997-08-13
Anticipated expiration: 2016-08-16
Also published as: DK0788572T3; WO1997007295A1; CZ151097A3; CZ292795B6; ATE203075T1; ES2158362T3; EP0788572B1; GR3036352T3; PT788572E; US6062770A

Abstract

PCT No. PCT/DE96/01526 Sec. 371 Date Jun. 11, 1997 Sec. 102(e) Date Jun. 11, 1997 PCT Filed Aug. 16, 1996 PCT Pub. No. WO97/07295 PCT Pub. Date Feb. 27, 1997A method for underpinning a building comprises arranging at least one elongated supporting element below and substantially parallel to the foundation of the building. A whole side wall of the building may thus be underpinned in a single operation without unnecessarily weakening the existing underground. By coupling a plurality of elongated supporting elements, a kind of large-surface foundation that securely supports the building can be created. The architectonic substance of very old buildings may thus be preserved in a non-aggressive manner. In addition, the underpinning method can be carried out very quickly and at a relatively low cost.

Description

Process for undertaking buildings

The invention relates to a method for undertaking buildings according to claim 1 and further to a method for forming reinforced concrete support elements according to the preamble of claim 17.

It has been known for a long time to stabilize foundations on an unstable subsurface by digging them in sections and supporting them with deeper concrete or masonry. Since part of the foundation is stripped of its support in the subsurface, there is a risk that cracks will appear in the masonry and, in the worst case, collapse of the building, especially if the building is ailing. This work must therefore be carried out with great care and is very time-consuming.

It is therefore an object of the invention to demonstrate a method with which the undertaking of buildings can be carried out quickly and safely with simple means.

This object is achieved in that at least one elongated support element is arranged substantially parallel to the foundation below the structure to be underpinned.

This has the major advantage that an entire foundation section of a building can be supported in one go. When creating the elongated support element, the base under the foundation is not so badly affected that settlement occurs. At the same time, however, there is a stabilizing element on the entire building side below the foundation after the elongated support element has been completed.

This significantly shortens the time required for the underpinning, since the entire foundation section is supported at once, in contrast to the previous method, in which the foundation was underpinned piece by piece.

Another major advantage is that the risk of accidents for the people working there can be significantly reduced, since they are not located directly below the wall to be underpinned, but laterally spaced from the building.

It is a further advantage that the structure to be underpinned is less stressed by this method and therefore the risk of cracking in the masonry or even collapse is significantly reduced.

Another advantage of this method is that common means can be used for this in building technology and sewer construction. The technology required for implementation is therefore available and relatively inexpensive.

REPLACEMENT BLAπ (RULE 26) Further advantages result if a plurality of elongate support elements are arranged below the foundation and are at least partially coupled to one another. This gradually underpins the foundation and can thus increasingly stabilize itself. When producing a single support element, its dimensions are chosen so that the base beneath the foundation is only slightly affected. In the interaction of several support elements, the foundation is then increasingly supported and ultimately lies securely. In this way, a kind of surface foundation is created, which acts like a "raft" on the foundation and carries it on the unstable subsurface.

The fact that support elements are arranged in the form of a grid or grid, an effective undertaking of the entire structure can be achieved in particular in larger buildings, such as churches and the like. Such structures are usually constructed so that the load of the structure is supported on a grid of supporting columns. These pillars are partly in the side walls and partly inside the building. The grid-like arrangement of the support elements enables targeted support of the respective load-bearing element. A gentle undertaking of the entire static support points of the building is therefore possible.

Furthermore, it is also possible to support individual columns in the interior of a building if the sinking of the foundation only occurs in one area of the building.

It is a further advantage if a system of supporting elements coupled to one another is formed under the structure to be underpinned. Here, support elements designed as tension and pressure elements can be specifically arranged and coupled to one another in such a way that they establish a connection to a solid base and absorb the load of the structure.

By producing the individual support elements in that a hole is made below the foundation and a hollow or closed rod with a circular cross section is produced in this hole, which can have tensile and pressure strands, a stable configuration of the elongate support element can be achieved become. The support element is thus able to absorb tensile and compressive forces. Particularly in the case of a changing floor structure under the building, it is necessary to intercept various load cases, which can also change over time. This provides a resilient support element, the load capacity of which can be increased in cooperation with other support elements and thus enables the required load to be absorbed. The ring shape of the support element also enables reinforcement elements and concrete to be introduced in the free core area, as a result of which the arrangement is further stabilized. In addition, it is possible, for example at intersections under load-bearing elements, to open concrete in the concrete ring at high pressure.

2

REPLACEMENT BLAπ (RULE 26) press and thus connect the individual support elements and thereby fill the space under the supporting element with concrete, the loose subsurface being displaced.

Alternatively, it is also advantageous to design the individual support elements in that a hole is made below the foundation and this hole is filled with steel mesh and pressed-in concrete. This significantly simplifies the effort in relation to the formation of the concrete ring with the tension and compression strands. Depending on the application, the simpler or more complex method can be used.

If the hole is made using an anchor drill or an earth rocket, it has the advantage that e.g. Devices known from sewer construction can be used. By means of these devices, which produce a stable borehole in the subsurface, which is also pressed outwards, particularly in the case of the earth rocket, the desired bore can be produced in a simple manner.

If the support elements are formed by drilling a hole below the foundation, pressing pipes into them and filling them with steel mesh and pressed concrete, then a stable hole can be created, especially on loose ground, such as gravel or sand. In the case of such substrates, the bore produced would collapse again very quickly under certain circumstances even before stabilization could be achieved by a concrete ring or reinforced concrete. This reduces the risk of further destabilization of the subsurface in this case.

Such a bore with pressed-in pipes is advantageously created by means of pipe pressing or shield driving. Here again, common methods from sewer construction can be used.

It is a further essential advantage if upright bores are drilled between the edge region of a supporting element and the at least one support element. This allows the subsurface to be further stabilized under the supporting element by being encircled by a ring of upright holes. The unstable subsoil is thus supported on the support elements lying parallel to the foundation and the upright holes or reinforcements made of reinforced concrete.

The upright bores are filled with concrete and preferably steel-reinforced concrete, which is made in particular by high-pressure injection. This results in a certain displacement of the unstable subsurface under the foundation and the space is filled with concrete. If the subsurface cannot be displaced, it is compacted to such an extent that it is now stable.

3

REPLACEMENT BLAπ (RULE 26) On the other hand, the area between the at least one support element and the supporting element can be excavated after the upright bores and the support provided therein have been made and with concrete, which is preferably reinforced with steel. fill out. A stable undertaking of the supporting element can also be achieved in this way.

If several support elements are arranged upright one below the other, the upright wall can be formed by coupling them. In this way, for example in tunnel construction, a shaft can be created between two points, which consists of outer walls made of individual support elements. The soil inside the shaft can then be removed. The basement of existing buildings is also conceivable in this way.

By flooding the cavities of the support elements, forces arising from the ground and the load can be balanced. This means that the building can be raised or prevented as required. With changing soil conditions, especially with regard to the groundwater level, the loads on the building can be balanced.

According to a further aspect of the invention, a method is shown with which voids in the floor can be stabilized.

This is achieved in that a binder is introduced into the periphery of the cavity in the course of the cavity production.

This can be particularly the case with loose ground, e.g. in the case of sand or gravel, or if the problem of instability in the drilling occurs when the water pressure is high. A major advantage here is that this stabilization can be achieved directly in connection with the production of the cavity. Thus, a device for injecting the binder can be arranged directly after the drilling device. The effect is used here that the ground is generally compacted immediately behind the rocket end and thus at least briefly maintains its shape. The subsequent introduction of a binder reliably stabilizes the cavity.

Single- or multi-component agents can be used as binders. Examples of this are concrete. Resins, silicates or other suitable mineral substances or plastics.

The outlay for forming stable bores can thus be significantly reduced, in particular in the present invention.

4

REPLACEMENT BLAπ (RULE 26) According to a further aspect of the invention, a method for forming reinforced concrete support elements is shown.

The construction of reinforced concrete support elements is conventionally carried out in such a way that so-called reinforcement baskets are bent out of structural steel elements and with further reinforcement elements. such as structural steel bars and the like, are connected by wires. The reinforcement designed in this way is then introduced into a formwork or an area to be concreted and embedded in concrete.

In the above-described method for undertaking buildings, elongated support elements are arranged essentially parallel to a foundation. For this purpose, a hole is formed below the area to be underpinned, into which a reinforcement is inserted. The hole is then poured with concrete.

Since such a hole is arranged below the foundation of the structure to be underpinned, a start and a target shaft must usually be made to form the hole. However, the dimensions of the start or target shaft are usually kept small, since as little soil as possible is to be moved and the space available is often restricted by adjacent buildings or the like. It follows from this that the length ratio of a prefabricated reinforcement to the available insertion space in the bore turns out to be unfavorable, as a result of which the introduction of the reinforcement into the bore can cause considerable difficulties.

The formation of reinforced concrete support elements can be considerably simplified by individually inserting steel strands into the bore after the production process of the bore and connecting it to further reinforcement elements during the introduction to form a reinforcement.

This ensures that the reinforcement can be gradually formed on site. The individual reinforcement elements can be brought separately to the bore opening, which means that the flexibility of the individual elements can be used. This greatly facilitates working in the work space in the shaft, which is usually limited. The elements of the reinforcement are connected to the steel strands to form a reinforcement cage which is essentially inherently stable in shape just before insertion into the bore. The insertion of such a reinforcement is therefore considerably simplified compared to a conventional prefabricated reinforcement. The production of reinforced concrete support elements can be considerably simplified in this way, particularly in the case of unfavorable local conditions.

5

REPLACEMENT BLAπ (RULE 26) It is a further advantage if a pulling element, in particular a steel cable, is pulled through the hole when the drilling device or the drive of the drilling device is pulled back into the starting area after completion of the hole, by means of which the reinforcement preferably arranged in the starting area subsequently is passed through the bore. As a result, the removal movement of the drilling device or the drive for the drilling device, which is necessary anyway, is connected to the introduction of a tension element, as a result of which the reinforcement can subsequently be introduced into the bore.

In this case, the reinforcement is connected to the tension element and drawn into the hole by this. An essential advantage here is that the reinforcement is guided into the hole. and further that insertion by means of tensile forces is much easier to manage than insertion by means of pressure forces. The risk of the reinforcement snagging with the bore wall and thus a blockage is significantly lower.

It is also advantageous here if the reinforcement at the end connected to the tension element is not yet fully developed and e.g. forms a cone shape that slides relatively easily through the bore.

Due to the fact that the steel cable with the reinforcement attached to it is pulled through the bore by means of a cable winch arranged in the target area, the forces necessary for introducing the reinforcement can be reliably applied. Furthermore, the progress of the introduction can be controlled continuously, whereby a jerky slip or the like, as e.g. can occur when pulling in by hand due to the reinforcement getting caught in the bore wall.

Alternatively, it is also possible for the reinforcement to be drawn into the bore in the starting area during the pulling back of the drilling device or the drive to the drilling device. This means that there is no need to insert a tension element, since the retraction movement of the drilling device is used as a drive for inserting the reinforcement. This further simplifies the arrangement of the reinforcement in the hole.

If the steel strands are connected with a spiral during the pulling into the bore, the reinforcement cage can be designed in its desired shape. The reinforcement itself remains dimensionally stable and is available at the desired points. This makes it possible to form easily predeterminable reinforced concrete support elements, the static properties of which can also be easily predicted.

Are the steel strands rolled up? in this way the rollers can be arranged in the start area and the strands unroll when pulled into the bore. Introducing the

6 REPLACEMENT BLAπ (RULE 26) Steel strands in the hole are simplified considerably. If the length of the steel strands on the roll is also predetermined, the space required in the starting area can be kept low.

The fact that at least one concrete delivery hose is drawn into the bore with the reinforcement means that the final concreting process can be prepared very well. If the concrete delivery hose is also continuously withdrawn during the concreting process, it is possible to achieve an even and controllable concreting of the borehole from one end to the other. The formation of cavities, in particular in the upper edge region between the reinforced concrete support elements and the bore wall, can thus be substantially avoided.

Further aspects of this invention are explained in the following in exemplary embodiments with reference to the figures of the drawing. It shows:

1 shows a front view of a building to be underpinned with the support elements introduced;

Figure 2 is a side view of the structure to be underpinned along the line I-I in Figure 1 with the support elements introduced.

3 shows a schematic plan view of a three-aisled church building with grid-shaped supporting elements;

4 shows a section along the line II-II in FIG. 3, on the basis of which the undertaking of a supporting column is shown;

Fig. 5 is a plan view showing in Fig. 4;

6 shows a side view of a building to be underpinned with a wedge-shaped arrangement of the support elements;

7 shows a side view of a building to be basemented with supporting elements arranged upright one below the other;

8 shows a section through an embodiment of a support element according to the invention;

9 shows a schematic representation of a fabric-like foundation of a surface from support elements according to the invention:

7 SPARE BLAπ (RULE 26) 10 shows a schematic illustration of a system of horizontal and upright arranged support elements;

Fig. 11 is a schematic representation of an upright support member support;

12 shows a schematic illustration of a support element arrangement with different soil layers;

13 shows a detailed view of the insertion opening of the bore when pulling in the reinforcement to form a reinforced concrete support element;

FIG. 14 shows a representation according to FIG. 13, a concrete delivery hose being drawn in in addition to the reinforcement; and

15 shows a cross section through an inventive reinforced concrete support element according to a further embodiment.

16 shows a cross section through a building to be underpinned with different floor layers and their load distribution after the underpinning, together with an anchor for regulating building elevations and a bore for lifting buildings directly.

1 and 2 represent a first embodiment variant for undertaking buildings. Here, a building 1 with a foundation 2 of its front wall is underpinned. To this end, a first shaft 3 and a second shaft 4 are created laterally spaced from the front wall. By means of a device, not shown, with an earth rocket, a bore 9 is produced between the first shaft 3 and the second shaft 4 at a distance below the foundation 2 of the building 1. In this bore 9, a support element 5 in the form of a concrete ring with tension or compression strands 6 is created by a concreting process and by means of a suitable formwork (cf. FIG. 8).

In a further embodiment, the support element 5 can also be designed as a concrete rod with appropriate reinforcement.

The support element 5 thus extends at a distance below the foundation 2. The diameter of the support element 5 is chosen such that the introduction of the bore 9 does not additionally destabilize the substrate underneath the foundation 2. After the first support element 5 has been introduced, further support elements 5 are produced laterally therefrom. The support elements 5 are coupled to one another and form a surface foundation which acts on the foundation 2 like a “raft”.

8 REPLACEMENT BLAπ (RULE 26) The stabilizing effect of this plurality of support elements 5 on the foundation 2 of the front wall of the building 1 may in some circumstances already be sufficient to protect the building structure.

Furthermore, it is also possible to drill upright holes 13 from the edge of the foundation 2 down to the support elements 5 and to press them into concrete. As a result, the subsurface under the foundation 2 can be further stabilized.

If it's necessary. to undertake a building side in order to create an extension with a basement, that is to say with a foundation that is substantially below the foundation of the existing building 1, it is also possible to arrange a sufficient number of supporting elements 5 upright below the foundation 2. In this way, a safe support of the existing building 1 can be achieved and guaranteed before the excavation for the basement of the extension.

An undertaking of the structure 1 in the manner described can be achieved in the case of an existing building on one side and, if necessary, also on all sides or under the intermediate partitions in the building.

Using a further example, the formation of a grid or grid on support elements 5 under a building 1 is described below.

3 shows a schematic illustration of a three-aisle church 10 in a plan view. The statics of the church 10 are essentially based on load-bearing elements or columns 11.

In order to be able to undertake the church 10 as a whole, it makes sense to transfer the grid formed by the column arrangement to the support elements 5. This process is shown as an example on a column 11.

For this purpose, four shafts 12A-12D are excavated to the side of the church 10. A plurality of support elements 5 in the transverse direction to the nave and a plurality of support elements 5 in the longitudinal direction of the nave are now produced from these shafts 12A-12D. The support elements 5 are spaced below the column 11 as shown in FIG. 4. A series of upright bores 13 are then made in the church floor in an arrangement according to FIG. 5. The upright bores 13 extend from the edge of the column 11 down to the support elements 5. The upright bores 13 are partly vertical and partly also obliquely downward. The upright bores 13 are then filled in by high-pressure injection of concrete, with the existing subsurface partially or completely

9 REPLACEMENT BLAπ (RULE 26) is ousted. A concrete foundation is formed above the support elements 5, which generally spreads out and is present in accordance with the dashed line in FIG. 5.

The upright bores 13 can alternatively be filled in from below by pressing concrete into the horizontal bores 9 for the support elements 5. This creates a good connection between the horizontal and upright holes.

The column 11 is thus underpinned by a concrete foundation and is securely supported. A corresponding procedure is also carried out on the other columns 11 of the church 10, and, if necessary, on the foundations of the outer walls.

In the case of particularly loose subsoil, such as sand, it is possible, as shown in FIG. 6, to construct the plurality of supporting elements 5 in a wedge shape with the tip pointing downward below the foundation of a building. By adding further groups of support elements arranged in a wedge shape, secure support of the structure is also possible in such a case, since the support element groups wedge against one another. This arrangement of the support elements 5 can be transferred to other applications for undertaking buildings as desired. Furthermore, further arrangements of the support elements 5 are also possible in any manner and according to the respective requirements.

According to the representation in FIG. 7, it is possible to form a wall in the ground by supporting elements 5 arranged upright one below the other and coupling them, which enable the formation of a basement under an existing structure. For this purpose, the underpinning would have to be designed as a wall of sufficient height on three sides of the building, and on the fourth side a sufficient underpinning would have to be created in the sense of a static beam. If the floor slab of the existing structure can absorb the static forces through the internal supporting walls or is provided with an underpinning in the sense of a beam, the soil can be discharged from the fourth side of the building. The support elements can be arranged in one row or in multiple rows, so that a kind of horizontal bar wall or bored pile wall is created.

Of course, a basement can also be formed in other ways with the help of the support elements 5, it only being necessary to ensure that the existing building is sufficiently supported on the ground.

FIG. 8 shows how a support element 5 is constructed in accordance with a first embodiment. This has a concrete ring. which is provided with tension or compression strands 6. These tensile or compressive strands 6 absorb the tensile or compressive loads that occur. The concrete ring

10 SPARE BLAπ (RULE 26) is created by filling the free space between an outer and inner steel pipe 7 and 8 and, if necessary, finally provided with reinforcement and poured with concrete.

Instead of forming this concrete ring with the pulling or pushing strands 6 in the bore 9 below the foundation 2 of the structure 1, prefabricated pipes can also be pressed in and filled with steel mesh or suitably arranged pulling or pushing strands and pressed-in concrete become.

Furthermore, it is also possible to fill the entire bore 9 with a steel mesh and pressed-in concrete and thus to form a rod-like support element.

Depending on the level of the loads and the nature of the subsoil, the simpler or more complex method can be used. The bore 9 itself can be created by means of an anchor drill or an earth rocket, and if pipes are to be pressed in in the process, this can be achieved by means of pipe pressing or a shield drive.

Pressing in prefabricated pipes is particularly recommended for very loose ground, such as sand or gravel, because it is very difficult to create a dimensionally stable hole here.

Furthermore, in the case of loose ground or high water pressure in the ground, it is expedient to introduce a binding agent into the surrounding wall of the bore 9 during the advance of the earth rocket in order to strengthen the bore. This binder injection can take place in a star-shaped manner of propagation directly behind the boring machine of the drilling device. Concrete can be used as a binder. Resins and others be used. The effort to form the bore 9 is significantly reduced.

This method for stabilizing a hole or a cavity in the floor can also be used for other applications. e.g. in tunnel construction.

In hard, e.g. rocky ground, the hole 9 can also be created by a milling process.

Furthermore, it is possible to arrange the support elements 5 crosswise one below the other in several horizontal planes. Each level here has a plurality of supporting elements 5 lying next to one another. If the planes that are aligned in the same direction are offset from one another, the effect of the foundation of the surface increases.

11 REPLACEMENT BLAπ (RULE 26) Since the technology enables the drilling devices to be steered, it is possible, in particular in the case of larger areas to be underpinned, to arrange a plurality of support elements 5 in a fabric-like manner as shown in FIG. 9. The surface foundation thus formed is thus stabilized in a form-fitting manner and can better absorb the loads.

The described, upright arrangement of the support elements 5 can also be used in tunnel construction.

The air in the cavity in a support element according to Fig. 8 can e.g. can also be used on a damp surface in such a way that buoyancy is generated. The hollow support element 5 therefore has a tendency to "float" on the water table, which may even raise buildings. To achieve this, additional buoyancy bodies, e.g. be arranged in the area of the side shafts. A "floating foundation" is created that stabilizes the building.

With e.g. Seasonal fluctuations in the groundwater level or, if the support element 5 should become too buoyant, constant underfilling behavior can be achieved by controlled flooding of the cavity in the support element 5. The building is therefore not exposed to alternating loads due to fluctuations in the nature of the subsurface.

According to the representation in FIG. 10, it is possible to form a system of support elements 5 in the sense of a "floating bearing" below a building to be underpinned, in order to achieve secure support of the building 1.

As shown in the figure, a building 1 stands on an unstable surface 20. Peat. Clay, sand or the like, with a stable base layer 21. e.g. Rock, present below. The building 1 is only indicated here by three supports 22, 23 and 24, which stand for the foundations of the building.

To support the building, a first pressure element 25 is first arranged horizontally in the area of the supports 22, 23 and 24. A first tension element 26 is guided below the supports 22, 23 and 24 and anchored on one side in the stable rock layer 21. The other side of the first tension element 26 is supported on the stable rock layer 21 by an upright support element in the form of a pillar 27.

The tension and compression elements can be formed with a single steel strand, or also with an arrangement of several steel strands or a reinforcement, which is embedded in concrete.

12 SPARE BLAπ (RULE 26) Further tension elements 28 and 29 are passed under supports 22, 23 and 24. 10, a pulling element 28 can reach under a single support 22 or, as indicated by the pulling element 29, a plurality of supports 23 and 24. In the latter case, the control element can be controlled between the supports by controlling the drilling device Earth's surface.

The further tension elements 28 and 29 are supported by means of further pressure elements 30-34 on the stable base layer 21 or on the first tension element 26. The tension elements 26, 28 and 29 are tensioned and the supports 22, 23 and 24 of the building 1 are supported.

The upright pressure elements 31-34 are e.g. placed directly on the first tension element 26 or on a plurality of first tension elements 26 in order to obtain a stable base.

FIG. 11 shows how the horizontal and upright support elements can be coupled to one another in order to avoid displacement or folding. Here, e.g. two essentially horizontally arranged support elements from two directions, an upright support element in one area. This wrap-around can take place again at a point spaced from the first wrap-around, so that the freedom of movement of the upright support element is limited. The upright support element is thus firmly gripped and clamped between the horizontal support elements.

Fig. 12 shows how the support elements 5 according to the invention with different floor layers to stabilize the subsurface e.g. can be used under a floor plate 37 made of concrete. Here, a bore 9 is created by a controlled drilling device which passes through the relevant soil layers alternately. Especially when mixing e.g. a layer of gravel 38 and a layer of clay 39 by washing can be stabilized in this way.

The procedure for forming a reinforced concrete support element is explained in more detail below.

First, a bore 9 is created, for example, by means of an earth rocket. The earth rocket (not shown in the figures) is introduced into the starting area 3 and moved towards the target area 4 by means of a drive such that a stable bore 9 is formed by displacing the soil. In target area 4, the head of the earth rocket is removed and the drive device is finally pulled back into start area 3.

13 REPLACEMENT BLAπ (RULE 26) Before retracting the drive device of the earth rocket, however, a steel cable 16 is attached to it, which in turn pulls it through the bore 9. The steel cable 16 is unwound in the target area 4 by a cable winch, not shown. After the steel cable 16 has reached the start area 3, the drive device of the drapes is removed from the start area 3.

In the starting area 3, several strand rolls are arranged, of which only one strand roll 18 is shown in FIGS. 13 and 14. Steel strands are wound up on these strand rolls, of which only four strands 6 are shown in FIGS. 13 and 14. These steel strands 6 are fastened to the steel cable 16 like the other steel strands (not shown). A spiral 14 made of structural steel is arranged around the steel strands 6 and connected in a known manner to the steel strands at predetermined intervals, so that these result in the desired shape of the structural steel basket. In this case, the ends of the steel strands 6 are left free, as a result of which they are arranged conically when attached to the steel cable 16. The risk of the reinforcement getting caught when drawn into the bore 9 is therefore substantially reduced.

Here, the spiral 14 is fastened in the initial area of the steel strands 6. During the pulling-in of the reinforcement 15 thus formed into the bore 9, the spiral 14 is then continuously fastened to the steel strands 6, which are now freely again in front of the opening of the bore 9.

In this way, the reinforcement 15 is gradually formed immediately on site and gradually drawn into the bore 9.

As soon as the reinforcement 15 has reached the end of the bore 9 in the target area 4. the ends of the steel strands 6 are separated from the steel cable 16. These ends of the steel strands 6 are then formed with the spiral 14 to the desired shape of the reinforcement 15. Thus, the reinforcement 15 is in the desired shape over the entire length of the bore 9.

According to the illustration in FIG. 14, a concrete delivery hose 17 is also drawn into the bore 9 with the steel strands 6 and is now present at the end of the bore 9 in the area of the target area 4. If necessary, the opening of the hole 9 at the target area 4 can now be closed by a formwork and then the hole 9 is concreted in concrete. For this purpose, concrete is introduced into the hole 9 through the concrete delivery hose 17. The concrete conveyor hose 17 is continuously withdrawn in a coordinated manner with the amount of concrete conveyed in the direction of the starting area 3. A complete filling of the bore 9 in each area below the foundation 2 of the building 1 is thus achieved.

14 SPARE BLAπ (RULE 26) If necessary, a repressing hose can also be inserted into the bore 9 in order to enable a concrete pressure which ensures that the bore 9 is completely filled.

The concreting process continues until essentially the entire area up to the starting area 3 is filled with concrete.

After hardening, there is now a reinforced concrete support element. which is suitable as an underpinning for a building 1 with ailing structure. The reinforced concrete support element 5 is designed as shown in FIG. 15. This shape with ring-shaped steel strands allows e.g. the good absorption of tensile and compressive forces perpendicular to the main direction of the reinforced concrete support element 5.

In this way, not only can the supporting walls of buildings be supported, but also, for example, weakly reinforced floor slabs of industrial buildings etc. can be renovated. With such reinforced concrete support elements, basement walls and basement floor slabs can also be subsequently formed or refurbished under existing buildings, only relatively small starting or target shafts being required.

Since the size of the start and target shafts can be kept small and, furthermore, no further excavations are necessary underneath the structures, large-scale lowering of the same can be dispensed with to a large extent if the groundwater level is high. Only the start or target shaft has to be designed so that it is essentially groundwater-free.

Since the reinforcement for the reinforced concrete support elements is formed directly on site, prefabrication is not necessary. Furthermore, the difficulties due to the low flexibility of such a prefabricated reinforcement when introducing it across corners through a narrow shaft into a horizontal hole in the ground are avoided.

In addition to the points of view shown here, the invention permits further design approaches.

In principle, the method shown can always be used as soon as any reinforced concrete element is to be formed between a start and a destination. This is not only limited to bores, but can e.g. can also be used for open formwork.

15 REPLACEMENT BLAπ (RULE 26) In this way, tubular reinforced concrete support elements can also be formed if further formwork is used for the core.

It is also possible to pull the reinforcement into the bore 9 by the retraction movement of the drive of the drake. In this case, however, the drive device for the earth rocket is bound to this place of work for a certain period of time, namely until the reinforcement is formed, and cannot be used elsewhere.

The number of steel strands used to form the reinforcement can vary as desired, although in some cases a single steel strand could also be sufficient. The type of additional reinforcement elements is not limited to the spiral 14 shown here, but also other elements such as steel baskets e.g. with steel mats or similar can be used. Instead of the spiral 14 in practice, in part. also ring elements used, which are cheaper in some applications. As a rule, however, the high bending stiffness and the high load resistance as when using the spiral are not achieved. The spiral 14 can also be arranged on the steel strands both outside and inside.

It is also possible not only to insert a concrete delivery hose into the borehole, but as many concrete delivery hoses as required depending on the diameter of the borehole or the available space.

The application of the method according to the invention is furthermore not limited to horizontally formed reinforced concrete elements, but can also be used, for example, to form vertical support columns in old walls or to stabilize the soil or gesture information.

The steel strands wound on the strand rolls can be of any length or can be set to the desired length in advance. It is of course also possible to dispense with the label rolls and to feed the strands individually from the upper edge of the shaft.

The steel strands 6 are joined to the reinforcement 15 in a known manner with the further reinforcement elements. This can be done by connecting by means of wires, the so-called structural steel braiding, or e.g. also by welding the reinforcement elements together.

The static calculation of the underpinning according to the invention can be carried out using a combination of the known static calculation methods for the bored pile wall or the foundation of the surface. The arrangement of the support elements, e.g. 7, can be treated in the sense of a lying bored pile wall, which results in a calculation with low

16 REPLACEMENT BLAπ (RULE 26) Modifications are possible. The results can be usefully applied to the invention in connection with results from a calculation method similar to the foundation of the surface. The undertaking of buildings can therefore be carried out on the basis of a reliable static calculation.

The invention thus shows a method for undertaking buildings. whereby at least one elongate support element 5 is arranged below the structure 1 to be underpinned, essentially parallel to the foundation 2 of the structure 1. An underpinning of an entire side wall of the building 1 can thus be achieved in one go without unnecessarily weakening the existing subsurface. By coupling a plurality of the elongated support elements 5 to one another, a type of surface foundation and also a secure foundation of the building 1 can be created. This means that the structure of very old buildings can be preserved in a gentle manner. In addition, the method can be carried out very quickly and with relatively little effort. The earthquake safety of buildings can also be increased in this way. A weakening of shock waves can be achieved by means of water-filled cavities in the solid subsurface.

It also shows how a reinforced concrete support element can be formed in a simple manner. Here, the structural steel reinforcement elements are joined together on site and then gradually inserted into the area to be concreted. The greater flexibility of the individual reinforcement elements compared to the rigid arrangement of the finished reinforcement is used in order to ensure, in particular where space is limited, that the reinforcement can be inserted in a defined manner into the area to be concreted. This makes it possible to form precisely predictable reinforced concrete elements which fulfill the desired properties.

According to the illustration in FIG. 16, it is possible to pierce the edge of the spreading zone of the foundation discharge without any danger to buildings. It is an advantage. if this is carried out close to the settlement-sensitive layer, so that the surrounding area of the floor is also stiffened when the hole is subsequently pressed with binding agent. The load spreading angle flattens out and the building is more stable. When the holes are pressed. which could be stiffened with perforated PE pipes, is operated at different pressures (currently up to 200 bar are offered). For example, in FIG. 13, hole no. 2 is drawn as an underpinning hole centrally under the foundation. With the appropriate pressure during pressing, this foundation can even be raised. So that this can be done in a controlled manner, vertical anchors are inserted, which then allow the appropriate lifting by loosening.

17 SPARE BLAπ (RULE 26)

Claims

Expectations

1. A method for undertaking structures (1), characterized in that at least one elongated support element (5) is arranged substantially parallel to a foundation (2) below the structure to be underpinned (1).

2. The method according to claim 1, characterized in that a plurality of elongate support elements (5) below the foundation (2) are arranged and at least partially coupled with each other.

3. The method according to claim 2, characterized in that the support elements (5) are arranged in the form of egg nes grid or grid.

4. The method according to claim 3, characterized in that the crossing points of the grid on support elements (5) below the supporting elements or columns (11) are arranged.

5. The method according to any one of claims 1 to 4, characterized in that under the structure to be underpinned (1) a system of substantially horizontal and upright arranged support elements (5) is formed, which are coupled together.

6. The method according to any one of claims 1 to 5, characterized in that the individual support elements (5) are formed in that a bore (9) is introduced below the foundation (2) and in this bore (9) a concrete ring or - rod is generated, the tension and compression strands (6).

7. The method according to any one of claims 1 to 5, characterized in that the individual support elements (5) are formed in that a hole (9) is introduced below the foundation (2) and this hole (9) filled with steel mesh and pressed concrete becomes.

8. The method according to claim 6 or 7, characterized in that the bore (9) is created by means of an anchor drill or an earth rocket.

9. The method according to any one of claims 1 to 5, characterized in that the individual support elements (5) are formed in that a bore (9) is introduced below the foundation (2), pipes are pressed therein and these are pressed out with steel mesh and pressed-in concrete ¬ be filled.

18 REPLACEMENT BLAπ (RULE 26)

10. The method according to claim 9, characterized in that the bore (9) is created by means of a pipe pressure or a shield jacking.

11. The method according to any one of claims 1 to 10, characterized in that between the edge region of a supporting element (11) and the at least one support element (5) upright bores (13) are inserted with supports arranged therein.

12. The method according to claim 11, characterized in that in the supports in the upright bores (13) made of concrete, preferably steel-reinforced concrete, which is introduced in particular by high pressure injection.

13. The method according to Anspmch 11, characterized in that the area between the at least one supporting element (5) and the supporting element (2) is excavated and with concrete, which is preferably steel-reinforced. is filled out.

14. The method according to any one of claims 1 to 13, characterized in that a plurality of support elements (5) are arranged upright one below the other.

15. The method according to any one of claims 1 to 14, characterized in that the cavities of the support elements (5) are flooded.

16. A method for stabilizing cavities in the soil, characterized in that a binder is introduced into the periphery of a cavity and the introduction of binder is carried out in the course of the cavity production.

17. A method for forming reinforced concrete support elements (5), which are used in particular for undertaking buildings (1) according to one of claims 1 to 16, in which a bore (9) is formed below the element to be supported by means of a drilling device by the drilling device is moved from a starting area (3) to a target area (4), and in which a reinforced concrete support element (5) is subsequently formed in the hole (9), characterized in that after the hole (9) has been made, steel strands (6) are introduced into the bore (9), which are connected to further reinforcement elements (14) during the introduction to form a reinforcement (15).

19

REPLACEMENT BLAπ (RULE 26)

18. The method according to Anspmch 17, characterized in that when pulling back the drilling device or the drive of the drilling device into the starting area (3) after completion of the bore (9), a tension element, in particular a steel cable (16), through the bore ( 9) is pulled through, by means of which the reinforcement (15), which is preferably arranged in the starting area (3), is then passed through the bore (9).

19. The method according to Anspmch 18, characterized in that the steel cable (16) with the reinforcement (15) attached thereto is pulled through the bore (9) by means of a cable winch preferably arranged in the target area (4).

20. The method according to Anspmch 17, characterized in that the reinforcement (15) is pulled into the bore (9) during the retraction of the drilling device or the drive of the drilling device in the start region (3).

21. The method according to any one of claims 17 to 20, characterized in that the steel bits (6) are connected with a spiral to form the reinforcement (15) during the drawing into the bore (9).

22. The method according to any one of claims 17 to 21, characterized in that the steel lits (6) are rolled up, preferably in a predetermined length, and are rolled off when drawn into the bore (9).

23. The method according to any one of claims 17 to 22, characterized in that with the reinforcement (15) at least one concrete delivery hose (17) is drawn into the bore (9) and this is continuously withdrawn during concreting.

24. The method according to Anspmch 1, characterized in that elongate support elements (Figure 7) are arranged below the foundation and the building is lifted during the pressing with binder, and the building differences are eliminated using anchors in a controlled manner.

20th

REPLACEMENT BLAπ (RULE 26)