EP1980712A1 - Load cell for ground anchors - Google Patents
Load cell for ground anchors Download PDFInfo
- Publication number
- EP1980712A1 EP1980712A1 EP07007601A EP07007601A EP1980712A1 EP 1980712 A1 EP1980712 A1 EP 1980712A1 EP 07007601 A EP07007601 A EP 07007601A EP 07007601 A EP07007601 A EP 07007601A EP 1980712 A1 EP1980712 A1 EP 1980712A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- load cell
- locking body
- locking
- soil
- strain
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000011435 rock Substances 0.000 claims abstract description 11
- 239000002689 soil Substances 0.000 claims abstract description 11
- 238000012544 monitoring process Methods 0.000 claims abstract description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 4
- 230000035945 sensitivity Effects 0.000 claims description 4
- 239000010959 steel Substances 0.000 claims description 4
- 239000011241 protective layer Substances 0.000 claims description 2
- 238000009434 installation Methods 0.000 description 2
- 238000004873 anchoring Methods 0.000 description 1
- 238000011088 calibration curve Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/74—Means for anchoring structural elements or bulkheads
- E02D5/80—Ground anchors
- E02D5/805—Ground anchors with deformable anchoring members
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/74—Means for anchoring structural elements or bulkheads
- E02D5/80—Ground anchors
- E02D5/801—Ground anchors driven by screwing
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
- E21D21/02—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection having means for indicating tension
Definitions
- the present invention relates to a load cell for monitoring residual forces in soil and rock anchors.
- Ground e.g., soil and rock anchors are widely used in civil engineering to resist forces acting on retaining structures.
- Anchors installed for a long service term (say 50 years) are considered permanent, while those supposed to act over a short period only (say two years) are defined as temporary.
- the anchors are pre-stressed to a specified tensile force, in order to minimize displacements of the retaining structures.
- the force in the anchor may decrease for various reasons such as relaxation and creep.
- anchored elements such as foundations and retaining structures, may displace excessively and eventually fail. Therefore, it is extremely important to have suitable permanent means, which can monitor the residual force and verify that the anchor is functioning properly and according to design.
- Load cells whether electrical, hydraulic or pneumatic, for monitoring these forces exist, but suffer from several disadvantages and drawbacks. Not being integral parts of the anchor system, they have to be added to the system, consuming extra space, which makes the setup bulkier, difficult to approach and visually disturbing. Existing systems are also expensive, and their cost may exceed the cost of the anchor proper. This severely curtails the widespread application of anchor force monitoring. This situation, where only a minority of the anchors is monitored, may lead to failures with considerable losses in economic terms and even human lives.
- a load cell for monitoring the residual forces in a pre-stressed soil and rock anchor comprising a locking body having at least one hole through which a tensioning element passes, and an electronic bridge circuit containing strain-responsive elements affixed to the circumference of said locking body, said elements being oriented to detect changes in axial and circumferential dimensions of the locking body caused by changes in the residual forces of said soil and rock anchor.
- FIGs. 1 and 2 There is seen in Figs. 1 and 2 an anchor to be used with the load cell of the present invention.
- the anchor consists of a fixed or grouted portion 2 and a free portion 4.
- Multi-strand steel cables 6, advantageously four of them, with one of their ends fixedly attached to the grouted anchor portion 2, are lead through a central hole in a bearing plate 8 which is then brought into contact with the retaining structure 10.
- a locking body 12 a cross-sectional view of which is seen in Fig. 2 , is then placed over bearing plate 8, with cables 6 passing through bores 14 in the split plugs 16 seated in the conical holes 18 in locking body 12.
- the conicity of the split plugs 16 fit the conicity of the conical holes 18 in the locking body 12, thus when the split plugs 16 accommodating cables 6 are driven into the locking body 12, the cables 6 are fixedly clamped into the locking body 12.
- cables 6 pass through a first hollow hydraulic jack 20, and then through a second hollow jack 22, and are then attached to a tensioning plate 24 seated on ram 26 of the second jack 22.
- the required tension can now applied to cables 6 by the second jack 22, after which split plugs 16 are forced into conical holes 18 in the locking body 12 by means of the first jack 20.
- Both jacks, 20 and 22, are then removed and the cable surplus is trimmed, rendering the anchor functional.
- the load cell 28 consists of a body 30 and strain-responsive elements, e.g., strain gages 32 forming part of an electronic circuit 34, illustrated in Fig. 4 .
- the electronic circuit 34 is affixed in a groove 36 made in the circumference of the body 30 of the load cell 28.
- the circuit 34 can be affixed on the body 30 or in the groove 36 by using one of the bonding compounds manufactured for this purpose, e.g., M-Bond 43-B (Vishay).
- the gages 32 are covered with a special protective coat.
- the electronic circuit 34 shown in Fig 4 is in the form of a four-arm double Wheatstone Bridge.
- Each arm of the Wheatstone Bridge contains two strain gages.
- Two opposite arms contain strain gages, S, S', while the other two opposite arms contain strain gages Sp, S'p.
- the arms with the strain gages S, S' have their axes of sensitivity in the direction of the axial strain of the load cell 28, while the arms having strain gages Sp, S'p have their axes of sensitivity in the direction of the circumferential strain on the body cell 28.
- the strain gages S, S' and Sp, S'p, respectively, are connected in series. Thus, when a compressive load is applied to the load cell 28, it contracts along the longitudinal axis and expands in the circumferential direction (Poisson's Effect).
- each strain gage typically is 350 Ohm, and thus, the total resistance of each arm is 700 Ohm.
- direct current with a stabilized voltage between 3 V and 10 V is applied.
- the circuit 34 is connected to a readout unit 38 which transforms the analog output of the load cell 28 into a digital one and connects via a suitable USB cable to a portable computer 40.
- the load cell 28 Before installation as part of the anchor, the load cell 28 is put in a suitable calibration device, and stressed to the maximum permissible load. The load is then relaxed in stages, and the readout for each load saved as a calibration table or curve.
- an initial reading of the device is performed. Further readings are later taken on demand. If these are identical to the initial reading, it means that there was no loss in the anchoring force. By use of the calibration curve, lower readings may be retransformed to obtain the residual anchor force.
- FIG. 5 Another embodiment of the load cell is shown in Fig. 5 , in which cables 6 of the anchor are replaced by a single steel rod 42 with a threaded end, and the substantially cylindrical load cell 28 by a cylindrical nut 44.
- the latter may be of the self-locking type, or a counter-nut (not shown) may be applied.
- the protective layer or coating 46 covering the gages affixed to the nut 44, or into a groove made therein.
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Piles And Underground Anchors (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
Abstract
There is provided a load cell for monitoring the residual forces in a pre-stressed soil and rock anchor, including a locking body having one hole through which a tensioning element passes, and an electronic bridge circuit containing strain-responsive elements affixed to the circumference of the locking body. The elements are oriented to detect changes in axial and circumferential dimensions of the locking body caused by changes in the residual forces of the soil and rock anchor,
Description
- The present invention relates to a load cell for monitoring residual forces in soil and rock anchors.
- Ground, e.g., soil and rock anchors are widely used in civil engineering to resist forces acting on retaining structures. Anchors installed for a long service term (say 50 years) are considered permanent, while those supposed to act over a short period only (say two years) are defined as temporary. As a rule, after installation, the anchors are pre-stressed to a specified tensile force, in order to minimize displacements of the retaining structures.
- With time, the force in the anchor may decrease for various reasons such as relaxation and creep. As a result, anchored elements, such as foundations and retaining structures, may displace excessively and eventually fail. Therefore, it is extremely important to have suitable permanent means, which can monitor the residual force and verify that the anchor is functioning properly and according to design.
- Load cells, whether electrical, hydraulic or pneumatic, for monitoring these forces exist, but suffer from several disadvantages and drawbacks. Not being integral parts of the anchor system, they have to be added to the system, consuming extra space, which makes the setup bulkier, difficult to approach and visually disturbing. Existing systems are also expensive, and their cost may exceed the cost of the anchor proper. This severely curtails the widespread application of anchor force monitoring. This situation, where only a minority of the anchors is monitored, may lead to failures with considerable losses in economic terms and even human lives.
- It is thus one of the objects of the present invention to overcome the disadvantages of the existing monitoring arrangements and to provide a load cell that is an integral component of a soil and rock anchor, and is inexpensive enough to allow the monitoring all, or at least most of, the anchors on a given site.
- According to the invention, this is achieved by providing a load cell for monitoring the residual forces in a pre-stressed soil and rock anchor, comprising a locking body having at least one hole through which a tensioning element passes, and an electronic bridge circuit containing strain-responsive elements affixed to the circumference of said locking body, said elements being oriented to detect changes in axial and circumferential dimensions of the locking body caused by changes in the residual forces of said soil and rock anchor.
- The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures, so that it may be more fully understood.
- With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
- In the drawings:
- Fig. 1
- is a cross-sectional view of a soil and rock anchor system, according to the present invention;
- Fig. 2
- is a cross-sectional view of the mechanical part of the cell, according to the invention;
- Fig. 3
- illustrates a load cell, according to the present invention;
- Fig. 4
- is an electrical circuit of the strain gages, according to the present invention, and
- Fig. 5
- illustrates another embodiment of the load cell according to the invention.
- There is seen in
Figs. 1 and 2 an anchor to be used with the load cell of the present invention. The anchor consists of a fixed or groutedportion 2 and afree portion 4.Multi-strand steel cables 6, advantageously four of them, with one of their ends fixedly attached to the groutedanchor portion 2, are lead through a central hole in a bearing plate 8 which is then brought into contact with the retaining structure 10. Alocking body 12, a cross-sectional view of which is seen inFig. 2 , is then placed over bearing plate 8, withcables 6 passing throughbores 14 in thesplit plugs 16 seated in theconical holes 18 inlocking body 12. The conicity of thesplit plugs 16 fit the conicity of theconical holes 18 in thelocking body 12, thus when thesplit plugs 16 accommodatingcables 6 are driven into thelocking body 12, thecables 6 are fixedly clamped into thelocking body 12. - The free ends of
cables 6 pass through a first hollowhydraulic jack 20, and then through a secondhollow jack 22, and are then attached to atensioning plate 24 seated onram 26 of thesecond jack 22. The required tension can now applied tocables 6 by thesecond jack 22, after whichsplit plugs 16 are forced intoconical holes 18 in thelocking body 12 by means of thefirst jack 20. Both jacks, 20 and 22, are then removed and the cable surplus is trimmed, rendering the anchor functional. - Referring to
Fig. 3 , there is illustrated a preferred embodiment of the present invention, according to which thelocking body 12 is turned into aload cell 28, becoming an integral part of the anchor rather than an extraneous element introduced for monitoring the forces. Theload cell 28 consists of abody 30 and strain-responsive elements, e.g.,strain gages 32 forming part of anelectronic circuit 34, illustrated inFig. 4 . Advantageously, theelectronic circuit 34 is affixed in agroove 36 made in the circumference of thebody 30 of theload cell 28. Thecircuit 34 can be affixed on thebody 30 or in thegroove 36 by using one of the bonding compounds manufactured for this purpose, e.g., M-Bond 43-B (Vishay). After the bonding procedure, thegages 32 are covered with a special protective coat. Other types of strain-responsive elements, such as hydraulic elements or devices, could also be utilized. - The
electronic circuit 34 shown inFig 4 is in the form of a four-arm double Wheatstone Bridge. Each arm of the Wheatstone Bridge contains two strain gages. Two opposite arms contain strain gages, S, S', while the other two opposite arms contain strain gages Sp, S'p. As further indicated inFig. 4 , the arms with the strain gages S, S' have their axes of sensitivity in the direction of the axial strain of theload cell 28, while the arms having strain gages Sp, S'p have their axes of sensitivity in the direction of the circumferential strain on thebody cell 28. The strain gages S, S' and Sp, S'p, respectively, are connected in series. Thus, when a compressive load is applied to theload cell 28, it contracts along the longitudinal axis and expands in the circumferential direction (Poisson's Effect). - Typically, the resistance of each strain gage is 350 Ohm, and thus, the total resistance of each arm is 700 Ohm. For excitation, direct current with a stabilized voltage between 3 V and 10 V is applied. The
circuit 34 is connected to areadout unit 38 which transforms the analog output of theload cell 28 into a digital one and connects via a suitable USB cable to aportable computer 40. - Before installation as part of the anchor, the
load cell 28 is put in a suitable calibration device, and stressed to the maximum permissible load. The load is then relaxed in stages, and the readout for each load saved as a calibration table or curve. - After the anchor is installed, tested and locked, an initial reading of the device is performed. Further readings are later taken on demand. If these are identical to the initial reading, it means that there was no loss in the anchoring force. By use of the calibration curve, lower readings may be retransformed to obtain the residual anchor force.
- Another embodiment of the load cell is shown in
Fig. 5 , in whichcables 6 of the anchor are replaced by asingle steel rod 42 with a threaded end, and the substantiallycylindrical load cell 28 by acylindrical nut 44. The latter may be of the self-locking type, or a counter-nut (not shown) may be applied. Also seen is the protective layer or coating 46 covering the gages affixed to thenut 44, or into a groove made therein. - It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (15)
- A load cell for monitoring the residual forces in a pre-stressed soil and rock anchor, comprising:a locking body having at least one hole through which a tensioning element passes, andan electronic bridge circuit containing strain-responsive elements affixed to the circumference of said locking body, said elements being oriented to detect changes in axial and circumferential dimensions of the locking body caused by changes in the residual forces of said soil and rock anchor.
- The load cell as claimed in claim 1, wherein said locking body is a cylindrical body.
- The load cell as claimed in claim 1, wherein said locking body is a prismatic body.
- The load cell as claimed in claim 1, wherein said bridge circuit is a Wheatstone Bridge comprising four arms.
- The load cell as claimed in claim 4, wherein each arm of said Wheatstone Bridge includes two strain gages connected in series.
- The load cell as claimed in claim 5, wherein the strain gages of one arm have their axes of sensitivity in the direction of the axial strain applied to said locking body, and the strain gages of the other two arms have their axes of sensitivity in the direction of the circumferential strain applied to said locking body.
- The load cell as claimed in 1, wherein said locking body comprises a circumferential groove and said electronic bridge circuit is affixed in said groove.
- The load cell as claimed in claim 1, further comprising readout instruments converting analogue output signals from said strain gages into digital signals.
- The load cell as claimed in claim 1, wherein said electronic circuit is covered by a protective layer.
- The load cell as claimed in claim 1, wherein said locking body contains at least one axial conical hole and further comprises tapered locking means consisting of a conical and split plug, wherein the conicity of said hole and of said plug is matching.
- The load cell as claimed in claim 10, wherein said soil and rock anchor further comprising:at least one tensioning element having one free end, the other end of which is fixedly attached to the soil-side end of said anchor;said locking body being mounted on a bearing plate making contact with a structure to be anchored, andsaid locking means fixedly lock at least one tensioning element inside said locking body after a predetermined pre-stressing force has been applied to said tensioning means.
- The load cell as claimed in claim 11, wherein said hole tapers towards the face of said locking body that is mounted on said bearing plate.
- The load cell as claimed in claim 11, wherein said tensioning element is a steel cable.
- The load cell as claimed in claim 11, wherein said tensioning element is a steel rod, at least one end portion of which is threaded.
- The load cell as claimed in claim 11, wherein said locking means is a self-locking nut.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07007601A EP1980712A1 (en) | 2007-04-13 | 2007-04-13 | Load cell for ground anchors |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07007601A EP1980712A1 (en) | 2007-04-13 | 2007-04-13 | Load cell for ground anchors |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1980712A1 true EP1980712A1 (en) | 2008-10-15 |
Family
ID=38441916
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP07007601A Withdrawn EP1980712A1 (en) | 2007-04-13 | 2007-04-13 | Load cell for ground anchors |
Country Status (1)
Country | Link |
---|---|
EP (1) | EP1980712A1 (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2085521A1 (en) * | 2008-01-28 | 2009-08-05 | Dywidag-Systems International GmbH | Soil or rock anchor with an anchor pull made of one or more individual elements with corrosion protected anchor head design |
EP2248951A1 (en) * | 2009-05-08 | 2010-11-10 | Keller Holding gmbh | Method and device for determining the axial force progression in a pressure-grouted anchor |
CN102296606A (en) * | 2011-07-22 | 2011-12-28 | 山东大学 | Mortar anchor rod for supporting in underground engineering model test and construction method |
CN103912027A (en) * | 2014-04-24 | 2014-07-09 | 中国科学院武汉岩土力学研究所 | Site anchoring test manufacturing, installing and automatic data collection method |
WO2014049529A3 (en) * | 2012-09-28 | 2015-05-07 | Wekaba Engineering (Proprietary) Limited | Installation of stressing assemblies |
JP2017043949A (en) * | 2015-08-26 | 2017-03-02 | 国立大学法人京都大学 | Assessment device for remnant tensile force of anchorage body |
CN109060525A (en) * | 2018-07-02 | 2018-12-21 | 中国科学院武汉岩土力学研究所 | The test method and device of drawing process force analysis |
CN109556770A (en) * | 2019-01-15 | 2019-04-02 | 法智达(北京)科技有限公司 | A kind of intelligence anchor bolt and the steel plate support construction with the intelligence anchor bolt |
JP2019512626A (en) * | 2016-11-18 | 2019-05-16 | 蘇州市能工基礎工程有限責任公司Suzhou Ng.Foundation Engineering Co.,Ltd | Hot melt anchor head |
JP2019128272A (en) * | 2018-01-25 | 2019-08-01 | 西日本高速道路株式会社 | Estimation method of tensioning force of tendon in ground anchor |
CN111395413A (en) * | 2020-03-20 | 2020-07-10 | 广东交科检测有限公司 | Post-construction anchor cable prestress sensor mounting system and method |
CN113653522A (en) * | 2021-09-16 | 2021-11-16 | 河海大学 | Self-tapping type yielding anchor rod capable of controlling large deformation of soft rock and having displacement monitoring function |
EP4102199A1 (en) | 2021-06-10 | 2022-12-14 | Fundación Tecnalia Research & Innovation | Strain gauge load cell for monitoring the strain in prestressed elements or elements subjected to axial strain |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2199952A (en) * | 1987-01-16 | 1988-07-20 | Coal Ind | Method and apparatus for measuring load on a rock bolt |
DE4408043A1 (en) * | 1994-03-10 | 1995-09-28 | Hochtief Ag Hoch Tiefbauten | Clamping force monitoring device for clamp element |
US5919006A (en) * | 1997-02-14 | 1999-07-06 | Jennmar Corporation | Tensionable cable bolt with mixing assembly |
WO2003033877A1 (en) * | 2001-10-15 | 2003-04-24 | Johannes Diderick De Klerk | A rock anchor load indicator |
US20050231377A1 (en) * | 2001-12-31 | 2005-10-20 | Sunderman Carl B | Instrumented rock bolt, data logger and user interface system |
-
2007
- 2007-04-13 EP EP07007601A patent/EP1980712A1/en not_active Withdrawn
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2199952A (en) * | 1987-01-16 | 1988-07-20 | Coal Ind | Method and apparatus for measuring load on a rock bolt |
DE4408043A1 (en) * | 1994-03-10 | 1995-09-28 | Hochtief Ag Hoch Tiefbauten | Clamping force monitoring device for clamp element |
US5919006A (en) * | 1997-02-14 | 1999-07-06 | Jennmar Corporation | Tensionable cable bolt with mixing assembly |
WO2003033877A1 (en) * | 2001-10-15 | 2003-04-24 | Johannes Diderick De Klerk | A rock anchor load indicator |
US20050231377A1 (en) * | 2001-12-31 | 2005-10-20 | Sunderman Carl B | Instrumented rock bolt, data logger and user interface system |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2085521A1 (en) * | 2008-01-28 | 2009-08-05 | Dywidag-Systems International GmbH | Soil or rock anchor with an anchor pull made of one or more individual elements with corrosion protected anchor head design |
EP2248951A1 (en) * | 2009-05-08 | 2010-11-10 | Keller Holding gmbh | Method and device for determining the axial force progression in a pressure-grouted anchor |
CN102296606A (en) * | 2011-07-22 | 2011-12-28 | 山东大学 | Mortar anchor rod for supporting in underground engineering model test and construction method |
CN102296606B (en) * | 2011-07-22 | 2013-08-28 | 山东大学 | Mortar anchor rod for supporting in underground engineering model test and construction method |
WO2014049529A3 (en) * | 2012-09-28 | 2015-05-07 | Wekaba Engineering (Proprietary) Limited | Installation of stressing assemblies |
CN103912027B (en) * | 2014-04-24 | 2015-10-21 | 中国科学院武汉岩土力学研究所 | A kind of fabrication and installation of anchored in situ test and automatic data collection method |
CN103912027A (en) * | 2014-04-24 | 2014-07-09 | 中国科学院武汉岩土力学研究所 | Site anchoring test manufacturing, installing and automatic data collection method |
JP2017043949A (en) * | 2015-08-26 | 2017-03-02 | 国立大学法人京都大学 | Assessment device for remnant tensile force of anchorage body |
JP2019512626A (en) * | 2016-11-18 | 2019-05-16 | 蘇州市能工基礎工程有限責任公司Suzhou Ng.Foundation Engineering Co.,Ltd | Hot melt anchor head |
JP2019128272A (en) * | 2018-01-25 | 2019-08-01 | 西日本高速道路株式会社 | Estimation method of tensioning force of tendon in ground anchor |
CN109060525A (en) * | 2018-07-02 | 2018-12-21 | 中国科学院武汉岩土力学研究所 | The test method and device of drawing process force analysis |
CN109556770A (en) * | 2019-01-15 | 2019-04-02 | 法智达(北京)科技有限公司 | A kind of intelligence anchor bolt and the steel plate support construction with the intelligence anchor bolt |
CN111395413A (en) * | 2020-03-20 | 2020-07-10 | 广东交科检测有限公司 | Post-construction anchor cable prestress sensor mounting system and method |
EP4102199A1 (en) | 2021-06-10 | 2022-12-14 | Fundación Tecnalia Research & Innovation | Strain gauge load cell for monitoring the strain in prestressed elements or elements subjected to axial strain |
CN113653522A (en) * | 2021-09-16 | 2021-11-16 | 河海大学 | Self-tapping type yielding anchor rod capable of controlling large deformation of soft rock and having displacement monitoring function |
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