A rock-like compression pressure curing device and its test method

Abstract

The present invention relates to a rock-like compression pressure maintenance device and a test method thereof. The maintenance device comprises: a compression maintenance box, the interior of which can be filled with hydraulic oil to form a pressurized space, an exhaust hole is provided on the top, an oil inlet pipe and an oil outlet pipe are provided on the bottom, and a specimen placement table for placing the specimen is provided inside; a sealing door is connected to the side of the compression maintenance box; a pressurizing hole is provided in the middle of the top of the compression maintenance box, a sealing ring group is installed at the pressurizing hole, an upper pressure head can be axially moved in the compression space through the pressurizing hole by a hydraulic rod, and coincides with the center of the specimen and the specimen placement table; the hydraulic rod is controlled to apply pressure by an external hydraulic pump station hydraulic press. After the compression maintenance box is closed, the interior is filled with hydraulic oil, which provides confining pressure for the specimen during specimen maintenance, and a compressive strength test is directly carried out in the device after maintenance, so that the test results are closer to the actual situation and the test error is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of rock-like test devices, and more particularly to a rock-like compression and pressure curing device and a test method thereof. Background Art

[0002] Under natural conditions, rock-like materials are subjected to complex three-dimensional geostress under formation conditions, which has a significant impact on the deformation and damage of the materials. Under the action of in-situ stress, the materials may suffer compression damage, which has a significant impact on engineering problems such as drilling and fracturing. Therefore, it is of particular significance to study the deformation of rock-like materials under in-situ stress and determine the compressive strength of rock-like materials.

[0003] In the current rock-like compression test simulation, the basic steps are to load the mixed materials into a standard casting specimen mold, compact them into specimens through mechanical compaction, then demould them statically, put the demoulding specimens into a curing box until the curing is completed, and finally put the cured specimens into a compressor for compression testing. However, in actual situations, rock-like materials are subject to complex geostresses. Conventional experimental simulation devices and curing place rock-like materials in a pressure-free environment and cannot truly simulate the stress they are subjected to under natural conditions, which causes experimental errors and brings many uncertainties to subsequent work.

[0004] Therefore, how to provide a rock-like compression test device is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] To this end, one purpose of the present invention is to propose a rock-like compression pressure curing device, which ensures that the rock-like material is in a curing environment with confining pressure during the curing stage. At the same time, compression tests can be carried out in this environment after the curing is completed, so that the test results are closer to the actual situation.

[0006] The present invention provides a rock-like compression and pressure maintenance device, comprising:

[0007] A compression curing box, the interior of which can be filled with hydraulic oil to form a pressurized space, with an exhaust hole on the top, an oil inlet pipe and an oil outlet pipe on the bottom, and a specimen placement table for placing the specimen inside;

[0008] Sealed door: a sealed door is connected to the side of the compression curing box;

[0009] The upper pressure head and the compression curing box are provided with a pressure hole in the middle of the top, and a sealing ring group is installed at the pressure hole. The upper pressure head can be axially moved in the compression space through the pressure hole by the hydraulic rod, and coincide with the center of the specimen and the specimen placement table; the hydraulic rod is controlled by the external hydraulic pump station hydraulic press to apply pressure.

[0010] It can be seen from the above technical scheme that compared with the prior art, the present invention discloses a rock-like compression pressure curing device. After the compression curing box is closed, it is filled with hydraulic oil. During the specimen curing, confining pressure is provided for the specimen, and after curing, a compressive strength test can be carried out directly in the device, ensuring that the rock-like material is in a curing environment with confining pressure during the curing stage. At the same time, after the curing is completed, a compression test can also be carried out in this environment, so that the test results are closer to the actual situation.

[0011] Furthermore, the compression curing box comprises: a base, side walls and a top cover; a groove is arranged on the base, the specimen placing table is integrally connected to the base and protrudes from the bottom of the groove; the bottom of the side wall is inserted into the groove and fixed; the oil inlet pipe enters the compression space through the side and side wall of the base; the oil outlet pipe is connected to the base through the bottom of the groove; the sealing door is connected to the side wall; the top cover is fixed to the top of the side wall by screws, the pressurizing hole is opened in the middle of the top cover, and the exhaust hole is arranged close to the pressurizing hole; a sealing strip is installed between the top cover and the top of the side wall.

[0012] Furthermore, the sealing ring group includes an integrally connected support ring, a Y-shaped sealing ring and a dust ring, and a mounting groove is correspondingly provided on the pressurized hole, and the support ring is installed near the compression space. The support ring supports the hydraulic rod to prevent the hydraulic rod from being subjected to non-vertical force, which causes uneven pressure on its seal, resulting in poor sealing effect of the pressurized hole and short service life of the rod.

[0013] Furthermore, a filter is installed in the oil pipe through a flange on the outlet side of the oil pipe; two flanges can be selected and connected by bolts, and a 0.075mm filter is placed between the two flanges to filter the rock chips generated after the shear test. The flange can be disassembled regularly to clean and replace the filter.

[0014] Furthermore, the exhaust hole is provided with an openable and closable plugging cover, which is integrally connected thereto to prevent loss.

[0015] Furthermore, the specimen placing table and the bottom plane of the upper pressure head are both provided with gaskets, which are low carbon steel metal gaskets.

[0016] Furthermore, valves are installed on both the oil inlet pipe and the oil outlet pipe. The valves can be mechanical valves that are manually controlled to open and close.

[0017] Another object of the present invention is to provide a test method based on the above-mentioned rock-like compression pressure curing device, comprising the following steps:

[0018] S1. Open the sealing door, wrap the demoulding specimen with a soft specimen sealing sleeve, and place it on the specimen placement table in the compression space. Use the hydraulic press of the external hydraulic pump station to drive the hydraulic rod to push the upper pressure head so that the upper pressure head contacts the top of the specimen, ensuring that the center lines of the upper pressure head, the specimen and the specimen placement table coincide, and then close the sealing door and tighten the bolts;

[0019] S2. Calculate the required confining pressure according to the pore pressure formula, then open the vent hole and fill the compression space with oil through the oil inlet pipe. When hydraulic oil overflows from the vent hole, continue to drain the fluid into the compression space, apply the confining pressure to the required size, close the vent hole, keep the hydraulic pressure stable, and maintain for 28 days.

[0020] S3. The hydraulic machine of the external pump station controls the hydraulic rod to gradually apply axial pressure to the upper pressure head until the specimen is destroyed, and the compression change and deformation of the specimen during the destruction process are recorded. The external hydraulic pump station gives the specimen destruction load and compression displacement, and the formula is: compressive strength (MPa) = specimen destruction load (N) / specimen pressure bearing area (mm 2 ) Calculate the compressive strength of the specimen.

[0021] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a test method for a rock-like compression pressure curing device. The rock-like material is in a curing environment with confining pressure during the curing stage. At the same time, after the curing is completed, a compression test can be directly carried out in this environment, so that the test results are closer to the actual situation, the test error is reduced, and a more accurate reference is provided for subsequent work.

[0022] Furthermore, when placing the specimen in S1, a gasket is placed on the specimen placement table, and a circumferential strain gauge for measuring the circumferential deformation of the specimen is installed in the middle of the outer side of the sealing sleeve of the specimen. The circumferential strain gauge can be a BX120-3AA model, which is connected to an external controller by using a wireless transmission module. The controller is connected to a data processing module and a display module through the wireless transmission module, and the circumferential expansion degree of the specimen during the compression process is recorded, and the crushing degree of different specimens is compared by reference to provide a reference for subsequent tests.

[0023] Furthermore, after the test is completed, the external hydraulic pump station hydraulic press is controlled to release pressure by suction, so that the upper pressure head force is gradually reduced, and then the oil inlet pipe is controlled to stop supplying oil to unload the confining pressure. After the pressure in the confining pressure cylinder is unloaded, the exhaust hole is opened and the oil outlet pipe is opened at the same time, and the hydraulic oil in the compression space is extracted through the oil outlet pipe oil pump; then the sealing door is opened, the test piece is taken out, and the flange is removed to clean the filter.

[0024] In the uniaxial compression test, the compression change to be measured is the displacement change of the sample during the compression process, which is measured by the linear displacement sensor on the hydraulic press. The deformation is the shape change caused by the crushing and compression of the sample, which is measured by the annular strain gauge. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 The accompanying drawing is a cross-sectional view of a rock-like compression and pressure curing device provided by the present invention;

[0027] Figure 2 The accompanying drawing is a rear view (perspective view) of a rock-like compression maintenance device provided by the present invention;

[0028] Figure 3 The accompanying drawing is a schematic diagram of the installation of a sealing component group of a rock compression maintenance device provided by the present invention;

[0029] Figure 4 The accompanying drawing is a schematic diagram of the installation of an oil discharge pipe, a flange and a filter screen of a rock compression maintenance device provided by the present invention;

[0030] In the figure: 100-compression curing box, 101-exhaust hole, 102-oil inlet pipe, 103-oil outlet pipe, 104-test piece placement table, 105-base, 106-side wall, 107-top cover, 200-sealing door, 300-upper pressure head, 301-sealing ring group, 3011-support ring, 3012-Y-type sealing ring, 3013-dust ring, 400-test piece, 500-hydraulic rod, 600-filter. DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0032] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] The embodiment of the present invention discloses a rock-like compression pressure curing device, which ensures that the rock-like material is in a curing environment with confining pressure during the curing stage. At the same time, a compression test can be carried out in this environment after the curing is completed, so that the test results are closer to the actual situation.

[0037] See attached Figure 1-2 The present invention provides a specific embodiment of a rock-like compression maintenance device, including:

[0038] A compression curing box 100, the interior of which can be filled with hydraulic oil to form a pressurized space, a vent hole 101 is opened on the top, an oil inlet pipe 102 and an oil outlet pipe 103 are provided on the bottom, and a specimen placement table 104 for placing the specimen 400 is provided inside the compression curing box 100;

[0039] Sealing door 200: A sealing door 200 is connected to the side of the compression curing box 100;

[0040] The upper pressure head 300 is provided with a pressure hole in the middle of the top of the compression curing box 100, and a sealing ring group 301 is installed at the pressure hole. The upper pressure head 300 can be axially moved in the compression space through the pressure hole through the hydraulic rod 500, and coincides with the center of the test piece 400 and the test piece placement table 104; the hydraulic rod 500 is controlled to apply pressure through the hydraulic press of the external hydraulic pump station. The upper pressure head and the hydraulic rod can be threaded or bolted.

[0041] The present invention discloses a rock-like compression pressure curing device. After the compression curing box is closed, the interior is filled with hydraulic oil. During the specimen curing period, confining pressure is provided for the specimen. After the curing, a compressive strength test can be directly carried out in the device, thereby ensuring that the rock-like material is in a curing environment with confining pressure during the curing stage. At the same time, after the curing is completed, a compression test can also be carried out in this environment, so that the test result is closer to the actual situation.

[0042] The hydraulic press of the external hydraulic pump station in the embodiment of the present invention can adopt a vertical single-column hydraulic press to achieve vertical movement.

[0043] In one embodiment of the present invention, the compression curing box 100 includes: a base 105, a side wall 106 and a top cover 107; a groove is provided on the base 105, and the test piece placement table 104 is integrally connected with the base 105 and protrudes from the bottom of the groove; the bottom of the side wall 106 is inserted into the groove and fixed; the oil inlet pipe 102 enters the compression space through the side of the base 105 and the side wall 106; the oil outlet pipe 103 is connected to the base 105 through the bottom of the groove; the sealing door 200 is connected to the side wall 106; the top cover 107 is fixed to the top of the side wall 106 by screws, the pressure hole is opened in the middle of the top cover 107, and the exhaust hole 101 is arranged near the pressure hole; a sealing strip is installed between the top cover 107 and the top of the side wall 106. The top cover is fixedly embedded in the side wall and fastened by fastening bolts.

[0044] Among them, see Appendix Figure 3The sealing ring group 301 includes an integrally connected support ring 3011, a Y-shaped sealing ring 3012 and a dust ring 3013. A mounting groove is correspondingly provided on the pressurized hole, and the support ring 3011 is installed near the compression space. The support ring supports the hydraulic rod to prevent the hydraulic rod from being subjected to non-vertical force, which causes uneven pressure on its seal, resulting in poor sealing effect of the pressurized hole and short service life of the rod. The box body can be split here to facilitate the installation of the sealing ring.

[0045] In another embodiment of the present invention, see the attached Figure 4 A filter screen 600 is installed in the oil pipe through a flange at the outlet side of the oil pipe 103. Two flanges can be selected and connected by bolts. A 200-mesh filter screen is placed between the two flanges to filter the rock debris generated after the shear test. The flange can be removed regularly to clean and replace the filter screen.

[0046] Advantageously, the exhaust hole 101 is provided with an openable and closable plugging cover, which is integrally connected thereto to prevent loss.

[0047] More advantageously, both the specimen placement platform 104 and the bottom plane of the upper pressure head 300 are provided with gaskets, and the gaskets are low-carbon steel metal gaskets.

[0048] In the above embodiment, valves are installed on both the oil inlet pipe 102 and the oil outlet pipe 103. The valves can be mechanical valves, which are manually controlled to open and close. The valves have oil inlet and outlet holes of 50-100 mm.

[0049] The test method of the rock-like compression curing device provided by the present invention comprises the following steps:

[0050] S1. Open the sealing door, wrap the demoulding specimen with a soft specimen sealing sleeve, and place it on the specimen placement table in the compression space. Use the hydraulic press of the external hydraulic pump station to drive the hydraulic rod to push the upper pressure head so that the upper pressure head contacts the top of the specimen, ensuring that the center lines of the upper pressure head, the specimen and the specimen placement table coincide, and then close the sealing door and tighten the bolts;

[0051] S2. Calculate the required confining pressure according to the pore pressure formula, then open the vent hole, fill the compression space with oil through the oil inlet pipe, and when hydraulic oil overflows from the vent hole, continue to drain the fluid into the compression space, apply the confining pressure to the required size, close the vent hole, keep the hydraulic pressure stable, and maintain for 28 days; the confining pressure can generally be selected within the range of 20-30Mpa;

[0052] S3. The hydraulic machine of the external pump station controls the hydraulic rod to gradually apply axial pressure to the upper pressure head until the specimen is destroyed, and the compression change and deformation of the specimen during the destruction process are recorded. The external hydraulic pump station gives the specimen destruction load and compression displacement, and the formula is: compressive strength (MPa) = specimen destruction load (N) / specimen pressure bearing area (mm 2) Calculate the compressive strength of the specimen.

[0053] When placing the specimen in S1, a gasket is placed on the specimen placement table, and a circumferential strain gauge for measuring the circumferential deformation of the specimen is installed in the middle of the outer side of the sealing sleeve of the specimen. The circumferential strain gauge can be a BX120-3AA model, which is connected to an external controller by using a wireless transmission module. The controller is connected to a data processing module and a display module through the wireless transmission module to record the circumferential expansion degree of the specimen during the compression process, and compare the crushing degree of different specimens to provide a reference for subsequent tests.

[0054] Compression changes and deformations refer to the degree of rock crushing and expansion, as well as the amount of pressure applied longitudinally.

[0055] Among them, for example, the specifications of concrete cube specimens are 150*150*150mm and 100*100*100mm; the compressive strength of concrete specimens MPa = specimen failure load (N) / specimen pressure bearing area (mm*mm): its value is: 1.05 for 200mm×200mm×200mm specimens; 0.95 for 100mm×100mm×100mm specimens. When the concrete strength grade is ≥C60, the standard specimen 150mm×150mm×150mm specimen should be used. The conversion coefficient of 150mm×150mm×150mm specimen is 1.0.

[0056] After the test is completed, the external hydraulic pump station hydraulic press is controlled to release pressure by suction, so that the upper pressure head force is gradually reduced, and then the oil inlet pipe is controlled to stop supplying oil to unload the confining pressure. After the pressure in the confining pressure cylinder is unloaded, the exhaust hole is opened, and the oil outlet pipe is opened at the same time, and the hydraulic oil in the compression space is extracted through the oil outlet pipe oil pump; then the sealing door is opened, the test piece is taken out, and the flange is removed to clean the filter.

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0058] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A rock-like compression and pressure curing device, characterized in that: include: A compression curing box (100), wherein the interior of the compression curing box (100) can be filled with hydraulic oil to form a pressurized space, an exhaust hole (101) is opened on the top, an oil inlet pipe (102) and an oil outlet pipe (103) are provided on the bottom, and a specimen placement table (104) for placing the specimen (400) is provided inside the compression curing box (100); A sealing door (200), wherein the side of the compression curing box (100) is connected with the sealing door (200); An upper pressure head (300), a pressure hole is opened in the middle of the top of the compression curing box (100), a sealing ring group (301) is installed at the pressure hole, and the upper pressure head (300) can be axially moved in the compression space through the pressure hole by a hydraulic rod (500) and coincides with the center of the test piece (400) and the test piece placement table (104); The hydraulic rod (500) applies pressure through the control of an external hydraulic pump station hydraulic machine; The compression curing box (100) comprises: a base (105), a side wall (106) and a top cover (107); a groove is provided on the base (105); the specimen placement table (104) is integrally connected to the base (105) and protrudes from the bottom of the groove; the bottom of the side wall (106) is inserted into the groove and fixed; the oil inlet pipe (102) enters the compression space through the side of the base (105) and the side wall (106); the oil outlet pipe (103) is connected to the base (105) through the bottom of the groove; the sealing door (200) is connected to the side wall (106); the top cover (107) is fixed to the top of the side wall (106) by screws, the pressurizing hole is opened in the middle of the top cover (107), and the exhaust hole (101) is arranged close to the pressurizing hole; a sealing strip is installed between the top cover (107) and the top of the side wall (106); The sealing ring assembly (301) comprises an integrally connected support ring (3011), a Y-shaped sealing ring (3012) and a dust ring (3013); a mounting groove is correspondingly provided on the pressurizing hole; and the support ring (3011) is installed close to the compression space side.

2. The rock-like compression and pressure curing device according to claim 1 is characterized in that: A filter screen (600) is installed in the oil pipe via a flange at the outlet side of the oil outlet pipe (103).

3. The rock-like compression and pressure curing device according to claim 1 is characterized in that: The exhaust hole (101) is provided with an openable and closable blocking cover.

4. The rock-like compression and pressure curing device according to claim 1 is characterized in that: Gaskets are provided on the test piece placement platform (104) and on the bottom plane of the upper pressure head (300).

5. The rock-like compression and pressure curing device according to claim 1 is characterized in that: Valves are installed on the oil inlet pipe (102) and the oil outlet pipe (103).

6. A test method for the rock-like compression curing device according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Open the sealing door, wrap the demoulding specimen with a soft specimen sealing sleeve, and place it on the specimen placement table in the compression space. Use the hydraulic press of the external hydraulic pump station to drive the hydraulic rod to push the upper pressure head so that the upper pressure head contacts the top of the specimen, ensuring that the center lines of the upper pressure head, the specimen and the specimen placement table coincide, and then close the sealing door and tighten the bolts; S2. Calculate the required confining pressure according to the pore pressure formula, then open the vent hole and fill the compression space with oil through the oil inlet pipe. When hydraulic oil overflows from the vent hole, continue to drain the fluid into the compression space, apply the confining pressure to the required size, close the vent hole, keep the hydraulic pressure stable, and maintain for 28 days. S3. The hydraulic press of the external pump station controls the hydraulic rod to gradually apply axial pressure to the upper pressure head until the specimen is destroyed, and records the compression changes and deformation of the specimen during the destruction process. The external hydraulic pump station gives the specimen destruction load and compression displacement, and the compressive strength of the specimen is calculated by the formula: compressive strength = specimen destruction load / specimen pressure-bearing area.

7. A test method based on rock-like compression and pressure curing device according to claim 6, characterized in that: When placing the specimen in S1, a gasket is placed on the specimen placement table, and a circumferential strain gauge for measuring the circumferential deformation of the specimen is installed in the middle portion of the outer side of the sealing sleeve of the specimen.

8. A test method based on rock-like compression and pressure curing device according to claim 6, characterized in that: After the test is completed, the external hydraulic pump station hydraulic machine is first controlled to release pressure by suction, so that the upper pressure head force is gradually reduced, and then the oil inlet pipe is controlled to stop supplying oil to unload the confining pressure. After the pressure in the confining pressure cylinder is unloaded, the exhaust hole is opened, and the oil outlet pipe is opened at the same time, and the hydraulic oil in the compression space is extracted through the oil outlet pipe oil pump; Then open the sealing door, take out the test piece, remove the flange and clean the filter.

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