CN106840019B - Sensitivity test system for borehole strain gauge - Google Patents
Sensitivity test system for borehole strain gauge Download PDFInfo
- Publication number
- CN106840019B CN106840019B CN201710146085.8A CN201710146085A CN106840019B CN 106840019 B CN106840019 B CN 106840019B CN 201710146085 A CN201710146085 A CN 201710146085A CN 106840019 B CN106840019 B CN 106840019B
- Authority
- CN
- China
- Prior art keywords
- strain gauge
- pressure head
- probe
- laser displacement
- displacement sensor
- 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.)
- Active
Links
- 230000035945 sensitivity Effects 0.000 title claims abstract description 30
- 238000012360 testing method Methods 0.000 title claims abstract description 23
- 239000000523 sample Substances 0.000 claims abstract description 60
- 238000006073 displacement reaction Methods 0.000 claims abstract description 42
- 238000005553 drilling Methods 0.000 claims abstract description 38
- 101100328887 Caenorhabditis elegans col-34 gene Proteins 0.000 description 5
- RRLHMJHRFMHVNM-BQVXCWBNSA-N [(2s,3r,6r)-6-[5-[5-hydroxy-3-(4-hydroxyphenyl)-4-oxochromen-7-yl]oxypentoxy]-2-methyl-3,6-dihydro-2h-pyran-3-yl] acetate Chemical compound C1=C[C@@H](OC(C)=O)[C@H](C)O[C@H]1OCCCCCOC1=CC(O)=C2C(=O)C(C=3C=CC(O)=CC=3)=COC2=C1 RRLHMJHRFMHVNM-BQVXCWBNSA-N 0.000 description 5
- 238000005259 measurement Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
- G01B7/22—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in capacitance
Abstract
The invention provides a sensitivity test system of a borehole strain gauge, which comprises the following components: the drilling strain gauge probe comprises a manual hydraulic pump, a laser displacement sensor, a support, an upper pressure head and a lower pressure head, wherein the manual hydraulic pump is used for installing the drilling strain gauge probe at the central part of the support through the upper pressure head and the lower pressure head, the upper pressure head and the lower pressure head are provided with grooves at the contact part with the drilling strain gauge probe and used for fixing the drilling strain gauge probe, and the laser displacement sensor is positioned near the grooves to measure the displacement change of the drilling strain gauge probe at the contact part. The drilling strain gauge probe outer cylinder is subjected to concentrated stress in the radial measuring direction through the manual hydraulic pump, the deformation of the probe outer cylinder at the stress position is measured through the high-precision laser displacement sensor, the readings of the laser displacement sensor and the differential capacitance sensor arranged in the probe are recorded, and the parameters such as the sensitivity and the linearity of the instrument can be calculated. The invention not only can provide larger and stable calibration force, but also has higher calibration precision.
Description
Technical Field
The invention relates to a mechanical hydraulic and electronic measurement system, in particular to a sensitivity test system for a drilling strain gauge, which can test basic parameters such as sensitivity, linearity and the like of a long cylinder drilling observation instrument of a drilling strain gauge with higher equivalent elastic modulus.
Background
In geophysical and earth observation, various borehole instruments are often used to observe earth stress and strain in a borehole. In observation, firstly, holes are punched in the part to be measured of the crust, then, an observation probe is lowered to a hole section to be measured, and the observation probe is coupled with the hole wall in a cement pouring or mechanical supporting mode, so that the boundary condition of welding coupling between the probe and the hole wall is achieved. Therefore, the deformation of the rock in the drill hole can be transmitted to the probe, and the observation instrument can achieve the purpose of observing the ground stress strain according to the deformation of the probe. In order to adapt to the observation environment and the requirement of observation, the equivalent modulus of the instrument is higher (generally 10 3 On the order of Mpa or higher), with a measurement resolution of 10 -10 The strain magnitude, therefore, the testing device can provide larger calibration force and meet the requirement of high-resolution measurement precision, which brings difficulty to the whole machine testing of the sensitivity and linearity of the instrument.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides an indoor whole machine sensitivity test system for a borehole strain gauge.
The invention provides a sensitivity test system of a drilling strain gauge, which is used for testing the sensitivity of the drilling strain gauge and comprises the following components: a manual hydraulic pump, a laser displacement sensor, a bracket, an upper pressure head and a lower pressure head, wherein,
the manual hydraulic pump is characterized in that the drilling strain gauge probe is arranged at the central part of the support through an upper pressure head and a lower pressure head, the upper pressure head and the lower pressure head are provided with grooves at the contact part with the drilling strain gauge probe and used for fixing the drilling strain gauge probe, and the laser displacement sensor is positioned near the grooves to measure the displacement change of the drilling strain gauge probe at the contact part.
Preferably, the manual hydraulic pump comprises a plunger, a plunger cavity, a rubber tube and a pump body, wherein the plunger can slide up and down along an axis in the plunger cavity, and the pump body is connected with the plunger cavity through the rubber tube.
Preferably, the bracket comprises a base, a column and a top plate, and the base and the top plate are connected through the column.
Preferably, a plunger cavity of the manual hydraulic pump is fixed on a top plate of the bracket, the plunger cavity is abutted against an upper pressure head, and a lower pressure head is fixed on the base.
Preferably, the plunger is contacted with and separated from the upper pressure head under the control of the pump body, and the pressure is transmitted to the drill strain gauge probe through the plunger and the upper pressure head, so that the drill strain gauge probe is elastically deformed at the grooves of the upper pressure head and the lower pressure head.
Preferably, the laser displacement sensor comprises an upper laser displacement sensor and a lower laser displacement sensor which are positioned near grooves of the upper pressure head and the lower pressure head, and the displacement changes of two positions of the radial symmetry of the drilling strain gauge probe are respectively measured.
Preferably, the axes of the differential capacitive sensors inside the laser displacement sensor and the borehole strain gauge are located on the same vertical line.
Preferably, the groove is a V-shaped groove or a circular arc groove.
The beneficial effects of the invention are as follows: the drilling strain gauge probe outer cylinder is subjected to concentrated stress in the radial measuring direction through the manual hydraulic pump, the deformation of the probe outer cylinder at the stress position is measured through the high-precision laser displacement sensor, the readings of the laser displacement sensor and the differential capacitance sensor arranged in the probe are recorded, and the parameters such as the sensitivity and the linearity of the instrument can be calculated. The sensitivity test system of the borehole strain gauge can provide larger and stable calibration force (5000N) and has higher calibration precision.
Drawings
FIG. 1 is a schematic diagram of a borehole strain gauge sensitivity test system according to the present invention.
Fig. 2 is a schematic diagram of a straight line fit of input and output.
Detailed Description
The invention is further illustrated by the following examples, which are only intended to better understand the content of the study of the invention and are not intended to limit the scope of the invention.
As shown in fig. 1, the borehole strain gauge sensitivity test system of the present invention is used for testing the sensitivity of a borehole strain gauge 6, and comprises: the drilling strain gauge probe comprises a manual hydraulic pump 1, a laser displacement sensor 2, a support 3, an upper pressing head 4 and a lower pressing head 5, wherein the manual hydraulic pump 1 is used for fixing a drilling strain gauge probe 61 at the central part of the support 3 through the upper pressing head 4 and the lower pressing head 5, grooves are formed in the contact positions of the upper pressing head 4 and the lower pressing head 5 with the drilling strain gauge probe and used for fixing the drilling strain gauge probe, and the laser displacement sensor 2 is located near the grooves to measure displacement changes of the drilling strain gauge probe at the contact positions.
In the present invention, the borehole strain gauge 6 as a test object includes a borehole strain gauge probe 61 and a differential capacitance sensor 62, and the differential capacitance sensor 62 is mounted inside the borehole strain gauge probe 61 to measure the strain after deformation of the probe 61.
Specifically, the manual hydraulic pump 1 includes a plunger 11, a plunger chamber 12, a hose 13, and a pump body 14. The plunger 11 can slide up and down along the axis in the plunger cavity 12, and the pump body 14 and the plunger cavity 12 are connected through a rubber tube 13. Shaking the handle on the pump body 14 forces oil into the plunger cavity 12 and transfers pressure by downward movement of the plunger 11. Opening the relief valve on the pump body 14 releases pressure, retracting the plunger 11 upward into the plunger cavity 12.
The bracket 3 includes a base 31, a column 32, and a top plate 33. The base 31 and the top plate 33 are connected by a column 32.
The plunger chamber 12 of the manual hydraulic pump 1 is fixed to the top plate 33 of the bracket 3. The plunger cavity 12 abuts against the upper ram 4 (the two can be separated freely for easy assembly and disassembly) and the lower ram 5 is fixed on the base 31. The drilling strain gauge probe 61 is placed on the groove 51 of the lower ram 5, and the groove 41 of the upper ram 4 is pressed down on the drilling strain gauge probe 61, thereby fixing the drilling strain gauge probe 61 to the central portion of the bracket 3. The grooves 41,51 are matched with the curved arc of the outer cylinder of the probe so as to stably fix the probe. Preferably, the grooves 41,51 may be V-shaped grooves or circular arc-shaped grooves.
When the pump body 14 of the manual hydraulic pump 1 is controlled so that the plunger 11 and the upper ram 4 are brought into contact and separated, pressure can be transmitted to the borehole strain gauge probe 61 through the plunger 11 and the upper ram 4, so that it is elastically deformed at the V-grooves of the upper and lower rams 4, 5. Specifically, the pump body 14 is operated to pressurize, so that the plunger 11 moves downwards, pressure is generated after the plunger is pressed against the upper pressing head 4, the pressure is transmitted to the drilling strain gauge probe 61 through the upper pressing head 4, and the drilling strain gauge probe 61 deforms at the contact position of the grooves of the upper pressing head 4 and the lower pressing head 5.
The laser displacement sensor 2 includes a pair of upper and lower laser displacement sensors 21,22 respectively located near the grooves (upper and lower contact deformation positions) of the upper and lower indenters 4,5, and measures the displacement variation of the upper and lower positions (upper and lower contact positions) of the borehole strain gauge probe 61 radially symmetrical by the laser triangulation method, while measuring the strain variation generated by the borehole strain gauge probe 61 by the differential capacitance sensor 62. And, the axes of the differential capacitance sensors 62 inside the pair of laser displacement sensors 21 and 22 and the drilling strain gauge 6 are positioned on the same vertical line, and the positioning of the laser displacement sensors and the differential capacitance sensors on the same line can ensure that the laser displacement sensors and the differential capacitance sensors measure the deformation of the same position of the probe outer cylinder, so that the error of sensitivity measurement is reduced. In addition, the laser displacement sensor measures the deformation of the outer wall of the measuring point, the differential capacitance sensor measures the deformation of the inner wall of the measuring point, and the difference between the two is very small, so that the two sensors can be regarded as the same object.
The operation of the sensitivity test system of Kong Yingbian instrument of the drill of the present invention will be described in detail.
First, the base 31, the lower ram 5, the column 32, the plunger 11, the top plate 33, the plunger cavity 12, the hose 13, and the pump body 14 are installed as in fig. 1. The oil drain valve on the pump body 14 is opened to retract the plunger 11 into the plunger cavity 12. The borehole strain gauge probe 61 is placed on the recess 51 of the lower ram 5 and kept horizontally stable, and the borehole strain gauge probe 61 is rotated to ensure that both ends of the differential capacitive sensor 62 are in a vertical position and located near the recess 51 in a horizontal plane. The groove 41 of the upper ram 4 is pressed down on the borehole strain gauge probe 61 and on the same vertical line as the groove 51 of the lower ram 5. The oil drain valve on the pump body 14 is closed and pressurized, so that the plunger 11 moves downwards until a certain pre-pressure is generated after the plunger abuts against the upper pressure head 4.
Next, a pair of laser displacement sensors 2 (upper laser displacement sensor 21, lower laser displacement sensor 22) are installed so that the measuring light spots thereof are aligned with the upper and lower ends of the differential capacitive sensor 62, respectively, and the laser displacement sensors 2 are ensured to be within the effective measuring range.
The pump body 14 of the manual hydraulic gauge 1 is operated to be pressurized again, so that the drilling strain gauge probe 61 is elastically deformed at the contact position of the grooves 41,51 of the upper and lower rams 4, 5. The pair of laser displacement sensors 21,22 measure the displacement variation of the two positions (upper and lower contact positions) of the drill strain gauge probe 61 radially symmetrical by the laser triangulation method, while the differential capacitance sensor 62 measures the strain variation generated by the drill strain gauge probe 61. The change in readings of the next pair of laser displacement sensors 21,22 is recorded as a standard input, while the change in readings of the differential capacitive sensor 62 is recorded as an output, and the sensitivity and linearity of the borehole strain gauge are calculated after measuring several times in succession. Sensitivity refers to the response of an instrument to a unit input and indicates how sensitive the instrument is to the input. Linearity refers to a measure of whether the input and output remain linearly proportional over the span. After the sensitivity is measured, the linearity can be calculated from the data. How the sensitivity and linearity of the rotation hole strain gauge are calculated from the output of the sensor is described in detail below by way of examples.
Around 10 points are measured sequentially in the range, and the number of times the input xi and the output yi of each point, i representing the measured point, are recorded (table 1 below). Then, straight line fitting (as shown in fig. 2) is performed, and a fitting formula is obtained: y= 1.0011x-5.4131, 1.0011 in the formula is the sensitivity. Subtracting the fitting value Si from the instrument output yi to obtain a fitting deviation delta yi, dividing the maximum value delta ymax in the fitting deviation by the measuring range Y to obtain the linearity delta, wherein delta= ±delta ymax/Y is 100% = ±0.038%.
TABLE 1
According to the sensitivity test system for the drilling strain gauge, the outer cylinder of the probe of the drilling strain gauge is subjected to concentrated stress in the radial measuring direction through the manual hydraulic pump, the deformation of the outer cylinder of the probe at the stress position is measured through the high-precision laser displacement sensor, the readings of the laser displacement sensor and the differential capacitance sensor arranged in the probe are recorded, and the parameters such as the sensitivity and the linearity of the instrument can be calculated. The sensitivity test system of the borehole strain gauge can provide larger and stable calibration force (about 5000N) and has higher calibration precision. Generally, the magnitude of the calibration force is related to the diameter and wall thickness of the probe outer barrel, and the thicker the outer barrel, the smaller the diameter, the greater the calibration force required. For RZB type four-component borehole strain gauges (probe diameter 100mm, wall thickness 3 mm), at least a nominal force of 1000N or more is required to achieve full-scale deformation (about 40 microns). The sensitivity test system of the drilling strain gauge can meet the calibration force requirements of most drilling strain gauges.
It will be apparent to those skilled in the art that the above embodiments are provided for illustration only and not for limitation of the invention, and that variations and modifications of the above described embodiments are intended to fall within the scope of the claims of the invention as long as they fall within the true spirit of the invention.
Claims (3)
1. A borehole strain gauge sensitivity test system for testing the sensitivity of a borehole strain gauge, comprising: a manual hydraulic pump, a laser displacement sensor, a bracket, an upper pressure head and a lower pressure head, wherein,
the manual hydraulic pump installs the drilling strain gauge probe at the central part of the bracket through an upper pressure head and a lower pressure head, the upper pressure head and the lower pressure head are provided with grooves at the contact part with the drilling strain gauge probe for fixing the drilling strain gauge probe, a laser displacement sensor is positioned near the grooves for measuring the displacement change of the drilling strain gauge probe at the contact part,
the manual hydraulic pump comprises a plunger, a plunger cavity, a rubber tube and a pump body, wherein the plunger can slide up and down along the axis in the plunger cavity, the pump body is connected with the plunger cavity through the rubber tube,
the bracket comprises a base, an upright post and a top plate, wherein the base is connected with the top plate through the upright post,
the plunger cavity of the manual hydraulic pump is fixed on the top plate of the bracket, the plunger cavity is abutted with the upper pressure head, the lower pressure head is fixed on the base,
the plunger contacts and separates with the upper pressure head under the control of the pump body, the pressure is transmitted to the drill strain gauge probe through the plunger and the upper pressure head, so that the drill strain gauge probe is elastically deformed at the grooves of the upper pressure head and the lower pressure head,
the laser displacement sensor comprises an upper laser displacement sensor and a lower laser displacement sensor which are positioned near grooves of the upper pressure head and the lower pressure head, and displacement changes of two positions of the radial symmetry of the drilling strain gauge probe are measured respectively.
2. The borehole strain gauge sensitivity testing system of claim 1, wherein the axes of the laser displacement sensor and the differential capacitive sensor inside the borehole strain gauge are on the same vertical line.
3. The borehole strain gauge sensitivity test system of claim 1, wherein the groove is a V-groove or a circular arc groove.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710146085.8A CN106840019B (en) | 2017-03-13 | 2017-03-13 | Sensitivity test system for borehole strain gauge |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710146085.8A CN106840019B (en) | 2017-03-13 | 2017-03-13 | Sensitivity test system for borehole strain gauge |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106840019A CN106840019A (en) | 2017-06-13 |
| CN106840019B true CN106840019B (en) | 2024-01-12 |
Family
ID=59144173
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710146085.8A Active CN106840019B (en) | 2017-03-13 | 2017-03-13 | Sensitivity test system for borehole strain gauge |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106840019B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107388955A (en) * | 2017-08-18 | 2017-11-24 | 武汉地震科学仪器研究院有限公司 | A kind of Four component seismic technology probe |
| CN114593665B (en) * | 2022-02-22 | 2023-06-16 | 应急管理部国家自然灾害防治研究院 | Indoor complete machine calibration device of vertical drilling strain gauge |
| CN114485380B (en) * | 2022-02-24 | 2023-06-20 | 应急管理部国家自然灾害防治研究院 | Indoor simulation self-checking device of component type drilling strain gauge |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4852262A (en) * | 1988-01-21 | 1989-08-01 | United States Of America, As Represented By The Secretary Of The Interior | Gauge for in situ measurement of borehole diameter |
| US5355715A (en) * | 1992-06-29 | 1994-10-18 | Pile Dynamics, Inc. | Strain transducer calibration device |
| CN102927959A (en) * | 2012-08-02 | 2013-02-13 | 南京航空航天大学 | Automatic calibration device and calibration method for strain gauge |
| CN103712552A (en) * | 2014-01-02 | 2014-04-09 | 吴书贵 | Multi-component borehole strain gauge |
| CN203705315U (en) * | 2014-02-25 | 2014-07-09 | 中国矿业大学 | Permeameter with radial displacement measuring device |
| CN104089571A (en) * | 2014-07-21 | 2014-10-08 | 中国地震局地壳应力研究所 | Remote calibration device of borehole deformation instrument for borehole ground deformation measurement |
| CN206523143U (en) * | 2017-03-13 | 2017-09-26 | 中国地震局地壳应力研究所 | A kind of drilling strain gauge sensitivity test system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9778393B2 (en) * | 2014-05-05 | 2017-10-03 | Vale S.A. | Method and system for density correction for geophysical well logging inside drilling rods |
-
2017
- 2017-03-13 CN CN201710146085.8A patent/CN106840019B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4852262A (en) * | 1988-01-21 | 1989-08-01 | United States Of America, As Represented By The Secretary Of The Interior | Gauge for in situ measurement of borehole diameter |
| US5355715A (en) * | 1992-06-29 | 1994-10-18 | Pile Dynamics, Inc. | Strain transducer calibration device |
| CN102927959A (en) * | 2012-08-02 | 2013-02-13 | 南京航空航天大学 | Automatic calibration device and calibration method for strain gauge |
| CN103712552A (en) * | 2014-01-02 | 2014-04-09 | 吴书贵 | Multi-component borehole strain gauge |
| CN203705315U (en) * | 2014-02-25 | 2014-07-09 | 中国矿业大学 | Permeameter with radial displacement measuring device |
| CN104089571A (en) * | 2014-07-21 | 2014-10-08 | 中国地震局地壳应力研究所 | Remote calibration device of borehole deformation instrument for borehole ground deformation measurement |
| CN206523143U (en) * | 2017-03-13 | 2017-09-26 | 中国地震局地壳应力研究所 | A kind of drilling strain gauge sensitivity test system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106840019A (en) | 2017-06-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106840019B (en) | Sensitivity test system for borehole strain gauge | |
| CN108562498B (en) | Device for high-temperature high-pressure axial compression test and application method thereof | |
| CN101180528B (en) | sheath used in test platform and measuring assembly for measuring side deformation under compression test | |
| JP5619263B1 (en) | Loading test equipment | |
| CN202170792U (en) | Measuring device of radial deformation of well hole | |
| CN107882011B (en) | miniature probe with temperature compensation function | |
| EP3671140B1 (en) | Balance scale for testing air resistance | |
| CN104155333A (en) | Device and method for measuring wire and cable expansion coefficient | |
| CN110954282B (en) | Packer rubber cylinder sealing performance testing device and method | |
| CN104749036A (en) | In-situ rock-mass mechanic test system and in-situ rock-mass mechanic test method | |
| CN102103065A (en) | Device for calibrating extraction instrument | |
| CN108458639B (en) | Device and method for measuring axial clearance of aircraft accessory | |
| CN104849143A (en) | Uniaxial tension device and testing method thereof | |
| CN213175626U (en) | Extrusion type deformation prediction device for tunnel weak surrounding rock | |
| CN107532958A (en) | Deformation measurement torquemeter | |
| CN206523143U (en) | A kind of drilling strain gauge sensitivity test system | |
| CN203069580U (en) | Mechanical calibration device for output load of lever type consolidometer | |
| CN110424362B (en) | Optical fiber type temperature self-compensating static sounding sensor | |
| CN106908226A (en) | A kind of Pipeline Crossing by Horizontal Directional Drilling churn drilling tools performance testing device and its method of testing | |
| CN114593665B (en) | Indoor complete machine calibration device of vertical drilling strain gauge | |
| CN108169454B (en) | Expansive soil expansive force-deformation relation joint tester | |
| CN114264546B (en) | Self-balancing hydraulic system, rock test piece surface normal displacement monitoring device and method | |
| CN104314561B (en) | A kind of boring elastic modulus instrument with flexible loading plate | |
| CN114993162A (en) | Device and method for measuring circumferential strain and axial stress of grouting material | |
| CN104567655B (en) | Dynamic angular displacement measuring device and method |
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 | ||
| CB02 | Change of applicant information | ||
| CB02 | Change of applicant information |
Address after: 100085, Anning Road, Haidian District, Beijing, 1, Xisanqi Applicant after: National natural disaster prevention and Control Research Institute Ministry of emergency management Address before: 100085, Anning Road, Haidian District, Beijing, 1, Xisanqi Applicant before: THE INSTITUTE OF CRUSTAL DYNAMICS, CHINA EARTHQUAKE ADMINISTRATION |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |