EP3118376B1 - Device for activating the surface friction of post-like carrier members - Google Patents

Description

Field of the Invention

The present invention relates to a device for activating the skin friction of pile-like support members, pile-like support members and structures which comprise such a device, a method for activating the skin friction of pile-like support members and a method for erecting a structure.

Background of the Invention

In the presence of low-load-bearing subsoil layers and high requirements of structures for stability and suitability for use, deep foundations are often used for the removal of building loads. It is usually around pile-like load-bearing elements, which are integrated into the deeper, load-bearing floor layers and initiate the loads on the building with little deformation.

In loose stone soils, the load-bearing elements of the pile-like support elements are transferred to the surrounding ground by the two resistance components of the skin friction and the peak pressure. The sum of the resistance depends on the settlement of the pile-like supporting elements. As a rule, it is assumed that the maximum peak resistance is mobilized with a head setting of s / D = 0.1 (with s = head setting of the support element, D = diameter of the support element). Lower settlements are usually required for maximum skin friction.

If the supporting element is integrated into unyielding soils / solid rock, in contrast to loose rock, very little or no subsidence is required to mobilize the resistance. However, the transfer of load takes place (theoretically) exclusively via the peak pressure / resistance, since the casing friction is not mobilized due to the lack of settlement.

In design practice, this means that mostly only the peak resistance is used in the calculations. This means that by eliminating the skin friction in load-bearing elements that are founded in unyielding soils, loads can only be transferred to the ground via the peak resistance. Load reserves from the skin friction can therefore not be used. The consequences are a higher number of required piles and / or larger diameters or longer lengths of the piles. Supporting members founded in this way have a relatively low load-bearing capacity due to the lack of jacket friction.

However, if a certain degree of settlement can be permitted and ensured, then it is possible to mobilize the skin friction and thus increase the overall resistance. With high to very high strength of the rock horizon, however, it cannot normally be assumed that sufficiently large settlements will occur, which allow the skin friction to be applied.

The aim of the present invention is therefore to provide constructive measures and methods which enable a targeted minimum setting of the pile-like support members and thereby always ensure the activation of the skin friction. The slump should be definable and predictable.

DE 10 2009 039 570 A1 discloses a reinforcement for a foundation element in the ground, which has metal bars which are connected to form a reinforcement cage. An expandable hollow sheet metal body is fastened via a holder in a foot area of the parole. A supply line and a discharge line for supplying and discharging a fluid into the sheet metal body are on the Reinforcement cage attached and led to an upper area of the reinforcement cage.

The DE 10 2006 007 144 A1 discloses a pile lifting cushion for pile test loads, which can be fastened in the middle of the pile shaft and which has a bushing for a concrete pipe. Similar lifting devices are also from the EP1930506A1 and the GB2159961A1 known.

Summary of the invention

The present invention relates to a device for activating the skin friction on pile-like support members according to claim 1, pile-like support members according to claim 12, structures according to claim 14, a method for activating the skin friction of pile-like support members according to claim 15 and a method for erecting a structure according to claim 16 .

According to a first aspect, a device for activating the skin friction of pile-like support members comprises a device which is suitable for reducing a height of the device when the device is loaded with a compressive force. The load with the compressive force can cause a controlled setting of a pile-like support member in the ground, which is sufficient for the activation of the skin friction on the pile-like support member. The device comprises an upper part and a lower part and the device comprises at least one compression element, the at least one compression element being arranged between the upper part and the lower part such that the at least one compression element serves as a spacer in order to close a gap between the upper part and the lower part form. The at least one compression element is designed such that it is compressed in a controlled manner under a predetermined load by the compressive force and the height of the device is reduced until the gap is closed and the upper part and the lower part come into contact with one another, thereby further reducing the Height of the device is largely prevented. The invention The device has the advantage that the jacket friction can be activated by allowing the pile-like support member to settle. In contrast to pile-like load-bearing members that have pure peak resistance, such load-bearing member systems are characterized by larger, targeted mobilizations and, consequently, by a higher total resistance. In terms of design, this means that the number of supporting elements, the required diameters and / or the lengths of the supporting elements can be reduced for given structural loads. This saves material (concrete and / or reinforcement material) and at the same time shortens the construction time.

In embodiments, the device can be designed such that a substantial reduction in the height of the device only begins after the pressure force acting on the device has exceeded a predetermined limit value. The limit value can be at least 100 kN, preferably at least 150 kN, extremely preferably at least 200 kN and should be able to be adapted to the building requirements. In addition, the device can be designed in such a way that, after the reduction in the height of the device has begun by exceeding the predetermined limit value, the course of the reduction in height is in an approximately linear relationship to the compressive force acting on the device. That is, the higher the pressing force on the device, the greater the decrease in the height of the device without causing a sudden decrease in the height of the device. This enables a controlled reduction in the height of the device and thus a controlled and targeted induction of a desired settlement and thus the activation of the skin friction. The height of the device can be reduced by a predetermined maximum value. That is, after the device has decreased in height by a certain amount, even with an increase in the pressing force acting on the device, there is no further decrease in the height of the device. The height of the device can be reduced by 0.5 to 5 cm, preferably by 1 to 3 cm, in particular by approximately 2 cm.

In configurations that can be combined with all the configurations described so far, at least one recess for the at least one compression element, in which the compression element is arranged, and which is dimensioned in this way, can be provided on an inside of the upper part and / or an inside of the lower part. that it can also accommodate the compressed compression element. That is, if the height of the device is reduced by the pressure load, then the compression element is compressed and changes its shape. The cutouts can be dimensioned such that they can completely accommodate the compressed compression element, so that the gap between the upper part and the lower part can be completely closed. The at least one compression element can comprise, for example, an elastomer, preferably a two-component elastomer, in particular an elastomer that comprises polyurethane. The shape of the at least one compression element can have a honeycomb and / or accordion structure, which yields in a controlled manner from a predetermined load by the compressive force. Alternatively or additionally, the at least one compression element can comprise a structure made of pipes that can be compressed in a controlled manner, in particular a structure made of pipes stacked one above the other. Alternatively or additionally, the at least one compression element can comprise concrete with plastic and / or polystyrene components. The number, the shape and the material properties of the compression element or the compression elements can be used to set a specific resistance characteristic of the device and thus of the device, which realizes a defined, predictable setting of the pile-like support member for activating the skin friction. In contrast, load-bearing parts, for example the upper part and the lower part of the device, can consist of high-strength material. Preferably concrete or steel, but also very strong plastics can be used. This does not reduce the tip resistance at the base of the support member which is activated after the height of the device has been reduced. The combination of compressible and high-strength components enables the same peak resistance compared to the support member without the device according to the invention, so that the total resistance of the pile-like support member can be increased by the amount of skin friction. The device can comprise a circumferential protective device, which is arranged between the upper part and the lower part Prevent foreign matter, dirt and the like from entering the gap. This has the advantage that disruptive influences by foreign substances, concrete, dirt or the like on the device, which could impair the closing of the gap and thereby the reduction in the height of the device, can be reduced or eliminated. The circumferential protective device can comprise a rubber sleeve or a fabric sleeve. Alternatively, the circumferential protective device can comprise steel and / or plastic elements which slide into one another, preferably at least one element each being arranged on the upper part and on the lower part. The upper part and / or the lower part can also have a receiving space for the protective device, so that the protective device does not hinder the reduction in the height of the device. The upper part and / or the lower part can have an overhang in order to protect the protective device against mechanical stresses. The protrusion on the upper part and / or on the lower part can have a conical shape. The protrusion can also be formed in that the upper part and / or the lower part itself have a conical shape.

In embodiments, the device can comprise a reservoir with an outlet, in particular wherein the reservoir is filled with a fluid. The device can be designed in such a way that the fluid can be released from the reservoir in a controlled manner in order to reduce the height of the device. The fluid can include, for example, a Bingham fluid. Alternatively or additionally, the fluid can comprise an activatable material that hardens through activation, in particular through activation with a second material component. The fluid can be activated after dispensing from the reservoir, whereby a base for the pile-like support member can be formed.

In configurations that can be combined with all configurations described so far, the device can have a fastening in order to attach the device to the pile-like support member. The attachment can, for example, comprise a rod, in particular a threaded rod or a reinforcing bar. The rod can at the same time be suitable for the spatial adjustment of the device with respect to the pile-like support member.

The rod can be mounted in a sleeve on the device, in particular on the upper part of the device, wherein the sleeve can be designed to enable movement of the rod in the sleeve so that the reduction in the height of the device is not hindered by the rod . A freedom of movement of the rod in the sleeve can correspond to an opening width of the gap between the upper part and the lower part. Alternatively or additionally, a depression can be provided in the lower part in the extension of the rod, so that the rod does not impede the reduction in the height of the device.

In a second aspect, a pile-like support member comprises any configuration of the device described above. The device must be attached to the tip of the support member, the tip being the deepest part of the pile-like support member penetrating into the ground. The device can be designed in such a way that the weight of the pile-like support member essentially does not result in a reduction in the height of the device, in particular if the pile-like support member is positioned in the ground.

According to a third aspect, a structure comprises any configuration of the pile-like support member described above. According to a fourth aspect, a method for activating the casing friction of pile-like support members comprises the following steps: establishing a pile-like support member in a building ground, applying a compressive force to a device for activating the jacket friction on pile-like support members according to a previously described embodiment above a predetermined limit value, and thereby Reduction of a height of the device for activating the casing friction, whereby a settlement of the pile-like support member is specifically caused, which causes the activation of the jacket friction on the pile-like support member. The device must be attached to the tip of the support member, the tip being the deepest part of the pile-like support member penetrating into the ground, in particular the Device is attached to a reinforcement cage of the support member. The predetermined limit value can be at least 100 kN, preferably at least 150 kN, most preferably at least 200 kN. After the reduction in the height of the device has begun by exceeding the predetermined limit value of the applied compressive force, the course of the reduction in the height can have an approximately linear relationship with the compressive force acting on the device. The height of the device can be reduced by a predetermined maximum value. For example, the height of the device can be reduced by 0.5 to 5 cm, preferably by 1 to 3 cm, in particular by approximately 2 cm. Reducing the height of the device may include reducing the height of a gap between a top and a bottom of the device. The height of the device can be reduced until the gap is closed and the upper part and the lower part come into contact with one another, thereby largely preventing a further reduction in the height of the device. The reduction in the height of the device can be controlled, for example, by means of a compression element. The reduction in the height of the device may include dispensing fluid from the device. In addition, the method can include activating the dispensed fluid after dispensing from the device, in particular activating it by contact with a second material component, as a result of which the dispensed fluid hardens. As a result, a base for the pile-like support member can be formed by the hardened fluid.

A fifth aspect comprises the use of a device for activating the casing friction described above for erecting a building, comprising the steps of: establishing a predetermined number of pile-like support members in a building ground, wherein a device for activating the jacket friction is attached to at least the tips of some of the pile-like support members and the tips are the deepest part of the pile-like support member that penetrates into the ground; Erecting a structure on the pile-like support members, with a predetermined building progress during the erection of the structure, a pressure force of the structure on the pile-like support members and thereby on the device exceeds a predetermined limit, so that a height of the device for activating the Skin friction on the pile-like support members is reduced. As a result, the settlement of the pile-like support members is specifically brought about and the jacket friction on the pile-like support member is activated. The device can be attached to the tip of the respective support member, the tip being the deepest part of the pile-like support member penetrating into the ground, in particular the device can be attached to a reinforcement cage of the support member. The method can also include the dimensioning of the devices for activating the skin friction on the basis of an expected building mass, supporting member mass and number of supporting members.

Further details and features of the invention are described with reference to the following figures.

Brief description of the figures

Fig. 1

shows an inventive device according to an embodiment;

Fig. 2

shows an exploded view of the inventive device of the embodiment Fig. 1 ;

Fig. 3

shows alternative embodiments of the device according to the invention.

Detailed description

The load-bearing behavior of pile-like load-bearing elements, eg bored piles, depends on the external pile resistance, which is formed in the interaction between the ground / rock and the mantle of the load-bearing element. In the axial direction, loads are removed on the one hand via the direct pressure contact on the foot surface of the support member and on the other hand via the casing friction, that is to say the friction in the joint between the casing of the support member and the surrounding floor. The skin friction is activated by settlement of the support member. Especially in solid or very solid soils (rock, rock) are usually enough small settlements to mobilize the skin friction. However, if the pile-like support members are based in such solid or very solid floors, even a small settlement must be questioned and thus also the skin friction to be activated.

To ensure a defined settlement of pile-like support members, it is provided to arrange a device 10 in the foot area of the support members, by means of which the structural loads are removed via the tip resistance of the support member. The device 10 is installed below the support member between its foot and the ground, so that the height of the device is reduced by loading the support member and settlement can occur. By setting the stiffness or the resistance to pressure loading of the device, the settlements can be controlled in such a way that any part of the skin friction on the pile-like support members is mobilized. Both the complete mobilization of the skin friction can take place and, depending on the requirements for the suitability for use, only a proportional mobilization of the skin friction resistance can be permitted by keeping the settlement selectively low (e.g. by a predetermined limitation of the reduction in the height of the device). In the same way, the device can be adapted to the expected load (corresponding to the diameter and length of the support member and the structure provided thereon).

Fig. 1 shows an embodiment of a device 10 according to the invention for activating the skin friction of pile-like support members. The device comprises a device 100 which is suitable for reducing the height of the device 10 when the device 10 is loaded with a compressive force. The compressive force can act on the upper part of the device 10, for example. The load with the compressive force causes a controlled setting of a pile-like support member in the ground, which is sufficient for the activation of the skin friction on the pile-like support member. In particular, if the pile-like support member opens into hard or very hard ground (rock), the device 10 according to the invention has the advantage that, by allowing the pile-like support member to settle, the jacket friction can be activated. In contrast to pile-like load-bearing members that have pure peak resistance, such load-bearing member systems are characterized by larger, targeted mobilizations and, consequently, by a higher total resistance. In terms of design, this means that the number of supporting elements, the required diameters and / or the lengths of the supporting elements can be reduced for given structural loads. This saves material (concrete and / or reinforcement material) and at the same time shortens the construction time.

A substantial reduction in the height of the device 10 should only begin after the pressure force acting on the device 10 has exceeded a predetermined limit value. The limit is, for example, at least 100 kN, preferably at least 150 kN, most preferably at least 200 kN. The limit value must be adapted to the respective application. The limit value therefore varies depending on the number and dimensions of the supporting elements used and the structure erected on them. In addition, it is provided that the device 100 is designed such that after the reduction in the height of the device 10 has begun by exceeding the predetermined limit value, the course of the reduction in the height is in an approximately linear relationship to the compressive force acting on the device 10. That is, the higher the pressing force on the device 10, the greater the reduction in the height of the device 10 without the result that the height of the device 10 drops suddenly. This enables a targeted and predetermined reduction in the height of the device 10 and thus a controlled and targeted induction of a desired settlement and thus the activation of the skin friction. The height of the device 10 can be reduced by a predetermined maximum value. That is, after the device 10 decreases in height by a certain amount, even with an increase in the pressing force acting on the device, there is no further decrease in the height of the device. For example, the height of the device can be reduced by 0.5 to 5 cm, preferably by 1 to 3 cm, in particular by approximately 2 cm.

The example of the device 10 from Fig. 1 has an upper part 200 and a lower part 300. A compression element 110 is arranged between the upper part 200 and the lower part 300, the compression element 110 serving as a spacer in order to form a gap 400 between the upper part 200 and the lower part 300. Furthermore, a recess 120, 130 for the at least one compression element 110 is provided on the inside of the upper part 200 and on the inside of the lower part 300 (alternatively, there can only be a single recess either in the upper part 200 or in the lower part 300), in which the compression element 110 is arranged. The recesses 120, 130, particularly clearly in the exploded view of the Fig. 2 are dimensioned such that they can also accommodate the compressed compression element 110. That is, if the height of the device 10 is reduced by the pressure load, then the compression element 110 is compressed and changes its shape. The cutouts 120, 130 are dimensioned such that they can completely accommodate the compressed compression element 110, so that the gap 400 between the upper part 200 and the lower part 300 can be completely closed. The compression element 110 can be compressed in a controlled manner under a predetermined load by the compressive force. As a result, the height of the device 10 can continuously decrease until the gap 400 is closed and the upper part 200 and the lower part 300 come into contact with one another, thereby largely preventing a further reduction in the height of the device 10.

The compression element 110 can comprise, for example, an elastomer, preferably a two-component elastomer, in particular an elastomer that comprises polyurethane. For example, a two-component cast resin based on polyurethane can be used. With such casting resins, any dimensions can be produced and thus heights and cross sections suitable for the intended purpose can be produced. As an alternative to the elastomer or in addition, the at least one compression element 110 can comprise concrete with plastic and / or polystyrene parts. In particular, when selecting the material for the compression element 110, care must be taken that the material has a certain intrinsic initial strength in order to avoid the inherent weight of the pile-like support member (for example fresh concrete before hardening) Resist deformation / compression. The desired compression and consequently reduction in the height of the device 10 must not yet arise during the installation of the pile, but should occur during the first loading phase (ideally during the first loads occurring during construction). During the first loading phase (eg increasing dead weight of the rising structure), the compression element 110 in the device 10 should compress in a controlled manner until the gap 400 between the upper part 200 and the lower part 300 is closed. After the gap 400 has closed, the force-deformation behavior (ie the behavior of the compression) of the compression element 110 is virtually irrelevant. That is, ideally, the force-deformation curve of the material used has a high initial strength, then a linear, controlled stiffness until the gap 400 closes and then any arbitrary, approximately plastic behavior.

The shape of the at least one compression element 110 can, in addition to the solid body indicated in the figures, also have a honeycomb and / or accordion structure which yields in a controlled manner from a predetermined load by the compressive force. Alternatively or additionally, the at least one compression element can comprise a structure made of pipes that can be compressed in a controlled manner, in particular a structure made of pipes stacked one above the other. The number, the shape and the material properties of the upsetting element 110 or the upsetting elements allow a defined, predictable setting of the pile-like support member to activate the skin friction. In contrast, load-bearing parts, for example the upper part 200 and the lower part 300 of the device 10, can consist of high-strength material. For example, concrete or steel, but also very strong plastics can be used. The use of high strength materials does not reduce the tip resistance at the base of the support member which is activated after the height of the device 10 has been reduced. The combination of compressible and high-strength components enables the same peak resistance in comparison to the support member without the device 10 according to the invention, so that the total resistance of the pile-like support member can be increased by the amount of skin friction.

Fig. 3 shows further exemplary embodiments of the device 10 according to the invention Fig. 3 recognizable, the device can have a round / circular, rectangular or square basic shape. The shape of the compression element 110 and the cutouts 120, 130 can be adapted accordingly. The number of compression elements 110 in the device can be varied as desired depending on the requirement profile. In Fig. 3 Exemplary embodiments with one and three compression elements 110 are shown. However, any other number and arrangement of the compression elements 110 in the device 10 is also possible, from one compression element to more than 10, more than 20, more than 50 or more than 100 compression elements.

The device 10 can also comprise a circumferential protective device (not shown in the figures). The protective device is arranged between the upper part 200 and the lower part 300 in order to prevent foreign substances, dirt and the like from penetrating into the gap 400. This has the advantage that disruptive influences by foreign substances, concrete, dirt or the like on the device 10, which could impair the closing of the gap 400 and thereby the reduction in the height of the device 10, are reduced or eliminated. The circumferential protective device can have, for example, a rubber sleeve or a fabric sleeve. Alternatively, the circumferential protective device can comprise steel and / or plastic elements which slide into one another, preferably at least one element each being arranged on the upper part 200 and on the lower part 300. The upper part 200 and / or the lower part 300 should then also have a receiving space for the protective device, so that the protective device does not hinder the reduction in the height of the device (10). Furthermore, the upper part 200 and / or the lower part 300 can have an overhang in order to protect the protective device against mechanical stresses when the device is conveyed into the ground. The protrusion on the upper part 200 and / or on the lower part 300 can have a conical shape, for example. The protrusion can also be formed in that the upper part 200 and / or the lower part 300 itself have a conical shape.

Alternatively or in addition to those in the Figs. 1 to 3 The upsetting elements 110 shown can include a reservoir with an outlet, the reservoir being filled with a fluid. The device can be designed in such a way that the fluid can be released from the reservoir in a controlled manner in order to reduce the height of the device 10. The fluid can include, for example, a Bingham fluid. As an alternative or in addition, the fluid can comprise an activatable material which hardens by activation, in particular by activation with a second material component (which, for example, is also accommodated in the device or is supplied in another way). After being released from the reservoir, the fluid can be activated, for example, by means of such a second material component or in another way (for example thermal radiation or another type of radiation), thereby forming a base for the pile-like support member.

All previously described embodiments of the device 10 can have a fastening in order to fasten the device to the pile-like support member (in FIGS Figs. 1 to 3 not shown). The attachment can, for example, comprise a rod, in particular a threaded rod or a reinforcing bar. At the same time, the rod can also be suitable for the spatial adjustment of the device 10 with respect to the pile-like support member. For example, the rod may be mounted in a sleeve on the device 10, particularly on the top 200 of the device 10, wherein the sleeve may be configured to allow the rod to move within the sleeve so that the height of the device 10 is reduced is not hindered by the staff. The freedom of movement of the rod in the sleeve is to be adapted in accordance with the opening width of the gap 400 between the upper part 200 and the lower part 300. Alternatively or additionally, a depression can be provided in the lower part 300 in the extension of the rod, so that the rod does not impede the reduction in the height of the device 10.

The device 10 described so far is used in particular in combination with pile-like support members. The device 10 is attached to the tip of the support member, the tip being the deepest part of the pile-like support member penetrating into the ground. The device 100 of the Device 10 can be designed such that the weight of the pile-like support member to which it is attached essentially does not cause a reduction in the height of device 10, in particular if the pile-like support member is positioned in the ground. The devices 10 described and the pile-like support members with such devices can be used for all types of buildings.

In the following, a method is described which leads to the activation of the skin friction on pile-like support members. In particular, this should be done, for example, for use with a pile-like support member in the form of a bored pile, in particular in connection with the progress of the construction of a structure on such piles. In this method, for example, the device 10 described above can be used. As a preparatory step, the device 10 should be dimensioned in accordance with its intended use (construction project) and accordingly produced in sufficient quantity. The devices 10 can be provided for each or only a part of the piles planned for the building. The finished device 10 is mounted on the lower end of a reinforcement cage of a bored pile. Irrespective of this, the pile is drilled, that is, the production of the cased borehole for the later bored pile up to the rock horizon of the building ground. The reinforcement cage with the attached device 10 is then placed in the pile bore. The device 10 should stand as fully as possible on the bottom of the pile bore in the rock. After adjustment, the device 10 is loaded with the weight of the reinforcement cage. The height of the device 10 should not yet decrease. This is followed by the concreting of the bored pile. The device 10 is initially loaded with the fresh concrete weight and should not yet decrease in height. Then the pile concrete hardens. Since no significant change in weight occurs on the device 10, there should be no reduction in height in this step either. However, the hardening of the concrete also results in the device 10 including the compression element 110 being heated. The compression element 110 should have no (or at least only small) creep deformations. Due to the slowly growing shell construction (on the piles), the load increases on everyone Pile and the respective device 10. From the loads of the shell structure, the necessary compressive force results which is sufficient to trigger the reduction in the height of the device 10 and thus to bring about the settlement of the pile. This activates the full length of the skin friction on the pile shaft, i.e. both in the rock / hard rock layers and in the loose soil layers. The further structural work, expansion and loading with traffic loads has no further influence as soon as the maximum reduction in the height of the device 10 is reached. All loads that act on the device 10 are transmitted via the high-strength load-bearing part of the device 10 and the device 100 no longer transmits loads by calculation. The material behavior of the compression element 110 therefore also no longer plays a role. The loads are now fully transferred to the building ground via the pile in the classic manner using skin friction and peak resistance.

The activation of the sheath friction on the pile-like support members thus takes place above a predetermined limit value for a pressure load (by the pile itself and the structure that rises thereon), by reducing the height of the device 10 for activating the jacket friction, thereby deliberately initiating settlement of the pile-like support member which in turn activates the skin friction. For this purpose, the device 10 is attached to the tip of the support member, the tip being the part of the pile-like support member that penetrates deepest into the ground. Depending on the structure and size or number of supporting members used, the predetermined limit value can be, for example, at least 100 kN, preferably at least 150 kN, extremely preferably at least 200 kN. After the decrease in the height of the device 10 has begun by exceeding the predetermined limit value of the applied compressive force, the course of the decrease in the height is in an approximately linear relationship to the compressive force acting on the device 10. The height of the device 10 is reduced by a predetermined maximum value during the construction progress. For example, the height of the device 10 can be reduced by 0.5 to 5 cm, preferably by 1 to 3 cm, in particular by approximately 2 cm. Referring to the embodiments of the device 10 of FIG 1 to 3 , The height of the device 10 is reduced until the gap 400 closes and the upper part 200 and the lower part 300 come into contact with one another, thereby largely preventing a further reduction in the height of the device 10. The reduction in the height of the device 10 is controlled via the compression element 110. Alternatively or additionally, reducing the height of device 10 as described above may include dispensing fluid from the device. In addition, the method can include activating the dispensed fluid after dispensing from the device, in particular activating it by contact with a second material component, as a result of which the dispensed fluid hardens. As a result, a base for the pile-like support member can be formed in the ground by the hardened fluid.

Claims (16)

1. An apparatus (10) for activating the surface friction of post-like carrier members, wherein the apparatus (10) comprises a device (100) which is suitable for reducing a height of the apparatus (10) when the apparatus (10) is loaded with a compressive force, wherein a controlled settlement of a post-like carrier member in the building ground can be evoked that is sufficient for activating the surface friction;
   characterized in that the apparatus (10) comprises an upper part (200) and a lower part (300) and the device (100) comprises at least one compression element (110), wherein the at least one compression element (110) is arranged between the upper part (200) and the lower part (300) in such a way that the at least one compression element (110) serves as a spacer in order to form a gap (400) between the upper part (200) and the lower part (300); and
   in that the at least one compression element (110) is configured to be compressed in a controlled manner under a predetermined load by the compressive force and wherein the height of the apparatus (10) is reduced to such an extent until the gap (400) is closed and the upper part (200) and the lower part (300) come into contact with one another, wherein a further reduction in the height of the apparatus (10) is prevented as far as possible.
2. The apparatus according to Claim 1, characterized in that the device (100) is configured in such a way that a substantial reduction in the height of the apparatus (10) begins only after the compressive force acting on the apparatus (10) has exceeded a predetermined threshold value, in particular wherein the threshold value is at least 100 kN, preferably at least 150 kN, most preferably at least 200 kN.
3. The apparatus according to Claim 2, characterized in that the device (100) is configured in such a way that, after the reduction in the height of the apparatus (10) has begun as a result of exceeding the predetermined threshold value, the progression of the reduction in the height is in an approximately linear relationship with the compressive force acting on the apparatus (10).
4. The apparatus according to any one of the preceding claims, characterized in that the height of the apparatus (10) can be reduced by a predetermined maximum value, in particular wherein the height of the apparatus (10) can be reduced by 0.5 to 5 cm, preferably by 1 to 3 cm, in particular by approximately 2 cm.
5. The apparatus according to any one of the preceding claims, characterized in that at least one recess (120, 130) for the at least one compression element (110), in which the compression element (110) is arranged, is provided on an inner side of the upper part (200) and/or an inner side of the lower part (300), and is dimensioned in such a way that it can also accommodate the compressed compression element (110).
6. The apparatus according to any one of the preceding claims, characterized in that the at least one compression element (110) has a honeycomb and/or accordion structure which yields in a controlled manner above a predetermined load by the compressive force and/or characterized in that the at least one compression element (110) comprises a structure of tubes which can be pressed together in a controlled manner, in particular a structure of tubes which are stacked above one another.
7. The apparatus according to any one of the preceding claims, characterized in that the at least one compression element (110) comprises an elastomer, preferably a two-component elastomer, in particular an elastomer which comprises polyurethane and/or wherein the at least one compression element (110) comprises concrete with plastic and/or polystyrene fractions.
8. The apparatus according to any one of the preceding claims, characterized in that the apparatus (10) comprises an encircling protective device which is arranged between the upper part (200) and the lower part (300) in order to prevent intrusion of foreign matter, dirt and the like into the gap (400).
9. The apparatus according to Claim 8, characterized in that the encircling protective device comprises a rubber sleeve or a woven-fabric sleeve, or in that the encircling protective device comprises steel and/or plastic elements which can slide inside one another, wherein preferably at least one element is arranged on the upper part (200) and on the lower part (300), respectively.
10. The apparatus according to any one of Claims 8 to 9, characterized in that the upper part (200) and/or the lower part (300) has an accommodating space for the protective device, such that the protective device does not impede the reduction in the height of the apparatus (10), and optionally wherein the upper part (200) and/or the lower part (300) has a projection in order to protect the protective device from mechanical stress.
11. The apparatus according to any one of the preceding claims, characterized in that the apparatus (10) comprises a fastening means in order to fasten the apparatus to the post-like carrier member, optionally wherein the fastening means comprises a bar, in particular a threaded rod or a reinforcing bar.
12. A post-like carrier member which comprises an apparatus (10) according to any one of the preceding claims, wherein the apparatus (10) is mounted on the tip of the carrier member, wherein the tip is that part of the post-like carrier member which advances deepest into the building ground.
13. A post-like carrier member according to Claim 12, characterized in that the device (100) of the apparatus (10) is configured in such a way that the intrinsic weight of the post-like carrier member substantially evokes no reduction in the height of the apparatus (10), in particular when the post-like carrier member is positioned in the building ground.
14. A structure which comprises a post-like carrier member according to any one of Claims 12 to 13.
15. A method for activating the surface friction of post-like carrier members, comprising:

    founding a post-like carrier member in a building ground;

    applying a compressive force to an apparatus (10) for activating the surface friction on post-like carrier members according to any one of Claims 1 to 11 above a predetermined threshold value, wherein the apparatus (10) is mounted on the tip of the carrier member, and the tip is that part of the post-like carrier member which advances deepest into the building ground, and thereby

    reducing a height of the apparatus for activating the surface friction, wherein a settlement of the post-like carrier member is evoked in a targeted manner and effects the activation of the surface friction on the post-like carrier member.
16. Use of an apparatus (10) for activating the surface friction according to any one of Claims 1 to 11 for erecting a structure, comprising:

    founding a predetermined number of post-like carrier members in a building ground, wherein an apparatus (19) for activating the surface friction is mounted at least on the tips of some of the post-like carrier members, and the tips are that part of the post-like carrier member which respectively advances deepest into the building ground;

    erecting a structure on the post-like carrier members;

    wherein, at a predetermined stage of construction during the erection of the structure, a compressive force of the structure acting on the post-like carrier members exceeds a predetermined threshold value, such that a height of the apparatuses (10) for activating the surface friction on the post-like carrier members is reduced, wherein a settlement of the post-like carrier members is evoked in a targeted manner, and wherein the surface friction on the post-like carrier member is activated.

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