CN115014951A - Unsaturated soil static cone penetration test device based on PIV technology real-time measurement suction - Google Patents

Unsaturated soil static cone penetration test device based on PIV technology real-time measurement suction Download PDF

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CN115014951A
CN115014951A CN202111683733.6A CN202111683733A CN115014951A CN 115014951 A CN115014951 A CN 115014951A CN 202111683733 A CN202111683733 A CN 202111683733A CN 115014951 A CN115014951 A CN 115014951A
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transparent model
model box
tensiometer
test device
probe
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张俊然
熊潭清
许家强
姜彤
宋陈雨
王俪锦
赵金玓
赵鑫鑫
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North China University of Water Resources and Electric Power
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North China University of Water Resources and Electric Power
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • G01L5/0028—Force sensors associated with force applying means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/02—Details
    • G01N3/06—Special adaptations of indicating or recording means
    • G01N3/068—Special adaptations of indicating or recording means with optical indicating or recording means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0001—Type of application of the stress
    • G01N2203/0003—Steady
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0014—Type of force applied
    • G01N2203/0016—Tensile or compressive
    • G01N2203/0019—Compressive
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0058—Kind of property studied
    • G01N2203/006—Crack, flaws, fracture or rupture
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0058—Kind of property studied
    • G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
    • G01N2203/0075—Strain-stress relations or elastic constants
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/06—Indicating or recording means; Sensing means
    • G01N2203/0641—Indicating or recording means; Sensing means using optical, X-ray, ultraviolet, infrared or similar detectors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/06—Indicating or recording means; Sensing means
    • G01N2203/067—Parameter measured for estimating the property
    • G01N2203/0676—Force, weight, load, energy, speed or acceleration
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/06—Indicating or recording means; Sensing means
    • G01N2203/067—Parameter measured for estimating the property
    • G01N2203/0682—Spatial dimension, e.g. length, area, angle
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/30—Assessment of water resources

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  • General Health & Medical Sciences (AREA)
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Abstract

The invention provides an unsaturated soil static cone penetration test device for measuring suction in real time based on PIV technology, which comprises a frame fixed on a base surface, wherein the middle of the frame is movably connected with a loading movable beam, the bottom side of the loading movable beam is connected with a sensor and a penetration mechanism, the sensor and the penetration mechanism are respectively in signal connection with a data collector, the unsaturated soil static cone penetration test device is also provided with a transparent model box, a floodlight, a first CCD high-speed camera, two second CCD high-speed cameras, a Davis image acquisition processor, a computer, a probe cone tip, a Davis image acquisition processor, a data collector and a tension meter, the moisture content and the suction of a soil body at the cone tip can be measured through the optical fiber of a soil layer where the probe cone tip is positioned and the reading of the tension meter in the penetration process, and the water content and the suction force value measured by the optical fiber and the tensiometer are transmitted to the regulator and fed back to the computer, and obtaining the change of the suction force value of the soil body at the conical tip of the probe in the penetration process through software preset in a computer.

Description

Unsaturated soil static cone penetration test device based on PIV technology real-time measurement suction
Technical Field
The invention belongs to the technical field of geotechnical and engineering test devices, and particularly relates to an unsaturated soil static sounding test device for measuring suction force in real time based on a PIV (particle image velocimetry) technology.
Background
Static sounding is an important in-situ testing technology, mainly obtains parameters such as cone tip resistance, side friction resistance, friction-resistance ratio and the like to realize the functions of dividing soil layers, providing foundation bearing capacity, selecting pile end bearing layers, estimating single pile bearing capacity and the like, and is suitable for the investigation and design of large-scale projects such as railways, expressways, subways and the like. However, because the field test cost is high, and the penetration test difficulty of a soil layer buried deeply is high, the research and development of the indoor static sounding test device are started. The method has the advantages that the strength index of the soil body can be measured through the penetration resistance, the data of one line along the depth direction can be obtained, and compared with the data obtained by unit body tests such as conventional direct shear, triaxial and unconfined compression tests, the method is richer in data. And influenced by rainfall and evaporation, most of the soil body in the engineering is unsaturated soil, the moisture content is changed along the depth direction, and the device can simulate the natural state and the dry-wet cycle process of the soil body, so that the device is more in line with the engineering practice.
In order to quantitatively describe the water amount change in soil during penetration, many scholars at home and abroad begin to research and develop devices for measuring the water content of the soil, such as a probe capable of measuring resistivity, an optical fiber capable of measuring the water content of the soil and the like, but few devices for considering the soil suction value are available. The suction is used as the stress state quantity in the soil body, is an important mechanical parameter of water-soil coupling in unsaturated soil, can reflect the change process of the soil body strength more truly, is more reliable in predicting the soil body strength, researches the influence of the suction on the soil body penetration resistance, and has certain theoretical guidance significance and engineering practice significance.
At present, the suction force can be measured by a shaft translation control technology, a steam balance method, a hygrometer method, a filter paper method and a tensiometer method, but the tensiometer has good applicability for directly measuring the suction force in the penetration process. The tensiometer is small in size, easy to carry and high in sensitivity, and can directly measure a suction force value, but a water body in a cavity of a common tensiometer is easy to generate cavitation under the action of high tensile force, so that the high suction force cannot be measured, and the measuring range of the tensiometer is only 0-90 kPa. In order to prevent cavitation, the device is additionally provided with a water storage device with small volume on the basis of the original tensiometer, so that the measured suction value can reach 2.6 MPa.
Therefore, the invention introduces an unsaturated soil static sounding test device capable of measuring suction force in real time based on a PIV technology.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a device and a method for unsaturated soil static sounding test based on PIV technology to measure suction force in real time, so as to solve the problems in the background art.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: the unsaturated soil static sounding test device for measuring the suction force in real time based on the PIV technology comprises a frame fixed on a base surface, wherein the middle of the frame is movably connected with a loading movable beam, the bottom side of the loading movable beam is connected with a sensor and a penetration mechanism, and the sensor and the penetration mechanism are respectively in signal connection with a data acquisition unit;
the device comprises a base surface and is characterized in that a transparent model box is arranged below a penetration mechanism on the base surface, floodlights are arranged on two sides in front of the transparent model box, a first CCD high-speed camera is arranged in front of the transparent model box, two second CCD high-speed cameras are arranged above the transparent model box in a staggered mode, a Davis image acquisition processor is further arranged on one side of the transparent model box on the base surface and used for capturing displacement of cracks, and the Davis image acquisition processor and a data acquisition device are further respectively connected with a computer in a signal mode.
Furthermore, the transparent model box is specifically a box body with an opening arranged above the transparent model box, a test soil body is placed in the transparent model box, tension meters extending into the transparent model box are arranged on one side of the transparent model box at equal intervals, optical fibers extending into the transparent model box are arranged on the other side of the transparent model box at equal intervals, an optical fiber demodulator is connected to the optical fiber signals, and the optical fiber demodulator is in signal connection with a computer.
Furthermore, a plurality of groups of small holes are formed in one side of the transparent model box, the tensiometer extends into the test soil body through the small holes in one side of the transparent model box, and the optical fibers are distributed in notches formed in the inner wall of the transparent model box.
Furthermore, the tensiometer comprises a tensiometer main body and a tensiometer cap, wherein a porous argil plate is arranged on one side, close to the transparent model box, in the tensiometer main body, a water storage device is arranged on one side, close to the porous argil plate, in the tensiometer main body, a diaphragm is arranged in the middle of the tensiometer main body, a strain gauge is arranged on the other side of the diaphragm, and the tensiometer cap is sleeved on the other side of the tensiometer main body.
Furthermore, the injection mechanism comprises a probe, a probe rod, a sleeve, a pore pressure sensor, a force sensor, a strain gauge and a signal device, wherein the probe is a cone and is fixed at the bottom end of the probe rod, the sleeve is arranged outside the probe rod, the pore pressure sensor is arranged on the inner side of the probe, the force sensor and the strain gauge are symmetrically arranged on the inner surface of the sleeve, and the pore pressure sensor, the force sensor and the strain gauge are connected with the data acquisition unit through signals of the signal device.
Furthermore, the probe is a cone, and the probe rod is cylindrical.
Furthermore, the two second CCD high-speed cameras are arranged on two sides of the transparent model box in a centrosymmetric mode.
Furthermore, the first CCD high-speed camera and the second CCD high-speed camera are high-speed cameras with the resolution of 1626 pixels multiplied by 1236 pixels, the pixel size of 4.4 mu m multiplied by 4.4 mu m, the exposure time of 100 mu s multiplied by 80ms and the acquisition rate of 200 fps.
Furthermore, Camlink special interfaces are respectively arranged on the first CCD high-speed camera and the second CCD high-speed camera.
Compared with the prior art, the invention has the following advantages:
1. the invention has simple structure and convenient operation, can simulate not only the injection process but also the pile pressing process by arranging the loading movable beam, the injection mechanism, the data collector and the transparent model box, has high precision, wide speed regulation range, compact structure, convenient operation and stable performance, and can strictly control the injection rate; the invention can measure the total resistance of the loading system end, and can check and correct the end resistance and the side resistance through the value of the total resistance.
2. The invention can measure the end resistance of the probe in the penetration process, can also measure the side resistance and the pore water pressure of the probe rod, can process pictures of the penetration process shot by a CCD high-speed camera through a Davis image acquisition processor, can obtain a displacement field, a strain field and a shear field of the surface of the soil body, can observe the generation and development processes of the displacement, the strain and the crack of the surface of the soil body in real time, and has important significance for researching the generation and development of the crack of the soil body.
3. The invention can realize real-time measurement of the suction force value of soil in the injection process by burying a group of tensiometers along the depth direction, is simple and efficient, can carry out real-time measurement on the water content of the soil body by the optical fiber arranged on the inner wall of the transparent model box, and is convenient and practical.
Drawings
Fig. 1 is a schematic view of the overall structure of the present invention.
FIG. 2 is a schematic view of the transparent mold box structure of the present invention.
FIG. 3 is a schematic view of the structure of the penetration mechanism of the present invention.
Fig. 4 is a schematic view of the structure of the tensiometer of the present invention.
FIG. 5 is a top view of the second CCD high-speed camera layout position of the present invention.
1-a frame; 2-loading the movable beam; 3-a sensor; 4-a data collector; 5-a penetration mechanism; 6-floodlight; 7-a first CCD high-speed camera; 8-a second CCD high-speed camera; 9-Davis image acquisition processor; 10-a computer; 11-a tensiometer; 12-optical fiber 13-optical fiber demodulator; 14-a transparent mold box; 15-a probe; 16-a probe rod; 17-a sleeve; 18-pore pressure sensor; 19-a force sensor; 20-a strain gauge; 21-a signal device; 22-a tensiometer body; 23-porous china clay plates; 24-a membrane; 25-a water reservoir; 26-a strain gage; 27-a tensiometer cap; 28-test soil.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1 to 5, the present invention provides a technical solution: the unsaturated soil static sounding test device for measuring the suction force in real time based on the PIV technology comprises a frame 1 fixed on a base surface, wherein the middle of the frame 1 is movably connected with a loading moving beam 2, the bottom side of the loading moving beam 2 is connected with a sensor 3 and a penetration mechanism 5, and the sensor 3 and the penetration mechanism 5 are respectively in signal connection with a data acquisition unit 4;
the penetration mechanism comprises a probe 15, a probe rod 16, a sleeve 17, a hole pressure sensor 18, a force sensor 19, a strain gauge 20 and a signal device 21, wherein the probe 15 is specifically conical, the probe rod 16 is cylindrical, the probe 15 is conical and is fixed at the bottom end of the probe rod 16, the sleeve 17 is arranged outside the probe rod 16, the hole pressure sensor 18 is arranged on the inner side of the probe rod 15, the force sensor 19 and the strain gauge 20 are symmetrically arranged on the inner surface of the sleeve 17, and the hole pressure sensor 18, the force sensor 19 and the strain gauge 20 are in signal connection with the data acquisition unit 4 through the signal device.
A transparent model box 14 is arranged below the penetration mechanism 5 on the base surface, a plurality of groups of small holes are arranged on one side of the transparent model box 14, the tensiometer 11 extends into a test soil body 28 through the small hole on one side of the transparent model box 14, and the optical fibers 12 are distributed in the notch grooves arranged on the inner wall of the transparent model box 14.
The transparent model box 14 is a box body with an opening arranged above the transparent model box 14, a test soil body 28 is placed in the transparent model box 14, tension meters 11 extending into the transparent model box 14 are arranged on one side of the transparent model box 14 at equal intervals, optical fibers 12 extending into the transparent model box 14 are arranged on the other side of the transparent model box 14 at equal intervals, the optical fibers 12 are in signal connection with an optical fiber modem 13, and the optical fiber modem 13 is in signal connection with the computer 10.
The tension meter 11 comprises a tension meter main body 22 and a tension meter cap 27, a porous argil plate 23 is installed on one side, close to the transparent model box 14, in the tension meter main body 22, a water storage device 25 is arranged on one side, close to the porous argil plate 23, in the tension meter main body 22, a diaphragm 24 is arranged in the middle of the tension meter main body 22, a strain gauge 27 is arranged on the other side of the diaphragm 24, and the tension meter cap 27 is sleeved on the other side of the tension meter main body 22.
Floodlights 6 are arranged on two sides in front of the transparent model box 14, a first CCD high-speed camera 7 is arranged in front of the transparent model box 14, two second CCD high-speed cameras 8 are arranged above the transparent model box 14 in a staggered mode, and the two second CCD high-speed cameras 8 are arranged on two sides of the transparent model box 14 in a centrosymmetric mode.
The first CCD high-speed camera 7 and the second CCD high-speed camera 8 are high-speed cameras with the resolution of 1626 pixels multiplied by 1236 pixels, the pixel size of 4.4 mu m multiplied by 4.4 mu m, the exposure time of 100 mu s multiplied by 80ms and the acquisition rate of 200 fps.
The first CCD high-speed camera 7 and the second CCD high-speed camera 8 are respectively provided with a Camlink special interface
A Davis image acquisition processor 9 is further arranged on one side of the transparent model box 14 on the base surface, the Davis image acquisition processor 9 is used for capturing displacement of the crack, and the Davis image acquisition processor 9 and the data collector 4 are further respectively connected with a computer 10 through signals.
In use, the test soil 28 is placed in the transparent model box 14, the computer 10 controls the vertical displacement of the loading mobile beam 2 to apply a constant penetration rate to the penetration mechanism 5, and the total resistance and displacement applied by the penetration rate are transmitted to the computer 10 through the data collector 4 and the force sensor arranged in the sensor 3 and the displacement sensor.
After the penetration mechanism 5 is acted by force, the penetration mechanism starts to move downwards, after the probe 15 is contacted with a test soil body 28, the penetration mechanism is acted by external force, the pore pressure sensor 18 at the bottom of the cone can measure the pore water pressure of the cone tip in the static sounding process, the force sensor 19 on the inner wall of the sleeve can measure the resistance of the cone tip in the static sounding process, and the strain gauge 20 can measure the lateral resistance of the side wall of the sleeve in the static sounding process.
Meanwhile, the first CCD high-speed camera 7 positioned right in front of the transparent model box 14 and the second CCD high-speed camera 8 positioned above the transparent model box under the irradiation of the floodlight 6 can clearly shoot the microscopic change of the soil surface in the injection process, and then the computer 10 analyzes the pictures shot in the injection process by utilizing the Davis image acquisition processor 9, so that the change process of the generation and development of the displacement, the strain and the crack of the soil surface can be obtained.
And in the process of penetration, the optical fibers 12 and the tensiometer 11 which are positioned at different heights of the transparent model box 14 are used for measuring the water content and the suction of each layer of soil body.
The invention realizes real-time measurement of the water content and the suction value change of the soil body in the penetration process by the following modes that firstly, a group of optical fibers 12 are distributed in a left side notch groove in a transparent model box 14, then, when a test soil body 28 is filled in layers, a group of tensiometer 11 is buried in each layer of soil body along the depth direction, the water content and the suction value of the soil body at the cone tip position are measured by reading the optical fibers 12 and the tensiometer 11 of the soil layer at the cone tip position of a probe 15 in the penetration process, the water content and the suction value measured by the optical fibers 12 and the tensiometer 11 are transmitted to a regulator and are fed back to a computer 10, and the suction value change of the soil body at the cone tip position of the probe 15 in the penetration process is obtained by software preset in the computer 10.
Experimental example 1, the influence of dry density on soil body strength was investigated
a. Placing a transparent model box 14 below the penetration mechanism 5, arranging optical fibers 12 on the inner wall of one side of the transparent model box 14 in a notch manner, compacting a test soil body 28 by 3 layers, wherein each layer is 20cm thick, and the dry density of the test soil body is 1.4g/cm 3 And the two layers of contact surfaces are subjected to shaving treatment, a tensiometer 11 is inserted through a small hole on the side of a transparent model box 14, the tensiometer 11 is not inserted too long to avoid being penetrated by a probe 15, the tensiometer 11 is subjected to vacuum saturation for 24 hours by applying pre-pressure of at least 1.5MPa before use, and the soil body suction force cannot be too large to exceed the measuring range.
b. The floodlight 6 and the first CCD high-speed camera 7 and the second CCD high-speed camera 8 are adjusted in angle, so that the shot area shown in the computer 10 is clear and bright. And the first CCD high-speed camera 7 and the second CCD high-speed camera 8 are connected with a Davis image acquisition processor 9, and parameters such as photographing frequency and pixels are debugged and set in a computer 10.
c. The penetration mechanism 5 is arranged on a disc below the loading movable beam 2, the downward movement speed of the loading movable beam 2 is controlled through the computer 11 to control the penetration speed, the line connection of the sensor 3 is checked, the cone tip of the penetration mechanism 5 is slowly moved downwards to be just in contact with the surface of the test soil 28 in the transparent model box 14, at the moment, all numerical values are cleared in the computer, the test preparation is finished, and the test is prepared to start.
d. One minute before the test starts, the PIV test system is opened to start photographing, so that the state before soil body penetration can be captured. The computer 10 processes the pictures shot by the first CCD high-speed camera 7 and the second CCD high-speed camera 8 through the Daxis image acquisition processor 9, so as to facilitate the result analysis after the test.
The loading moving beam 2 descends at a constant speed to enable the penetration mechanism 5 to penetrate into the soil at a constant speed, a signal device 21 in the penetration mechanism 5 transmits the measured resistance of the conical tip of the probe 15, the pore water pressure and the side wall side resistance of the sleeve 17 to the data collector 4, the sensor 3 positioned below the loading moving beam 2 also transmits the displacement and the total resistance to the data collector 4, the data collector 4 feeds back the data to the computer 10, when the penetration depth is set by the test, the data are stored, the loading system of the universal testing machine is closed, and the PIV speed measuring system is closed.
e. Filling the soil body to 1.5g/cm in dry density layer by layer 3 And repeating the steps.
f. Filling the soil body to 1.6g/cm in dry density layer by layer 3 And repeating the steps.
Experimental example 2, the influence of evaporation under natural conditions on soil strength was simulated
The present example differs from experimental example 1 in that: after the test soil 28 is filled in the transparent model box 14 in a layered manner, the soil is naturally placed for a set time in order to simulate the influence of evaporation under natural conditions on the soil strength, then the suction force value of the soil is increased after water is evaporated, and when the suction force of the soil is larger than the measuring range, the tensiometer 11 is pulled out in time, and the small hole on the side surface of the transparent model box 14 is plugged by glass.
Experimental example 2, study on the influence of the Dry and Wet cycles on the soil Strength
This example differs from experimental example 1 in that: after the test soil 28 is filled in the transparent model box 14 in a layered mode, in order to achieve the dry-wet cycle working condition under the natural condition, natural evaporation is adopted to dry the test soil 28, distilled water is uniformly sprayed on the surface of the test soil 28 to moisten the test soil, the operation is repeated until the test soil reaches the target dry-wet cycle times, then the test is started, and the optical fiber 12 is arranged on the left side of the transparent model box 15 to monitor the water content change of the soil without inserting the tensiometer 11 in the dry-wet cycle process.
It should be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (9)

1. The unsaturated soil static sounding test device for measuring the suction force in real time based on the PIV technology is characterized by comprising a frame (1) fixed on a base surface, wherein the middle of the frame (1) is movably connected with a loading moving beam (2), the bottom side of the loading moving beam (2) is connected with a sensor (3) and a penetration mechanism (5), and the sensor (3) and the penetration mechanism (5) are respectively in signal connection with a data acquisition unit (4);
be provided with transparent model case (14) below penetrating mechanism (5) on the base face, transparent model case (14) the place ahead both sides are provided with floodlight (6), and transparent model case (14) the place ahead is provided with a first CCD high-speed camera (7) transparent model case (14) top is crisscross to be provided with two second CCD high-speed cameras (8), still be provided with Davis image acquisition processor (9) on transparent model case (14) one side on the base face, Davis image acquisition processor (9) are used for catching fissured displacement, Davis image acquisition processor (9) and data collection station (4) still respectively signal connection have computer (10).
2. The unsaturated soil static cone penetration test device based on the PIV technology for measuring the suction force in real time as claimed in claim 1, wherein the transparent model box (14) is a box body with an opening arranged above the transparent model box (14), a test soil body (28) is placed in the transparent model box (14), tension meters (11) extending into the transparent model box (14) are arranged on one side of the transparent model box (14) at equal intervals, optical fibers (12) extending into the transparent model box (14) are arranged on the other side of the transparent model box (14) at equal intervals, an optical fiber demodulator (13) is connected to the optical fibers (12) in a signal mode, and the optical fiber demodulator (13) is connected to the computer (10) in a signal mode.
3. The unsaturated soil static cone penetration test device based on the PIV technology for measuring the suction force in real time as claimed in claim 2, wherein a plurality of groups of small holes are formed at one side of the transparent model box (14), the tension meter (11) extends into the test soil body (28) through the small holes at one side of the transparent model box (14), and the optical fibers (12) are arranged in the notches formed in the inner wall of the transparent model box (14).
4. The unsaturated soil static sounding test device based on the PIV technology real-time suction measurement of claim 2, wherein the tensiometer (11) comprises a tensiometer main body (22) and a tensiometer cap (27), a porous clay plate (23) is installed on one side of the tensiometer main body (22) close to the transparent mold box (14), a water storage device (25) is arranged on one side of the tensiometer main body (22) close to the porous clay plate (23), a diaphragm (24) is arranged in the middle of the tensiometer main body (22), a strain gauge (27) is arranged on the other side of the diaphragm (24), and the tensiometer cap (27) is sleeved on the other side of the tensiometer main body (22).
5. The unsaturated soil static sounding test device based on the PIV technology for measuring the suction force in real time according to claim 1 is characterized in that the penetration mechanism comprises a probe (15), a probe rod (16), a sleeve (17), a pore pressure sensor (18), a force sensor (19), a strain gauge (20) and a signal device (21), the probe (15) is a cone and is fixed at the bottom end of the probe rod (16), the sleeve (17) is arranged outside the probe rod (16), the pore pressure sensor (18) is arranged on the inner side of the probe (15), the force sensor (19) and the strain gauge (20) are symmetrically arranged on the inner surface of the sleeve (17), and the pore pressure sensor (18), the force sensor (19) and the strain gauge (20) are in signal connection with the data acquisition unit (4) through the signal device.
6. The unsaturated soil static cone penetration test device based on the PIV technology for measuring the suction force in real time according to claim 5, wherein the probe (15) is specifically conical, and the probe rod (16) is cylindrical.
7. The PIV technology-based unsaturated soil static cone penetration test device for measuring suction force in real time according to claim 1, wherein the two second CCD high-speed cameras (8) are arranged in a central symmetry manner on two sides of the transparent model box (14).
8. The device for testing unsaturated soil static cone penetration test based on PIV technology real-time suction measurement according to claim 1, wherein the first CCD high-speed camera (7) and the second CCD high-speed camera (8) are high-speed cameras with a resolution of 1626 pixels x 1236 pixels, a pixel size of 4.4 μm x 4.4 μm, an exposure time of 100 μ s x 80ms and a collection rate of 200 fps.
9. The PIV technology-based unsaturated soil static cone penetration test device for measuring suction force in real time according to claim 1, wherein Camlink dedicated interfaces are further respectively arranged on the first CCD high-speed camera (7) and the second CCD high-speed camera (8).
CN202111683733.6A 2021-12-29 2021-12-29 Unsaturated soil static cone penetration test device based on PIV technology real-time measurement suction Pending CN115014951A (en)

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Publication number Priority date Publication date Assignee Title
US20030141110A1 (en) * 2002-01-29 2003-07-31 Lennart Jonsson Probing device with microwave transmission
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CN111044366A (en) * 2019-12-30 2020-04-21 华北水利水电大学 Test device for real-time measurement of tensile stress and crack in unsaturated soil in full-suction range
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CN110824139A (en) * 2019-10-22 2020-02-21 中国电建集团华东勘测设计研究院有限公司 Indoor piezocone penetration test device and method considering soil body temperature effect
CN111044366A (en) * 2019-12-30 2020-04-21 华北水利水电大学 Test device for real-time measurement of tensile stress and crack in unsaturated soil in full-suction range
CN213709465U (en) * 2020-10-22 2021-07-16 南京智探岩土科技有限公司 Pore pressure static sounding probe

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