CN111537415A - Test system and test method for observing soil particle movement in vacuum preloading process - Google Patents
Test system and test method for observing soil particle movement in vacuum preloading process Download PDFInfo
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- CN111537415A CN111537415A CN202010185736.6A CN202010185736A CN111537415A CN 111537415 A CN111537415 A CN 111537415A CN 202010185736 A CN202010185736 A CN 202010185736A CN 111537415 A CN111537415 A CN 111537415A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/082—Investigating permeability by forcing a fluid through a sample
- G01N15/0826—Investigating permeability by forcing a fluid through a sample and measuring fluid flow rate, i.e. permeation rate or pressure change
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- G—PHYSICS
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- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C5/00—Measuring height; Measuring distances transverse to line of sight; Levelling between separated points; Surveyors' levels
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L21/00—Vacuum gauges
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
Abstract
The test system for observing the movement of soil particles in the vacuum preloading process comprises a soil body vacuum consolidation system, a vacuum driving system and a monitoring system; the soil body vacuum consolidation system comprises a model box provided with an observation window, and a high-definition camera is arranged on the outer side of the observation window; the top end of the model box is provided with an LVDT displacement sensor, a plastic drainage plate, a pore water pressure sensor and a vacuum gauge probe are arranged in the model box, and the plastic drainage plate is connected with a vacuum driving system through a vacuum pipeline; the vacuum driving system comprises a vacuum water-vapor separation box, a vacuum jet pump and a vacuum load air pressure control device; the monitoring system comprises a pore water pressure sensor, a vacuum gauge probe, an LVDT displacement sensor and a high-definition camera; the invention also provides a method for testing by adopting the testing system for observing the movement of the soil particles in the vacuum preloading process. The invention can efficiently, accurately and completely obtain the individual movement information of the soil particles in the vacuum preloading process.
Description
Technical Field
The invention relates to a test system for observing the movement of soil particles in the vacuum preloading process, and further provides a method for testing by adopting the test system for observing the movement of the soil particles in the vacuum preloading process.
Background
The vacuum preloading drainage consolidation method is a common method for treating soft soil foundations, and is widely applied to treatment of silt soil foundations due to the advantages of short treatment time, simple and safe construction, low cost and the like. In the process of treating the ultra-soft soil foundation by vacuum preloading, the periphery of the vertical drainage body can form a raised compaction layer which takes the drainage body as the center, the compaction layer is called as a soil pile in the engineering, the concrete shape is like an inverted cone with a big top and a small bottom, and the soil body strength in the range of the soil pile in the reinforcing process and after the reinforcing process is finished can be greatly higher than the soil body outside the range. At present, for the clogging behavior of macroscopic plastic drainage plates, the aggregation of fine particles near the drainage plates is considered to be the reason of clogging and forming the phenomenon of soil piles, but at present, the research for verifying the conjecture is still lacking. Therefore, a method for quantitatively measuring and analyzing the movement condition of individual particles in the soil is needed, and the reason for the occurrence of the soil pile phenomenon is analyzed by combining a macroscopic soil measurement method.
In addition, in the research in the geotechnical engineering field, many problems are related to the movement of particles and particle interaction, such as the movement of soil particles in seepage, the accumulation of particle materials, the formation of a skeleton structure and the like, and the research on the phenomena requires a new explanation of the phenomena through observing the individual movement of the soil particles by an observation means with proper scale and combining with a macroscopic measurement means, thereby providing a solution to the problems. However, an effective observation method is still lacked for observing and measuring the individual movement and interaction of the small soil particles at present, and a reasonable observation scale and an observation means need to be provided to complete the research on the individual movement condition of the particles.
Disclosure of Invention
The invention aims to provide a test system-level test method for observing particle motion in a vacuum preloading process, which can efficiently, accurately and completely obtain individual motion information of soil particles in the vacuum preloading process.
In order to solve the technical problem, according to an aspect of the present invention, the present invention provides a test system for observing the movement of soil particles in a vacuum preloading process, including a soil vacuum consolidation system, a vacuum driving system and a monitoring system;
the soil body vacuum consolidation system comprises: the model box is used for filling a test soil body, and is a rectangular box body with an open top; an observation window is arranged on the front side wall of the model box and used for observing the motion condition of clay particles; a glass plate matched with the observation window in size is covered on the observation window, and a mark point for calibrating the test result is arranged on the glass plate; the left side wall of the model box is provided with a vacuum pipeline interface, a first sensor wire hole, a second sensor wire hole and a third sensor wire hole; a bracket for fixing the plastic drainage plate is arranged in the model box, and the plastic drainage plate is vertically buried in a test soil body; the top end of the plastic drainage plate is connected with a vertical connecting pipe, the top end of the vertical connecting pipe is connected with a transverse connecting pipe, and the transverse connecting pipe penetrates through a vacuum pipeline interface to be connected with a vacuum pipeline;
a rectangular first sealing frame is outwards arranged at the edge of the top end of the model box, and the upper surface of the first sealing frame is connected with a second sealing frame through a bolt; the upper part of a test soil body is covered with geotextile, the upper part of the geotextile is covered with a vacuum film, the outer edge of the vacuum film is clamped between a first sealing frame and a second sealing frame, and a sealing gasket is arranged between the vacuum film and the second sealing frame;
the vacuum drive system includes: the vacuum water-vapor separation box is used for collecting water and gas exhausted from the model box, the vacuum jet pump is used for providing negative pressure, and the vacuum pressure control device is used for adjusting vacuum load in the test system; the top of the vacuum water-vapor separation box is provided with a first connecting port, a second connecting port and a third connecting port, the first connecting port is connected with the model box through a vacuum pipeline, the second connecting port is connected with a vacuum pressure control device, and the third connecting port is connected with a vacuum jet pump; the side wall of the lower part of the vacuum water-vapor separation box is provided with a water outlet which is externally connected with a water drainage pipe, and the water drainage pipe is provided with a water drainage valve;
the monitoring system includes: the device comprises a pore water pressure sensor for monitoring the change of pore water pressure value in a soil body in the vacuum preloading process, a vacuum gauge probe for measuring the vacuum degree of the soil body at the bottom of a model box, an LVDT displacement sensor for acquiring settlement data of the surface of a tested soil body, and a high-definition camera for capturing and tracking particles in the experimental process; a sensor fixing bracket is arranged at the top end of the model box, and the LVDT displacement sensor is fixed on the sensor fixing bracket; a camera bracket is arranged on the outer side of the observation window, and the high-definition camera is fixed on the camera bracket; the first sensor wire hole is inserted into a pore water pressure sensor from the outside, and the pore water pressure sensor is buried in a test soil body; the second sensor wire hole is externally inserted into a vacuum gauge probe, which is embedded in the test soil.
Furthermore, the glass plate of the observation window is made of organic aircraft glass.
Further, the model box is made of an aluminum plate.
Furthermore, sealing plugs are arranged in the first sensor wire hole, the second sensor wire hole and the third sensor wire hole.
Further, the size calculation method of the vacuum film is as follows: setting the width of a model box as a, the length of the model box as b, designing the settling volume as l, reserving the width of 10cm on the left and the right of the vacuum film, and calculating the area of the vacuum film as follows:
S＝(a+l+20)×(b+l+20)。
further, the calculation process of the condition that the particle capturing and tracking needs to be satisfied is as follows, where the particle diameter of the target particle is set to be r, the pixel size of the camera picture is a (width) × b (height), the pixel size is e, and the shooting view field size is c (width) × d (height), and needs to satisfy:
the field of view size of the shot is determined according to the above two equations.
According to the gaussian formula:
the object space and the image space have the same medium, and the method comprises the following steps:
f′＝-f
wherein l is the object distance, l ' is the image distance, f is the object space focal length, f ' is the image space focal length, y is the object height, y ' is the image height, and β is the magnification. And I is the actual object distance.
In order to solve the above technical problem, according to another aspect of the present invention, there is provided a test method for observing movement of soil particles during vacuum preloading, comprising the steps of:
Firstly, determining the soil sample quality required by a model box, and preparing a test soil sample; fixing the plastic drainage plate at a set position through a support, installing a vacuum pipeline, a pore water pressure sensor and a vacuum gauge measuring head, adding a prepared test soil sample into a model box, covering geotextile and a vacuum film, and sealing the model box; connecting a model box in a soil body vacuum consolidation system with a vacuum driving system through a vacuum pipeline to ensure the sealing property of the whole test system;
And starting a data monitoring system, setting and adjusting the data of the pore water pressure sensor and the LVDT displacement sensor, starting a vacuum pressure control device, observing the readings of the vacuum gauge and the sensors, and zeroing to ensure that the data correspond to the correct data. Installing a high-definition camera on the camera fixing support, adjusting the shooting field of vision, and adjusting the aperture and the focal length to enable soil body particles to be imaged clearly in the field of vision;
In the test process, a high-definition camera records a picture of soil particles in a visual field shot in the vacuum preloading process, and the picture is transmitted to a computer for processing through a data acquisition system; the method comprises the steps of firstly separating an image of soil particles from background and noise through threshold segmentation, secondly determining soil particle boundaries through an identification and contour extraction method, then determining the central coordinates of individual particles, obtaining a coordinate set of particles concentrated in the whole test picture, finally determining the movement track of the particles through matching the particles, obtaining the movement information of the individual particles in silt soil, and comparing the difference of the movement conditions of the individual particles with different particle sizes.
The invention has the beneficial effects that: (1) the test image measuring method has high precision, the measured soil particle size reaches the micron level, the motion information of the soil particles in the specified size range can be tracked and measured, the data resolution is high, and the long-time continuous measurement can be carried out.
(2) The test arrangement of the model is similar to the field construction conditions, the vacuum consolidation of the field soil body can be well simulated, the movement of soil body particles in the process can be measured, and the test data has practical research significance;
(3) the model can ensure good sealing performance in the test process, can record and measure the change of a soil body displacement field, the vertical displacement of the surface of the soil body, the pore water pressure in the soil body and the vacuum degree in the vacuum preloading process by matching with the pore water pressure sensor, the displacement meter, the vacuum gauge and the PIV measuring system, monitors the test process in real time, simulates the field construction of the vacuum preloading, and provides a better engineering practice scheme.
Drawings
FIG. 1 is a system diagram of the present invention.
FIG. 2 is a front view of the mold box of the present invention.
FIG. 3 is a top view of the mold box of the present invention.
FIG. 4 is a left side view of the mold box of the present invention.
FIG. 5 is a schematic view of the vacuum driving system according to the present invention.
FIG. 6 is an object-image relationship diagram of the present invention.
Description of reference numerals: 1. a model box; 2. a first seal frame; 3. a second seal frame; 4. a vacuum film; 5. a sealing gasket; 6. a sensor fixing bracket; 7. an observation window; 8. marking points; 9. a plastic drain board; 10. a pore water pressure sensor; 11. a vertical connecting pipe; 12. a transverse connecting pipe; 13. bolt holes; 14. a vacuum line interface; 15. a first sensor wire guide; 16. a second sensor wire guide; 17. a third sensor wire guide; 18. a vacuum water-vapor separation tank; 19. a vacuum jet pump; 20. a vacuum pressure control device; 21. a vacuum line; 22. a water outlet; 23. and (4) draining the water valve.
Detailed Description
The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto:
referring to the attached drawings, the test system for observing the particle motion in the vacuum preloading process comprises a soil body vacuum consolidation system, a vacuum driving system and a monitoring system;
the soil body vacuum consolidation system comprises: the test device comprises a model box 1 for filling a test soil body, wherein the model box 1 is a rectangular box body with an open top, and the model box 1 is made of an aluminum plate; an observation window 7 is arranged on the front side wall of the model box 1 and is used for observing the motion condition of clay particles; a glass plate matched with the observation window 7 in size is covered on the observation window, a mark point 8 for calibrating the test result is arranged on the glass plate, and the glass plate is made of organic aviation glass; a vacuum pipeline interface, a first sensor wire hole 15, a second sensor wire hole 16 and a third sensor wire hole 17 are formed in the left side wall of the model box, and sealing plugs are arranged in the first sensor wire hole 15, the second sensor wire hole 16 and the third sensor wire hole 17; a bracket for fixing the plastic drainage plate is arranged in the model box, and the plastic drainage plate 9 is vertically buried in a test soil body; the top end of the plastic drainage plate 9 is connected with a vertical connecting pipe 11, the top end of the vertical connecting pipe 11 is connected with a transverse connecting pipe 12, and the transverse connecting pipe 12 passes through a vacuum pipeline interface to be connected with a vacuum pipeline 21;
the edge of the top end of the model box is outwards provided with a rectangular first sealing frame 2, the upper surface of the first sealing frame 2 is connected with a second sealing frame 3 through bolts, the first sealing frame 2 and the second sealing frame 3 are the same in shape, bolt holes 13 are arranged on the first sealing frame 2 at equal intervals, and bolt holes are also arranged at the corresponding positions of the second sealing frame 3; the upper part of a test soil body is covered with geotextile, the upper part of the geotextile is covered with a vacuum film 4, the outer edge of the vacuum film 4 is clamped between the first sealing frame 2 and the second sealing frame 3, and a sealing gasket 5 is arranged between the vacuum film 4 and the second sealing frame 3;
the vacuum drive system includes: a vacuum water-vapor separation box 18 for collecting water and gas exhausted from the mold box 1, a vacuum jet pump 19 for providing negative pressure, and a vacuum load air pressure control device 20 for adjusting the test system; the top of the vacuum water-vapor separation box 18 is provided with a first connecting port, a second connecting port and a third connecting port, the first connecting port is connected with the model box 1 through a vacuum pipeline 21, the second connecting port is connected with a vacuum pressure control device 20, and the third connecting port is connected with a vacuum jet pump 19; a water outlet 22 is arranged on the side wall of the lower part of the vacuum water-vapor separation box 18, the water outlet 22 is externally connected with a water drain pipe, and a water drain valve 23 for controlling water drainage is arranged on the water drain pipe;
the monitoring system includes: the device comprises a pore water pressure sensor for monitoring the change of pore water pressure value in a soil body in the vacuum preloading process, a vacuum gauge probe for measuring the vacuum degree of the soil body at the bottom of a model box, an LVDT displacement sensor for acquiring settlement data of the surface of a tested soil body, and a high-definition camera for capturing and tracking particles in the experimental process; a sensor fixing bracket 6 is arranged at the top end of the model box, and the LVDT displacement sensor is fixed on the sensor fixing bracket 6; a camera bracket is arranged on the outer side of the observation window, and the high-definition camera is fixed on the camera bracket; the first sensor wire hole is inserted into a pore water pressure sensor from the outside, and the pore water pressure sensor is buried in a test soil body; the second sensor wire hole is externally inserted into a vacuum gauge probe, which is embedded in the test soil.
The calculation process of the conditions required to be met by capturing and tracking soil particles is shown as follows. The particle diameter of the target particles is set to be 10 μm, the pixel size of the camera picture is 4912pixel (a) x 3684pixel (b), the pixel size e is 1.25 μm x 1.25 μm, the shooting view size is c (width) x d (height), and when c is 36.98mm d is 27.74mm, the following conditions are satisfied:
according to the gaussian formula:
the object space and the image space have the same medium, and the method comprises the following steps:
f′＝-f f＝50mm
I＝f(1+1/β)＝50(1+1/β)＝34.4mm
wherein l is the object distance, l ' is the image distance, f is the object space focal length, f ' is the image space focal length, y is the object height, y ' is the image height, and β is the magnification. And I is the actual object distance.
According to the calculation, the parameter values of the image measuring system are shown in the following table 1:
TABLE 1 image measurement System parameter Table
The invention also provides a test method for observing the movement of particles in the vacuum preloading process, which comprises the following steps:
Firstly, the soil sample quality required by the model box is determined, and a test soil sample is prepared. Fixing the plastic drainage plate 9 at a set position through a bracket, and arranging a pore water pressure sensor at a corresponding position at a certain distance away from the plastic drainage plate; connecting a plastic drainage plate with a hand-shaped interface, connecting a vertical connecting pipe and a transverse connecting pipe, and connecting the transverse connecting pipe with a vacuum pipe interface on a model box; mounting the observation window on the model box and fixing the observation window by using a bolt connecting flange; adding the prepared test soil sample into a model box 1, and covering the geotextile and the vacuum membrane 4; calculating the size of the vacuum film, ensuring that the test soil body is tightly attached to the vacuum film at the later stage of vacuumizing, and cutting the vacuum film with the size in a phase-to-phase manner and placing the vacuum film on the geotextile and a first sealing frame of the model box; the vacuum film size calculation method is as follows:
assuming that the width of a model box is a, the length of the model box is b, the design settling amount is l, the left and right sides of a vacuum film are respectively reserved with 10cm width, and the calculated area of the vacuum film is as follows:
S＝(a+l+20)×(b+l+20)。
a sealing gasket is arranged between the sealing film and the second sealing frame, and the sealing gasket is fixed with the sealing frame and then is pressed tightly, so that good air tightness is ensured; arranging an LVDT displacement sensor on the surface of the sealing film; the model box in the soil body vacuum consolidation system is connected with the vacuum driving system through the vacuum pipeline, so that the sealing performance of the whole test system is ensured.
And starting a data monitoring system, setting and adjusting the data of the pore water pressure sensor 10 and the LVDT displacement sensors, starting a vacuum pressure control device, observing the readings of the vacuum gauge and the sensors, and zeroing to ensure that the data correspond to the correct data. A high-definition camera is arranged on a camera fixing support, a light source and the high-definition camera are arranged in front of the model box 1 and are focused, the shooting field of vision is adjusted, and the aperture and the focal length are adjusted, so that soil body particles can form clear images in the field of vision.
After the model preparation is completed and the measurement system is arranged, the vacuum pump is started to perform a vacuum preloading test. In the test process, the high-definition camera records the picture of soil particles in the visual field shot in the vacuum preloading process, and the picture is transmitted to a computer for processing through a data acquisition system. The method comprises the steps of firstly separating an image of soil particles from background and noise through threshold segmentation, secondly determining soil particle boundaries through an identification and contour extraction method, then determining the central coordinates of individual particles, obtaining a coordinate set of particles concentrated in the whole test picture, finally determining the movement track of the particles through matching the particles, obtaining the movement information of the individual particles in silt soil, and comparing the difference of the movement conditions of the individual particles with different particle sizes.
The embodiments described in this specification are merely illustrative of implementations of the inventive concept and the scope of the present invention should not be considered limited to the specific forms set forth in the embodiments but rather by the equivalents thereof as may occur to those skilled in the art upon consideration of the present inventive concept.
Claims (7)
1. Survey test system of soil particles motion among the vacuum preloading process, its characterized in that: the device comprises a soil body vacuum consolidation system, a vacuum driving system and a monitoring system;
the soil body vacuum consolidation system comprises: the model box is used for filling a test soil body, and is a rectangular box body with an open top; an observation window is arranged on the front side wall of the model box and used for observing the motion condition of clay particles; a glass plate matched with the observation window in size is covered on the observation window, and a mark point for calibrating the test result is arranged on the glass plate; the left side wall of the model box is provided with a vacuum pipeline interface, a first sensor wire hole, a second sensor wire hole and a third sensor wire hole; a bracket for fixing the plastic drainage plate is arranged in the model box, and the plastic drainage plate is vertically buried in a test soil body; the top end of the plastic drainage plate is connected with a vertical connecting pipe, the top end of the vertical connecting pipe is connected with a transverse connecting pipe, and the transverse connecting pipe penetrates through a vacuum pipeline interface to be connected with a vacuum pipeline;
a rectangular first sealing frame is outwards arranged at the edge of the top end of the model box, and the upper surface of the first sealing frame is connected with a second sealing frame through a bolt; the upper part of a test soil body is covered with geotextile, the upper part of the geotextile is covered with a vacuum film, the outer edge of the vacuum film is clamped between a first sealing frame and a second sealing frame, and a sealing gasket is arranged between the vacuum film and the second sealing frame;
the vacuum drive system includes: the vacuum water-vapor separation box is used for collecting water and gas exhausted from the model box, the vacuum jet pump is used for providing negative pressure, and the vacuum pressure control device is used for adjusting vacuum load in the test system; the top of the vacuum water-vapor separation box is provided with a first connecting port, a second connecting port and a third connecting port, the first connecting port is connected with the model box through a vacuum pipeline, the second connecting port is connected with a vacuum pressure control device, and the third connecting port is connected with a vacuum jet pump; the side wall of the lower part of the vacuum water-vapor separation box is provided with a water outlet which is externally connected with a water drainage pipe, and the water drainage pipe is provided with a water drainage valve;
the monitoring system includes: the device comprises a pore water pressure sensor for monitoring the change of pore water pressure value in a soil body in the vacuum preloading process, a vacuum gauge probe for measuring the vacuum degree of the soil body at the bottom of a model box, an LVDT displacement sensor for acquiring settlement data of the surface of a tested soil body, and a high-definition camera for capturing and tracking particles in the experimental process; a sensor fixing bracket is arranged at the top end of the model box, and the LVDT displacement sensor is fixed on the sensor fixing bracket; a camera bracket is arranged on the outer side of the observation window, and the high-definition camera is fixed on the camera bracket; the first sensor wire hole is inserted into a pore water pressure sensor from the outside, and the pore water pressure sensor is buried in a test soil body; the second sensor wire hole is externally inserted into a vacuum gauge probe, which is embedded in the test soil.
2. The test system for observing the movement of soil particles during vacuum preloading of claim 1, wherein: the glass plate of the observation window is made of organic aviation glass.
3. The test system for observing the movement of soil particles during vacuum preloading of claim 1, wherein: the model box is made of aluminum plates.
4. The test system for observing the movement of soil particles during vacuum preloading of claim 1, wherein: and sealing plugs are arranged in the first sensor wire hole, the second sensor wire hole and the third sensor wire hole.
5. The test system for observing the movement of soil particles during vacuum preloading of claim 1, wherein: the size calculation method of the vacuum film comprises the following steps: setting the width of a model box as a, the length of the model box as b, designing the settling volume as l, reserving the width of 10cm on the left and the right of the vacuum film, and calculating the area of the vacuum film as follows:
S＝(a+l+20)×(b+l+20)。
6. the test system for observing the movement of soil particles during vacuum preloading of claim 1, wherein: the calculation process of the condition that the particle capturing and tracking needs to meet is as follows, the particle diameter of the target particle is set as r, the pixel size of the related camera picture is a (width) multiplied by b (height), the pixel size is e, the shooting view field size is c (width) multiplied by d (height), and the condition that the particle capturing and tracking needs to meet is set as follows:
the field of view size of the shot is determined according to the above two equations.
According to the gaussian formula:
the object space and the image space have the same medium, and the method comprises the following steps:
f′＝-f
wherein l is the object distance, l ' is the image distance, f is the object space focal length, f ' is the image space focal length, y is the object height, y ' is the image height, and β is the magnification. And I is the actual object distance.
7. The test method adopted by the test system for observing the movement of the soil particles in the vacuum preloading process according to claim 1, is characterized by comprising the following steps of:
step 1, model preparation
Firstly, the soil sample quality required by the model box is determined, and a test soil sample is prepared. Fixing the plastic drainage plate at a set position through a support, installing a vacuum pipeline, a pore water pressure sensor and a vacuum gauge measuring head, adding a prepared test soil sample into a model box, covering geotextile and a vacuum film, and sealing the model box; connecting a model box in a soil body vacuum consolidation system with a vacuum driving system through a vacuum pipeline to ensure the sealing property of the whole test system;
step 2, debugging the system
Starting a data monitoring system, setting and adjusting data of the pore water pressure sensor and the LVDT displacement sensor, starting a vacuum pressure control device, observing readings of a vacuum gauge and each sensor, and carrying out zero setting to ensure that the data correspond correctly; installing a high-definition camera on the camera fixing support, adjusting the shooting field of vision, and adjusting the aperture and the focal length to enable soil body particles to be imaged clearly in the field of vision;
step 3, analyzing test pictures
In the test process, a high-definition camera records a picture of soil particles in a visual field shot in the vacuum preloading process, and the picture is transmitted to a computer for processing through a data acquisition system; the method comprises the steps of firstly separating an image of soil particles from background and noise through threshold segmentation, secondly determining soil particle boundaries through an identification and contour extraction method, then determining the central coordinates of individual particles, obtaining a coordinate set of particles concentrated in the whole test picture, finally determining the movement track of the particles through matching the particles, obtaining the movement information of the individual particles in silt soil, and comparing the difference of the movement conditions of the individual particles with different particle sizes.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2416081C1 (en) * | 2009-12-30 | 2011-04-10 | Общество с ограниченной ответственностью "Научно-производственное предприятие "Геотек" (ООО "НПП "Геотек") | Method to automatically measure pore and side pressure under conditions of soil compression |
| CN102011388A (en) * | 2010-11-19 | 2011-04-13 | 中交第四航务工程局有限公司 | Underwater vacuum preloading centrifugal model testing device and method |
| CN104264719A (en) * | 2014-09-03 | 2015-01-07 | 上海大学 | Vacuum preloading indoor model testing apparatus |
| CN104569341A (en) * | 2014-11-28 | 2015-04-29 | 温州大学 | Vacuum preloading and electroosmosis combined testing device and vacuum preloading and electroosmosis combined testing method |
| CN104790442A (en) * | 2015-05-05 | 2015-07-22 | 温州大学 | Large-sized testing device of model test for treating soft soil foundation by vacuum preloading method and testing method thereof |
| CN104914008A (en) * | 2015-06-11 | 2015-09-16 | 同济大学 | Quasi-rectangular shield soil chamber residue soil flow characteristic visualization observation test system and method |
| CN105954168A (en) * | 2016-04-15 | 2016-09-21 | 华北水利水电大学 | Testing apparatus for high-temporal-spatial-resolution observation of three-dimensional seepage field of unsaturated soil |
| CN107976164A (en) * | 2017-11-16 | 2018-05-01 | 温州大学 | Measure the bath scaled model experimental device and its measuring method of displacement model in high-moisture stream silt particle well consolidation process under vacuum pressure |
| CN108414728A (en) * | 2018-02-07 | 2018-08-17 | 南京科兴新材料科技有限公司 | Weak soil displacement field and the visual experimental rig of seepage field and test method under a kind of vacuum method |
| CN109307622A (en) * | 2018-11-05 | 2019-02-05 | 浙江工业大学 | The settling column test instrument and test method that lateral pressure and vacuum preloading combine |
-
2020
- 2020-03-17 CN CN202010185736.6A patent/CN111537415B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2416081C1 (en) * | 2009-12-30 | 2011-04-10 | Общество с ограниченной ответственностью "Научно-производственное предприятие "Геотек" (ООО "НПП "Геотек") | Method to automatically measure pore and side pressure under conditions of soil compression |
| CN102011388A (en) * | 2010-11-19 | 2011-04-13 | 中交第四航务工程局有限公司 | Underwater vacuum preloading centrifugal model testing device and method |
| CN104264719A (en) * | 2014-09-03 | 2015-01-07 | 上海大学 | Vacuum preloading indoor model testing apparatus |
| CN104569341A (en) * | 2014-11-28 | 2015-04-29 | 温州大学 | Vacuum preloading and electroosmosis combined testing device and vacuum preloading and electroosmosis combined testing method |
| CN104790442A (en) * | 2015-05-05 | 2015-07-22 | 温州大学 | Large-sized testing device of model test for treating soft soil foundation by vacuum preloading method and testing method thereof |
| CN104914008A (en) * | 2015-06-11 | 2015-09-16 | 同济大学 | Quasi-rectangular shield soil chamber residue soil flow characteristic visualization observation test system and method |
| CN105954168A (en) * | 2016-04-15 | 2016-09-21 | 华北水利水电大学 | Testing apparatus for high-temporal-spatial-resolution observation of three-dimensional seepage field of unsaturated soil |
| CN107976164A (en) * | 2017-11-16 | 2018-05-01 | 温州大学 | Measure the bath scaled model experimental device and its measuring method of displacement model in high-moisture stream silt particle well consolidation process under vacuum pressure |
| CN108414728A (en) * | 2018-02-07 | 2018-08-17 | 南京科兴新材料科技有限公司 | Weak soil displacement field and the visual experimental rig of seepage field and test method under a kind of vacuum method |
| CN109307622A (en) * | 2018-11-05 | 2019-02-05 | 浙江工业大学 | The settling column test instrument and test method that lateral pressure and vacuum preloading combine |
Non-Patent Citations (2)
| Title |
|---|
| 武亚军等: "真空荷载下超软土固结试验及土颗粒移动数值模拟研究", 《水运工程》 * |
| 陈庚等: "异步真空预压法处理超软土的室内试验及机理", 《水运工程》 * |
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