CN114018694A - Unconfined compressive strength's sample surface state survey device - Google Patents
Unconfined compressive strength's sample surface state survey device Download PDFInfo
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- CN114018694A CN114018694A CN202111439897.4A CN202111439897A CN114018694A CN 114018694 A CN114018694 A CN 114018694A CN 202111439897 A CN202111439897 A CN 202111439897A CN 114018694 A CN114018694 A CN 114018694A
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- 238000001514 detection method Methods 0.000 claims abstract description 26
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- 230000008569 process Effects 0.000 abstract description 7
- 238000012512 characterization method Methods 0.000 abstract description 3
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- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
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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
- G01N3/02—Details
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
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- 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
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- 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
- G01N2203/0067—Fracture or rupture
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- 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
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- 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
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Abstract
The invention discloses a sample surface state measuring device of unconfined compressive strength, which comprises an action detection unit, a test block bearing table and a lifting mechanism, wherein a radial following assembly is arranged on the test block bearing table, a sample cavity is formed in the radial following assembly, the inner wall of the radial following assembly is in contact connection with the circumferential surface of a sample, the radial following assembly is used for enlarging the diameter of the sample cavity when the sample generates axial strain, a surface state acquisition unit is arranged on the inner wall of the radial following assembly and is used for acquiring surface state data when the sample generates axial strain and generating a control signal for enlarging the diameter of the sample cavity by the radial following assembly. According to the invention, the time for the sample to reach the peak value state is shortened, and the instantaneous state of the sample in the process of reaching the peak value is collected, so that the accuracy of the peak value of the sample and the characterization relation between the peak value and the surface state of the sample are accurately described, and more accurate structural characteristics of the sample are obtained.
Description
Technical Field
The invention relates to the technical field of unconfined compressive strength tests, in particular to a sample surface state measuring device for unconfined compressive strength.
Background
The unconfined compressive strength is used for measuring the strength of the inorganic binder stabilizing material, namely the strength of the semi-rigid base layer and the subbase layer materials, the unconfined compressive strength is the ultimate strength of a solidified soil sample for resisting axial stress under the condition of no lateral pressure, is the most basic mechanical property index of the solidified soil, and is one of important indexes for evaluating the solidification effect of cement or other cementing materials on a soil body,
the unconfined compressive strength measuring method widely applied at present comprises the following steps: during the test, the sample is subjected to axial pressure gradually under the condition of no lateral limitation, namely the ambient pressure is zero, clear fracture surface traces can be seen on the side surface of the sample when the sample is fractured, and the pressure at the moment is the unconfined compressive strength; when some soil is cracked, the plastic flow phenomenon occurs, the sample is pressed into a barrel shape, but no cracking surface occurs, the pressure when the axial strain reaches 20% is taken as the unconfined compressive strength, in the unconfined compressive strength measuring method, the most important point is that the standard precision of the numerical value of the applied axial pressure is determined to be the instant characterization relation of the pressure value at the moment when the crack surface mark appears on the surface of the sample and the sample surface is cracked and changed, and when the unconfined compressive strength of the existing sample is measured, the axial strain speed is 1% -3% of strain per minute. And rotating the handle to lift the lifting equipment for testing, wherein when the axial strain is less than 3%, reading the axial strain at intervals of 0.5% strain (or 0.4mm) is equal to or more than 3%, and reading the axial strain at intervals of 1% strain (or 0.8 mm). The test is preferably completed within 8-10 min. When the reading of the dynamometer has a peak value, continuing to perform the test after 3% -5% of strain; when the reading has no peak value, the test is carried out until the strain reaches 20%, that is, in the process, the peak value of the sample is determined, but the surface state of the sample corresponding to the peak value of the sample has uncertainty, although the sample can be shot by a high-speed camera in the prior art, the shot multi-frame pictures need to be artificially described, the artificial description has no certainty, the multi-frame pictures cannot well correspond to the axial stress peak value of the sample, and particularly when the sample has a plastic flow condition, the state of the sample is difficult to describe.
Disclosure of Invention
The invention aims to provide a sample surface state measuring method without confined compressive strength, which aims to solve the technical problem that the prior art lacks of representation of the instantaneous relationship of pressure values at the moment when a fracture surface mark appears on the surface of a sample and the surface of the sample changes in a collapsing way.
In order to solve the technical problems, the invention specifically provides the following technical scheme:
a sample surface state measuring device without lateral limit compressive strength comprises an action detecting unit for axial compressive strain and axial displacement, a test block bearing platform which is positioned below the action detecting unit and bears a test sample, and a lifting mechanism which is arranged at the bottom of the test block bearing platform and is used for driving the test block bearing platform to move up and down, the test block bearing table is provided with a radial following assembly, a test sample cavity is formed in the radial following assembly, the inner wall of the radial following assembly is in contact connection with the circumferential surface of the sample, the radial following assembly is used for expanding the diameter of the sample cavity when the sample generates axial strain, and a surface state acquisition unit is arranged on the inner wall of the radial following assembly and is used for acquiring surface state data when the sample generates axial strain and generating a control signal for expanding the diameter of the sample cavity by the radial following assembly.
Wherein the surface state acquisition unit comprises a thin film pressure sensitive sensor.
As a preferred scheme of the present invention, the radial following assembly includes an outer cylindrical cavity and a cylindrical curved body sleeved in the outer cylindrical cavity, and the inside of the cylindrical curved body forms the sample cavity;
the post curved surface body includes a plurality of cambered surface cylinder units, and is a plurality of cambered surface cylinder unit annular is connected in order, and adjacent two the side of cambered surface cylinder unit is connected through the elastic joint, cambered surface cylinder unit is towards the surface mounting of sample the surface condition acquisition unit, cambered surface cylinder unit inside is provided with sealed chamber, and connects the air supply in sealed chamber provides the unit.
As a preferable mode of the present invention, the sealed cavity has a plurality of partition plates arranged along a radial direction of the cylindrical curved body, an independent cavity is formed between two adjacent partition plates, a flat tube is hermetically connected to a top and a bottom of each independent cavity, the gas source providing unit is connected to the flat tubes through pipes, and the pipes and the flat tubes correspond to each other one by one.
In a preferred embodiment of the present invention, the side edges of two adjacent separators in the length direction and the middle of the two separators are connected by a folded strip.
As a preferable scheme of the present invention, the motion detection unit includes a torque transmission rod for applying an axial force to the sample, a pressure-bearing plate is connected to a lower end of the torque transmission rod, a force measuring ring is disposed above the torque transmission rod, a first digital dial indicator for detecting deformation of the force measuring ring is disposed in the middle of the force measuring ring, and axes of the torque transmission rod, the force measuring ring, and the outer column cavity are kept consistent.
As a preferred scheme of the invention, the top of the outer column cavity is provided with a fixing ring, the diameter of the fixing ring is larger than that of the outer column cavity, and the bottom of the outer column cavity is mounted on the test block bearing table through a spring piece;
a plurality of microspur detection devices are arranged on the pressure bearing plate in an annular array and are in contact connection with the fixing ring;
the microspur detection device is used for detecting a height change signal of the edge of the fixing ring.
As a preferable scheme of the present invention, the test block bearing table is provided with a concave ring groove for installing the outer column cavity, the bottom of the outer column cavity is installed in the concave ring groove through the elastic member, and the width of the concave ring groove is greater than the width of the outer column cavity.
As a preferable scheme of the present invention, a driving bolt is disposed in the middle of the pressure bearing plate, the driving bolt includes a first cylinder and a second cylinder, a diameter of the first cylinder is smaller than a diameter of the second cylinder, the first cylinder penetrates through the top of the pressure bearing plate and is connected to the torque transmission rod, and a fitting groove for fitting a sample is disposed on a bottom surface of the second cylinder.
As a preferable scheme of the present invention, the elastic joint includes a radial compression and extension unit and a circumferential tension unit, the circumferential tension unit is connected to a side edge of the cambered surface cylinder unit in the length direction, and a surface of the circumferential tension unit is identical to a surface of the cambered surface cylinder unit;
the radial compression and expansion unit is connected with the surface of the cambered surface cylinder unit in the thickness direction, and the radial compression and expansion unit and the folding strip are identical in structure.
In a preferred embodiment of the present invention, the macro detection device includes an infrared laser sensor.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, on the basis of the existing experiment of unconfined compressive strength, under the condition that no confining pressure is applied to the surface of the sample, the instant state of the sample in the process of reaching the peak value is collected by shortening the time of the sample to reach the peak value, and the accuracy of the peak value of the sample and the characterization relation between the peak value and the surface state of the sample can be accurately described through the data collected in the instant state, so that the more accurate structural characteristics of the sample are obtained.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.
FIG. 1 is a schematic structural view of a surface condition measuring apparatus for providing unconfined compressive strength according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a radial follower assembly according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a radial follower assembly with a retaining ring according to an embodiment of the present invention;
FIG. 4 is an enlarged view of portion A of FIG. 3 according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a drive bolt according to an embodiment of the present invention.
The reference numerals in the drawings denote the following, respectively:
1-an action detection unit; 2-test block bearing platform; 3-a lifting mechanism; 4-a radial follower assembly; 5-a sample chamber; 6-a surface state acquisition unit; 7-fixing the ring; 8-a spring element; 9-a drive bolt; 10-sample;
101-a torque transmission rod; 102-a pressure-bearing plate; 103-force measuring ring; 104-a first digital dial indicator; 105-a fixed support; 106-macro detection means; 107-a concave ring groove;
41-outer column cavity; 42-cylindrical curved body; 43-cambered surface cylinder unit; 44-an elastic joint; 45-sealing the cavity; 46-a separator; 47-independent chamber; 48-folding the strip; 91-a first cylinder; 92-a second column; 93-sleeving groove.
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 sample surface state measuring apparatus of unconfined compressive strength, and the main object of the present invention is to collect a sample surface in an instantaneous state of a peak value process by shortening a time for a sample to reach a peak state without applying a confining pressure to the sample in addition to a conventional unconfined compressive strength test.
The test sample experiment foundation part of unconfined compressive strength comprises an action detection unit 1 of axial compressive strain and axial displacement, a test block bearing table 2 which is positioned below the action detection unit 1 and bears a test sample, and a lifting mechanism 3 which is arranged at the bottom of the test block bearing table 2 and is used for driving the test block bearing table 2 to move up and down.
The invention mainly comprises a radial following component 4 arranged on a test block bearing platform 2, the data acquisition of the surface state of the sample is realized through the radial following component 4, and the pressure is not applied to the surface of the sample:
for this reason, be formed with sample chamber 5 in the radial subassembly 4 of following, sample chamber 5 is used for installation and cladding sample, the inner wall of radial subassembly 4 of following is connected with the circumferential surface contact of sample (i.e. no pressure laminating), radial subassembly 4 of following is used for enlarging the diameter of sample chamber 5 when the sample produces axial strain, be provided with surface state acquisition unit 6 on the inner wall of radial subassembly 4 of following, surface state acquisition unit 6 is used for gathering the surface state data when the sample produces axial strain to produce the control signal that radial subassembly 4 enlarges the diameter of sample chamber 5.
The surface state acquisition unit 6 includes a thin film pressure sensitive sensor, and specifically, a dot matrix thin film pressure sensitive sensor may be used.
The specific working principle of the invention is as follows: when an experiment is started (the initial pressure value of a sample is adjusted to be zero), a lifting mechanism 3 drives a test block bearing table 2 to apply external force to the sample, so that the sample obtains axial strain force, an action detection unit 1 detects the axial strain force obtained by the test block, when the axial extension speed of the sample is kept between 0.9mm/min and 1.5mm/min, the external force is applied to the sample once every other minute, and the external force value added to the sample is recorded; when the axial conversion speed of the sample is 0.4mm/min-0.6mm/min, applying external force to the sample every other half minute, and recording the value of the external force added to the sample, and when the axial conversion speed of the sample is 0.1mm/min-0.2mm/min, continuously applying the set external force to the sample until the motion detection unit 1 reaches the peak value and the value is reduced (in the process, the radial following component 4 and the surface state acquisition unit 6 start to work and start timing from the set time point), at the moment:
at the moment of structural change of the surface of the sample, the surface of the sample is contacted with the surface of the surface state acquisition unit 6, and a part of the sample surface where the "collapse" (the detection value of the motion detection unit 1 is reduced) is contacted with the thin film pressure sensitive sensor, so that the thin film pressure sensitive sensor obtains data, wherein the data signal acquired by the surface state acquisition unit 6 comprises two parts: the relative position of the sample surface which is broken up is shown, and the sample broken up part generates stress tendency, when the surface state acquisition unit 6 acquires the surface state data of the sample which generates axial strain, a control signal for expanding the diameter of the sample cavity 5 is sent to the radial following assembly 4, the control signal is completed instantly, namely the surface state acquisition unit 6 acquires the acting force generated instantly when the sample surface is broken up, then the control signal for triggering the expansion of the diameter of the sample cavity 5 is given to the radial following assembly 4 instantly, the expansion of the diameter of the sample cavity 5 by the radial following assembly 4 can be completed in a very short time, so that the sample can be subjected to collection of the surface state (in the state after the breaking up moment and the breaking up resistance moment) while the unconfined strength of the sample is realized.
In terms of how to not apply confined compression resistance to the axial direction of the sample, the invention provides a radial following assembly 4, which comprises an outer cylindrical cavity 41 and a cylindrical curved body 42 (in a pipe structure) sleeved in the outer cylindrical cavity 41, wherein a sample cavity 5 is formed inside the cylindrical curved body 42.
Wherein, cylindrical surface body 42 includes a plurality of cambered surface cylinder units 43, and a plurality of cambered surface cylinder units 43 ring-type are connected in order (are formed cylindrical surface body 42's body structure), and the side of two adjacent cambered surface cylinder units 43 is connected through elastic joint 44, cambered surface cylinder unit 43 towards the surface mounting surface state acquisition unit 6 of sample, cambered surface cylinder unit 43 is inside to be provided with seal chamber 45 to and connect the air supply of seal chamber 45 and provide the unit, the air supply provide the unit be used for to provide gas in seal chamber 45 or take out the gas in the seal chamber 45, make cambered surface cylinder unit 43 along the radial deformation of outer column cavity 41 (be the thickness of compression post curved surface body 42), and then make the diameter of sample chamber 5 enlarge, its purpose certainly is the contact that breaks away from and sample surface ("collapses" part).
At the beginning of the experiment, gas is injected into the sealed cavity 45 through the gas pressure source providing unit, so that the inner wall of the cylindrical curved body 42 is in contact with the surface of the sample, and the pressure value displayed by the surface state collecting unit 6 is zero at the moment.
Further, in order to improve the fine control of the diameter expansion of the sample cavity 5 and to obtain data information of the sample surface as much as possible under the unconfined compressive strength of the sample, the seal cavity 45 of the present invention is provided with a plurality of partition plates 46 along the radial array of the cylindrical curved body 42, an independent cavity 47 is formed between two adjacent partition plates 46, the top and the bottom of each independent cavity 47 are hermetically connected with flat tubes, the air supply units are connected with the flat tubes through pipelines, and the pipelines and the flat tubes correspond to each other one by one, so that the air supply units are required to connect each independent cavity 47 to control the compression and expansion of each independent cavity 47, since the compression of the independent cavity 47 (mainly the diameter expansion of the sample cavity 5 due to the compression) needs to be completed instantaneously, in order to avoid the stability of the surface state collection unit 6 when the independent cavity 47 is completed instantaneously, after the radial follower 4 is given a control signal that triggers the expansion of the diameter of the sample chamber 5, the individual chambers 47 are sequentially evacuated and the process starts with the individual chamber 47 that is close to the outer column chamber 41. Because the width of the independent cavity 47 is small, instantaneous air suction can be realized, the whole cylindrical curved body 42 is instantaneously compressed, and the sample cavity 5 is instantaneously expanded.
The side edges of the two adjacent partition plates 46 along the length direction are connected with the middles of the two partition plates 46 through folding strips 48, the independent cavities 47 are compressed mainly through the folding of the folding strips 48, the folding strips 48 aim at stably compressing and guiding the independent cavities 47, the phenomenon that the contact state of the surface state acquisition unit 6 and the surface of a sample is influenced due to the fact that large fluctuation occurs in the air suction process is avoided, and the folding strips 48 are formed by sequentially connecting elastic sheet silica gel plates in a folding mode.
Further, the thickness of the plurality of independent cavities 47 may be gradually increased from near the outer column cavity 41 to the sample cavity 5.
The action detection unit 1 comprises a torque transmission rod 101 for applying axial force to a sample, a bearing plate 102 is connected to the lower end of the torque transmission rod 101, a force measuring ring 103 is arranged above the torque transmission rod 101, a first digital dial indicator 104 for detecting deformation of the force measuring ring 103 is arranged in the middle of the force measuring ring 103, and the axes of the torque transmission rod 101, the force measuring ring 103 and the outer column cavity 41 are kept consistent.
The top of outer column cavity 41 is provided with solid fixed ring 7, and the diameter of solid fixed ring 7 is greater than the diameter of outer column cavity 41, and the bottom of outer column cavity 41 is installed on test block plummer 2 through bullet movable 8.
Furthermore, in order to know that the torque transmission rod 101 is sleeved with the fixing bracket 105, a plurality of macro detection devices 106 are arranged on the annular array on the pressure bearing plate 102, and the macro detection devices 106 are in contact connection with the fixing ring 7.
The macro detection device 106 is used to detect the height variation signal of the edge of the fixing ring 7, and the macro detection device 106 may specifically employ an infrared laser sensor, or a mechanical height sensor capable of contacting with the fixing ring 7.
Further, the test block bearing platform 2 of the present invention is provided with a concave ring groove 107 for installing the outer column cavity 41, the bottom of the outer column cavity 41 is installed in the concave ring groove 107 through the elastic component 8, and the width of the concave ring groove 107 is greater than the width of the outer column cavity 41, so as to provide a slight degree of freedom of the outer column cavity 41 in the radial direction of the outer column cavity 41, that is, the outer column cavity 41 can shake, and the purpose of the shaking is to enable the fixing ring 7 to shift (the initial state is a horizontal state), and the slight shifting action can be captured by the macro detection device 106, so that the action change of the surface of the test block in the axial direction at the instant of the "collapse", especially when the test block generates plastic flow, the instantaneous state of the plastic flow can be clearly known.
Further, the invention provides a driving bolt 9 arranged in the middle of a bearing plate 102, the driving bolt 9 comprises a first cylinder 91 and a second cylinder 92, the diameter of the first cylinder 91 is smaller than that of the second cylinder 92, the first cylinder 91 penetrates through the top of the bearing plate 102 to be connected with a torque transmission rod 101, the bottom surface of the second cylinder 92 is provided with a sleeving groove 93 for installing a sample, so that the acting force of the torque transmission rod 101 acts on the first cylinder 91 and is transmitted to the second cylinder 92 through the first cylinder 91, the diameter of the second cylinder 92 is larger than that of the first cylinder 91, and the second cylinder 92 cannot pass through the bearing plate 102 to play the role of limiting and protecting.
It is further noted that the elastic joint 44 includes a radial compression extension unit and a circumferential extension unit, and the purpose is to achieve that the two adjacent cambered surface cylinder units 43 can be compressed in the radial direction and also can adapt to surface expansion in the circumferential direction, the radial compression extension unit is not connected with the circumferential extension unit, the circumferential extension unit is connected with the side edge of the cambered surface cylinder unit 43 in the length direction, and the surface of the circumferential extension unit is consistent with the surface of the cambered surface cylinder unit 43.
The radial compression and expansion unit is connected with the surface of the cambered surface cylinder unit 43 in the thickness direction, and the radial compression and expansion unit and the folded strip 48 have the same structure.
It is further noted that the present invention contemplates that cylindrical surface 42 within outer cylindrical cavity 41 is configured as a plurality of sequentially connected annular structures distributed axially along outer cylindrical cavity 41.
The above embodiments are only exemplary embodiments of the present application, and are not intended to limit the present application, and the protection scope of the present application is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present application and such modifications and equivalents should also be considered to be within the scope of the present application.
Claims (10)
1. The device for measuring the surface state of the sample without the confined compressive strength comprises an axial compressive strain and axial displacement motion detection unit (1), a test block bearing table (2) which is positioned below the motion detection unit (1) and bears the sample, and a lifting mechanism (3) which is arranged at the bottom of the test block bearing table (2) and is used for driving the test block bearing table (2) to move up and down, and is characterized in that a radial following assembly (4) is arranged on the test block bearing table (2), a sample cavity (5) is formed in the radial following assembly (4), the inner wall of the radial following assembly (4) is in contact connection with the circumferential surface of the sample, the radial following assembly (4) is used for expanding the diameter of the sample cavity (5) when the sample generates the axial strain, a surface state acquisition unit (6) is arranged on the inner wall of the radial following assembly (4), the surface state acquisition unit (6) is used for acquiring surface state data when a sample generates axial strain and generating a control signal for expanding the diameter of the sample cavity (5) by the radial following assembly (4); the surface state acquisition unit (6) comprises a thin film pressure sensitive sensor.
2. The unconfined compressive strength sample surface condition measuring device according to claim 1, wherein the radial follower assembly (4) comprises an outer cylindrical cavity (41) and a cylindrical curved body (42) sleeved in the outer cylindrical cavity (41), and the inside of the cylindrical curved body (42) forms the sample cavity (5);
post curved surface body (42) are including a plurality of cambered surface cylinder units (43), and are a plurality of cambered surface cylinder unit (43) ring shape is connected in order, and adjacent two the side of cambered surface cylinder unit (43) is connected through elastic joint (44), cambered surface cylinder unit (43) is towards the surface mounting of sample surface condition acquisition unit (6), cambered surface cylinder unit (43) inside is provided with seal chamber (45), and connects the air supply of seal chamber (45) provides the unit.
3. The unconfined compressive strength sample surface condition measuring device according to claim 2, wherein the sealed cavity (45) is provided with a plurality of partition plates (46) along a radial array of the cylindrical curved body (42), an independent cavity (47) is formed between every two adjacent partition plates (46), a flat tube is hermetically connected to the top and the bottom of each independent cavity (47), the air supply units are connected with the flat tubes through pipelines, and the pipelines and the flat tubes are in one-to-one correspondence.
4. A sample surface condition measuring device without confined compressive strength as claimed in claim 3, wherein the lengthwise side edges of two adjacent partitions (46) and the middle of two said partitions (46) are connected by a folded strip (48).
5. The device for measuring the surface state of the sample without the confined compressive strength as claimed in claim 4, wherein the motion detection unit (1) comprises a torque transmission rod (101) for applying an axial force to the sample, a pressure bearing plate (102) is connected to the lower end of the torque transmission rod (101), a force measuring ring (103) is arranged above the torque transmission rod (101), a first digital dial indicator (104) for detecting the deformation of the force measuring ring (103) is arranged in the middle of the force measuring ring (103), and the axes of the torque transmission rod (101), the force measuring ring (103) and the outer column cavity (41) are kept consistent.
6. The unconfined compressive strength sample surface state measuring device according to claim 5, wherein a fixing ring (7) is arranged at the top of the outer column cavity (41), the diameter of the fixing ring (7) is larger than that of the outer column cavity (41), and the bottom of the outer column cavity (41) is mounted on the test block bearing table (2) through a spring piece (8);
a plurality of macro detection devices (106) are arranged on the pressure bearing plate (102) in an annular array mode, and the macro detection devices (106) are in contact connection with the fixing ring (7);
the macro detection device (106) is used for detecting a height change signal of the edge of the fixing ring (7).
7. The apparatus for measuring the surface state of a sample without confined compressive strength as claimed in claim 1, wherein the test block holder (2) is provided with a concave ring groove (107) for installing the outer column cavity (41), the bottom of the outer column cavity (41) is installed in the concave ring groove (107) through the elastic member (8), and the width of the concave ring groove (107) is greater than the width of the outer column cavity (41).
8. The apparatus for determining the surface state of a sample without confined compressive strength as claimed in claim 6, wherein a driving bolt (9) is disposed in the middle of the pressure bearing plate (102), the driving bolt (9) comprises a first cylinder (91) and a second cylinder (92), the diameter of the first cylinder (91) is smaller than that of the second cylinder (92), the first cylinder (91) penetrates the top of the pressure bearing plate (102) to be connected with the torque transmission rod (101), and the bottom surface of the second cylinder (92) is provided with a sleeving groove (93) for installing the sample.
9. The unconfined compressive strength sample surface condition measuring device according to claim 4, wherein the elastic joint (44) comprises a radial compression and extension unit and a circumferential tension unit, the circumferential tension unit is connected with the side edge of the cambered cylinder unit (43) in the length direction, and the surface of the circumferential tension unit is consistent with the surface of the cambered cylinder unit (43);
the radial compression and expansion unit is connected with the surface of the cambered surface cylinder unit (43) in the thickness direction, and the structure of the radial compression and expansion unit is the same as that of the folded strip (48).
10. The apparatus for determining the surface condition of a sample without confined compressive strength as claimed in claim 6, wherein said macro detection means (106) comprises an infrared laser sensor.
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