CN116678529B - Soil pressure sensor and burying and recycling method thereof - Google Patents
Soil pressure sensor and burying and recycling method thereof Download PDFInfo
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- CN116678529B CN116678529B CN202310665883.7A CN202310665883A CN116678529B CN 116678529 B CN116678529 B CN 116678529B CN 202310665883 A CN202310665883 A CN 202310665883A CN 116678529 B CN116678529 B CN 116678529B
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- 238000005553 drilling Methods 0.000 claims abstract description 14
- 238000011084 recovery Methods 0.000 claims abstract description 7
- 239000013307 optical fiber Substances 0.000 claims abstract description 4
- 238000009434 installation Methods 0.000 claims description 23
- 239000000853 adhesive Substances 0.000 claims description 19
- 230000001070 adhesive effect Effects 0.000 claims description 19
- 229910000831 Steel Inorganic materials 0.000 claims description 8
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- 238000004026 adhesive bonding Methods 0.000 claims description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 3
- 150000001412 amines Chemical class 0.000 claims description 3
- 239000003822 epoxy resin Substances 0.000 claims description 3
- 238000013007 heat curing Methods 0.000 claims description 3
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- 229920000647 polyepoxide Polymers 0.000 claims description 3
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- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
- G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
- G01L1/246—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre using integrated gratings, e.g. Bragg gratings
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- Testing Or Calibration Of Command Recording Devices (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
Abstract
The invention relates to a soil pressure sensor, comprising a sensor assembly and a sleeve; the sensor assembly comprises a cylindrical mounting part, wherein an optical fiber grating sensor is arranged on the cylindrical mounting part, a positioning rod is arranged on the upper bottom surface of the cylindrical mounting part, a drill bit is arranged on the lower bottom surface of the cylindrical mounting part, and a gyroscope is arranged in the cylindrical mounting part; the sleeve is detachably connected with the cylindrical mounting part, a fixing piece used for fixing the cylindrical mounting part is arranged in the sleeve, and the positioning rod, the cylindrical mounting part and the sleeve are coaxially arranged. Meanwhile, the invention also relates to a burying and recycling method of the soil pressure sensor. According to the soil pressure sensor, the fiber bragg grating is arranged and subjected to temperature correction, so that the measurement accuracy is high; the sensor is connected with the drill bit and the sleeve, so that the burying and recycling of the sensor are facilitated, the repeated utilization of the sensor is realized, and the monitoring cost is reduced; the problem that the existing drilling method cannot realize sensor recovery and cannot determine whether measured data are in an actual direction can be effectively solved.
Description
Technical Field
The invention relates to the technical field of soil pressure monitoring, in particular to a soil pressure sensor and a burying and recycling method thereof.
Background
In geotechnical engineering, strength and displacement indexes play an important role in local and overall stability of a geotechnical body, technical means are required to be adopted for monitoring so as to judge the safety of the engineering, and a reliable basis is provided for actual engineering design. Along with the rapid development of electronic information technology and computer technology, the geotechnical engineering informatization process is continuously accelerated, and the innovation of a monitoring mode and a monitoring instrument also provides powerful support for engineering informatization.
Due to the complex geological environment, load and other factors in the construction process, the soil pressure is one of the most basic parameters in geotechnical engineering, and the real-time monitoring of the soil pressure is particularly important to prevent engineering accidents. The pressure sensor has wide development prospect and wider application as a key instrument for acquiring stress parameters. For example, the lining stress monitoring and the side slope support stress monitoring of the tunnel can accurately reflect the stability of the structure, and meanwhile, numerical simulation work can be carried out on the basis of data analysis, so that the structure and the support thereof can be better optimized and designed.
At present, a drilling method is generally adopted for burying the sensor in the soil, the sensor is pressed into a designated elevation by utilizing a drill rod of a drilling machine, the sensor is buried and backfilled with a compacted soil body, but the method cannot realize the recovery of the sensor, and the sensor can only be abandoned in the drilling after the use, so that the monitoring cost is increased. In addition, the soil pressure sensor is easy to deviate when buried in actual engineering, whether the measured data is in the actual direction cannot be determined, and accurate characterization of the soil stress state is difficult.
Disclosure of Invention
The invention aims to provide a soil pressure sensor and a burying and recycling method thereof, which can effectively solve the problems that the existing drilling method can not realize sensor recycling and can not determine whether measured data is in an actual direction.
In order to solve the technical problems, the invention adopts the following technical scheme:
a soil pressure sensor comprising a sensor assembly and a sleeve; the sensor assembly comprises a cylindrical mounting part, wherein an optical fiber grating sensor is arranged on the cylindrical mounting part, a positioning rod is arranged on the upper bottom surface of the cylindrical mounting part, a drill bit is arranged on the lower bottom surface of the cylindrical mounting part, and a gyroscope is arranged in the cylindrical mounting part; the sleeve is detachably connected with the cylindrical mounting part, a fixing piece used for fixing the cylindrical mounting part is arranged in the sleeve, and the positioning rod, the cylindrical mounting part and the sleeve are coaxially arranged.
The fixing piece comprises movable buckles which are circumferentially and equidistantly arranged along the inner wall of the sleeve, and each movable buckle comprises a first connecting piece, a second connecting piece and a third connecting piece; the arrangement direction of the first connecting sheet is consistent with the radial direction of the sleeve, the head end of the first connecting sheet is fixedly connected with the inner wall of the sleeve, the tail end of the first connecting sheet is fixedly connected with the head end of the second connecting sheet, the arrangement direction of the second connecting sheet is consistent with the axial direction of the sleeve, the tail end of the second connecting sheet is fixedly connected with the head end of the third connecting sheet, the third connecting sheet is obliquely arranged, and the tail end of the third connecting sheet and the head end of the first connecting sheet are positioned on the same plain wire of the sleeve; the second connecting piece of each movable buckle encloses into the space cylindric structure that is used for fixed cylindric installation department.
The fiber grating sensor comprises a strain grating and a temperature compensation grating, wherein the strain grating and the temperature compensation grating are fixed on the upper bottom surface and the side wall of the cylindrical installation part through fiber grating adhesives; the fiber bragg grating adhesive is prepared by mixing epoxy resin and fatty amine solution according to the proportion of 1:8-12 and continuously stirring until the mixture turns to cream yellow or white. The fiber bragg grating sensors are circumferentially arranged at intervals around the cylindrical mounting part and used for measuring soil pressure in different directions.
The method comprises the steps of polishing a grating pasting position before the strain grating and the temperature compensation grating are pasted to the cylindrical installation part, cleaning with alcohol after polishing, coating silicon rubber at two ends of the grating pasting position, coating an adhesive on the strain grating and the temperature compensation grating, and performing heat curing treatment on the adhesive after the adhesive is coated.
In addition, the invention also provides a burying and recycling method of the soil pressure sensor, which comprises the following steps:
firstly, determining the burying place of the soil pressure sensor according to the burying scheme, inserting steel bars at two sides of the section position, and recording the relative position of the soil pressure sensor and the steel bars;
connecting the sleeve with the cylindrical mounting part to seal the cylindrical mounting part inside, then burying the soil pressure sensor in a designated position, pulling out the sleeve, backfilling the sleeve to the elevation of a drilling hole, and recording the burying depth of the sensor assembly;
when the sensor assembly is recovered, drilling is firstly carried out at the burying place, the positioning rod in the hole is utilized to position the cylindrical installation part when the burying depth is reached, then the sleeve is connected with the cylindrical installation part, and the recovery of the sensor assembly is realized by pulling out the sleeve.
According to the soil pressure sensor provided by the technical scheme, the gyroscope is arranged in the cylindrical installation part to correct the deviation, so that the soil stress state is accurately depicted; and a plurality of fiber gratings are arranged, temperature correction is carried out, six effective stress components of the soil body are obtained through conversion, and the measurement accuracy is high.
In addition, the technical scheme also provides a burying and recycling method of the soil pressure sensor, when the sleeve is connected with the drill bit for burying and recycling, the fiber bragg grating is sealed in the sleeve, so that the sealing protection effect on the fiber bragg grating is achieved, and the long-term stability of the fiber bragg grating in the use process is ensured; the sensor is connected with the drill bit and the sleeve, so that the sensor is buried and recycled conveniently, the sensor is reused, and the monitoring cost is reduced.
Drawings
FIG. 1 is a schematic view of a soil pressure sensor according to the present invention;
FIG. 2 is a schematic view of a sensor assembly as it is buried and recovered;
fig. 3 is a graph showing the change of the earth pressure component in the space coordinate system.
In the figure: 1. a drill bit; 2. a temperature compensation grating; 3. a cylindrical mounting portion; 4. a positioning rod; 5. a sleeve; 6. a strain grating; 7. a gyroscope; 8. a movable buckle; 81. a first connecting piece; 82. a second connecting piece; 83. and a third connecting piece.
Detailed Description
The present invention will be specifically described with reference to examples below in order to make the objects and advantages of the present invention more apparent. It should be understood that the following text is intended to describe only one or more specific embodiments of the invention and does not limit the scope of the invention strictly as claimed.
Example 1
The technical scheme adopted by the invention is as shown in fig. 1, the soil pressure sensor comprises a sensor component and a sleeve 5, wherein the sensor component comprises a cylindrical installation part 3, a fiber bragg grating sensor is arranged on the cylindrical installation part 3, a positioning rod 4 is arranged on the upper bottom surface of the cylindrical installation part 3, a drill bit 1 is arranged on the lower bottom surface, and a gyroscope is arranged in the cylindrical installation part 3; the sleeve 5 is detachably connected with the cylindrical mounting part 3, a fixing piece for fixing the cylindrical mounting part 3 is arranged in the sleeve 5, the fixing piece comprises movable buckles 8 which are equidistantly arranged along the circumferential direction of the inner wall of the sleeve 5, and each movable buckle 8 is an elastic steel sheet and comprises a first connecting sheet 81, a second connecting sheet 82 and a third connecting sheet 83; the arrangement direction of the first connecting sheet 81 is in radial agreement with the sleeve 5, the head end of the first connecting sheet 81 is fixed on the inner wall of the sleeve 5, the tail end of the first connecting sheet 81 is fixedly connected with the head end of the second connecting sheet 82, the arrangement direction of the second connecting sheet 82 is in axial agreement with the sleeve 5, the tail end of the second connecting sheet 82 is fixedly connected with the head end of the third connecting sheet 83, the third connecting sheet 83 is obliquely arranged, and the tail end of the third connecting sheet 83 and the head end of the first connecting sheet 81 are positioned on the same plain wire of the sleeve 5; the second connecting piece 81 of each movable buckle 8 encloses a space cylindrical structure for fixing the cylindrical mounting part 3, refer to fig. 2; the positioning rod 4, the cylindrical mounting part 3 and the sleeve 5 are coaxially arranged, the positioning rod 4 is a steel pipe, the lower end of the positioning rod 4 is connected with the cylindrical mounting part 3, so that the sensor is conveniently positioned during recycling, and the sleeve 5 is deeply positioned along the positioning rod 4, so that the cylindrical mounting part (sensor) is conveniently searched; compared with the traditional resistance type and sine type pressure sensors, the fiber grating pressure sensor has the advantages of high sensitivity, small volume, light weight, strong adaptability and the like.
The fiber grating sensor comprises a strain grating 6 and a temperature compensation grating 2, wherein the strain grating 6 and the temperature compensation grating 2 are fixed on the upper bottom surface and the side wall of the cylindrical installation part through fiber grating adhesive. Before the fiber bragg grating is adhered to the sensing surface, the surface of the cylindrical installation part 3 is firstly required to be cleaned, polished and polished, the position of the grating adhesion on the pressed round diaphragm (positioned on the upper bottom surface of the cylindrical installation part) is polished by sand paper, the polishing area is larger than the fiber bragg grating adhesion range, and after polishing is finished, the cylindrical installation part is cleaned by an alcohol cotton ball. And mixing the epoxy resin and the fatty amine solution according to the proportion of 1:10, and continuously stirring until the mixture is milky yellow or white, so as to prepare the fiber grating adhesive. Specifically, the two ends of the area needing to be glued are coated with the Kafute RTV silicone rubber, the adhesive is prevented from diffusing towards the two ends in the gluing process, the adhesive is coated on the fiber bragg grating, the gluing area is controlled to exceed the two ends of the grating area by about 2mm respectively, and meanwhile, the coating width is controlled to be about 3mm and the thickness is less than 1mm. After the gluing is finished, the adhesive is subjected to heat curing treatment, the color change condition of the adhesive is observed when the adhesive is heated, the adhesive is taken out when the adhesive turns dark brown, and the adhesive is continuously heated by utilizing waste heat.
During operation, four strain gratings are connected into a square and fixed on the pressed round membrane, the positioning rod is positioned at the center of the square, and the strain gratings are tightly attached to the round membrane, so that gaps are avoided. Similarly, four strain gratings and a temperature compensation grating are arranged on the side wall of the cylindrical installation part and used for sensing the change of the ambient temperature, so that the influence of the temperature in the grating monitoring process is eliminated. The method comprises the steps of connecting a distributed grating with a fiber bragg grating demodulator, calculating according to the wavelength variation value of light in the distributed optical fiber to obtain a full stress component of a certain point of a soil body, measuring the wavelength variation value of light in four distributed gratings through the fiber bragg grating demodulator, correcting the temperature, and obtaining six effective stress components in the soil body through a conversion formula, thereby obtaining the full stress component of the certain point in the soil body. The gyroscope is fixed at the centroid of the sensor and is responsible for positioning the rotation angle of the sensor, when the soil pressure sensor is buried and is deviated, the gyroscope can measure the rotation angle, and six effective stress components in the soil body can be deduced by combining the pressure reading of the sensor.
After the soil pressure sensor is assembled, calibrating is needed, fine sand is placed at the bottom of a calibrating container, and the soil pressure sensor is placed in the middle of the fine sand, so that the calibrated surface of the sensor is vertically upwards; then placing the liquid bag filled with liquid on a sensor in a calibration box, and simultaneously enabling the liquid bag to be in close contact with a pressure-bearing surface of the sensor; and finally, placing a movable bearing plate on the liquid sac, applying an external load above the bearing plate, and loading and calibrating step by step to obtain a calibration curve of the sensor.
The principle of converting the wavelength variation of the fiber bragg grating into soil pressure is as follows:
the strain grating and the temperature compensation grating in the fiber grating soil pressure sensor are assumed to be linearly changed under the actions of temperature and strain and are not mutually influenced, the strain grating is distributed on the inner side surface of the cylinder, and the wavelength is lambda 1 The method comprises the steps of carrying out a first treatment on the surface of the The material of the temperature compensation grating is the same as that of the cylindrical mounting part, the temperature field is consistent, the temperature compensation grating is only affected by temperature, and the wavelength lambda of the temperature compensation grating is equal to that of the cylindrical mounting part 2 . The two gratings are positioned in the same temperature field, and the change of the wavelength is affected by the temperature effectConsistent, the influence of temperature can be effectively eliminated, and stable and reliable strain values can be obtained.
The wavelength of the grating is changed as follows:
two kinds of simultaneous availability:
the formula is a mathematical relation of temperature compensation by a built-in temperature compensation grating method, wherein lambda is the central wavelength quantity, delta lambda is the central wavelength variation quantity, S ε S is a strain sensitivity coefficient T The temperature sensitivity coefficient is epsilon, the strain value and delta T, the temperature change value;
(1) The appearance of the cylindrical installation part is cylindrical, the upper bottom surface of the cylinder is provided with a pressed circular diaphragm, and the strain grating is attached to the circumference of the pressed circular diaphragm with the radius r. The periphery of the pressed round diaphragm is assumed to be of a fixed structure, the contact part of the diaphragm and the soil body is uniformly distributed with the soil pressure, and the pressed round diaphragm is in a small deflection state at the moment and is deformed, so that the central wavelength of the fiber bragg grating is caused to deviate towards the long wave direction. The pressure can be measured by detecting the wavelength shift and by temperature correction.
Under the action of uniform pressure p, the tangential strain of the fiber bragg grating positioned on the circumference with the radius r can be obtained by combining a small deflection theory, a deflection formula and a stress strain formula:
wherein E, mu is the elastic modulus and Poisson's ratio of the membrane material; h is the thickness of the membrane; r is the radius of the membrane;
when the strain grating is attached to the circumference of a circular diaphragm with the radius r, the strain grating is obtained by the following formulas 3 and 4:
(2) 5 distributed gratings are distributed on the side wall of the cylinder, wherein 4 of the distributed gratings are strain gratings, and 1 of the distributed gratings are temperature compensation gratings for sensing the change of the ambient temperature, so that the influence of the temperature on the grating in the monitoring process is eliminated. And connecting the distributed grating with a fiber bragg grating demodulator, and calculating to obtain the soil pressure according to the wavelength variation value of the light in the distributed fiber.
Assuming that the contact part of the cross section of the sensor and the foundation pit soil body is uniformly distributed with the action of soil pressure, taking a section of circular ring as a research object, and taking the stress state that a thin-wall circular ring is uniformly pressed outwards, wherein the circular ring is in a small deflection state at the moment, deformation occurs, so that the central wavelength of the fiber bragg grating is caused to deviate towards the long wave direction, and the soil pressure is obtained through temperature compensation.
Let the soil pressure be p, because wall thickness delta is far less than internal diameter r, its ratio is far less than 1, can simplify into thin wall section of thick bamboo formula through the lame formula:
the strain formula is:
combining from formulas 3 and 7:
the corresponding soil pressure can be measured by the different wavelength variation of each strain grating.
Wherein r is the inner diameter, delta is the wall thickness, E is the elastic modulus of the membrane material, and p is the soil pressure;
and establishing a space rectangular coordinate system by taking a sensor centroid as an origin, taking a connecting line of the sensor centroid and any fiber bragg grating as an x-axis, taking a horizontal and vertical x-axis as a y-axis, and taking an origin upward and vertical xy-plane direction as a z-axis. And calculating the angles of the normal direction of each sensing surface and the x-axis, the y-axis and the z-axis of the coordinate system according to the normal angle arrangement of the sensing surfaces of the pressure heads of the fiber bragg grating pressure sensing units.
The sensors used in IMUs are essentially microelectromechanical systems (MEMS), a branch of importance in the semiconductor industry. The IMU data mainly comprises: heading angle, pitch angle and roll angle. MEMS gyroscope data is generally represented by X, Y, Z and represents the geographic location of the exposure point time.
The gyroscope is fixed at the centroid of the sensor and is responsible for positioning the rotation angle of the sensor, when the soil pressure sensor is buried and is deviated, the gyroscope can measure the rotation angles of the x axis, the y axis and the z axis, and the soil pressure component in the soil body can be pushed out by combining the pressure reading of the sensor.
When the soil pressure sensor is buried and offset, the angles of the normal line of the sensing surface and the x-axis, the y-axis and the z-axis are unchanged, the components of the soil pressure can be obtained according to cosine values, the gyroscope can measure the angle offset values of the x-axis, the y-axis and the z-axis (the z ' -axis is assumed to be the x ' -axis y ' -axis), the soil pressure components are corrected, and the corrected soil pressure is obtained by combining the normal line with the cosine values inherent to the x-axis, the y-axis and the z-axis.
[p ix p iy p iz ] T =[K]p i (i is the sensing surface 1,2,3,4, 5)
p′ ij =p ij ·cos<jj′>(j is x-axis, y-axis, z-axis)
p′ i =[K] -1 [p′ ix p′ iy p′ iz ] T
Wherein: p is p ix p iy p iz Is the soil pressure component to be measured; p is p i The normal soil pressure of each sensing surface is measured; [ K ]]Is the normal direction of the sensing surface, the x axis, the y axis, the,A matrix of directional cosines of the z-axis.
Example 2
The present embodiment provides a method for burying and recovering a soil pressure sensor of embodiment 1, comprising the steps of:
referring to the downward burying of fig. 2, firstly, determining burying places of the soil pressure sensor according to burying schemes, inserting steel bars at two sides of a section position, and recording relative positions of the soil pressure sensor and the steel bars so as to facilitate later recovery; clear away sharp and great stone, avoid damaging the sensor, with sleeve and cylindricality installation department zonulae occludens (cylindricality installation department is fixed between each activity buckle this moment) in order to seal cylindricality sensor inside after the clearance finishes, utilize the drilling machine to dig vertical drilling, buries soil pressure sensor into the assigned position, later pull out the sleeve and backfill to the drilling elevation with bentonite, record sensor assembly's buries depth.
Referring to "recovery upwards" of fig. 2, when the soil pressure sensor is recovered, drilling is performed at the burying place by using a drilling machine, when the soil pressure sensor reaches the burying depth, the positioning rod in the hole is used for positioning the cylindrical mounting part (sensor), the sleeve is connected with the cylindrical mounting part (until the cylindrical mounting part is positioned above the movable buckle), and the recovery of the sensor assembly can be realized by pulling out the sleeve.
While the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above embodiments, and it will be apparent to those skilled in the art that various equivalent changes and substitutions can be made therein without departing from the principles of the present invention, and such equivalent changes and substitutions should also be considered to be within the scope of the present invention.
Claims (6)
1. A soil pressure sensor, characterized by: comprises a sensor assembly and a sleeve; the sensor assembly comprises a cylindrical mounting part, wherein an optical fiber grating sensor is arranged on the cylindrical mounting part, a positioning rod is arranged on the upper bottom surface of the cylindrical mounting part, a drill bit is arranged on the lower bottom surface of the cylindrical mounting part, and a gyroscope is arranged in the cylindrical mounting part; the sleeve is detachably connected with the cylindrical mounting part, a fixing piece for fixing the cylindrical mounting part is arranged in the sleeve, and the positioning rod, the cylindrical mounting part and the sleeve are coaxially arranged;
the fixing piece comprises movable buckles which are circumferentially and equidistantly arranged along the inner wall of the sleeve, and each movable buckle comprises a first connecting piece, a second connecting piece and a third connecting piece; the first connecting piece is fixedly connected with the inner wall of the sleeve, the tail end of the first connecting piece is fixedly connected with the first end of the second connecting piece, the arrangement direction of the second connecting piece is consistent with the axial direction of the sleeve, the tail end of the second connecting piece is fixedly connected with the first end of the third connecting piece, the third connecting piece is obliquely arranged, and the tail end of the third connecting piece and the first end of the first connecting piece are positioned on the same plain wire of the sleeve; the second connecting piece of each movable buckle encloses into the space cylindric structure that is used for fixed cylindric installation department.
2. The soil pressure sensor of claim 1, wherein: the arrangement direction of the first connecting sheet is consistent with the radial direction of the sleeve.
3. The soil pressure sensor of claim 1, wherein: the fiber grating sensor comprises a strain grating and a temperature compensation grating, wherein the strain grating and the temperature compensation grating are fixed on the upper bottom surface and the side wall of the cylindrical installation part through fiber grating adhesives.
4. A soil pressure sensor according to claim 3, characterized in that: the fiber bragg grating adhesive is prepared by mixing epoxy resin and fatty amine solution according to the proportion of 1:8-12 and continuously stirring until the mixture turns to cream yellow or white.
5. A soil pressure sensor according to claim 3, characterized in that: the strain grating and the temperature compensation grating are firstly polished at the grating pasting position before being pasted on the cylindrical installation part, the polished grating is cleaned by alcohol, then silicone rubber is smeared at two ends of the grating pasting position, the adhesive is coated on the strain grating and the temperature compensation grating, and the adhesive is subjected to heat curing treatment after the gluing is finished.
6. A method for burying and recovering a soil pressure sensor as claimed in any one of claims 1 to 5, comprising the steps of:
firstly, determining the burying place of the soil pressure sensor according to the burying scheme, inserting steel bars at two sides of the section position, and recording the relative position of the soil pressure sensor and the steel bars;
connecting the sleeve with the cylindrical mounting part to seal the cylindrical mounting part inside, then burying the soil pressure sensor in a designated position, pulling out the sleeve, backfilling the sleeve to the elevation of a drilling hole, and recording the burying depth of the sensor assembly;
when the sensor assembly is recovered, drilling is firstly carried out at the burying place, the positioning rod in the hole is utilized to position the cylindrical installation part when the burying depth is reached, then the sleeve is connected with the cylindrical installation part, and the recovery of the sensor assembly is realized by pulling out the sleeve.
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CN101358455A (en) * | 2008-08-14 | 2009-02-04 | 上海交通大学 | Lateral earth pressure sensor embedment method and device in earth |
CN202182703U (en) * | 2011-08-20 | 2012-04-04 | 大连理工大学 | Soil mass packaging fiber grating soil mass strain transducer |
CN205449355U (en) * | 2016-03-28 | 2016-08-10 | 长安大学 | Fiber grating earth pressure sensor |
CN112834099A (en) * | 2021-03-09 | 2021-05-25 | 中国人民解放军军事科学院国防工程研究院 | Three-dimensional directional burying device for soil pressure measuring equipment |
CN217304225U (en) * | 2022-03-03 | 2022-08-26 | 广州市地质调查院 | Soil pressure box embedding device and soil pressure detection device |
CN217384517U (en) * | 2022-06-14 | 2022-09-06 | 郑州航空工业管理学院 | Fiber grating soil pressure sensor |
CN218035441U (en) * | 2022-07-25 | 2022-12-13 | 上海勘察设计研究院(集团)有限公司 | Recoverable press-in type soil pressure testing device |
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2023
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CN217304225U (en) * | 2022-03-03 | 2022-08-26 | 广州市地质调查院 | Soil pressure box embedding device and soil pressure detection device |
CN217384517U (en) * | 2022-06-14 | 2022-09-06 | 郑州航空工业管理学院 | Fiber grating soil pressure sensor |
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