WO1996014475A1 - Process and device for laying deep foundations - Google Patents

Abstract

A process and device are disclosed for laying deep foundations, such as pile foundations, subterraneous curtains or foundations with prefabricated parts. The device has a motor-driven cutter with at least one cutting head and means for evacuating the excavated earth from the cavity and for supporting the walls of the cavity. The object of the invention is to develop a process and device for laying deep foundations in as short a time as possible using a simple technology. For that purpose, the device has a separating element (2, 27) and other elements designed or arranged on the device and/or separating element (2, 27) that allow the device to be used both for excavating the cavity and for subsequently filling the concrete body remaining in the ground. The device allows the excavated sludge to be used as cavity supporting medium.

Description

 Device and method for producing deep foundations

The invention relates to an apparatus and a method for producing deep foundations, such as pile foundations, diaphragm walls or foundations, using prefabricated parts. The device consists of a driven milling device with at least one milling head and means for removing the milled earth from the cavity and for supporting the cavity walls.

Methods for the production of deep foundations are already known, in which a cavity is introduced into the ground under the protection of supporting liquid, if necessary a reinforcement cage is inserted into the cavity and concreted using the contractor method. It is also known to use this method to insert prefabricated reinforced concrete parts into the cavity supported with self-hardening suspension.

These methods are not only time-consuming, the use of support fluid also requires a very special care, since in particular the following requirements have to be met:

The supporting liquid must have such a density that the stability of the cavity walls is guaranteed. The stability of the support fluid must be ensured over a certain period of time so that there is no reduction in density within the necessary downtimes in the construction process.

The support liquid must have a consistency such that it is completely is pushing.

A method for the production of cased drilling piles is also known, a drilling pipe being introduced into the ground and the soil being simultaneously cleared out of the borehole. After concreting, the drill pipe is pulled out of the ground. The steel tube can also remain in the ground if it is to be used, for example, for the establishment of a foundation in the river area.

Because of the number of different work steps, some of which are carried out with different devices, a great amount of time must also be accepted with these methods. There is also the danger that fine parts will be extracted from the surrounding earth below the water level, which can have a negative effect on neighboring buildings.

The invention is therefore based on the object of developing a device and an associated method for producing deep foundations, with which or with which any possible implementation of deep foundations can be produced in a technologically simple manner and with a minimal expenditure of time, and mixing is largely prevented by soil and concrete. In particular, the cavity walls should be supported inexpensively and yet with the greatest possible security.

According to the invention, the object is achieved in that a separating element is arranged on the device and that further devices are designed or arranged on the separating element and / or the device in such a way that the device both for milling out the cavity and for subsequently filling the cavity concrete bodies remaining in the ground can be used and that milled soil mixed with water is used as a means for supporting the cavity. 3

The device according to the invention uses already existing support liquid, namely earth sludge, to support the cavity walls, so that an additional introduction of other support liquids is not necessary. Furthermore, the device not only serves to mill out the cavity, but with the same device it is also possible to support the cavity walls during the milling process and during the subsequent concreting process. Likewise, the same device can be used to fill the cavity with concrete while ensuring the required quality.

According to a preferred embodiment of the device according to the invention, the separating element is arranged directly above the milling head or milling heads of the milling device and has a cross section such that it projects beyond the overall cross section of the milling head or milling heads. The separating element is box-shaped or cylindrical and has at least one lower separating disc, in which openings equipped with controlled locking elements are arranged, which serve both for the supply and the removal of material into or from the space below the separating element . In addition, further devices are arranged on the milling device and / or the separating element, which serve to transport the materials to be supplied or removed.

The arrangement and design of the separating element ensures that the cavity walls are properly supported first and at the same time earth sludge and concrete are separated from one another without mixing.

In order to implement the individual possible method steps, the invention provides that the separating element has a concrete opening to which a concrete pump is connected, a water opening which is connected to a water pump, a sludge opening for discharging the soil sludge from the milling area into the area above the separating element and additionally has a flushing opening for flushing out the residual sludge after the end depth of the device has been reached. Since all openings can be opened or closed alternately or simultaneously via control devices, different method steps can be implemented during the manufacture of the deep foundation by means of this arrangement. The following states can be set:

Condition 1:

The concrete opening and rinsing opening are blocked, water opening and sludge opening are released. Condition 2:

Water opening, sludge opening and flushing opening are blocked, only the concrete opening is released.

Condition 3:

The water opening and rinsing opening are blocked, the concrete opening and sludge opening are released.

Condition 4:

Concrete opening and sludge opening are blocked, water opening and rinsing opening are released.

State 5: water opening and sludge opening are blocked, concrete opening and rinsing opening are released.

With the setting of the respective state, the entire process sequence according to the invention can be implemented.

According to another advantageous embodiment, the device can be secured against vertical displacement by means of securing elements that are laterally clamped between the cavity walls.

In this way, both the final depth of the foundation can be fixed and, if necessary, a vertical displacement of the device from the cavity can be interrupted or prevented during the concreting phase.

In particular, during the return phase of the device, it is advantageous if, in order to discharge the excess sludge from the area above the separating element, an additional 5 orderly facility is provided.

According to the invention it is also provided that the side walls of the separating element have such a shape and are designed such that the cross section of the cavity corresponds to the outer circumference of the separating element.

According to an advantageous embodiment of the separating element, its side walls protrude beyond the lower separating disc and are formed with sharp bevels inward in this area below the separating disc. This ensures that the earth within the separating element cross section, which is not reached by the milling heads due to its smaller overall cross section, is sheared off and that the cavity has almost exactly the cross section of the separating element. This prevents concrete and earth sludge from mixing, particularly during the return phase.

The task according to the invention is achieved on the process side by first milling the earth and mixing it with water that is pumped through the released water opening into the area below the separating element, that the device is continuously sunk into the ground and at the same time that the formed Sludge is displaced through the released sludge opening into the space above the separating element and fills the cavity, that after reaching the final depth the sludge and water opening are blocked and concrete is pumped through the simultaneously opened concrete opening into the space below the separating element. that the pumped-in concrete moves the device continuously upwards and completely fills the cavity below the separating element.

The process sequence according to the invention mainly consists of two phases:

In the first phase, state 1 is set using the milling device loosened soil and water (and possibly scavenging air) that is led through the water opening into the space below the separating element. The device is continuously lowered into the ground by the device's own weight or by shaking. The sludge forming below the separating element is displaced through the released sludge opening through this into the space above the separating element. As already described, this displaced sludge is used to support the earth walls of the cavity.

Once the desired final depth has been reached, the second phase can be initiated. In this second phase, the device is changed from state 1 to state 2, so that concrete is now pressed through the released concrete opening into the space below the separating element. As a result of the concrete pressure, the device is pushed up out of the cavity and the cavity is filled with concrete.

An advantageous further development of the method according to the invention provides that an additional pressing of the concrete, in particular in the area of the foot of the concrete body, takes place during the concreting and return phase of the device in that securing elements secure the device laterally against vertical displacement.

In the concreting phase (that is, in the second phase), an even higher concrete pressure is achieved in that the device is clamped in the cavity with the aid of securing elements consisting of pressure plates which are pressed against the lateral cavity walls by working cylinders. By means of hydraulic pressing of the concrete in the pipe, concrete can then be pressed into the space below the separating element at a higher pressure. In this way, the base of the concrete body can be pressed into the ground during the deep founding phase.

At the beginning of the concreting process, that is, at the beginning of the 2nd phase, a mixture of concrete and the sludge still located below the separating element is formed as a result of the change from state 1 to state 2. This lack of concrete quality at the beginning of the concreting process is remedied by the tight compression of the base of the concrete body. It is also possible to provide the separating element with further openings in order to specifically feed cement liquid into the space below the separating element. This can also improve the concrete quality which is reduced by contamination.

According to the method, it is further provided that immediately before the concrete is introduced into the space below the separating element, residual sludge is removed by placing concrete through the open concrete opening into the space below the separating element when the water and flushing opening is blocked and the sludge opening is briefly released is pumped, which at least partially displaces the sludge through the released sludge opening due to its higher density.

This process step, which can be carried out independently of other process steps depending on requirements and local conditions, also serves to increase the quality of the concrete. For this purpose, the device is set from state 1 to state 3, that is, concrete is passed through the concrete opening into the space below the separating element, which due to its higher density at least partially displaces the sludge through the sludge opening. If the space below the separating element is completely filled with concrete, the device is switched from state 3 to state 2. As described, the foot pressing can take place with simultaneous concreting, or the actual concreting process is initiated.

According to the invention, it is also provided according to the invention that residual sludge can be removed from the space below the separating element immediately before the concreting process in the end position of the device by blocking the concrete opening and the sludge opening so that water can water supply continuously and for as long, sludge is stirred with the aid of the milling device and this is removed through the flushing opening until only sludge-free water is present below the separating element.

This second independent process step can be carried out after the first phase by changing the device from state 1 to state 4, that is to say water is now supplied through the water opening, the sludge below the separating element, and through the milling device which is still working is formed, is pumped out through the rinsing opening until only mud-free water is present in the cavity below the separating element. The device is then switched from state 4 to state 5, that is to say concrete is supplied through the concrete opening until the water has been completely displaced or pumped out of the cavity below the separating element through the cleared flushing opening. The device can then be changed from state 5 to state 2 and, as described, the foot pressing or simultaneous concreting can take place.

Since the lowering of the device (possibly by means of electronic control), the removal or eventual rinsing of the sludge before concreting, the pressing of the foot and the concreting process per se advance very quickly, the time, material and Workload considerably. The small amount of sludge - if any - that comes into contact with concrete can be easily controlled and compensated for.

The foot pressing, with which a low-settlement foundation and a higher load-bearing capacity is achieved, does not have to be carried out subsequently, as is the case with conventional methods. Since the sludge has a higher density in comparison with a normally used supporting liquid and can therefore exert a greater pressure, the stability of the earth walls of the cavity is not jeopardized at any time during the manufacture of the deep foundation. This increases 9 the reliability in the manufacture of deep foundations.

It is advantageous according to the invention if the device is secured against vertical displacement during and to support the rinsing phase. This prevents inadvertent deep milling.

According to a further advantageous embodiment of the method according to the invention, it is provided that prefabricated reinforced concrete parts can be introduced into the milled cavity, the lower part of which is filled with concrete and the upper end of which is filled with earth sludge, that the reinforced concrete parts have a different transverse than the milled cavity Have cut, so that openings are formed when sinking the reinforced concrete parts into the cavity, through which both sludge and concrete is displaced and that the openings can then be filled with concrete if necessary.

The method according to the invention also proves to be advantageous when prefabricated reinforced concrete parts are used for the production of deep foundations, since the production of the deep foundation can be carried out without additional effort, such as, for example, remaining steel pipes in the subsurface. The cavity is not completely, but only partially filled with concrete. The upper part of the cavity remains supported with mud. Precast reinforced concrete parts, the cross section of which has a different shape than the cross section of the cavity, are sunk into this cavity. During the lowering process, the sludge is first displaced through the openings formed by different shapes, and concrete is pressed into the openings. If necessary, the openings can then be completely filled with concrete.

A preferred embodiment, which affects the device and the method equally, provides that other hardenable building materials can be used instead of concrete. This is to emphasize that the invention can also be used when using other building materials. The invention will be explained in more detail below on the basis of exemplary embodiments. The accompanying drawing shows in

1 shows a basic sectional view of the device according to the invention for producing a pile foundation,

2 shows the device according to FIG. 1 according to section B / B,

3 shows the device according to FIG. 1 according to section C / C,

4 shows the device according to section D / D according to FIG. 2,

5 is a schematic diagram illustrating the lowering process of the device into the ground,

6 shows a schematic diagram to illustrate the device with the state 4 set,

7 is a schematic diagram showing the device with the set state 2, including pressing the foot of the concrete body,

8 is a schematic diagram showing the actual concreting process,

9 shows a further embodiment of the device according to the invention for producing a diaphragm wall in a sectional view,

10 shows a horizontal section according to FIG. 9,

11 shows a schematic diagram to illustrate a finished diaphragm wall,

12 shows a basic illustration to illustrate the opening between the reinforced concrete part and the borehole, 13 shows a cross section through a deep foundation after inserting a reinforced concrete part,

Fig. 14 is a sectional view illustrating the deep foundation before inserting a reinforced concrete part and

Fig. 15 the deep foundation with inserted reinforced concrete part as a sectional view.

A device according to the invention, which is provided for the manufacture of pile foundations, is shown in more detail in FIGS. It consists of a frame 1, which is made of hollow steel profile, in which all the necessary supply and discharge pipes are arranged and at the lower end of which a separating element 2 and a milling device 3 with milling heads 4 arranged therein are fastened. The separating element 2 has a circular cross section and consists of a cylindrical part 5 and the actual tennis disc 6, which is inserted into the lower end of the cylindrical part 5. The side walls of the cylindrical part 5 protrude beyond the cutting disc 6 and are sharply bevelled in this part. The separating element 2 thus additionally assumes the function of detaching earth when the device penetrates the ground. The milling device 3 is driven by means of a hydraulic motor 7.

The cutting disc 6 of the separating element 2 is equipped with four openings, a concrete opening 8, a water opening 9, a mud opening 10 and a rinsing opening 11. The concrete opening 8 is connected via a concrete pipe 12 to a concrete pump (not shown in the drawing) and the water opening 9 is connected via a water pipe 13 to a water pump, which is also not shown in the drawing. Concrete 14 is pumped through the concrete opening 8 into the space below the separating element 2. The water opening 9 is required when sludge 15 is formed or when the sludge is to be rinsed out of the cavity below the separating element 2. The sludge opening 10 serves to remove the sludge 15 from the To convey space below the separating element 2 in the cavity above, in order to support the cavity walls there. The flushing opening 11 has the task, if necessary, of flushing the sludge 15 located below the separating element 2 out of the cavity immediately before the concreting process. The operation of the rinsing opening 11 is particularly clear from Figure 4.

The concrete opening 8 has a locking element, which consists of a piston 16, which is arranged in a tube 17 and is controlled by a hydraulic cylinder 18. The remaining openings 9, 10, 11 are also equipped with locking elements, each consisting of a rotary valve 19, which are controlled by a hydraulic motor, not shown in the drawing.

The guide elements for holding and securing against vertical displacement of the device in the cavity consists of pressure plates 20, each of which cooperate with a working cylinder 21 and a pressure rod 22 and hold the device in its vertical position as required. The securing elements are attached to the frame 1 of the device.

Different production phases of a pile foundation are shown in FIGS. 5 to 8. FIG. 5 illustrates state 1, that is to say the production of the cavity or the sinking of the device in the floor. The entire process proceeds as described above. The excess sludge 15 which is not required in the cavity above the separating element 2 is pumped out by means of an additionally arranged device 23.

According to FIG. 6, the desired final depth has been reached; the device is set to state 4. The sludge 15 is rinsed in the cavity below the separating element 2 in that water is continuously supplied through the water opening 9, the sludge 15 is stirred by means of the milling head 4 and is removed through the rinsing tube 25 with the aid of the rinsing pump 24 until there is only sludge-free water 26 below the separating element 2. The device is then set to state 5 and the sludge-free water 26 is displaced by adding concrete 14.

Figure 7 illustrates a pile-foot pressing. The device is in state 2 and is secured in the cavity against vertical displacement. With the piston 16, the concrete 14 located in the pipe 17 is pressed together and pressed into the space, which is largely filled with concrete 14, below the separating element 2. The entire concrete mass 14, which is located in the foot region of the pile foundation, is thus compacted.

FIG. 8 shows the second phase of the production of the deep foundation, that is, the actual concreting process. After concreting has been carried out, if necessary, a reinforcement cage, which is not shown in the drawing, can be shaken into the not yet hardened concrete 14.

Figures 9 to 11 show a further embodiment of a device according to the invention, which is provided for the production of a diaphragm wall. The essential parts of the device have the same structure as the device for producing a pile foundation. There are differences in the design of the separating element 27 and the milling device 3. The separating element 27 then consists of a box-shaped part 28, into which, as stated in the first exemplary embodiment, the separating disc 29 is inserted. The box-shaped design of the separating element 27 determines the size and shape of the cavity to be introduced. Otherwise, the structure and the mode of operation of the separating element 27 correspond to that of the separating element 2. The shape of the diaphragm wall is shown in FIG.

To achieve a rectangular cavity, the milling device 3 is equipped with a plurality of milling heads 4 arranged in steps, as shown in particular in FIG. For the sake of clarity, FIG. 9 does not show the securing elements against vertical displacement and the flushing opening 11.

The procedure is analogous to that of the first exemplary embodiment and therefore requires no further explanation.

Finally, FIGS. 12 to 14 show a further area of application for the device according to the invention and the associated method. The principle sketches show the creation of a foundation for a bridge pier in the river area. It can be seen from FIGS. 12 and 13 that the cavity to be introduced into the floor has a different cross-sectional shape than the cross-section of the precast reinforced concrete part 30. With the introduction of an essentially square reinforced concrete prefabricated part 30 into the round cavity filled with concrete 14 or sludge 15 it is achieved that there are sufficiently large openings 31 through which the sludge 15 can escape. FIGS. 14 and 15 illustrate the introduction of a precast reinforced concrete part 30 into the prepared cavity. In Figure 15 it is shown that both sludge 15 and concrete 14, in the uncured state, are displaced through the openings 31. In addition, it can be provided that after removal of the residual sludge 15 from the openings 31, these are filled with concrete 14. The further procedure is as described above. The structure and mode of operation of the device corresponds to that of FIGS. 1 to 4.

Reference list

1 frame

2 separating element 3 milling device

4 milling heads

5 cylindrical part

6 cutting disc

7 hydraulic motor 8 concrete opening

9 water opening

10 mud opening

11 rinse opening

12 concrete pipe 13 water pipe

14 concrete

15 mud

16 pistons

17 tube 18 hydraulic cylinder

19 rotary valve

20 pressure plate

21 working cylinders

22 pressure rod 23 device for sludge removal

24 irrigation pump

25 flushing pipe

26 sludge-free water Partition box-shaped part Cutting disc reinforced concrete precast opening

Claims

claims 1. Device for the production of deep foundations, such as pile foundations or diaphragm walls and foundations using prefabricated parts, consisting of a driven milling device with at least one milling head and means for removing the milled earth from the cavity and for supporting the cavity walls, thereby ¬ indicates that a separating element (2 _; 27) is arranged on the device and that further devices are designed or arranged on the separating element (2, 27) and / or the device in such a way that the device both for milling out the cavity and also for the subsequent backfilling of the concrete body (14) remaining in the ground and that the milled earth sludge (15) can be used as a means for supporting the cavity. 2. Device according to claim 1, characterized in that the separating element (2, 27) is arranged directly above the milling head (s) (4) of the milling device (3) and has a cross section such that it has the total cross section of the or the Milling heads (4) protrude from the fact that the separating element (2, 27) is box-shaped or cylindrical and has at least one lower separating disc (6, 29) in which openings (8, 9, 10, 31) equipped with controlled blocking elements are arranged, which both the supply and the discharge of material into or out of the space below the separation element (2, 27) and that on the frame (1) of the device and / or the separating element (2, 27) there are further devices which serve to transport the materials to be fed in or out. 3. Device according to claim 1 to 3, dadurchge ¬ indicates that the separating element (2, 27) has a concrete opening (8) to which a concrete pump is connected, a water opening (9) which is connected to a water pump, a Sludge opening (10) for removing the earth sludge (15) from the milling area into the area above the separating element (2, 27) and additionally a flushing opening (11) for rinsing out the residual sludge (15) after reaching the final depth of the device, having. 4. The device according to claim 1 and one of claims 2 and 3, so that the device can be secured against vertical displacement by means of securing elements (20, 21, 22) braced laterally between the cavity walls. 5. The device according to claim 1 and one of claims 2 to 4, so that an additional device (23) is provided to remove the excess sludge (15) from the area above the separating element (2, 27). 7. The device according to claim 1 and one of claims 2 to 6, characterized in that the side walls of the separating element (2, 27) have such a shape and are designed such that the cross section of the cavity to the outer periphery of the separating element (2, 27) corresponds. Device according to claim 7, characterized in that the side walls of the separating element (2, 27) protrude beyond the lower separating disc (6, 29) and in Area below the cutting disc (6, 29) are formed with sharp edges sloping inwards. 9. A method for producing deep foundations using the device according to claim 1 to 8, characterized in that first milled earth and with water that through the released Wasseröff¬ opening (9) in the area below the separating element (2, 27) is pumped, mixed, that the device is continuously sunk into the ground and at the same time displaces the sludge (15) that forms through the released sludge opening (10) into the space above the separating element (2, 27) and fills the cavity that after reaching the final depth sludge (10) and water opening (9) are blocked and concrete is pumped through the simultaneously opened concrete opening (8) into the space below the separating element (2, 27), that the pumped concrete (14) the device is moved continuously upwards and completely fills the cavity below the separating element (2, 27). 10. The method of claim 9, d a d u r c h g e k e n n - z e i c h n e t that an additional compression of the Concrete (14), in particular in the area of the base of the concrete body, takes place during the concreting and return phase of the device in that lateral securing elements (20, 21, 22) secure the device against vertical displacement. 11. The method according to claim 9, dadurchgekenn ¬ characterized in that immediately before the introduction of the concrete (14) in the space below the separating element (2, 27) residual sludge (15) is eliminated in that when the water (9) and flushing opening is blocked (11) and briefly released sludge opening (10) concrete (14) through the open concrete opening (8) into the space below the 20th Separating element (2, 27) is pumped, which at least partially displaces the sludge (15) through the sludge opening (10) due to its higher density. 12. The method according to claim 9, dadurchge ¬ indicates that immediately before the concreting in the end position of the device residual mud (15) can be removed from the space below the separating element (2, 27) in that the concrete opening (8) and the sludge opening (10) are blocked so that water is continuously and so long supplied through the water opening (9), sludge (15) is stirred with the aid of the milling heads (4) and is removed through the flushing opening (11) until only sludge-free water (26) is present below the separating element (2, 27). 13. The method according to claim 12, d a d u r c h g e k e n n ¬ z e i c h n e t that the device is secured against vertical displacement during and to support the rinsing phase. 14. The method according to claim 9, characterized in that reinforced concrete prefabricated parts (30) can be introduced into the milled cavity, the lower part of which with concrete (14) and the upper end of which is filled with earth mud (15), that the Reinforced concrete parts (30) have a different cross-section than the milled hollow space, so that when the reinforced concrete parts (30) are lowered into the hollow space openings (31) are formed through which sludge and concrete have been displaced and that afterwards, if necessary, a The openings (31) can be filled with concrete (14). 15. The apparatus and method according to claims 1 to 14, d a d u r c h g e k e n n z e i c h n e t that instead Concrete (14) other hardenable building materials can be used.