FORCE MONITOR AND GEOTECHNICAL ANCHOR SYSTEM

Description

[0001] The invention relates to a force transducer for a geotechnical anchor, wherein the force transducer is designed in a ring shape and is intended to surround the anchor in a plane perpendicular to a longitudinal axis of the anchor.

[0002] Furthermore, the invention relates to a geotechnical anchoring system as well as a method for force measurement in a geotechnical anchoring system according to the invention and a method for retrofitting or replacing a force measurement in a geotechnical anchoring system according to the invention.

[0003] Many structures utilize so-called "geotechnical" anchors for stabilization against mass movement or for permanent fixation to the subsoil. These anchors create a tensile-resistant connection between a structure to be secured (especially a building) and the subsoil (especially soil or rock).

[0004] The main types of anchors are prestressed wire systems (strand anchors), rod anchors, and micropiles. In each case, these anchor types are elongated elements with a clearly defined longitudinal axis. Anchoring in the ground can be achieved by wedging or expansion, by bonding, or by grouting.

[0005] For the purposes of this document, all the anchor types mentioned are referred to collectively as "anchors" without further distinction. Geotechnical anchors can be designed for temporary or permanent use. The main difference between anchor systems lies in the durability of their corrosion protection. Particularly with permanent anchors and / or in safety-critical applications, (force) measuring systems are regularly incorporated for monitoring purposes.

[0006] To measure and monitor the forces acting on such anchors (especially permanent anchors), so-called force transducers are available on the market, which can be installed during the anchor installation process. These force transducers are slid over the anchor, i.e., the anchor rod, anchor pile, or anchor cable, like a washer, and then tightened with an anchor head, such as an anchor nut, an anchoring washer, or a wedge-shaped anchor. This is state of the art and has been known for decades.

[0007] For example, such a force transducer is described in German patent application DE 24 39 782 B1. The previously known force transducer is ring-shaped, specifically circular, and is designed to completely enclose the anchor in a plane perpendicular to a longitudinal axis of the anchor.

[0008] DE102019211868A1 discloses a force sensor for an anchor, wherein the force sensor is designed as a one-piece ring element and the sensor technology can be distributed in a circular segment around a central opening.

[0009] With such force transducers, or with geotechnical anchors equipped with corresponding force transducers, a problem arises when the anchor is tensioned and it is impossible or impermissible for structural reasons to release the tension. In such cases, according to the current state of the art, it is no longer possible to retrofit a force transducer or to remove an already installed one, which might be necessary, for example, in the event of a defect or for the purpose of retrofitting / recalibration.

[0010] Especially in the case of sensitive or important structures, there is interest and need for subsequent instrumentation (for force measurement) or for the possibility of testing or replacing an already installed force transducer at a future date.

[0011] The invention is based on the objective of providing a force transducer for a geotechnical anchor that avoids the aforementioned disadvantages and can be retrofitted or replaced in an already installed geotechnical anchor, even if relaxing the anchor itself is impermissible or impossible.

[0012] The invention also aims to provide a geotechnical anchoring system with a correspondingly equipped or equippable geotechnical anchor. Furthermore, methods for force measurement in a geotechnical anchoring system, or for retrofitting or replacing a force measurement device in a geotechnical anchoring system, are to be provided.

[0013] The aforementioned problems are solved according to the invention by a force transducer with the features of claim 1, and by a geotechnical anchoring system with the features of claim 7.

[0014] Advantageous embodiments of the invention are defined in the respective dependent claims.

[0015] A force transducer according to the invention for a geotechnical anchor, which force transducer is designed in a ring shape and is intended to surround the anchor, i.e. the anchor rod, the anchor pile or the anchor cable in a plane perpendicular to a longitudinal axis of the anchor, is characterized in that the force transducer is divided over its circumference into at least two separate force transducer parts, which are or can be designed in the form of ring sectors.

[0016] If the force transducer is preferably annular in shape, the force transducer components can have the form of annular sectors. These are segments of a ring that are bounded circumferentially by two radius segments.

[0017] A geotechnical anchoring system according to the invention comprises, in addition to an anchor, a force transducer according to the invention and is further characterized in that the force transducer, in its assembly state, essentially completely surrounds the anchor, i.e. the anchor rod, the anchor pile or the anchor cable, in a plane perpendicular to a longitudinal axis of the anchor with its force transducer parts.

[0018] The aforementioned assembly condition refers to the state in which the force transducer is properly and correctly mounted on the anchor in order to fulfill its force measuring function.

[0019] When it is stated that the force transducer "essentially" completely surrounds the anchor with its force transducer parts, this should also include designs in which a certain (small) distance remains between individual force transducer parts in the circumferential direction.

[0020] A distinction is made here between a "geotechnical anchoring system", which, in addition to the anchor rod, anchor pile or anchor rope, also has other components such as the force transducer mentioned, and an "anchor" as such, which is to be understood as a generic term for the aforementioned anchor types (rod, pile and rope).

[0021] In a first method for force measurement in a geotechnical anchoring system according to the invention, at least the following method steps are carried out: a) Inserting the anchor, i.e., an anchor rod, pile, or cable, into a structure or subsoil so that one end of the anchor protrudes from the structure or subsoil; b) Arranging the force-absorbing parts of the force transducer in a plane perpendicular to a longitudinal axis of the anchor around the anchor in the region of said end; c) Bracing the force-absorbing parts of the force transducer against the structure or subsoil; d) Performing the force measurement using the force transducer.

[0022] In a further development of the procedure, it is provided that in step c) first the first compensating plate, then the force absorber parts and finally the second compensating plate are arranged on the aforementioned end of the anchor and clamped against the building structure or substrate by means of an anchor nut.

[0023] Preferably, it is provided that before step d) the number of force sensor parts, preferably all force sensor parts, are connected to each other using measuring equipment.

[0024] In a second method for retrofitting or replacing a force measurement in a geotechnical anchoring system according to the invention, at least the following method steps are carried out: A) Removing or loosening a tensioning device of the anchor against a building structure or subsoil, so that the anchor becomes accessible at its end protruding from the building structure or subsoil, preferably, with a corresponding design of the method or the anchor, by creating mobility of at least a second compensating plate relative to the anchor, i.e., an anchor rod, pile, or cable, in particular by loosening an anchor nut; B) optionally, first removing the force-transmitting parts of an existing force transducer from the anchor substantially in a radial direction, then arranging the force-transmitting parts of a preferably new force transducer substantially in a radial direction in a plane perpendicular to a longitudinal axis of the anchor around the anchor in the region of said end; C) tensioning the force-transmitting parts of the force transducer against the building structure or subsoil by reattaching or tightening the tensioning device of the anchor..

[0025] Preferably, it is provided that during steps A) and B) the anchor is temporarily secured against movement relative to the building structure or subsoil by external means, in particular hydraulic means.

[0026] Preferably, in step B), an existing force transducer is first removed, then overhauled, serviced and / or recalibrated, and subsequently reattached to the armature.

[0027] The features mentioned in connection with the force measurement procedure for a geotechnical anchoring system can also be applied to the procedure for retrofitting or replacing a force transducer in a geotechnical anchoring system.

[0028] When step B) of the procedure refers to the optional removal of the force transducer components of an existing force transducer from the anchor, this applies to cases where a corresponding force transducer was previously installed on the anchor and is now to be removed for maintenance or replacement purposes. However, the procedure also includes configurations where no force transducer was originally installed on the anchor, thus also covering the retrofitting of an existing anchor that originally did not have a force measuring device.

[0029] The term "building structure or subsoil" has been used above and will be used below as a synonym for the terms "structure to be secured" and "building ground" used in the introduction.

[0030] When the term "anchor tensioning device" is used here and in the following, it specifically includes the anchor nuts already known from the prior art, which are screwed onto the threaded free end of the anchor to tension the load cell, and regularly also the previously mentioned compensating plate(s) (first compensating plate and second compensating plate), against a structure to be secured, and this in turn against the ground. This tensioning device ensures that, under normal operating conditions, no relative movement occurs between the anchor, i.e., the ground, and a structure to be secured.

[0031] The development described above in its essential features is therefore a split force transducer that can be retrofitted and reused in geotechnical anchors.

[0032] The force transducer assembly comprises several components which, in the assembled state, grip the anchor in such a way as to absorb clamping forces and transmit them to a suitably sensitive measuring unit provided in a corresponding further development of the invention. In this context, the specific physical principle of force measurement is initially irrelevant: any force transducer or measuring unit capable of absorbing or measuring the aforementioned forces can be used within the scope of the present invention.

[0033] A preferred embodiment of the invention provides that the applied anchor force is converted into hydraulic pressure across the (total) area of ​​the force transducer, i.e., the sum of the areas of the individual force transducer components. In this context, the force transducer itself can be designed as a slightly compressible measuring unit, comparable to a "steel cushion," which contains a fluid. The fluid pressure generated by the applied anchor force is preferably measured by means of a suitable pressure converter, which in turn can be designed in a variety of ways.

[0034] However, the invention is not fundamentally limited to a measurement principle based on compression. Alternatively, the applied anchor force can also be measured, for example, in the form of strain, in order to establish a relationship between strain and applied force.

[0035] Accordingly, another embodiment of the force transducer according to the invention provides that at least one measuring unit is available per force transducer part, which measuring units are designed to measure a pressure effect on the respective measuring unit in the form of a strain.

[0036] It has already been pointed out above that the present invention is by no means limited to a specific physical method of force measurement. In principle, other forms of force measurement are also possible, in particular electromechanical measurement methods familiar to those skilled in the art.

[0037] The crucial point is simply that, as already explained, the force transducer is divided or subdividable into at least two separate force transducer parts (ring sectors) around its circumference, in order to retrofit or replace it even after an anchor has been installed, if the anchor may not be removed or relieved.

[0038] A first embodiment of the force transducer according to the invention provides for exactly two force transducer parts, each extending over a circumferential angle of 180 degrees, thus each covering exactly half the circumference. However, the invention is by no means limited to such a symmetrical design. In principle, it may be sufficient if one of the ring sectors has an inner circular arc whose chord is longer than the diameter of the anchor.

[0039] Generally, the force transducer can be configured to have n, n = 1, 2, 3,..., force transducer elements, each extending over a circumferential angle of 360 / n degrees. However, the invention is by no means limited to embodiments in which all force transducer elements are identical.

[0040] The design with exactly two force-absorbing parts requires the smallest possible number of individual parts, which can also be essentially identical, thus simplifying manufacturing and handling.

[0041] Another further development of the force transducer according to the invention provides that a number of the force transducer parts, preferably all force transducer parts, are in operative connection with each other for measurement purposes.

[0042] This reduces the complexity of the circuitry required for force measurement. In the simplest case, all force sensor components are connected to a single higher-level unit, such as the pressure converter already mentioned, so that the overall equipment complexity remains as low as possible.

[0043] Accordingly, a highly preferred embodiment of the force transducer according to the invention provides that it has at least one pressure converter and at least one measuring unit per force transducer section, which measuring units contain a fluid whose fluid pressure can be detected by means of the pressure converter. As described above, the measuring units can be designed in the form of cushions containing the aforementioned fluid. Preferably, these measuring units are connected to a single pressure converter in order to reduce the complexity of the apparatus.

[0044] However, it is also within the scope of the invention to equip several measuring units with their own pressure converter and then to combine the (electrical) signals of the individual pressure converters using circuit technology.

[0045] In yet another further development of the force transducer according to the invention, it can be provided that the measuring units of the aforementioned number of force transducer parts are operatively connected to each other and to the at least one pressure converter via at least one fluid line.

[0046] The applicant has achieved particularly good and reproducible results in practice with such a design.

[0047] In yet another embodiment of the force transducer according to the invention, it has proven advantageous if the fluid line is led radially outwards from the respective force transducer part at each connection point and preferably extends between two connection points at a constant radial distance over a section of the circumference of the force transducer. This results in a compact component that is particularly easy to handle and install.

[0048] To enable the force transducer according to the invention to be used with a geotechnical anchor known per se or in a genetically engineered anchoring system, a first embodiment of this anchoring system provides that an outer diameter of the anchor, i.e., an outer diameter of the anchor rod, anchor pile, or anchor cable, essentially corresponds to a clear inner diameter of a central opening in the annular force transducer. In practice, it has proven advantageous if the anchor has a slightly smaller opening relative to its outer diameter, in order to easily arrange the force transducer or its components around the anchor.

[0049] Another embodiment of the geotechnical anchoring system according to the invention provides that at least one first compensating plate and at least one second compensating plate are provided, as already mentioned above, which first compensating plate and / or which second compensating plate is preferably ring-shaped and each has a central opening for receiving the anchor, so that in the assembly state the force transducer with its force transducer parts is arranged between the first compensating plate and the second compensating plate.

[0050] It has already been pointed out that known anchors or anchoring systems of the type under discussion here generally have a nut (anchor nut) that is screwed onto a suitable thread at the free end of the anchor, or can be screwed onto such a thread, in order to achieve the desired anchoring effect. This nut serves to brace the aforementioned compensating plates together with the load-bearing elements against the structure to be secured and, correspondingly, against the foundation. A corresponding design can also be provided within the scope of the present invention.

[0051] Another embodiment of the geotechnical anchoring system according to the invention provides that at least one of the compensating plates, preferably the second compensating plate, has a positive-locking structure on its side facing or to be faced with the load cell, which positive-locking structure interacts positively with the load cell in the assembled state. This allows for precise and reproducible positioning of the load cell or load cell components relative to the aforementioned compensating plate. This can facilitate handling during assembly and prevent damage.

[0052] It has proven particularly advantageous if, with appropriate further development of the geotechnical anchoring system according to the invention, the positive locking is effective in the radial direction with respect to the longitudinal axis of the anchor. For this purpose, it can be provided, in particular, that the positive locking structure is designed as an annular recess in the relevant side of the corresponding compensating plate, which, in the assembled state, interacts with a complementary projection on the force transducer, preferably on each of the force transducer parts, or vice versa.

[0053] In this way, the form-fitting structure ensures that the individual force transducer components can be assembled into the (complete) force transducer in a geometrically reproducible manner, without inaccuracies in relative positioning that could impair assembly and proper operation. In particular, this facilitates the desired (fluidic) connection between the individual force transducer components.

[0054] Another embodiment of the geotechnical anchoring system according to the invention provides that at least one of the compensating plates, preferably the second compensating plate, is subdivided around its circumference at corresponding separation points into at least two separate sub-sectors, preferably ring-shaped sub-sectors, each preferably extending over the same circumferential angular range. As with the force transducer, it has proven advantageous to have exactly two sub-sectors, each covering an angular range of 180°; however, the invention is by no means limited to such a configuration – rather, a different number of sub-sectors can also be used, and the sub-sectors can each cover different angular ranges. The subdivision of the aforementioned compensating plate(s) simplifies the assembly of the arrangement according to the invention.

[0055] To ensure sufficient stability despite the aforementioned subdivision, a further preferred embodiment of the geotechnical anchoring system according to the invention provides that the two sub-sectors can be detachably connected to one another by means of a number of connecting elements, preferably screw elements, in order to form at least one of the compensating plates. In this context, it can also be provided that radial flanges are provided in the area of ​​the aforementioned separation points, which, in the assembled state, have openings aligned relative to each other, through which connecting elements in the form of screw bolts are or can be guided in order to detachably connect the aforementioned sub-sectors to one another.

[0056] It has also proven advantageous if, with appropriate further development of the geotechnical anchoring system according to the invention, at least a number of the separation points in the assembled state coincide in their circumferential position with a connection point of the fluid line on a respective force transducer part. In particular, the aforementioned flanges or comparable connection structures on the sub-sectors can provide protection of the fluid line against external damaging influences in the area of ​​the connection point. With a corresponding embodiment of the invention, the aforementioned connection points can be arranged diametrically opposite one another.

[0057] As part of a further development of the first method, it can also be provided that in step c), first the first compensating plate, then the force transducer components, and finally the second compensating plate are arranged on the aforementioned end of the anchor and clamped against the structure or substrate by means of an anchor nut or similar device. Alternatively, it can also be provided that, with a suitable design, particularly of the second compensating plate with the aforementioned positive locking structure and / or the division into sub-sectors, the force transducer components are first assembled into the (complete) force transducer using the second compensating plate, after which this is then arranged on the anchor together with the second compensating plate and clamped there together with the first compensating plate. The latter design, in particular, can contribute to simplified assembly because fewer individual parts need to be handled.

[0058] Another refinement of the first method provides that, prior to step d), the number of force transducer components, preferably all force transducer components, are connected to each other for measurement purposes. In this way, preferably all force transducer components can contribute to the force measurement.

[0059] The two training courses described last in the first procedure can also be used in the second procedure.

[0060] Furthermore, in a further development of the second method, it can be provided that during steps A) and B), the anchor is temporarily secured against movement relative to the structure or subsoil by external means, in particular hydraulic means. In this way, a force transducer according to the invention can be retrofitted or replaced without damaging the structure being secured.

[0061] In this context, the invention is not limited to specific external securing devices for the anchor. Rather, within the scope of the present invention, all types of external securing devices that are familiar or will become familiar to those skilled in the art can be used.

[0062] Finally, as part of a further development of the second procedure, it may be stipulated that in step B) an existing force transducer is first removed, then overhauled, serviced and / or recalibrated, and subsequently reattached to the anchor. Therefore, it is not absolutely necessary to use a new force transducer unless required for safety reasons.

[0063] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing. Figure 1shows a force transducer according to the invention in a top view with a viewing direction along a longitudinal axis of an anchor (not shown); Figure 2 shows the force sensor Figure 1 in a perspective view; Figure 3 shows a geotechnical anchoring system according to the invention with a view along its longitudinal axis; Figure 4 shows a section along line AA in Figure 3 ; Figure 5 shows a final assembly state of a geotechnical anchoring system according to the invention; Figure 6 shows a first step in replacing the force transducer, starting from the assembly state in Figure 5 ; Figure 7 shows a second step in replacing the force transducer, starting from the assembly state in Figure 5 and Figure 8 shows a third step in replacing the force transducer, starting from the assembly state in Figure 5 .

[0064] In Figure 1A force transducer 1 according to the invention is shown in a top view, with the viewing direction oriented along the longitudinal axis of an anchor (not shown here). The force transducer 1 is designed as an annular shape and is intended to surround an anchor in a plane perpendicular to the anchor's longitudinal axis, which plane is oriented parallel to the plane of the drawing. The force transducer 1 is divided at its circumference into two separate force transducer parts 1a, 1b, which are designed as annular sectors and each extend over an angular range of 180°. A circular opening 1c is formed in the center of the force transducer 1, which is intended for guiding an anchor and has a suitable clear inner diameter for this purpose.

[0065] Each of the force transducer parts 1a, 1b contains or represents a measuring unit, which contains a suitable fluid, and is fluid-conductingly connected to a single pressure converter 1e via a fluid line 1d. The pressure converter 1e converts an incoming fluid pressure signal into an electrical signal, which can be further processed for evaluation purposes in a manner known per se. Electrical cables 1f extend from the pressure converter 1e. The fluid line 1d is led radially outwards from the respective force transducer part 1a, 1b at a given connection point 1g, 1h and extends between the connection points 1g, 1h at a constant radial distance over a section of the circumference of the force transducer 1.

[0066] Crucially, the force transducer parts 1a, 1b are not inseparably connected to each other, but are designed as separate components of the force transducer 1 and are accordingly removable from each other, so that they can in particular be subsequently placed around an anchor or removed from an already installed anchor without having to remove the anchor itself.

[0067] How to particularly improve perspective representation in Figure 2Each of the force-transmitting parts 1a, 1b comprises two half-shells 1aa, 1ab; 1ba, 1bb, which are each fluid-tightly connected to one another by a circumferential weld 1i, so that a (pressure) chamber for the fluid is formed between them. The fluid line 1d is fluid-conductingly connected to this chamber at the connection points 1g, 1h. This connection is mechanically stabilized by means of a sleeve-shaped adapter 1j. When an external force acts on the half-shells 1aa, 1ab; 1ba, 1bb, the fluid pressure in the chamber changes, which is converted into an evaluable electrical signal by the pressure converter 1e. This is known per se to those skilled in the art; however, the present invention is not fundamentally limited to this measuring principle.

[0068] In Figure 3 is one of the Figure 1A similar representation is shown, which, however, shows further components of a geotechnical anchoring system 2 in addition to the force transducer 1: the anchoring system 2 initially comprises, besides the actual anchor or anchor rod 2a, an anchor nut 2b, a first compensating plate 2c, and a second compensating plate 2d. The force transducer 1 is arranged between the first compensating plate 2c, which is to be installed on the structure side, and the second compensating plate 2d, as can be seen in particular from the sectional view shown in Figure 4 along line AA. Figure 3 The anchor rod 2a has a thread (not shown) at its free end 2e for screwing on the anchor nut 2b, in order to secure the second compensating plate 2d against the force transducer 1, the first compensating plate 2c and the structure (in Figure 4 not shown; compare Figures 5 to 8 ) to tighten. The anchor nut 2b accordingly represents a tensioning device.

[0069] The first compensating plate 2c and the second compensating plate 2b are annular in shape and each has a central opening (not labeled) which allows the anchor rod 2a to pass through, as shown. The second compensating plate 2d has an annular recess (groove) 2f on its side facing the force transducer 1 (compare Figure 4 ), which is designed to be complementary to an outer contour of the force transducer half-shells 1aa, 1ab; 1ba, 1bb, such that the force transducer 1 with its individual parts is positively locked in the aforementioned recess 2f in this area in a radial direction with respect to the anchor rod 2a. Figure 4 Reference symbol L further denotes the longitudinal axis of anchor 2 or anchor rod 2a.

[0070] According to the design in Figure 3The second compensating plate 2d is subdivided around its circumference at corresponding separation points TS1, TS2 into at least two separate ring segments 2da, 2db, each of which extends over an equal circumferential angle of 180°. The aforementioned recess 2f (Figure 4) is accordingly formed by recesses of the ring segments 2da, 2db. Figure 3A parting plane of the force transducer 1 is arranged rotated by 90° relative to a parting plane of the second compensating plate 2d. In this way, flange projections or radial flanges 2g, which are present in the area of ​​the parting points TS1, TS2 on the ring segments 2da, 2db, can provide mechanical protection for the aforementioned connection points 1g, 1h of the force transducer 1. The two ring segments 2da, 2db are detachably connected to each other by means of a number of fasteners, preferably screws (bolts 2h, nuts 2i), to form the second compensating plate 2d. For this purpose, pairs of aligned openings (not labeled) are provided in the area of ​​the flange projections 2g.

[0071] In the Figures 5 to 8 This illustrates a possible procedure that would occur if, in the case of an already installed geotechnical anchoring system 2, according to the Figures 3 and 4The force transducer 1, for example, is to be removed or replaced for maintenance purposes.

[0072] Figure 5 Figure 3 and Figure 4 show the geotechnical anchoring system 2 in a side view in its assembled state with tension against a structure 3, which structure 3 has a bore 3a for inserting the anchor rod 2a.

[0073] According to Figure 6 was based on the representation in Figure 5 The anchor nut 2b has been loosened. Arrow F symbolizes a holding force applied to the anchor rod 2a, which ensures that the anchor rod 2a does not move relative to the structure 3 despite the loosening of the tensioning device. This can be achieved by means of any suitable holding device, which is only shown symbolically at reference numeral 4.

[0074] In Figure 7The figure shows the state after the two-part second compensating plate 2d has been removed from the anchor rod 2a (after loosening the screws). In particular, if the second compensating plate 2d is not multi-part, it can also simply be lifted off the force transducer 1 in the direction of the loosened anchor nut 2b (not shown).

[0075] Now the multi-part force transducer 1 is exposed and can be – if necessary after removing or disconnecting the fluid line 1d (compare Figures 1 to 4 ) - from the anchor rod 2a.

[0076] This condition is in Figure 8 shown, in which only the anchor nut 2b and the first compensating plate 2c remain on the anchor rod 2a.

[0077] The holding force lies in the Figure 7 and 8 it continues to be attached to anchor rod 2a, which is not shown for the sake of clarity.

[0078] The subsequent restoration of the complete geotechnical anchoring system 2 is preferably carried out in reverse order.

Claims

1. Force transducer (1) for a geotechnical anchor (2a), the force transducer (1) being annular and being intended and suitable for surrounding the anchor (2a) in a plane perpendicular to a longitudinal axis (L) of the anchor (2a), characterized in that the force transducer (1) is subdivided over its circumference into at least two separate force transducer parts (1a, 1b) in the form of ring sectors.

2. Force transducer (1) according to claim 1, characterized in that exactly two force transducer parts (1a, 1b) are present, each preferably extending over a circumferential angle of 180 degrees.

3. Force transducer (1) according to claim 1 or 2, characterized in that at least some of the force transducer parts (1a, 1b), preferably all force transducer parts (1a, 1b), are operatively connected to each other for measurement purposes, at least one measuring unit per force transducer part (1a, 1b) and at least one pressure transducer (1e) being provided, the measuring units of the force transducer parts (1a, 1b) being operatively connected to each other and to the pressure transducer (1e) via at least one fluid line (1d).

4. Force transducer (1) according to claim 3, characterized in that the measuring units contain a fluid of which the fluid pressure is detectable by means of the pressure transducer (1e).

5. Force transducer (1) according to claim 3 or 4, characterized in that the fluid line (1d), at respective connection points (1g, 1h), is led radially outward from the relevant force transducer part (1a, 1b) and preferably extends over a portion of the circumference of the force transducer (1) between two connection points (1g, 1h) at a constant radial distance.

6. Force transducer (1) according to claim 1 or 2, characterized by at least one measuring unit per force transducer part (1a, 1b), which measuring units are designed to measure a pressure effect on the relevant measuring unit in the form of a strain.

7. Geotechnical anchor system (2) comprising an anchor (2a) insertable into a structure or subsoil such that one end of the anchor (22) protrudes from the structure or subsoil and comprising a force transducer (1) according to any of the preceding claims, characterized in that the force transducer (1) in its assembly state, by way of the force transducer parts (1a, 1b) thereof in the form of ring sectors, substantially surrounds the entire circumference of the anchor (2a) in a plane perpendicular to a longitudinal axis (L) of the anchor (2a).

8. Geotechnical anchor system (2) according to claim 7, characterized in that an outer diameter of the anchor (2a) substantially corresponds to a clear inner diameter of a central aperture (1c) of the annular force transducer (1).

9. Geotechnical anchor system (2) according to claim 7 or 8, characterized by at least one first compensating plate (2c) arranged or to be arranged on the side of the structure or subsoil and at least one second compensating plate (2d), which first compensating plate (2c) and / or which second compensating plate (2d) is preferably annular and in each case has a central opening for receiving the anchor (2a), at which in the assembly state the force transducer (1) is arranged between the first compensating plate (2c) and the second compensating plate (2d).

10. Geotechnical anchor system (2) according to claim 9, characterized in that at least one of the compensating plates (2c, 2d), preferably the second compensating plate (2d), has a form-fitting structure (2f) on the side thereof facing or to face the force transducer (1), which form-fitting structure (2f) in the assembly state interacts with the force transducer (1) in a form-fitting manner.

11. Geotechnical anchor system (1) according to claim 10, characterized in that the form fit is effective in the radial direction with respect to the longitudinal axis (L) of the anchor (2a).

12. Geotechnical anchor system (2) according to claim 10 or 11, characterized in that the form-fitting structure is designed as an annular recess (2f) in the relevant side of the corresponding compensating plate (2d), which recess (2f) in the assembly state interacts with a complementary projection on the force transducer (1), preferably on each of the force transducer parts (1a, 1b), or vice versa.

13. Geotechnical anchor system (2) according to any of claims 10 to 12, characterized in that the at least one of the compensating plates (2d), preferably the second compensating plate (2d), is subdivided over its circumference at corresponding separation points (TS1, TS2) into at least two separate subsectors (2da, 2db), preferably ring subsectors, which subsectors (2da, 2db) preferably extend over an equal circumferential angle range.

14. Geotechnical anchor system (2) according to claim 13, characterized in that the two subsectors (2da, 2db) are detachably connectable to each other by means of a number of connecting means (2h, 2i), preferably screw means, in order to form the at least one of the compensating plates (2d).

15. Geotechnical anchor system (2) according to claim 13 or 14, characterized in that at least some of the separation points (TS1, TS2) in the assembly state each coincide in their circumferential position with one connection point (1g, 1h) of the fluid line (1d) to a relevant force transducer part (1a, 1b).