CN113091629A - Method for measuring expansion deformation rate in horizontally protected coal seam - Google Patents
Method for measuring expansion deformation rate in horizontally protected coal seam Download PDFInfo
- Publication number
- CN113091629A CN113091629A CN202110372968.7A CN202110372968A CN113091629A CN 113091629 A CN113091629 A CN 113091629A CN 202110372968 A CN202110372968 A CN 202110372968A CN 113091629 A CN113091629 A CN 113091629A
- Authority
- CN
- China
- Prior art keywords
- monitoring
- plate
- coal seam
- horizontal
- monitoring device
- 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.)
- Pending
Links
Images
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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention relates to a method for measuring the expansion deformation rate in a horizontally protected coal seam, and belongs to the field of coal mine underground gas prevention and control. The device comprises a top plate monitoring device, a bottom plate monitoring device, a laser range finder and a horizontal calibrator. And the roof monitoring device and the bottom plate monitoring device are arranged on the top and bottom plates of the roadway intersected with the same plumb line after the installation is finished. The laser range finder is used for measuring the distance between the top plate monitoring device and the bottom plate monitoring device. The horizontal calibrator is used for detecting whether the installation of the rigid monitoring plate on the top and bottom plate monitoring device is horizontal. The measuring method comprises the steps of measuring the deformation of the horizontal protected coal seam roadway after the protective layer is mined by means of the device, and calculating the expansion deformation rate of the horizontal protected coal seam by combining the data of the thickness of the horizontal protected coal seam, the height of the roadway and the like. The invention solves the problem that the expansion deformation can not be directly measured in the horizontal protected coal seam, and has the advantages of simple operation, high precision and the like.
Description
Technical Field
The invention relates to the field of coal mine underground gas prevention and control, in particular to a method for measuring an expansion deformation rate in a horizontally protected coal bed.
Background
Deep coal seams in China generally have the characteristics of high ground stress, high gas pressure, high temperature and low gas permeability, so that the coal and gas outburst disasters of the deep coal seams are serious. The coal seam with the outburst mining level should be mined by a protective layer preferably, when the protective layer is mined, the coal seam with the gas-rich level being protected can generate pressure relief, the air permeability is increased, and the outburst risk of the coal seam with the level being protected can be eliminated or reduced by further pre-pumping gas.
The expansion deformation rate is one of main indexes for measuring the pressure relief and permeability increase effects of the coal seam to be protected. At present, the method for measuring the expansion deformation rate of the horizontal protected coal seam mainly adopts a deep base point method. Influenced by the mining layout, the construction site of the deep base point method is generally arranged in the near coal seam of the mined coal seam, and the expansion deformation of the horizontal protected coal seam is measured by drilling through the layer from the near coal seam roadway to the protected coal seam. However, when the distance between the roadway close to the coal seam and the protected coal seam is far, the difficulty of cross-layer drilling construction is multiplied, and the measurement error of the expansion deformation rate is larger and larger along with the layer spacing of the coal seam. Therefore, if the horizontal protected seam has been excavated, determining the dilatant deformation rate in the horizontal protected seam roadway is a primary choice for field engineers. However, the prior art methods lack a method for determining the dilatant deformation rate in a horizontally protected coal seam.
Disclosure of Invention
The invention aims to provide a method for measuring the expansion deformation rate in a horizontal protected coal seam, which can directly measure the expansion deformation amount in the horizontal protected coal seam and is used for quantitatively evaluating the pressure relief and permeability increasing effects of the horizontal protected coal seam.
The invention adopts the following technical scheme:
a method for measuring the expansion deformation rate in a horizontally protected coal seam is realized on the basis of the following four devices: roof monitoring devices, bottom plate monitoring devices, laser range finder and horizontal calibration appearance.
The roof monitoring device is composed of a fixed thread anchor rod, a connection type thread anchor rod, a turnbuckle, a butterfly bolt, a rigidity monitoring plate and a fixed screw cap. The fixed thread anchor rod body is attached with threads and is fixed at the top plate of the roadway after construction is finished; the connecting type thread anchor rod body is attached with threads and is used for connecting a turnbuckle and a rigid monitoring plate; the rigid monitoring plate is provided with four holes perpendicular to the plate body and located at four corners of the rigid monitoring plate respectively, and when the rigid monitoring plate is used, the connecting type threaded anchor rod needs to be inserted into the holes, and then the fixing screw cap is screwed into the connecting type threaded anchor rod, so that the connecting type threaded anchor rod is perpendicular to the rigid monitoring plate; the turnbuckle is provided with three screw holes, wherein one side of the upper side and the lower side of the turnbuckle is connected with the fixed threaded anchor rod, the other side of the turnbuckle is connected with the connecting threaded anchor rod, and the screw holes on the side edge of the turnbuckle are used for connecting the butterfly bolts; the butterfly bolt is used for fixing the position of the rigid monitoring plate, and the butterfly bolt is screwed after the rigid monitoring plate is adjusted to be horizontal.
The bottom plate monitoring device and the top plate monitoring device have the same structure, and the bottom plate monitoring device and the top plate monitoring device are respectively positioned on the top and bottom plates of the roadway with the same vertical line after installation.
The laser range finder is used for measuring the distance between the roadway top plate and the rigid monitoring plate of the roadway bottom plate which are fixed on the same plumb line.
The horizontal calibration instrument is used for adjusting the rigid monitoring plate in the installation process, so that the rigid monitoring plate is horizontal.
A method of determining the dilatant deformation rate in a horizontally protected coal seam, comprising the steps of:
and before the S001 protective layer is mined, a top plate monitoring device and a bottom plate monitoring device are installed. Firstly, four connecting type thread anchor rods penetrate through four holes reserved in a rigid monitoring plate, and fixing screw caps are screwed into the connecting type thread anchor rods from the lower side of the rigid monitoring plate, so that the connecting type thread anchor rods are perpendicular to the rigid monitoring plate.
S002 one side of the upper side and the lower side of the turnbuckle is connected with the upper side and the lower side of the connecting type threaded anchor rod.
And S003, connecting the other side of the turnbuckle with a fixed threaded anchor rod, and then fixing the fixed threaded anchor rod at the top plate of the roadway.
S004 uses a level calibrator to keep the rigid monitoring plate level.
And S005, after the rigid monitoring plate is adjusted to be horizontal, the butterfly bolt is screwed down, and the top plate monitoring device is installed.
And S006 determines the installation position of the bottom plate monitoring device at the roadway bottom plate along the vertical direction of the top plate monitoring device.
S007 steps S001-S005 are repeated, and the bottom plate monitoring device is installed.
Before the S008 protective layer is mined, the height h of a horizontal protected coal seam roadway is measured and recorded by using a laser range finder, and the distance L between two rigid monitoring plates of the top floor and the bottom floor at the same place1。
After the S009 protective layer is mined, a laser range finder is used for continuously monitoring and recording the distance between two rigid monitoring plates of the horizontal protected coal seam roadway roof and floor, and after the monitored numerical value is stable, the stable numerical value is recorded as L2。
In the process of mining the S010 protective layer, the deformation of the top plate monitoring device and the bottom plate monitoring device can be ignored and not recorded. Thus, the distance L between the two rigid monitoring plates before the mining of the protective layer1And the distance L between the two rigid monitoring plates after the protective layer is mined2And calculating the deformation L of the horizontal protected coal seam roadway before and after the protective layer is mined by adopting the following formula:
L＝L2-L1
s011, looking up geological data of a mine to obtain the thickness H of the horizontal protected coal seam, and calculating the ratio k of the thickness H of the horizontal protected coal seam to the height H of a roadway by adopting the following formula:
s012 further, calculating the expansion deformation x of the horizontal protected coal seam by adopting the following formula:
s013 further, the swell deformation ratio P of the horizontal protected coal seam was calculated using the following formula:
the invention has the beneficial effects that: the invention provides a method for measuring the expansion deformation rate in a horizontal protected coal seam, which can directly measure the expansion deformation amount in the horizontal protected coal seam and further calculate the expansion deformation rate of the horizontal protected coal seam. The method solves the problem that the expansion deformation cannot be directly measured in the horizontally protected coal seam in the prior art, and has the advantages of simple operation, high measurement precision and the like; the invention is also suitable for monitoring the surrounding rock deformation of the underground roadway of the coal mine in the complex stress environment.
Drawings
Fig. 1 is a schematic diagram of the application of the invention to roadway layout.
FIG. 2 is a schematic view showing the structure of the measuring apparatus of the present invention.
Graphic notation: 1. a roof monitoring device; 2. a floor monitoring device; 3. a laser range finder; 4. a horizontal calibrator; 1-1, fixing a threaded anchor rod; 1-2, connecting type thread anchor rod; 1-3, turnbuckle; 1-4, butterfly bolts; 1-5, a rigid monitoring plate; 1-6, fixing a screw cap; 5. a roadway roof; 6. a roadway floor; 7. a coal seam; 8. a rock formation.
Detailed Description
The following describes the practice of the present invention in further detail with reference to figures 1 and 2.
As shown in fig. 1 and 2, a method for measuring the swelling deformation rate in the horizontal protected coal seam is realized on the basis of the following four devices: the device comprises a top plate monitoring device 1, a bottom plate monitoring device 2, a laser range finder 3 and a horizontal calibrator 4.
The roof monitoring device 1 is composed of a fixed threaded anchor rod 1-1, a connection type threaded anchor rod 1-2, a turnbuckle 1-3, a butterfly bolt 1-4, a rigidity monitoring plate 1-5 and a fixed screw cap 1-6. The fixed threaded anchor rod 1-1 is provided with threads, and is fixed on a roadway top plate 5 after construction is finished; the connecting type threaded anchor rod 1-2 is provided with threads and is used for connecting a turnbuckle 1-3 and a rigid monitoring plate 1-5; the rigid monitoring plate 1-5 is provided with four holes perpendicular to the plate body, the four holes are respectively positioned at four corners of the rigid monitoring plate 1-5, when in use, the connecting type threaded anchor rod 1-2 needs to be penetrated into the holes, and then the fixing screw cap 1-6 is screwed into the connecting type threaded anchor rod 1-2, so that the connecting type threaded anchor rod 1-2 is perpendicular to the rigid monitoring plate 1-5; the turnbuckle 1-3 is provided with three screw holes, wherein one side of the upper side and the lower side is connected with the fixed threaded anchor rod 1-1, the other side is connected with the connecting threaded anchor rod 1-2, and the screw holes on the side of the turnbuckle 1-3 are used for connecting the butterfly bolts 1-4; the butterfly bolts 1-4 are used for fixing the positions of the rigid monitoring plates 1-5, and the butterfly bolts 1-4 are screwed after the rigid monitoring plates 1-5 are adjusted to be horizontal.
The bottom plate monitoring device 2 and the top plate monitoring device 1 have the same structure, and the bottom plate monitoring device and the top plate monitoring device are respectively located on the top and bottom plates of the roadway intersected with the same plumb line after installation.
The laser range finder 3 is used for measuring the distance between rigid monitoring plates 1-5 of a roadway top plate 5 and a roadway bottom plate 6 which are fixed on the same plumb line.
The horizontal calibration instrument is used for adjusting the rigid monitoring plates 1-5 in the installation process, so that the rigid monitoring plates 1-5 are horizontal.
A method of determining the dilatant deformation rate in a horizontally protected coal seam, comprising the steps of:
and before the S001 protective layer is mined, a top plate monitoring device 1 and a bottom plate monitoring device 2 are installed. Firstly, four connecting type threaded anchor rods 1-2 penetrate through four reserved holes of a rigid monitoring plate 1-5, and fixing screw caps 1-6 are screwed into the connecting type threaded anchor rods 1-2 from the lower side of the rigid monitoring plate 1-5, so that the connecting type threaded anchor rods 1-2 are perpendicular to the rigid monitoring plate 1-5.
S002, connecting the upper part of the connecting type threaded anchor rod 1-2 with one side of the upper side and the lower side of the turn buckle 1-3.
S003, the other side of the turnbuckle 1-3 is connected with the fixed threaded anchor rod 1-1, and then the fixed threaded anchor rod 1-1 is fixed on a roadway top plate 5.
S004 uses the level calibrator 4 to keep the rigid monitoring plates 1-5 horizontal.
And S005, after the rigid monitoring plates 1-5 are adjusted to be horizontal, the butterfly bolts 1-4 are screwed, and the roof monitoring device 1 is installed.
S006 determines the installation position of the floor monitoring device 2 at the roadway floor 6 in the vertical direction of the roof monitoring device 1.
S007 steps S001-S005 are repeated and the floor monitoring device 2 is installed.
Before the S008 protective layer is mined, the height h of a horizontal protected coal seam roadway and the distance L between two rigid monitoring plates 1-5 of the top and bottom plates at the same place are measured and recorded by using a laser range finder 31。
After the S009 protective layer is mined, a laser range finder 3 is used for continuously monitoring and recording the distance between two rigid monitoring plates 1-5 of the top floor and the bottom floor of the horizontal protected coal seam roadway, and after the monitored numerical value is stable, the stable numerical value is recorded as L2。
In the process of mining the S010 protective layer, the deformation of the top plate monitoring device 1 and the bottom plate monitoring device 2 can be ignored. Thus, the distance L between the two rigid monitoring plates 1-5 before the mining of the protective layer1And the distance L between the two rigid monitoring plates 1-5 after the protective layer is mined2And calculating the deformation L of the horizontal protected coal seam roadway before and after the protective layer is mined by adopting the following formula:
L＝L2-L1
s011, looking up geological data of a mine to obtain the thickness H of the horizontal protected coal seam, and calculating the ratio k of the thickness H of the horizontal protected coal seam to the height H of a roadway by adopting the following formula:
s012 further, calculating the expansion deformation x of the horizontal protected coal seam by adopting the following formula:
s013 further, the swell deformation ratio P of the horizontal protected coal seam was calculated using the following formula:
Claims (5)
1. a method of determining the rate of swelling deformation in a horizontally protected coal seam, comprising: the method is realized based on the following four devices, which are respectively: roof monitoring devices, bottom plate monitoring devices, laser range finder and horizontal calibration appearance.
The roof monitoring device is composed of a fixed thread anchor rod, a connection type thread anchor rod, a turnbuckle, a butterfly bolt, a rigidity monitoring plate and a fixed screw cap. The fixed thread anchor rod body is attached with threads and is fixed at the top plate of the roadway after construction is finished; the connecting type thread anchor rod body is attached with threads and is used for connecting a turnbuckle and a rigid monitoring plate; the rigid monitoring plate is provided with four holes perpendicular to the plate body and located at four corners of the rigid monitoring plate respectively, and when the rigid monitoring plate is used, the connecting type threaded anchor rod needs to be inserted into the holes, and then the fixing screw cap is screwed into the connecting type threaded anchor rod, so that the connecting type threaded anchor rod is perpendicular to the rigid monitoring plate; the turnbuckle is provided with three screw holes, wherein one side of the upper side and the lower side of the turnbuckle is connected with the fixed threaded anchor rod, the other side of the turnbuckle is connected with the connecting threaded anchor rod, and the screw holes on the side edge of the turnbuckle are used for connecting the butterfly bolts; the butterfly bolt is used for fixing the position of the rigid monitoring plate, and the butterfly bolt is screwed after the rigid monitoring plate is adjusted to be horizontal.
2. The method for determining the dilatant deformation rate in a horizontally protected coal seam according to claim 1, wherein: the bottom plate monitoring device and the top plate monitoring device have the same structure, and the bottom plate monitoring device and the top plate monitoring device are respectively positioned on the top and bottom plates of the roadway with the same vertical line after installation.
3. The method for determining the dilatant deformation rate in a horizontally protected coal seam according to claim 1, wherein: the laser range finder is used for measuring the distance between the roadway top plate and the rigid monitoring plate of the roadway bottom plate which are fixed on the same plumb line.
4. The method for determining the dilatant deformation rate in a horizontally protected coal seam according to claim 1, wherein: the horizontal calibration instrument is used for adjusting the rigid monitoring plate in the installation process, so that the rigid monitoring plate is horizontal.
5. A method for determining the dilatant deformation rate in a horizontally protected coal seam, characterised in that the method comprises the steps of:
and before the S001 protective layer is mined, a top plate monitoring device and a bottom plate monitoring device are installed. Firstly, four connecting type thread anchor rods penetrate through four holes reserved in a rigid monitoring plate, and fixing screw caps are screwed into the connecting type thread anchor rods from the lower side of the rigid monitoring plate, so that the connecting type thread anchor rods are perpendicular to the rigid monitoring plate.
S002 one side of the upper side and the lower side of the turnbuckle is connected with the upper side and the lower side of the connecting type threaded anchor rod.
And S003, connecting the other side of the turnbuckle with a fixed threaded anchor rod, and then fixing the fixed threaded anchor rod at the top plate of the roadway.
S004 uses a level calibrator to keep the rigid monitoring plate level.
And S005, after the rigid monitoring plate is adjusted to be horizontal, the butterfly bolt is screwed down, and the top plate monitoring device is installed.
And S006 determines the installation position of the bottom plate monitoring device at the roadway bottom plate along the vertical direction of the top plate monitoring device.
S007 steps S001-S005 are repeated, and the bottom plate monitoring device is installed.
Before mining of the S008 protective layer, the height h of the horizontal protected coal seam roadway is measured and recorded by using a laser range finder, and the height h of the horizontal protected coal seam roadway and the same place are measured and recordedDistance L between two rigid monitoring plates of point top bottom plate1。
After the S009 protective layer is mined, a laser range finder is used for continuously monitoring and recording the distance between two rigid monitoring plates of the horizontal protected coal seam roadway roof and floor, and after the monitored numerical value is stable, the stable numerical value is recorded as L2。
In the process of mining the S010 protective layer, the deformation of the top plate monitoring device and the bottom plate monitoring device can be ignored and not recorded. According to the distance L between two rigid monitoring plates before the protective layer is mined1And the distance L between the two rigid monitoring plates after the protective layer is mined2And calculating the deformation L of the horizontal protected coal seam roadway before and after the protective layer is mined by adopting the following formula:
L＝L2-L1
s011, looking up geological data of a mine to obtain the thickness H of the horizontal protected coal seam, and calculating the ratio k of the thickness H of the horizontal protected coal seam to the height H of a roadway by adopting the following formula:
s012 further, calculating the expansion deformation x of the horizontal protected coal seam by adopting the following formula:
s013 further, the swell deformation ratio P of the horizontal protected coal seam was calculated using the following formula:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110372968.7A CN113091629A (en) | 2021-04-07 | 2021-04-07 | Method for measuring expansion deformation rate in horizontally protected coal seam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110372968.7A CN113091629A (en) | 2021-04-07 | 2021-04-07 | Method for measuring expansion deformation rate in horizontally protected coal seam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113091629A true CN113091629A (en) | 2021-07-09 |
Family
ID=76674969
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110372968.7A Pending CN113091629A (en) | 2021-04-07 | 2021-04-07 | Method for measuring expansion deformation rate in horizontally protected coal seam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113091629A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202533068U (en) * | 2012-04-26 | 2012-11-14 | 淮南矿业(集团)有限责任公司 | Roadway surface distance measuring device |
| CN203203551U (en) * | 2013-03-19 | 2013-09-18 | 于俊洋 | Protected coal seam expansion deformation and coal seam floor seam separation amount determination device |
| CN105781523A (en) * | 2016-03-02 | 2016-07-20 | 重庆大学 | Method for measuring swelling capacity of coal seam through ground drilling |
| CN109292622A (en) * | 2018-11-19 | 2019-02-01 | 山西潞安环保能源开发股份有限公司漳村煤矿 | A kind of anti-deflection device and installation method of monorail crane rail |
| US20190323340A1 (en) * | 2017-11-24 | 2019-10-24 | Shandong University Of Science And Technology | Dynamically self-balancing pressurized borehole-sealing apparatus and method thereof for coal seam gas pressure measurement |
| AU2020103698A4 (en) * | 2020-11-01 | 2021-02-04 | Anhui University of Science and Technology | Monitoring method for dynamic height of overburden failure during underground coal seam mining |
-
2021
- 2021-04-07 CN CN202110372968.7A patent/CN113091629A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202533068U (en) * | 2012-04-26 | 2012-11-14 | 淮南矿业(集团)有限责任公司 | Roadway surface distance measuring device |
| CN203203551U (en) * | 2013-03-19 | 2013-09-18 | 于俊洋 | Protected coal seam expansion deformation and coal seam floor seam separation amount determination device |
| CN105781523A (en) * | 2016-03-02 | 2016-07-20 | 重庆大学 | Method for measuring swelling capacity of coal seam through ground drilling |
| US20190323340A1 (en) * | 2017-11-24 | 2019-10-24 | Shandong University Of Science And Technology | Dynamically self-balancing pressurized borehole-sealing apparatus and method thereof for coal seam gas pressure measurement |
| CN109292622A (en) * | 2018-11-19 | 2019-02-01 | 山西潞安环保能源开发股份有限公司漳村煤矿 | A kind of anti-deflection device and installation method of monorail crane rail |
| AU2020103698A4 (en) * | 2020-11-01 | 2021-02-04 | Anhui University of Science and Technology | Monitoring method for dynamic height of overburden failure during underground coal seam mining |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20200018164A1 (en) | Advanced monitoring device for whole-process deformation curve of surrounding rock of tunnel excavation and implementation method thereof | |
| CN111382504A (en) | Coal seam mining overburden settlement state identification method | |
| CN105783759B (en) | A kind of roadway surrounding rock overall deformation monitoring device and method | |
| CN109724865A (en) | Tunnel-liner water pressure monitoring STS system test set and test method | |
| WO2018090348A1 (en) | Automatic collision avoidance method for adjacent wells | |
| CN109781773A (en) | A kind of frost heave device and its detection method being layered telescopic detection soil | |
| CN103967479B (en) | A kind of rotary steerable drilling enters target prediction of situation method | |
| CN104457687B (en) | Laser Measuring ramp and tilt measurement thereof | |
| CN108536891B (en) | Calculation method, storage medium and device for water storage capacity of underground reservoir | |
| CN206095484U (en) | Rock pressure detection device | |
| CN113063366B (en) | Method for measuring expansion deformation rate in inclined protected coal seam | |
| CN113091629A (en) | Method for measuring expansion deformation rate in horizontally protected coal seam | |
| CN110174503A (en) | A method of determining that country rock weakens development range based on tunnel deformation | |
| CN110686918B (en) | Simulation system and experimental method for stabilizing excavation surface of gas drainage control tunnel | |
| CA1331840C (en) | Low-water-pressure controlled hydrologic test method | |
| CN107941137A (en) | Arbitrary angle drilling deformation measurement method | |
| CN206146897U (en) | A simulation experiment monitoring system for top of roadway board absciss layer | |
| CN109765260A (en) | Frost heave monomer, detection device and its detection method of flexible non-contact formula detection soil | |
| CN210441841U (en) | Rock-soil body layered monitoring mark | |
| CN110836125B (en) | Method for determining progressive breaking advance action range of multi-layer key layer | |
| CN115479568A (en) | Working face bottom rock layer deformation measuring method | |
| CN210533735U (en) | Stable simulation system of gas drainage regulation and control tunnel excavation face | |
| CN213932334U (en) | Sensing integrated device and deep well inclination measuring detection monitoring device | |
| CN205506271U (en) | Stress in surrounding rock field drilling monitoring probe rod | |
| CN209513414U (en) | Tunnel-liner water pressure monitoring STS system test set |
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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210709 |
|
| RJ01 | Rejection of invention patent application after publication |