WO2021139978A1

WO2021139978A1 - Method for creating a foundation element in the ground and foundation element

Info

Publication number: WO2021139978A1
Application number: PCT/EP2020/086375
Authority: WO
Inventors: Ulli Wiedenmann
Original assignee: Bauer Spezialtiefbau Gmbh
Priority date: 2020-01-07
Filing date: 2020-12-16
Publication date: 2021-07-15
Also published as: EP3848512B1; CN114466959A; EP3848512C0; EP3848512A1; US20220298738A1

Abstract

The invention relates to a method for creating a foundation element in the ground, wherein a hole is created in the ground and a curable mass is introduced into the hole, which mass cures to form the foundation element. According to the invention, an insert body is inserted approximately centrally into the hole, which insert body is spaced apart from a peripheral wall of the hole, wherein an annular gap is formed between the peripheral wall of the hole and the insert body, and a curable mass is introduced into the annular gap, which curable mass cures to form an annular foundation element.

Description

PROCEDURE FOR CREATING A FOUNDATION ELEMENT IN THE SOIL

AND FOUNDING ELEMENT

The invention relates to a method for creating a foundation element in the floor, in which a hole is created in the ground and a hardenable mass is introduced into the hole, which hardens to form the foundation element, according to the preamble of claim 1.

The invention also relates to a foundation element according to the preamble of claim 11.

It has been known for a long time to create foundation elements in the ground, in particular to divert larger structural loads into deeper soil layers. A hole is created by removing soil material or by displacing soil material in the soil. The hole produced in this way is filled with a hardenable mass which can harden to form the foundation element. The derivation of structural loads takes place for the most part via skin friction between the outer circumference of the cured foundation element and the surrounding borehole wall and, to a lesser extent, via the horizontal contact surface of the pile at the bottom of the borehole. To increase the load-bearing capacity of such a foundation element, it is known to design it with a corresponding axial length so that a desired skin friction is achieved. It is also known to use a foundation element for geothermal purposes in addition to the actual carrying function. A pipeline system for geothermal purposes can be used in the not yet hardened mass, which is filled into the bottom hole.

The invention is based on the issue of specifying a method and a foundation element with which a purpose of a foundation element can be significantly expanded in a particularly efficient manner.

According to the invention, the object is achieved by a method having the features of claim 1 or by a foundation element having the features of claim 11. Preferred embodiments of the invention are specified in the respective dependent claims.

The method according to the invention is characterized in that an insert body is inserted into the hole approximately in the middle, which is spaced from a peripheral wall of the hole, an annular gap is formed between the peripheral wall of the hole and the insert body, and that in the annular inter mediate space Hardenable mass is introduced, which hardens to an annular foundation element.

A basic idea of the invention can be seen in the fact that a foundation element in the ground is no longer solid over the entire foundation cross-section, but rather as an annular foundation element. This is achieved in that a preferably detachable insert body is provided approximately in the middle, the hardenable mass preferably being introduced exclusively into the annular space between a wall of the hole in the bottom and the outside of the insert body to the foundation element and hardening therein.

It is a finding of the invention that an annular design has no significant influence on a load-bearing function of the foundation element, since, as with a solid foundation element, there is the same skin friction on the outer circumferential side, which is particularly relevant for the load-bearing capacity. Only in the area of the contact area can the ring shape result in a certain reduction in the contact area. By providing a central, non-load-bearing area on the contact surface of the foundation element, so the load-bearing capacity is only slightly reduced, but at the same time the required hardenable mass is significantly reduced. This saves costs

In addition, a space within the ring-shaped foundation element can be used in a variety of ways, for example for geothermal purposes, for measuring purposes or for numerous other functions.

A preferred embodiment of the invention consists in that the insert body is annular. The insert body can essentially only serve to support and form the inner ring contour of the ring-shaped Gründungselemen tes. The insert body can remain in the foundation element or be detached from it. The insert body can consist of a metal, in particular steel, or a less stable plastic material.

If the insert body is intended to be recovered, it is advantageous according to a further development of the invention that the insert body is surrounded on its outside by a casing element and that after the hardening of the mass to form the annular foundation element, the insert body is pulled back from the foundation element, the casing element remains on the annular foundation element ver. The enveloping element can be a thin tube or preferably a film, a fabric or some other non-dimensionally stable flat structure. The wrap element is attached as a lost element on the outside of the insert body. The enveloping element can remain on the hardened foundation element, while the insert body can be easily withdrawn from the enveloping element and used again. This also leads to further material and cost savings.

In order to increase the load-bearing capacity of the ring-shaped foundation element made from the hardenable mass, it is expedient according to a variant of the method of the invention that one or more reinforcing elements can be inserted into the ring-shaped gap before the hardening of the mass. The reinforcing elements can in particular be rods, beams or baskets made of steel.

According to a development of the invention, it is advantageous that the ring-shaped green foundation element is designed to accommodate a desired foundation load, in particular a cross-sectional area of the ring-shaped foundation element can be be designed so that the necessary axial forces can be absorbed and removed via the outer circumferential surface. Furthermore, the foundation element can be designed with a base plate, so that upright forces can also be transmitted directly via this base plate of the foundation element, which is otherwise designed with a cavity.

In principle, the insert body can be designed in one piece. In particular for greater depths and thus for longer foundation elements, it may be useful after a further education that the insert body is built on from annular segments. The annular segments can be axially connected to one another so that a longer insert body is formed. The insert body can have the same diameter or a certain conicity over its length, the diameter widening upwards. This makes it easier to withdraw the insert body from the foundation element.

According to an advantageous embodiment of the invention it is provided that a central cavity is surrounded by the annular foundation element. The central cavity can be used for various purposes, such as for Einset zen a heat exchanger element for geothermal purposes. In this case, heat can be extracted from the ground by means of a heat pump and used for heating purposes, in particular in the structure that is created on the foundation element. Alternatively, heat can also be dissipated into the ground for cooling purposes, so that, for example, air conditioning and cooling can be achieved in the building. The cavity can also be used for metrological purposes and for checking.

According to a further development of the invention, it is particularly advantageous that soil material is removed when the hole is created and conveyed out of the hole as excavation and that at least part of the excavation is returned to the central cavity of the annular foundation element. This is advantageous in two ways: on the one hand, excavated material can be returned to the ground so that the excavated material does not have to be transported from the construction site and deposited. This saves transport and landfill costs. On the other hand, the foundation element is additionally stiffened by the filled central cavity, see above that the strength of the foundation element and thus also its load-bearing capacity are increased.

In principle, the hole for forming the foundation element can be created in any way. According to a variant embodiment of the invention, it is particularly advantageous that the hole is created by drilling with a circular cross section or by milling with an angular cross section. When drilling, both material-removing drilling and displacement drilling can be used. In displacement drilling, the soil material is displaced from the hole area into the surrounding soil by means of a displacement drill.

An angular cross-section can be achieved in particular by a trench wall cutter with which a trench wall segment with a preferably rectangular cross-section is created.

A foundation element in the ground is to be understood broadly within the meaning of the invention, this being used not only to absorb structural loads, but also, for example, to form a sealing wall through adjacent foundation elements.

Another preferred variant of the method of the invention consists in that the floor material is mixed with a concrete mass. So a so-called floor mortar can be created, which can be introduced into the ground as the hardenable mass for forming the ring-shaped foundation element. The ring-shaped green foundation element can also be created from a concrete mass or from a floor mortar with higher strength, while a floor mortar with lower strength is introduced into the central cavity. As a result, a saving in hub can be achieved with a relatively high strength and load-bearing capacity of the foundation element.

The invention further comprises a foundation element, which is characterized in that it is made in the form of a ring from a hardenable mass in the ground. The foundation element is therefore not produced from the hardenable mass over the entire cross section of the foundation element, but only in an annular area. The foundation element is in particular through the previously described method according to the invention produced. The advantages described above can be achieved with the foundation element according to the invention.

According to a development of the invention, it is particularly advantageous that a central cavity is formed in the annular foundation element. This can be used to record various functional components, such as heat exchanger elements or measuring instruments.

According to a further embodiment variant of the invention, it is particularly advantageous that the central cavity in the annular foundation element is filled with a non-hardenable material, in particular removed soil material. This can save transport costs and landfill costs.

The invention will be further described with reference to a preferred embodiment, which is shown schematically in the accompanying drawings. In the drawings show:

Fig. 1 is a cross-sectional view when creating a green formation element according to the invention with inserted insert body; and

Fig. 2 is a cross-sectional view of the foundation element of Fig. 1 after removing the insert body.

To create a foundation element 10 according to the invention in a floor 5, a hole 7 is first made in the floor 5. The hole 7 can be created in a conventional manner, for example by drilling or milling. The drilling can be cased or uncased drilling.

Before a hardenable mass is introduced into the hole 7, an insert body 20 is inserted into a central region of the hole 7. The insert body 20 can already be used during the sinking of the hole 7 or only after the hole 7 has been completed. In the exemplary embodiment shown, the insert body 20 is constructed from a total of three annular segments 22 which are axially connected to one another.

The insert body 20 is inserted approximately centrally into the hole 7 in such a way that a defined distance between an outer side of the insert body 20 and a peripheral wall 8 of the hole 7 is formed. This creates an interspace which is used to form the annular foundation element 10 with a hardenable mass.

In the illustrated embodiment, the insert body 20 is placed on a sole 14 of the hole 7. On its outside, the insert body 20 has a covering body 24, which can be, for example, a film or a fabric. The enveloping body 24 can be a lost element, which essentially serves to prevent un indirect adhesion of the hardenable mass to the insert body 20. The enveloping body 24 can be open or closed at its lower end.

After the hardenable material has hardened to form the annular foundation element 10, the insert body 20 is pulled upward out of the hole 7, so that a central cavity 12 is formed in the annular foundation element 10, as clearly shown in FIG. The enveloping body 24 remains on the inside of the annular foundation element 10 and can, for example, serve for an additional sealing of the central cavity 12 with respect to the annular Gründungsele element 10.

According to one embodiment of the invention, a material of the soil, which arises as an excavation 30 when creating the hole 7, can be brought into the central cavity 12. This reduces the amount of excavation 30 that has to be removed from the construction site and deposited. At the same time, the excavation 30 in the illustrated embodiment serves to stabilize and support the ring-shaped foundation element 10. Its ability to carry construction loads into the ground 5 is largely achieved by the skin friction between the outer side of the foundation element 10 and the peripheral wall 8 of the hole 7 .

Claims

PATENT CLAIMS

1. A method for creating a foundation element (10) in the ground (5), in which a hole (7) is created in the ground (5) and a hardenable mass is introduced into the hole (7), which compound leads to the foundation element (10) hardens, characterized in that an insert body (20) is inserted approximately centrally into the hole (7), which is spaced apart from a peripheral wall (8) of the hole (7), with an annular gap between the peripheral wall (8) of the hole (7) and the insert body (20) is formed, and that the hardenable mass is introduced into the annular gap, which hardens to form an annular foundation element (10).

2. The method according to claim 1, characterized in that the insert body (20) is tubular.

3. The method according to claim 1 or 2, characterized in that the insert body (20) on its outside of a casing element (24) will give and that after the hardening of the mass to the annular Gründungsele element (10) of the insert body (20) is withdrawn from the foundation element (10), the envelope element (24) remaining on the annular foundation element (10).

4. The method according to any one of claims 1 to 3, characterized in that one or more reinforcing elements are inserted into the annular gap before the mass hardens.

5. The method according to any one of claims 1 to 4, characterized in that the annular foundation element (10) is designed to accommodate a desired foundation load.

6. The method according to any one of claims 1 to 5, characterized in that the insert body (20) is constructed from annular segments (22).

7. The method according to any one of claims 1 to 6, characterized in that of the annular foundation element (10) is a central cavity (12) to give.

8. The method according to claim 7, characterized in that when creating the hole (7) soil material is removed and promoted as an off hub (30) from the hole (7), and that at least part of the excavation (30) into the central cavity ( 12) of the ringför shaped foundation element (10) is returned.

9. The method according to any one of claims 1 to 8, characterized in that the hole (7) is created by drilling with a circular cross-section or by milling with an angular cross-section.

10. The method according to any one of claims 1 to 9, characterized in that the soil material is mixed with a concrete mass.

11. Foundation element, in particular produced by a method according to one of claims 1 to 10, characterized in that the foundation element (10) is made in the form of a ring from a hardenable mass in the Bo (5).

12. Foundation element according to claim 11, characterized in that a central cavity (12) in the annular foundation element (10) is formed out.

13. Foundation element according to claim 12, characterized in that the central cavity (12) in the annular foundation element (10) is filled with egg NEM non-hardenable material, in particular removed soil material.