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EP-4130389-B1 - FORCE TRANSDUCER AND GEOTECHNICAL ANCHOR SYSTEM

EP4130389B1EP 4130389 B1EP4130389 B1EP 4130389B1EP-4130389-B1

Inventors

  • Schneider-Glötzl, Joachim
  • Pudelko, Achim
  • Kohl, Michael Maria
  • Zopf, Michael

Dates

Publication Date
20260513
Application Date
20220805

Claims (15)

  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).

Description

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. 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. 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). 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 prominent longitudinal axis. Anchoring in the ground can be achieved by wedging or spreading, by gluing or by mortaring. 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. 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. For example, in the printed text DE 24 39 782 B1 A force transducer of this type is described. The previously known force transducer is ring-shaped, specifically circular, and is designed to completely surround the anchor in a plane perpendicular to a longitudinal axis of the anchor. The DE102019211868A1 discloses a force transducer for an anchor, wherein the force transducer is designed as a one-piece ring element and the sensory elements can be distributed in a circular segment around a central opening. 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. 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. 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. 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. 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. Advantageous embodiments of the invention are defined in the respective dependent claims. 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. 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. A geotechnical anchoring system according to the invention comprises, in addition to an anchor, a