CN111397775B - Prestress monitoring device - Google Patents

Prestress monitoring device Download PDF

Info

Publication number
CN111397775B
CN111397775B CN202010313633.3A CN202010313633A CN111397775B CN 111397775 B CN111397775 B CN 111397775B CN 202010313633 A CN202010313633 A CN 202010313633A CN 111397775 B CN111397775 B CN 111397775B
Authority
CN
China
Prior art keywords
polar plate
wall
connecting piece
plate wall
plate
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.)
Expired - Fee Related
Application number
CN202010313633.3A
Other languages
Chinese (zh)
Other versions
CN111397775A (en
Inventor
王宗建
崔青松
卢谅
王志鹏
李博文
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chongqing Jiaotong University
Original Assignee
Chongqing Jiaotong University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Chongqing Jiaotong University filed Critical Chongqing Jiaotong University
Priority to CN202010313633.3A priority Critical patent/CN111397775B/en
Publication of CN111397775A publication Critical patent/CN111397775A/en
Application granted granted Critical
Publication of CN111397775B publication Critical patent/CN111397775B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01LMEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00Measuring force or stress, in general
    • G01L1/14Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
    • G01L1/142Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators using capacitors
    • G01L1/144Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators using capacitors with associated circuitry

Abstract

The invention discloses a prestress monitoring device, which is used for being installed on a tension member loaded with prestress, wherein the tension member comprises a first connecting piece and a second connecting piece, and an elastic component for storing force is connected between the first connecting piece and the second connecting piece; the monitoring device is characterized by comprising a first polar plate and a second polar plate which are parallel to each other and oppositely arranged, wherein the first polar plate and the second polar plate are respectively used for being fixedly arranged on the first connecting piece and the second connecting piece; and the first polar plate and the second polar plate are also connected with a measuring circuit for detecting capacitance change between the first polar plate and the second polar plate. The invention has the advantages of ingenious structural design, convenient installation and use, capability of accurately monitoring the prestress change and the like.

Description

Prestress monitoring device
Technical Field
The invention relates to the technical field of civil engineering, in particular to a prestress monitoring device.
Background
With the development of social technology and economy, people have higher and higher requirements on the aspects of structural stability and functional diversity of buildings, material saving, high-efficiency and economical materials and the like. By prestressing the member prior to loading, not only is the member's resistance to cracking and stiffness improved, but the life of the structural member is also increased. Therefore, the inventor has applied for a stress control type reinforcement inclusion structure and a Chinese patent of a foundation treatment construction method thereof, the application number is 2014107868852, the concrete structure is shown in figure 1, the stress control type reinforcement inclusion structure comprises at least one layer of geotechnical pad and a stress applying device; the geotechnical pad comprises a geogrid 1, a geotechnical non-woven fabric and a filler from outside to inside, wherein the geotechnical non-woven fabric is arranged on the inner side of the geogrid 1, and the filler is placed on the inner side of the geotechnical non-woven fabric; wherein, the stress applying device comprises upper and lower pressing plates 21, 22 and a tension member disposed between the upper and lower pressing plates 21, 22 for tensioning the upper and lower pressing plates 21, 22; the tension member comprises a connecting rod, the upper end of the connecting rod extends out of the upper pressure plate 21, the upper end of the connecting rod is provided with a nut 8 for screwing, the lower end of the connecting rod extends out of the lower pressure plate 22, and the lower end of the connecting rod is provided with a bolt 3; the connecting rod comprises lower connecting rod 4, upper connecting rod 5 and the spring 6 of setting between lower connecting rod 4 and upper connecting rod 5, the one end of spring 6 is connected with the lower extreme of upper connecting rod 4, and the other end of spring 6 is connected with the upper end of lower connecting rod 4. The section mechanical property of the whole reinforcement inclusion is changed by actively applying stress on the outer wrapping ribs through tensile stress applied by the tension members, so that the overall strength of the reinforcement inclusion is improved, and the deformation resistance of the reinforcement inclusion is improved.
However, due to the fact that the prestressed member is subjected to corrosion of different degrees, uneven settlement of a foundation, material characteristics and the like in the long-term use process, the working performance and stability of the structural member are affected by the loss of the prestress, and therefore it is necessary to establish an effective prestress monitoring and early warning device to monitor the prestressed structure in service.
Disclosure of Invention
Aiming at the defects of the prior art, the technical problems to be solved by the invention are as follows: how to provide a structural design ingenious, installation convenient to use can accurate monitoring prestressing force change's prestressing force monitoring devices.
In order to solve the technical problems, the invention adopts the following technical scheme:
a prestress monitoring device is used for being installed on a tension member loaded with prestress, the tension member comprises a first connecting piece and a second connecting piece, and an elastic component used for storing force is connected between the first connecting piece and the second connecting piece; the monitoring device is characterized by comprising a first polar plate and a second polar plate which are parallel to each other and oppositely arranged, wherein the first polar plate and the second polar plate are respectively used for being fixedly arranged on the first connecting piece and the second connecting piece; and the first polar plate and the second polar plate are also connected with a measuring circuit for detecting capacitance change between the first polar plate and the second polar plate.
In use, when the prestress of the tension member is changed, the length of the resilient member connected between the first link and the second link, which stores force, is also changed. The first polar plate and the second polar plate which are arranged oppositely in parallel are respectively and fixedly arranged on the first connecting piece and the second connecting piece of the tension member, the distance between the first connecting piece and the second connecting piece is changed by the length change of the elastic component, and further the distance between the first polar plate and the second polar plate which are fixedly arranged on the first connecting piece and the second connecting piece is changed, so that the capacitance between the first connecting piece and the second connecting piece is changed, the change of the distance between the first polar plate and the second polar plate can be reversely calculated by the change of the capacitance between the first polar plate and the second polar plate, and the monitoring of the prestress on the tension member can be realized.
Furthermore, the first polar plate and the second polar plate are both circular, one opposite sides of the first polar plate and the second polar plate are respectively provided with a first polar plate wall and a second polar plate wall which are integrally cylindrical, the outer diameter of the first polar plate wall is smaller than the inner diameter of the second polar plate wall, and the first polar plate wall faces towards one end of the second polar plate and is axially movably sleeved in the second polar plate wall.
Therefore, one end of the first plate wall is sleeved in the second plate wall, so that an overlapping area is formed between the first plate wall and the second plate wall in the radial direction, a capacitor is formed between the first plate wall and the second plate wall, once the prestress changes, the overlapping area of the area also changes, and the overlapping area is smaller in distance, so that the response to the change of the capacitor is more sensitive, and the detection precision can be improved.
Furthermore, a first filling layer and a second filling layer which are made of insulating materials are respectively arranged on the outer side of the first polar plate wall and the inner side of the second polar plate wall, and the outer diameter of the first filling layer is consistent with the inner diameter of the second filling layer.
Because the outer diameter of the first filling layer is consistent with the inner diameter of the second filling layer, when the first polar plate and the second polar plate move along with the first connecting piece and the second connecting piece, the first polar plate and the second polar plate can be always coaxial, the capacitance change between the first polar plate and the second polar plate is controllable, and the detection result is more reliable.
Furthermore, a first heat insulation layer and a second heat insulation layer which are made of heat insulation materials are respectively arranged on the inner side of the first polar plate wall or/and the outer side of the second polar plate wall.
Therefore, the capacitance change caused by expansion with heat and contraction with cold due to the change of the external temperature can be avoided as much as possible, and the detection accuracy and reliability are ensured.
Furthermore, the first polar plate wall and the second polar plate wall are both in a circular truncated cone shape, and the conicity of the first polar plate wall and the conicity of the second polar plate wall are equal; the diameter of the first polar plate wall is gradually reduced along the direction departing from the first polar plate, and the diameter of the second polar plate wall is gradually increased along the direction departing from the second polar plate.
Because the first plate wall and the second plate wall are in the shape of the circular truncated cone with the same taper, when the first plate wall and the second plate wall move relatively in the axial direction, the distance between the overlapping areas of the first plate wall and the second plate wall changes, so that the capacitance change between the first plate wall and the second plate wall is influenced by the double effects of the plate distance and the overlapping area, and the detection sensitivity is improved.
Furthermore, the outer wall of the first filling layer is provided with a first rib or a first groove which is arranged along the axial direction, the inner wall of the second filling layer is provided with a second groove or a second rib which is arranged corresponding to the first rib or the first groove along the axial direction, and the first rib is matched with the second groove or the first groove is matched with the second rib.
Thus, the relative positions of the first and second electrode walls in the circumferential direction can be restricted by the cooperation of the first rib and the first groove or the cooperation of the second groove and the second rib, so that the detected capacitance is affected only by the axial change of the tension member, thereby improving the accuracy and reliability of the detection.
Furthermore, a bearing is coaxially arranged in the middle of the first pole plate or/and the second pole plate, and the bearing is fixedly installed on the first connecting piece or/and the second connecting piece.
In this way, when the tension member rotates relative to the first connecting piece and the second connecting piece in the use process, the tension member can avoid the damage of the structures among the first polar plate, the first polar plate wall, the second polar plate and the second polar plate wall caused by applying a torsional force between the first polar plate and the second polar plate through the bearing connection, so that the reliability of the monitoring device is higher.
Further, the bearing is a spherical joint bearing.
Therefore, when the tension member deflects relatively between the first connecting piece and the second connecting piece in the use process, the first polar plate wall, the second polar plate and the second polar plate wall can be prevented from being damaged by extrusion, and the reliability of the monitoring device is higher.
In summary, compared with the prior art, the invention has the following advantages:
1. the principle of the device is that the change of the prestress is calculated by using the change of the capacitance, and a functional relation is established among the distance between the polar plates, the capacitance and the prestress. The monitored parameters are clear and easy to obtain, and the data processing is simple, efficient and easy to understand; the device of adoption is simple, can effectual reduction construction degree of difficulty.
2. The invention adopts the variable-gap capacitance sensor, has higher sensitivity, can measure micro linear displacement and realize non-contact measurement, and indirectly reduces the measurement error.
3. The device has the advantages of convenient acquisition of the materials of all elements and low cost.
4. Each part among the device of the invention highly integrates, small in size, does not have the influence to current prestressing force structural integrity, shallowly buries in the underground, only has capacitive sensor and relevant buried line in appearance, and is less to the disturbance of soil layer, has guaranteed the integrality of soil layer and the durability of whole structure.
5. The measured data can be monitored and analyzed in real time through the background of the computer data monitoring system, and timeliness of the monitoring process is guaranteed.
Drawings
Fig. 1 is a schematic diagram of a stress-controlled reinforcement package structure.
Fig. 2 is a sectional structural view illustrating an installation state of the tension member.
Fig. 3 is a sectional structural view of a portion of the tension member of fig. 2.
Fig. 4 is a schematic structural diagram of the first connecting member or the second connecting member in a deflected state.
Fig. 5 is an enlarged schematic view of the circle in fig. 4.
Detailed Description
The present invention will be described in further detail with reference to examples.
In the specific implementation: a prestress monitoring device for being installed on a tension member loaded with prestress as shown in fig. 2, wherein the tension member includes a first link 101 and a second link 102, and an elastic member 103 for accumulating force is connected between the first link 101 and the second link 102; the monitoring device comprises a first polar plate 301 and a second polar plate 401 which are parallel to each other and are arranged oppositely, wherein the first polar plate 301 and the second polar plate 401 are made of metal materials and are respectively fixedly arranged on the first connecting piece 101 and the second connecting piece 102; the first plate 301 and the second plate 401 are further connected with a measuring circuit for detecting capacitance change therebetween. The measuring circuit is a circuit for converting a capacitor into voltage or other electric quantities to detect, is mature in the prior art, is widely applied to a capacitive sensor, and can be a bridge circuit, a frequency modulation circuit, a pulse width modulation circuit, an operational amplifier circuit, a diode double-T-shaped alternating current bridge and the like in specific implementation. Since the improvement of the prior art by the present application is not a measurement circuit, it is not described herein in detail.
In use, when the prestress of the tension member is changed, the length of the resilient member connected between the first link and the second link, which stores force, is also changed. The first polar plate and the second polar plate which are arranged oppositely in parallel are respectively and fixedly arranged on the first connecting piece and the second connecting piece of the tension member, the distance between the first connecting piece and the second connecting piece is changed by the length change of the elastic component, and further the distance between the first polar plate and the second polar plate which are fixedly arranged on the first connecting piece and the second connecting piece is changed, so that the capacitance between the first connecting piece and the second connecting piece is changed, the change of the distance between the first polar plate and the second polar plate can be reversely calculated by the change of the capacitance between the first polar plate and the second polar plate, and the monitoring of the prestress on the tension member can be realized.
As shown in fig. 3, the first plate 301 and the second plate 401 are both circular, and the edges of the two extend in opposite directions to form a first plate wall 302 and a second plate wall 402 which are integrally cylindrical, the outer diameter of the first plate wall 302 is smaller than the inner diameter of the second plate wall 402, and one end of the first plate wall 302 facing the second plate 401 is axially movably sleeved in the second plate wall 402.
Therefore, one end of the first plate wall is sleeved in the second plate wall, so that an overlapping area is formed between the first plate wall and the second plate wall in the radial direction, a capacitor is formed between the first plate wall and the second plate wall, once the prestress changes, the overlapping area of the area also changes, and the overlapping area is smaller in distance, so that the response to the change of the capacitor is more sensitive, and the detection precision can be improved.
In practice, the outer side of the first plate wall 302 and the inner side of the second plate wall 402 are respectively provided with a first filling layer 303 and a second filling layer 403 made of insulating materials, and the outer diameter of the first filling layer 303 is consistent with the inner diameter of the second filling layer 403.
Because the outer diameter of the first filling layer is consistent with the inner diameter of the second filling layer, when the first polar plate and the second polar plate move along with the first connecting piece and the second connecting piece, the first polar plate and the second polar plate can be always coaxial, the capacitance change between the first polar plate and the second polar plate is controllable, and the detection result is more reliable.
In practice, the inner side of the first plate wall 302 or/and the outer side of the second plate wall 402 are respectively provided with a first heat insulation layer 304 and a second heat insulation layer 404 made of heat insulation materials.
Therefore, the capacitance change caused by expansion with heat and contraction with cold due to the change of the external temperature can be avoided as much as possible, and the detection accuracy and reliability are ensured.
As shown in fig. 3 to 5, the first plate wall 302 and the second plate wall 402 are both in a truncated cone shape, and the tapers of the two walls are equal; the diameter of the first plate wall 302 is gradually smaller in a direction away from the first plate 301, and the diameter of the second plate wall 402 is gradually larger in a direction away from the second plate 401.
Because the first plate wall and the second plate wall are in the shape of the circular truncated cone with the same taper, when the first plate wall and the second plate wall move relatively in the axial direction, the distance between the overlapping areas of the first plate wall and the second plate wall changes, so that the capacitance change between the first plate wall and the second plate wall is influenced by the double effects of the plate distance and the overlapping area, and the detection sensitivity is improved.
In implementation, the outer wall of the first filling layer 303 has a first rib or a first groove arranged along the axial direction, the inner wall of the second filling layer 403 has a second groove or a second rib arranged along the axial direction and corresponding to the first rib or the first groove, and the first rib is matched with the second groove or the first groove is matched with the second rib.
Thus, the relative positions of the first and second electrode walls in the circumferential direction can be restricted by the cooperation of the first rib and the first groove or the cooperation of the second groove and the second rib, so that the detected capacitance is affected only by the axial change of the tension member, thereby improving the accuracy and reliability of the detection.
In practice, the first polar plate 301 or/and the second polar plate 401 are coaxially provided with bearings at the middle thereof, and the bearings are fixedly mounted on the first connecting member 101 or/and the second connecting member 201.
In this way, when the tension member rotates relative to the first connecting piece and the second connecting piece in the use process, the tension member can avoid the damage of the structures among the first polar plate, the first polar plate wall, the second polar plate and the second polar plate wall caused by applying a torsional force between the first polar plate and the second polar plate through the bearing connection, so that the reliability of the monitoring device is higher.
As shown in fig. 5, the bearing is a spherical joint bearing. Therefore, when the tension member deflects relatively between the first connecting piece and the second connecting piece in the use process, the first polar plate wall, the second polar plate and the second polar plate wall can be prevented from being damaged by extrusion, and the reliability of the monitoring device is higher.
In this embodiment, the tension member of the prestressed reinforcement package shown in fig. 1 is monitored, wherein the lower connecting rod 4, the upper connecting rod 5 and the spring 6 correspond to the first connecting member 101, the second connecting member 102 and the elastic member 103 in fig. 2, respectively. In the specific monitoring process, the following steps are adopted:
1. uniformly coating a layer of insulating paint on the spring, the upper connecting rod and the lower connecting rod, then respectively installing the first polar plate and the second polar plate on the upper connecting rod and the lower connecting rod through the joint bearing, coaxially inserting the wall of the first polar plate into the wall of the second polar plate, and adjusting the design installation positions of the joint bearing to the upper connecting rod and the lower connecting rod.
2. Before monitoring, a group of tension members and a first polar plate 301, a first polar plate wall 302, a second polar plate 401 and a second polar plate wall 402 which are arranged on the tension members are selected, an external force along the axial direction is applied to the tension members, so that the distance between the first polar plate 301 and the second polar plate 401 is changed, meanwhile, a measuring circuit is adopted to detect the capacitance of the tension members, and the corresponding relation between the distance between the first polar plate 301 and the second polar plate 401 and the capacitance is determined.
3. When the device is installed on the spot, a round hole (namely a lead hole) with a diameter slightly larger than that of a lead is processed at one side of an upper connecting rod nut of the upper supporting pressure plate so as to lead out a data transmission line; and connecting the leads on the first polar plate and the second polar plate to a measuring circuit through the lead holes.
4. The tension member provided with the detection device is arranged at each key position of the soil rock foundation where uneven settlement easily occurs, the monitoring point positions are numbered, and data collection and arrangement are facilitated.
5. The capacitance is detected by the measuring circuit, and the implementation distance between the first plate and the second plate can be determined by the corresponding relation between the distance between the first plate 301 and the second plate 401 and the capacitance, so that the displacement deformation of the elastic component can be calculated, and the stress variation can be calculated according to the displacement deformation.
The above description is only exemplary of the present invention and should not be taken as limiting, and any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (2)

1. A prestress monitoring device is used for being installed on a tension member loaded with prestress, the tension member comprises a first connecting piece (101) and a second connecting piece (102), and an elastic component (103) used for accumulating force is connected between the first connecting piece (101) and the second connecting piece (102); the monitoring device is characterized by comprising a first polar plate (301) and a second polar plate (401) which are parallel to each other and oppositely arranged, wherein the first polar plate (301) and the second polar plate (401) are respectively used for being fixedly arranged on the first connecting piece (101) and the second connecting piece (102); the first polar plate (301) and the second polar plate (401) are also connected with a measuring circuit for detecting capacitance change between the first polar plate and the second polar plate;
the first polar plate (301) and the second polar plate (401) are both circular, one opposite sides of the first polar plate and the second polar plate are respectively provided with a first polar plate wall (302) and a second polar plate wall (402) which are integrally cylindrical, the outer diameter of the first polar plate wall (302) is smaller than the inner diameter of the second polar plate wall (402), and one end, facing the second polar plate (401), of the first polar plate wall (302) is axially movably sleeved in the second polar plate wall (402);
a first filling layer (303) and a second filling layer (403) made of insulating materials are respectively arranged on the outer side of the first plate wall (302) and the inner side of the second plate wall (402), and the outer diameter of the first filling layer (303) is consistent with the inner diameter of the second filling layer (403); a first heat insulation layer (304) and a second heat insulation layer (404) which are made of heat insulation materials are respectively arranged on the inner side of the first polar plate wall (302) or/and the outer side of the second polar plate wall (402);
the first plate wall (302) and the second plate wall (402) are both in a circular truncated cone shape, and the conicity of the first plate wall and the conicity of the second plate wall are equal; the diameter of the first polar plate wall (302) is gradually reduced along the direction departing from the first polar plate (301), and the diameter of the second polar plate wall (402) is gradually increased along the direction departing from the second polar plate (401);
the middle parts of the first polar plate (301) or/and the second polar plate (401) are coaxially provided with bearings, the bearings are fixedly arranged on the first connecting piece (101) or/and the second connecting piece (201), and the bearings are spherical joint bearings.
2. The prestress monitoring device according to claim 1, wherein the first filling layer (303) has a first rib or a first groove arranged along the axial direction on the outer wall, and the second filling layer (403) has a second groove or a second rib arranged along the axial direction on the inner wall and corresponding to the first rib or the first groove, and the first rib is matched with the second groove or the first groove is matched with the second rib.
CN202010313633.3A 2020-04-21 2020-04-21 Prestress monitoring device Expired - Fee Related CN111397775B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010313633.3A CN111397775B (en) 2020-04-21 2020-04-21 Prestress monitoring device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010313633.3A CN111397775B (en) 2020-04-21 2020-04-21 Prestress monitoring device

Publications (2)

Publication Number Publication Date
CN111397775A CN111397775A (en) 2020-07-10
CN111397775B true CN111397775B (en) 2021-11-19

Family

ID=71435504

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010313633.3A Expired - Fee Related CN111397775B (en) 2020-04-21 2020-04-21 Prestress monitoring device

Country Status (1)

Country Link
CN (1) CN111397775B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104155045A (en) * 2014-07-31 2014-11-19 中北大学 Built-in pressure test instrument
CN104532819A (en) * 2014-12-18 2015-04-22 重庆大学 Stress control type reinforcement enclosure structure and foundation treatment construction method thereof
CN106838510A (en) * 2017-04-07 2017-06-13 重庆巨龙管业有限公司 Prestressed concrete cylinder pipe bell and spigot connector
CN109838695A (en) * 2019-01-23 2019-06-04 洛阳双瑞特种装备有限公司 A kind of interior die mould expansion joint device for detecting axial displacement
CN110514345A (en) * 2019-08-23 2019-11-29 武汉科技大学 A kind of measurement monitoring device of condenser type bolt pretightening

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2224218B1 (en) * 2009-02-25 2018-11-28 Sensirion Automotive Solutions AG A sensor in a moulded package and a method for manufacturing the same
CN101502947B (en) * 2009-03-02 2011-02-09 南京大学 Acoustic emission sensor
CN201874246U (en) * 2010-09-26 2011-06-22 北京华泰天成科技发展有限公司 Prestressed tendon tensioning device
CN102154981B (en) * 2011-04-09 2013-03-06 刘喜元 Corrugated pipe capable of measuring prestress
JP6012069B2 (en) * 2012-09-13 2016-10-25 株式会社ワコム Electromagnetic induction type position indicator and electronic ink cartridge
CN104990649B (en) * 2015-07-29 2017-11-17 重庆交通大学 A kind of simple steel strand prestress measurement apparatus and method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104155045A (en) * 2014-07-31 2014-11-19 中北大学 Built-in pressure test instrument
CN104532819A (en) * 2014-12-18 2015-04-22 重庆大学 Stress control type reinforcement enclosure structure and foundation treatment construction method thereof
CN106838510A (en) * 2017-04-07 2017-06-13 重庆巨龙管业有限公司 Prestressed concrete cylinder pipe bell and spigot connector
CN109838695A (en) * 2019-01-23 2019-06-04 洛阳双瑞特种装备有限公司 A kind of interior die mould expansion joint device for detecting axial displacement
CN110514345A (en) * 2019-08-23 2019-11-29 武汉科技大学 A kind of measurement monitoring device of condenser type bolt pretightening

Also Published As

Publication number Publication date
CN111397775A (en) 2020-07-10

Similar Documents

Publication Publication Date Title
CN102839693B (en) Increase resistive shape anchor pole/anchorage cable anchoring quality monitoring device and application process
CN102720220B (en) Device and method for measuring counterforce of pile end of concrete pipe pile
CN101736728B (en) Elastic beam type side wall frictional resistance dynamometer
CN106705877A (en) High-sensitivity fiber Bragg grating strain sensor based on flexible hinges
CN111397775B (en) Prestress monitoring device
KR20090071102A (en) Load test apparatus for pile type structure
CN111413018B (en) Prestress monitoring method for stress control type reinforcement inclusion
CN204945097U (en) For the waveguide rod of acoustic emission detection
CN113532302A (en) Pipeline strain monitoring and early warning system and method
CN111075487A (en) Anchor rod with function of measuring surrounding rock strain and temperature coupling
CN105157999A (en) Method for assessing pile integrity and lateral displacement based on distributed optical fiber sensing technology
Dallyn et al. Prediction of wear in grouted connections for offshore wind turbine generators
CN109813368A (en) A kind of steel construction indirect cool tower risk monitoring system
CN106677812A (en) Fiber grating force measurement anchor rod
CN108592778B (en) Anchorage structure displacement monitoring devices based on electric capacity changes
CN207675142U (en) Pressure sensing type deformation monitoring device based on metal measurement pipe
CN105172838A (en) Punching-free type shear force sensor
CN107024306B (en) Intelligent bolt and method for monitoring complex load effect
CN101761097B (en) Device for testing pile bottom stress of bored concrete pile
CN201408095Y (en) Spring resistance type anchor stem dynamometer
CN201581419U (en) Elastic beam type side wall frictional resistance dynamometer
CN109443231B (en) Stress-free meter based on optical fiber sensing
CN206205921U (en) A kind of fiber grating force-measuring anchor stock
CN206756107U (en) A kind of nut strain and device for detecting temperature based on FBG Sensing Technology
CN218937604U (en) Steel-concrete beam temperature field and temperature effect measurement system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20211119