A three-axis compensation pressure experimental device, test system and test method

Abstract

The present invention relates to the technical field of sample testing equipment, and provides a three-axis compensation pressure experimental device, a testing system and a testing method. The three-axis compensation pressure experimental device includes a container body, the container body includes a container shell, a three-axis pressure assembly and a heating device, the container shell is provided with an annular groove structure between its two axial ends, the central axis of the annular groove structure coincides with the central axis of the container body, a main cavity is provided inside the container shell, the three-axis pressure assembly is installed in the main cavity, a sample bin for installing the sample is provided inside the three-axis pressure assembly, the annular groove structure is arranged around the sample bin, the heating device is sleeved on the annular groove structure and connected to the container shell; on the basis of ensuring that the container body meets a certain high-pressure resistance safety, the heating device located at the annular groove structure can transfer the generated heat to the sample bin faster and more concentratedly to improve the heating efficiency of the heating device on the sample bin.

Description

Technical Field

[0001] The present invention relates to the technical field of sample testing equipment, and in particular to a three-axis compensation pressure experimental device, a testing system and a testing method. Background Art

[0002] At present, the triaxial pressure test device of the related art is mainly used to apply pressure to samples in a high temperature environment, such as geological samples, in three spatial coordinate directions to perform triaxial experiments to measure the mechanical data of the samples.

[0003] Among them, the existing triaxial pressure experimental device mainly includes a container body, which includes a container shell, a triaxial pressure assembly and a heating device. An installation position for placing a sample is provided in the triaxial pressure assembly. The triaxial pressure assembly is arranged in the container shell, and the heating device is sleeved on the outer side of the straight cylindrical container shell, which is used to heat the container shell to transfer heat to the inside of the sample through the container shell; when designing the triaxial pressure experimental device, as the pressure of the container body increases, the wall thickness of the container shell needs to be increased accordingly, but the increase in the wall thickness of the container shell will significantly reduce the heating efficiency of the container shell by the heating device. In other words, since the upper limit of the pressure of the container body and the temperature are in a mutually competitive relationship, it is impossible to meet the current experimental needs for ultra-high temperature and high pressure. Summary of the Invention

[0004] The problem solved by the present invention is how to improve the heating efficiency of the sample in the container body while ensuring that the container body meets certain high-pressure resistance safety requirements.

[0005] In order to solve the above problems, the present invention provides a three-axis compensation pressure experimental device, which is applied to a testing system, including a container body, the container body including a container shell, a three-axis pressure assembly and a heating device, the container shell is provided with an annular groove structure between its two axial ends, the central axis of the annular groove structure coincides with the central axis of the container body, a main cavity is provided inside the container shell, the three-axis pressure assembly is installed in the main cavity, a sample chamber for installing a sample is provided inside the three-axis pressure assembly, the annular groove structure is arranged around the sample chamber, and the heating device is sleeved on the annular groove structure and connected to the container shell.

[0006] Optionally, the heating device includes a plurality of heating covers arranged in a ring shape, and the plurality of heating covers are used to surround and wrap the annular groove structure; the heating cover includes a cover body and two connecting parts, the two connecting parts are respectively arranged at both ends of the cover body along the central axis direction of the container body, and the connecting parts are used to connect to the portion of the container shell adjacent to the annular groove structure.

[0007] Optionally, the triaxial compensation pressure experimental device further comprises a protective cover, which is sleeved over at least a portion of the container shell and is used to provide heat insulation and safety protection for the heating device.

[0008] Optionally, the triaxial pressure assembly includes an axial pressure rod structure, a first thermal insulation member, a first sample plug, a second sample plug, a second thermal insulation member, and a first container plug, which are arranged in the main cavity and arranged in sequence along the axial direction of the container body, and the sample chamber is formed between the first sample plug and the second sample plug;

[0009] The first container plug is used to connect to the platform of the press of the testing system, and the end of the axial pressure rod structure away from the first thermal insulation component is connected to the telescopic rod of the press.

[0010] Optionally, the triaxial pressure assembly further includes a second container plug and a limit sleeve, the main cavity includes a first cavity, a second cavity, and a third cavity distributed along the axial direction of the container body and connected in sequence, the second container plug and the first container plug are respectively disposed in the first cavity and the third cavity, and the first sample plug and the second sample plug are both disposed in the second cavity;

[0011] The axial pressure rod structure includes a coaxially arranged axial pressure rod body and an annular protrusion, the annular protrusion is sleeved on the circumferential outer wall of the axial pressure rod body, the interior of the second container plug is provided with a fourth cavity and a fifth cavity which are sequentially connected along the axial direction of the axial pressure rod body, the annular protrusion is in the fourth cavity, and the limiting sleeve is sleeved on the axial pressure rod body and is in the fifth cavity.

[0012] Optionally, the three-axis pressure assembly also includes a sample sheath, which is sleeved on at least part of the first sample plug and the second sample plug and the sample; the second container plug is provided with a confining pressure inlet, an axial pressure compensation flow channel and a confining pressure flow channel, the confining pressure inlet is used to connect the confining pressure system, the axial pressure compensation flow channel and the confining pressure flow channel are respectively connected to the confining pressure inlet, an axial pressure compensation chamber is formed between the top of the annular protrusion and the inner top wall of the fourth cavity, the axial pressure compensation flow channel is connected to the axial pressure compensation chamber, and is used to compensate for the confining pressure fluctuation caused by the axial pressure rod structure entering and exiting the main cavity when the press is axially loaded, and the second cavity is connected to the confining pressure flow channel to guide the confining pressure fluid provided by the confining pressure system and passing through the confining pressure flow channel to the sample sheath.

[0013] Optionally, the triaxial pressure assembly further includes a plurality of connecting parts, and a plurality of spaced connecting holes are provided at relative positions of the first sample plug and the second sample plug, and the connecting parts sequentially pass through the connecting holes on the first sample plug and the second sample plug, the second thermal insulation part and are connected to the first container plug.

[0014] Optionally, the triaxial pressure assembly further includes a fluid inlet pipeline and a fluid outlet pipeline, the first container plug is provided with a fluid inlet flow channel and a fluid outlet flow channel, a plurality of installation grooves arranged at intervals are provided at the circumferential edge of the second sample plug, the first sample plug is further provided with a liquid inlet and a first diversion flow channel that are interconnected, one end of the fluid inlet pipeline is connected to the pore pressure system, the other end of the fluid inlet pipeline is sequentially passed through the fluid inlet pipeline, the second thermal insulation component, and the installation groove to connect to the liquid inlet, the first diversion flow channel is used to uniformly guide the pore fluid provided by the pore pressure system and entering through the fluid inlet through the fluid inlet pipeline to the surface of the sample, the second sample plug is further provided with a second diversion flow channel and a liquid return port that are interconnected, the second diversion flow channel is located below the sample, one end of the fluid outlet pipeline is connected to the liquid return port, and the other end of the fluid outlet pipeline is sequentially passed through the second thermal insulation component and the fluid outlet flow channel.

[0015] Optionally, the fluid inlet pipeline is wound around the outside of the sample at a position between the second sample plug and the liquid inlet.

[0016] Optionally, a first sealing ring is installed between the first container plug and the container shell at a position adjacent to the second thermal insulation component, and a first water cooling tank is provided inside the first container plug for cooling the first sealing ring. The first container plug is also provided inside the first container plug with a first liquid inlet cooling channel and a first liquid outlet cooling channel connected to the first water cooling tank.

[0017] Compared with the prior art, the present invention provides an annular groove structure between the two axial ends of the container shell, and the heating device is sleeved on the annular groove structure and connected to the container shell, so that the annular groove structure becomes the heating section of the container shell by the heating device; since the central axis of the annular groove structure coincides with the central axis of the container body, and the annular groove structure is arranged around the sample chamber, and the container shell at the annular groove structure has a small diameter and a thin wall, the heating device is closer to the sample chamber, so that the annular groove structure can transfer the heat generated by the heating device to the sample chamber more evenly.

[0018] Among them, the diameter of the annular groove structure is smaller than other parts of the container shell. In other words, the container shell has a smaller diameter and thinner container circumferential side wall at the annular groove structure, so that on the basis of ensuring that the container body meets a certain high-pressure safety requirement, the heating device located at the annular groove structure can transfer the generated heat to the sample chamber faster and more concentratedly, so as to improve the heating efficiency of the heating device on the sample chamber, so as to correspondingly increase the ambient temperature around the sample, thereby enabling the container body to meet the current ultra-high temperature and high-pressure experimental requirements.

[0019] In addition, since the triaxial pressure assembly is installed in the main cavity inside the container shell, and a sample chamber is set inside the triaxial pressure assembly, and samples are installed in the sample chamber, triaxial experiments can be performed on the samples in the sample chamber through the triaxial pressure assembly.

[0020] The present invention also provides a testing system, including a press, a confining pressure system, a pore pressure system and the three-axis compensation pressure experimental device as described above, and also including a rotating device, the rotating device including a support frame, a rotating shaft and a mounting frame, the container body of the three-axis compensation pressure experimental device can be detachably mounted on the mounting frame, the mounting frame is mounted on the support frame through the rotating shaft, and the mounting frame is used to drive the container body to rotate around the rotating shaft.

[0021] Since the test system includes the three-axis compensation pressure experimental device, the test system at least has all the technical effects of the three-axis compensation pressure experimental device, which will not be described in detail here.

[0022] The present invention also provides a testing method, based on the above-mentioned testing system, comprising the following steps:

[0023] Mounting the container body on a rotating device, assembling the sample and the triaxial pressure assembly of the container body into the container shell of the container body, and rotating the container body 180 degrees using the rotating device so that the axial pressure compensation chamber and axial pressure rod structure of the container body are above the sample;

[0024] The rotated container body is mounted on a press, and an axial pressure is applied to the triaxial pressure assembly of the container body by the press to perform an axial pressure test, and first axial pressure data is collected in real time;

[0025] Controlling the confining pressure system to fill the second cavity of the container body and the axial pressure compensation chamber with confining pressure fluid so that the axial pressure on the sample in the axial direction is the same as the confining pressure on the sample in the circumferential direction, so that the container body is in a static pressure state;

[0026] Controlling the operation of the heating device to heat the sample, and collecting the temperature of the sample when the sample temperature is close to equilibrium or at equilibrium; controlling the pore pressure system to input pore fluid into the sample, increasing the flow rate of the confining pressure fluid multiple times, applying axial pressure to the triaxial pressure assembly of the container body multiple times, and collecting and recording mechanical data of the sample; wherein the mechanical data includes current pore pressure data, current confining pressure data, and current axial pressure data corresponding to the sample each time the flow rate of the pore fluid, the flow rate of the confining pressure fluid, and the axial pressure are increased;

[0027] The mechanical data is saved, the pore pressure, the confining pressure fluid and the axial pressure are unloaded, the container body is rotated 180 degrees by the rotating device so that the sample is above the axial pressure compensation chamber and the axial pressure rod structure, and the sample is taken out.

[0028] Therefore, since the test method is based on the test system, the test method at least has all the technical effects of the test system, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is one of the structural diagrams of the triaxial compensation pressure experimental device in an embodiment of the present invention;

[0030] Figure 2 for Figure 1 Schematic diagram of the enlarged structure at A in the middle;

[0031] Figure 3 for Figure 1 Schematic diagram of the enlarged structure at B in the middle;

[0032] Figure 4 for Figure 1 Schematic diagram of the enlarged structure at C in the middle;

[0033] Figure 5 This is a schematic structural diagram of a first sample plug in an embodiment of the present invention;

[0034] Figure 6 This is one of the structural schematic diagrams of the second sample plug in an embodiment of the present invention;

[0035] Figure 7 This is the second structural diagram of the second sample plug in the embodiment of the present invention;

[0036] Figure 8 A schematic diagram of the structure of a test system according to an embodiment of the present invention;

[0037] Figure 9 This is the second structural diagram of the triaxial compensation pressure experimental device in an embodiment of the present invention;

[0038] Figure 10Schematic diagram of the explosion structure of the rotating device and the container body in an embodiment of the present invention;

[0039] Figure 11 Schematic diagram of the installation structure of the rotating device and the container body in an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] 1-Protective cover; 2-Container shell; 21-Shell body; 211-Annular groove structure; 22-End cap; 3-Triaxial pressure assembly; 301-Fluid inlet pipeline; 302-Fluid outlet pipeline; 31-Sample sheath; 32-Axial pressure rod structure; 321-Axial pressure rod body; 322-Annular protrusion; 33-First thermal insulation member; 34-First sample plug; 341-Connecting hole; 342-Liquid inlet; 343-First flow guide channel; 344-First sealing groove; 35-Second sample plug; 351-Mounting slot; 352-Second flow guide channel; 353-Liquid return port; 354-Second sealing groove; 36-Second thermal insulation member; 37-First container plug; 371-fluid inlet channel; 372-fluid outlet channel; 373-first water-cooling chamber; 374-first liquid inlet cooling channel; 375-first liquid outlet cooling channel; 38-second container plug; 381-confining pressure inlet; 382-axial pressure compensation channel; 383-confining pressure channel; 384-second water-cooling chamber; 385-connecting channel; 39-limiting sleeve; 4-heating device; 41-cover body; 42-connecting part; 5-sample; 6-press; 7-rotating device; 71-support frame; 72-rotating shaft; 73-mounting frame; 8-confining pressure system; 9-pore pressure system; 91-plunger pump; 92-pore fluid container; 93-pressure sensor; 94-vacuum pump. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0043] It should be noted that in the coordinate system XZ provided herein, the positive direction of the X axis represents the right direction, the negative direction of the X axis represents the left direction, the positive direction of the Z axis represents the top direction, and the negative direction of the Z axis represents the bottom direction. It should also be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than that illustrated or described herein.

[0044] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical connections; direct connections or indirect connections via an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0045] Throughout this specification, references to the terms "embodiment," "one embodiment," and "an implementation" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or implementation are included in at least one embodiment or implementation of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or implementations.

[0046] In order to solve the above technical problems, Figure 1 As shown, an embodiment of the present invention provides a three-axis compensation pressure experimental device, which is applied to a test system, including a container body, wherein the container body includes a container shell 2, a three-axis pressure assembly 3 and a heating device 4, and the container shell 2 is provided with an annular groove structure 211 between its two axial ends, and the central axis of the annular groove structure 211 coincides with the central axis of the container body, and a main cavity is provided inside the container shell 2, and the three-axis pressure assembly 3 is installed in the main cavity, and a sample chamber for installing a sample 5 is provided inside the three-axis pressure assembly 3, and the annular groove structure 211 is arranged around the sample chamber, and the heating device 4 is sleeved on the annular groove structure 211 and connected to the container shell 2.

[0047] It should be noted that the diameter of the container shell 2 at the annular groove structure 211 is smaller than the diameter of other parts of the container shell 2, so that the annular groove structure 211 can transfer the heat provided by the heating device 4 to the sample chamber more quickly, thereby correspondingly improving the heating efficiency of the heating device 4 on the container body, and correspondingly allowing the temperature of the sample 5 in the sample chamber to reach the temperature required for the experiment in the shortest possible time. Figure 1 The Z axis of the center coordinate system is parallel.

[0048] The present invention opens an annular groove structure 211 between the two axial ends of the container shell 2, and the heating device 4 is sleeved on the annular groove structure 211 and connected to the container shell 2, so that the annular groove structure 211 becomes the heating section of the container shell 2 by the heating device 4; since the central axis of the annular groove structure 211 coincides with the central axis of the container body, and the annular groove structure 211 is arranged around the sample chamber, and the container shell at the annular groove structure 211 has a small diameter and a thin wall, the heating device 4 is closer to the sample chamber, so that the annular groove structure 211 can transfer the heat generated by the heating device 4 to the sample chamber more evenly.

[0049] The diameter of the annular groove structure 211 is smaller than that of other parts of the container shell 2. In other words, the container shell 2 has a smaller diameter and thinner circumferential sidewall at the annular groove structure 211. This allows the heating device 4 located at the annular groove structure 211 to transfer the generated heat to the sample chamber more quickly and more concentratedly, while ensuring that the container body meets a certain high-pressure safety requirement. This improves the heating efficiency of the heating device 4 on the sample chamber, thereby correspondingly increasing the ambient temperature of the sample 5, and thus enabling the container body to meet the current ultra-high temperature and high-pressure experimental requirements. The container body achieves high temperature and high pressure resistance and can meet the in-situ high temperature and high pressure experimental conditions deep in fault / reservoir rock.

[0050] In addition, since the triaxial pressure assembly 3 is installed in the main cavity inside the container shell 2, and a sample chamber is set inside the triaxial pressure assembly 3, and the sample 5 is installed in the sample chamber, the triaxial test can be performed on the sample 5 in the sample chamber through the triaxial pressure assembly 3.

[0051] In one embodiment of the present invention, Figure 1 and Figure 2 As shown, the heating device 4 includes a plurality of heating covers arranged in a ring shape, and the plurality of heating covers are used to surround and wrap the annular groove structure 211 of the container shell 2; the heating cover includes a cover body 41 and two connecting parts 42, and the two connecting parts 42 are respectively arranged at both ends of the cover body 41 along the central axis direction of the container body, and the connecting parts 42 are used to connect to the portion of the container shell 2 adjacent to the annular groove structure 211.

[0052] It should be noted that, since the container shell 2 in the container body is a cylindrical structure with an annular groove structure 211 in the middle, the vertical section of the container body is in the shape of an "I", and the heating device 4 includes a plurality of heating covers arranged in a ring shape. When the plurality of heating covers arranged in a ring shape surround and wrap around a partial structure of the container shell 2, namely the annular groove structure 211 area, the heat generated can be evenly dissipated from the circumference through the plurality of heating covers arranged in a ring shape, and transferred to the sample chamber through the container shell 2 at the annular groove structure 211, and then the heating efficiency and heating effect of the sample 5 can be effectively improved through the plurality of heating covers arranged in a ring shape.

[0053] Specifically, two adjacent heating covers among the plurality of heating covers are rotatably connected, thereby facilitating the assembly and removal of the heating device 4 from the container shell 2. When there are two heating covers, one end of the two heating covers is rotatably connected, and the other ends of the two heating covers can be connected and fixed by means of a snap fastener. Of course, the number of heating covers is not limited to two, and can also be three, four, etc., which is not specifically limited here.

[0054] When the heating hood is assembled on the annular groove structure 211 of the container shell 2, the hood body 41 corresponds to the annular groove structure 211, and can be connected to the container shell 2 at the position close to the annular groove structure 211 by two connecting parts 42 provided at the axial ends of the hood body 41, thereby not only realizing the assembly of the heating hood and the container shell 2, but also the two connecting parts 42 can also play the role of sealing and heat preservation during the heating process of the annular groove structure 211 by the hood body 41, so as to prevent the problem of heat loss during the heating process, and further improve the heating effect and heating efficiency of the annular groove structure 211. Among them, the two ends of the central axis direction of the container body refer to the container body in the Figure 1 The top and bottom ends in the Z-axis direction.

[0055] Specifically, the housing body 41 may include an insulating layer and heating wires. The insulating layer may be cylindrical, and the heating wires are embedded within the insulating layer. The insulating layer may be made of ceramic fiber material. Furthermore, the housing body 41 and the two connecting portions 42 may be integrally formed, thereby effectively improving the mechanical strength of the heating housing and its sealing and heat-insulating properties.

[0056] In addition, the container shell 2 can be made of alloy steel material such as Inconel 625 alloy steel. Due to the characteristic of this material, it can still maintain good mechanical properties at high temperatures. At high temperatures, the decline in its mechanical properties such as compressive strength is not very obvious, which meets the requirements of high-pressure resistance under the heating conditions of the container body. While ensuring high-pressure resistance, the wall thickness of the container shell 2 can be minimized to improve the heating capacity.

[0057] In one embodiment of the present invention, Figure 1As shown, the triaxial compensation pressure experimental device further includes a protective cover 1, which is sleeved on at least a portion of the container shell 2 to provide heat insulation and safety protection for the heating device 4.

[0058] It should be noted that, by placing the protective cover 1 on at least a portion of the container shell 2, when the heating device 4 transfers the heat generated by itself to the sample chamber through the annular groove structure 211, the protective cover 1 can effectively reduce the heat transfer between the container shell 2 and the external environment. In other words, it reduces heat loss, which not only plays a role in heat preservation of the heating device 4, but also plays a role in safety protection to prevent the high temperature of the heating device 4 from scalding the staff.

[0059] Among them, the protective cover 1 is arranged on the outside of at least part of the container shell 2. It can be understood that the protective cover 1 is arranged on the outside of the entire container shell 2, or the protective cover 1 is only arranged on the outside of the heating device 4, or the protective cover 1 is not only arranged on the outside of the heating device 4, but also extends to the adjacent area of ​​the annular groove structure 211.

[0060] In one embodiment of the present invention, Figures 1 to 4 As shown, the triaxial pressure assembly 3 includes an axial pressure rod structure 32, a first thermal insulation member 33, a first sample plug 34, a second sample plug 35, a second thermal insulation member 36 and a first container plug 37, which are arranged in the main cavity and arranged in sequence along the axial direction of the container body. The sample chamber is formed between the first sample plug 34 and the second sample plug 35.

[0061] The first container plug 37 is used to connect to the platform of the press 6 of the testing system, and the end of the axial pressure rod structure 32 away from the first thermal insulation member 33 is connected to the telescopic rod of the press 6.

[0062] It should be noted that after the sample 5 is installed in the sample chamber between the first sample plug 34 and the second sample plug 35 and the components of the triaxial pressure assembly 3 are assembled, the axial compression test is performed. For example, the entire container body is moved to the position of the press 6, and then the first container plug 37 in the triaxial pressure assembly 3 is placed on the lowest platform in the press 6, so that the axial compression rod structure 32 and the telescopic rod position of the press 6 correspond to each other, and then the telescopic rod is extended downward to transmit the downward pressure to the sample 5 through the axial compression rod structure 32, the first thermal insulation member 33 and the first sample plug 34 in sequence. Since the first container plug 37 below the sample 5 is supported by the platform of the press 6, the axial compression test in the triaxial experiment of the sample 5 is achieved. The press 6 can be a uniaxial press.

[0063] Among them, the test system also includes an axial pressure detection component, which includes a displacement sensor and a detector. Among them, the displacement sensor can be installed at the end of the axial pressure rod structure 32 away from the first thermal insulation component 33, that is, the top end, and the detector can be installed on the fixed frame of the press 6. Therefore, through the mutual cooperation between the detector and the displacement sensor, the displacement of the axial pressure rod structure 32 can be accurately detected as one of the axial pressure test data in the triaxial experiment of the triaxial pressure assembly 3.

[0064] In addition, the first thermal insulation member 33 and the second thermal insulation member 36 can both be titanium alloy pads, and the first thermal insulation member 33 can reduce the upward transfer of the temperature of the sample 5 located below it, so as to reduce the influence of the temperature of the sample 5 on the sealing between the upper part of the container shell 2 and the triaxial pressure assembly 3; and the second thermal insulation member 36 can reduce the downward transfer of the temperature of the sample 5 located above it, so as to reduce the influence of the temperature of the sample 5 on the sealing between the lower part of the container shell 2 and the triaxial pressure assembly 3; the first sample plug 34 and the second sample plug 35 cooperate with each other to position and fix the sample 5.

[0065] In one embodiment of the present invention, Figures 2 to 4 As shown, the triaxial pressure assembly 3 further includes a second container plug 38 and a limiting sleeve 39. The main cavity includes a first cavity, a second cavity, and a third cavity distributed along the axial direction of the container body and connected in sequence. The second container plug 38 and the first container plug 37 are respectively disposed in the first cavity and the third cavity. The first sample plug 34 and the second sample plug 35 are both disposed in the second cavity.

[0066] The axial pressure rod structure 32 includes a coaxially arranged axial pressure rod body 321 and an annular protrusion 322, and the annular protrusion 322 is sleeved on the circumferential outer wall of the axial pressure rod body 321. The interior of the second container plug 38 is provided with a fourth cavity and a fifth cavity that are sequentially connected along the axial direction of the axial pressure rod body 321. The annular protrusion 322 is in the fourth cavity, and the limiting sleeve 39 is sleeved on the axial pressure rod body 321 and is in the fifth cavity.

[0067] It should be noted that the interior of the main cavity can be roughly divided into three cavities, and the three cavities are defined as the first cavity, the second cavity and the third cavity from top to bottom along the axial direction of the container body, wherein the second container plug 38 can be installed in the first cavity, the first container plug 37 is installed in the third cavity, and the first thermal insulation member 33, the first sample plug 34, the sample 5, the second sample plug 35 and the second thermal insulation member 36 are all installed in the second cavity, and the second cavity corresponds to the position of the annular groove structure 211. In other words, the annular groove structure 211 can surround Wrapped in the second cavity, the annular groove structure 211 is used to transfer the heat generated by the heating device to the sample chamber between the first sample plug 34 and the second sample plug 35 in the second cavity more quickly and evenly. In other words, the first container plug 37 and the second container plug 38 are respectively arranged at the protruding parts at the upper and lower ends of the container shell 2, so as to be away from the heating section of the annular groove structure 211 in the middle, so as to reduce the influence of the heat at the annular groove structure 211 on the sealing between the first container plug 37 and the second container plug 38 and the container shell 2.

[0068] Specifically, the first cavity and the third cavity are respectively located at the axial ends of the second cavity, and are used to install the second container plug 38 and the first container plug 37 respectively. Therefore, the second container plug 38 has at least the function of sealing the connection between the first cavity and the second cavity, and the first container plug 37 has at least the function of sealing the connection between the second cavity and the third cavity. The first thermal insulation member 33 is used to reduce the heat of the first sample plug 34 from being conducted upward to the second container plug 38, so as to reduce the sealing effect between the second container plug 38 and the container shell, and the second thermal insulation member 36 is used to reduce the heat of the second sample plug 35 from being conducted downward to the first container plug 37, so as to reduce the sealing effect between the first container plug 37 and the container shell, thereby improving the accuracy of the confining pressure test and pore pressure test of the sample by the confining pressure system 8 and the pore pressure system 9.

[0069] The axial pressure rod body 321 is a cylindrical structure, and the annular protrusion 322 is coaxially arranged with the axial pressure rod body 321. The annular protrusion 322 is sleeved on the outside of the axial pressure rod body 321, and two connected cavities are arranged inside the second container plug 38. The two connected cavities are distributed from top to bottom along the axial direction of the container body and are defined as the fourth cavity and the fifth cavity respectively. When the axial pressure rod structure 32 is passed through the second container plug 38, the annular protrusion 322 is in the fourth cavity, and the limiting sleeve 39 arranged in the fifth cavity is sleeved on the axial pressure rod body 321, so the limiting sleeve 39 is below the annular protrusion 322. When the axial pressure rod structure 32 moves downward under the action of the external press 6, the limiting sleeve 39 can play the role of lower limiting the annular protrusion 322 to prevent the axial pressure rod structure 32 from moving downward overtravel.

[0070] Among them, combined Figure 3 As shown, the limiting sleeve 39 can be a cylindrical structure so that it can be sleeved on the outside of the axial pressure rod body 321, and the limiting sleeve 39 is embedded in the fifth cavity of the second container plug 38. Therefore, a sealing ring is added between the inner wall of the limiting sleeve 39 and the axial pressure rod body 321, and between the outer wall of the limiting sleeve 39 and the inner wall of the fifth cavity of the second container plug 38, so as to play a sealing role between the limiting sleeve 39 and the axial pressure rod body 321 and the fifth cavity; at the same time, a sealing ring is provided between the annular protrusion 322 and the inner wall of the fourth cavity of the second container plug 38, and between the axial pressure rod body 321 and the inner wall of the second container plug 38, so as to play a sealing role between the axial pressure rod structure 32 and the second container plug 38; in addition, a sealing ring is added between the second container plug 38 and the container shell 2 to play a sealing role between the second container plug 38 and the container shell 2, and the above-mentioned sealing ring is shown in FIG. Figure 3 Solid sphere structure in .

[0071] In one embodiment of the present invention, Figure 2 and Figure 3 As shown, the three-axis pressure assembly 3 also includes a sample sheath 31, which is sleeved on at least part of the first sample plug 34 and the second sample plug 35 and the sample 5; the second container plug 38 is provided with a confining pressure inlet 381, an axial pressure compensation flow channel 382 and a confining pressure flow channel 383, the confining pressure inlet 381 is used to connect to the confining pressure system 8, the axial pressure compensation flow channel 382 and the confining pressure flow channel 383 are respectively connected to the confining pressure inlet 381, and an axial pressure compensation chamber is formed between the top of the annular protrusion 322 and the inner top wall of the fourth cavity. The axial pressure compensation flow channel 382 is connected to the axial pressure compensation chamber, which is used to compensate for the confining pressure fluctuation caused by the axial pressure rod structure 32 entering and exiting the main cavity when the press 6 is axially loaded. The second cavity is connected to the confining pressure flow channel 383 to guide the confining pressure fluid provided by the confining pressure system 8 and passing through the confining pressure flow channel 383 to the sample sheath 31.

[0072] It should be noted that by placing the sample sheath 31 over at least a portion of the first sample plug 34 and the second sample plug 35, as well as the sample 5, the sample sheath 31 not only positions the sample 5 but also effectively prevents the confining pressure fluid from entering the sample 5 along the first sample plug 34, thereby interfering with subsequent pore pressure testing of the sample 5. The sample sheath 31 can be made of a soft metal material, which not only has high-temperature resistance to meet the requirements of triaxial testing of the sample 5 under high-temperature conditions, but also prevents the confining pressure fluid from entering the interior of the sample 5.

[0073] Under normal circumstances, when the confining pressure system 8 performs a confining pressure test on the sample 5, the press 6 loads the sample 5 with axial pressure through the axial pressure rod structure 32, so that when the axial pressure rod structure 32 enters and exits the second container plug 38 of the container body, it is very likely to cause the confining pressure of the sample 5 to fluctuate, thereby affecting the accuracy of the confining pressure test on the sample 5; therefore, a confining pressure inlet 381, an axial pressure compensation flow channel 382 and a confining pressure flow channel 383 are provided on the second container plug 38, and the axial pressure compensation flow channel 382 is connected to the axial pressure compensation chamber between the annular protrusion 322 and the second container plug 38, so that When conducting a confining pressure test, for example, after the confining pressure system 8 outputs the confining pressure fluid into the confining pressure inlet 381, it is diverted, with one part entering the axial pressure compensation chamber through the axial pressure compensation flow channel 382, ​​and the other part entering the second cavity through the confining pressure flow channel 383, and then flowing downward from the gap between the first sample plug 34 and the inner wall of the container shell 2 until it flows to the sample sheath 31. At this time, the space between the sample sheath 31 and the container shell 2 can serve as a confining pressure cavity, and the confining pressure fluid in the confining pressure cavity passes through the sample sheath 31 to apply confining pressure to the sample 5, thereby realizing a confining pressure test on the sample 5.

[0074] Among them, an axial pressure compensation chamber is formed between the top of the annular protrusion 322 and the inner top wall of the fourth cavity. Since the axial pressure compensation flow channel 382 is connected to the axial pressure compensation chamber, and the axial pressure compensation chamber is also connected to the surrounding pressure flow channel 383, the sample 5 is also subjected to a pressure consistent with the surrounding pressure in the axial direction, so that the entire container body is in a static pressure state. Subsequently, the axial pressure is loaded according to the experimental requirements to simulate different deformation conditions. At this time, the existence of the axial pressure compensation chamber can compensate for the surrounding pressure fluctuations caused by the axial pressure rod structure 32 entering and exiting the container shell 2.

[0075] In one embodiment of the present invention, Figure 5 and Figure 6 As shown, the triaxial pressure assembly 3 also includes a plurality of connecting parts, and a plurality of spaced connecting holes 341 are provided at relative positions of the first sample plug 34 and the second sample plug 35. The connecting parts pass through the connecting holes 341 on the first sample plug 34 and the second sample plug 35, the second thermal insulation part 36 and are connected to the first container plug 37 in sequence.

[0076] It should be noted that after the sample 5 is installed in the sample chamber, it can be passed through a plurality of connecting parts corresponding to the plurality of connecting holes 341. For example, each connecting part may include a bolt part and two fastening nuts. Each bolt part is passed through each connecting hole 341 opened on the first sample plug 34 and the second sample plug 35, and the bottom end of the bolt part is connected to the first container plug 37. The two fastening nuts are both sleeved on the bolt part and are respectively located above the first sample plug 34 and the second sample plug 35. Therefore, through the multiple connecting parts, not only the first sample plug 34, the sample 5, the second sample plug 35 and the first container plug 37 are fixed more firmly, but also the two fastening nuts do not affect the axial compression deformation of the sample 5 when pressurized.

[0077] In one embodiment of the present invention, Figure 2 、 Figure 4 、 Figures 5 to 8 As shown, the triaxial pressure assembly 3 also includes a fluid inlet pipeline 301 and a fluid outlet pipeline 302. The first container plug 37 is provided with a fluid inlet flow channel 371 and a fluid outlet flow channel 372. The circumferential edge of the second sample plug 35 is provided with a plurality of installation grooves 351 arranged at intervals. The first sample plug 34 is also provided with a liquid inlet 342 and a first guide flow channel 343 that are interconnected. One end of the fluid inlet pipeline 301 is connected to the pore pressure system 9, and the other end of the fluid inlet pipeline 301 is sequentially passed through the fluid inlet pipeline 301, the second thermal insulation member 36, and one of the installation grooves. 351 is connected to the liquid inlet 342, and the first diversion channel 343 is used to uniformly guide the pore fluid provided by the pore pressure system 9 and entering through the liquid inlet 342 via the fluid inlet pipeline 301 to the surface of the sample 5. The second sample plug 35 is also provided with a second diversion channel 352 and a return liquid port 353 that are interconnected. The second diversion channel 352 is located below the sample 5, one end of the fluid discharge pipeline 302 is connected to the return liquid port 353, and the other end of the fluid discharge pipeline 302 is sequentially passed through the second thermal insulation component 36 and the fluid discharge channel 372.

[0078] It should be noted that a positioning groove is provided at a position corresponding to the installation groove 351 in the circumferential direction of the second thermal insulation component 36 to facilitate the passage of the fluid inlet pipeline 301, the fluid outlet pipeline 302 and the thermocouple; by opening a fluid inlet channel 371 and a fluid outlet channel 372 on the first container plug 37, it is convenient for the fluid inlet pipeline 301 and the fluid outlet pipeline 302 to pass through the fluid inlet channel 371 and the fluid outlet channel 372 respectively, and pass through the bottom end of the first container plug 37 to connect to the pore pressure system 9, so that the pore fluid flows in the closed loop formed by the fluid inlet pipeline 301, the fluid outlet pipeline 302 and the pore pressure system 9.

[0079] A plurality of mounting grooves 351 may be provided on the second sample plug 35, and the number of the mounting grooves 351 may be more than three. For example, two of the mounting grooves 351 are used for the fluid inlet pipeline 301 and the fluid outlet pipeline 302 to pass through respectively, and the third mounting groove 351 is used for the thermocouple to pass through, wherein the thermocouple is electrically connected to the temperature control device outside the container body through a cable, and the thermocouple is located in the sample chamber after passing upward from the mounting groove 351, and is used to measure the temperature in the sample chamber in real time. The temperature of the sample chamber can feed back the temperature of the sample 5, and the temperature control device receives the temperature of the sample 5 collected by the thermocouple to control the operation and stop of the heating device 4, or the number of working heating wires, so as to control the heating power of the heating device 4 accordingly.

[0080] The distribution position of the mounting groove 351 on the second sample plug 35 can be seen. Figure 6 and Figure 7 As shown, the mounting slot 351 may be an open structure. When the pore pressure test is performed on the sample 5, the pore fluid can be output through the pore pressure system 9, and then the pore fluid flows along the fluid inlet pipeline 301 in sequence through the fluid inlet channel 371, passes through the installation groove 351 of the second sample plug 35, and continues to flow upward, and enters the first guide channel 343 from the liquid inlet 342 of the first sample plug 34. Then, the first guide channel 343 evenly guides the pore fluid to the upper end surface of the sample 5 and penetrates into the interior of the sample 5. Since the second guide channel 352 is provided at the top of the second sample plug 35, the pore fluid in the sample 5 can all flow out and then enter the second guide channel 352, and be discharged from the return liquid port 353 through the fluid discharge pipeline 302, thereby realizing the pore pressure test of the sample 5; wherein, the first guide channel 343 can be arranged at the bottom end of the first sample plug 34, and the first guide channel 343 can include a plurality of first channels arranged coaxially but with different diameters (see Figure 5 As shown), the first flow channel 343 can evenly guide the pore fluid entering from the liquid inlet 342 to the upper end surface of the sample 5, thereby improving the pore pressure test effect of the sample 5; similarly, the second flow channel 352 can be set at the top of the second sample plug 35, and the second flow channel 352 can include a plurality of coaxially arranged second flow channels with different diameters (see Figure 6 and Figure 7 As shown), all the pore fluid that permeates downward in the sample 5 can be received and diverted through the return liquid port 353 into the fluid discharge pipeline 302 to avoid leakage of the pore fluid coming out of the lower end of the sample 5, thereby improving the discharge effect of the pore fluid and correspondingly improving the pore pressure test effect of the sample.

[0081] In addition, the triaxial pressure assembly 3 further includes a third sealing ring and a fourth sealing ring, and a first sealing groove 344 ( Figure 5 As shown), the third sealing ring is installed in the first sealing groove 344, and a second sealing groove 354 is also opened on the circumferential side wall of the second sample plug 35 ( Figure 6 and Figure 7 As shown), the fourth sealing ring is installed in the second sealing groove 354, and when the sample sheath 31 is mounted on the first sample plug 34, at least part of the second sample plug 35 and the outside of the sample 5, the third sealing ring and the fourth sealing ring can respectively play a sealing role between the first sample plug 34 and the second sample plug 35 and the sample sheath 31, so as to effectively prevent the leakage of the pore fluid in the sample 5.

[0082] The three-axis pressure assembly 3 also includes a first sealing joint and a second sealing joint (not shown in the figure). The first sealing joint is arranged at the liquid inlet 342 for sealing communication between the fluid inlet pipeline 301 and the liquid inlet 342. The second sealing joint is arranged at the liquid return port 353 for sealing communication between the fluid discharge pipeline 302 and the liquid return port 353.

[0083] The three-axis pressure assembly 3 also includes a third sealing joint and a fourth sealing joint (not shown in the figure). The fluid inlet pipeline 301 and the fluid outlet pipeline 302 are respectively installed with a third sealing joint and a fourth sealing joint at the bottom end parts of the fluid inlet channel 371 and the fluid outlet channel 372, which not only realize the sealing effect between the fluid inlet pipeline 301 and the fluid outlet pipeline 302 and the first container plug 37, but also play a role in fixing the fluid inlet pipeline 301 and the fluid outlet pipeline 302.

[0084] In one embodiment of the present invention, the fluid inlet pipeline 301 is wound around the outside of the sample 5 at a location between the second sample plug 35 and the liquid inlet 342 .

[0085] It should be noted that the fluid inlet pipeline 301 is located between the upper part of the second sample plug 35 and the liquid inlet 342 of the first sample plug 34 and is wrapped around the outside of the sample 5 (sample sheath 31). In other words, the fluid inlet pipeline 301 is spirally wrapped around the outside of the sample 5 after passing upward from the installation groove 351 of the second sample plug 35, and is then sealed and connected to the liquid inlet 342, so that the fluid inlet pipeline 301 has a sufficient length, which is not only suitable for triaxial tests of samples 5 of different heights, but also suitable for axial compression deformation actions of sample 5.

[0086] In one embodiment of the present invention, Figure 1 and Figure 4As shown, the first container plug 37 is installed with a first sealing ring between the container shell 2 and the position adjacent to the second thermal insulation member 36. The interior of the first container plug 37 is provided with a first water cooling chamber 373 for cooling the first sealing ring. The interior of the first container plug 37 is also provided with a first liquid inlet cooling channel 374 and a first liquid outlet cooling channel 375 connected to the first water cooling chamber 373.

[0087] It should be noted that the first sealing ring is used to seal the connection between the first container plug 37 and the container shell 2 to prevent the confining pressure fluid from leaking from the connection between the two; the first liquid inlet cooling channel 374 and the first liquid outlet cooling channel 375 are used to connect to the external water cooling device through pipelines. When the container body is undergoing a triaxial test, cold water can be output through the water cooling device and enter the first water cooling chamber 373 through the first liquid inlet cooling channel 374 to cool the first container plug 37, thereby effectively reducing the temperature of the first sealing ring to prevent the first sealing ring from being affected by the high temperature of the sample 5 and causing sealing failure; wherein, the water cooling device can adopt a chiller in the existing technology. As long as it can provide cold water, any water cooling device that can cool the first container plug 37 is suitable for this technical solution, and no specific limitation is made here.

[0088] In addition, a second water cooling chamber 384 is also provided on the second container plug 38 (see Figure 3 As shown), a second liquid inlet cooling flow channel and a second liquid outlet cooling flow channel (not shown in the figure), a second sealing ring is installed between the second container plug 38 and the container shell 2 at a position adjacent to the first insulation member 33, and a second water-cooling tank 384 is used to cool the second sealing ring. When the container body is undergoing a triaxial test, cold water can be output through the water cooling device and enter the second water-cooling tank 384 through the second liquid inlet cooling flow channel to cool the second container plug 38, thereby effectively reducing the temperature of the second sealing ring to prevent the second sealing ring from failing to seal due to the high temperature of the sample 5.

[0089] Normally, the cavity between the bottom end of the annular protrusion 322 and the top end of the limit sleeve 39 is a closed space. When the press is loaded with axial pressure, the axial pressure rod structure 32 moves downward, which compresses the closed space, so that the air in the closed space generates pressure to prevent the axial pressure rod structure 32 from moving downward, thereby affecting the axial pressure test process of the axial pressure rod structure 32.

[0090] Therefore, combined Figure 3As shown, a connecting flow channel 385 is further provided inside the second container plug 38, and a pressure relief cavity can be formed between the bottom end of the annular protrusion 322 and the top end of the limit sleeve 39, wherein the axial pressure compensation chamber, the cavity occupied by the annular protrusion 322 and the pressure relief cavity together constitute a fourth cavity, and the second water-cooled chamber 384 is connected to the pressure relief cavity through the connecting flow channel 385, so as to balance the air pressure in the second water-cooled chamber 384 and the pressure relief cavity.

[0091] When conducting the axial compression test, the axial compression rod structure 32 moves downward, and the volume of the axial compression compensation chamber increases. Since the total spatial volume of the fourth cavity is fixed, the volume of the pressure relief chamber between the bottom end of the annular protrusion 322 and the top end of the limit sleeve becomes smaller, so that the gas in the pressure relief chamber can enter the second water-cooled chamber 384 through the connecting flow channel 385. Since the cold water in the second water-cooled chamber 384 is in a flowing state, the cold water pressure is relatively small, and there will be no obstruction to the gas entering the second water-cooled chamber 384 from the pressure relief chamber, thereby preventing the gas in the pressure relief chamber from obstructing the downward movement of the axial compression rod structure 32, so as to ensure that the axial compression rod structure 32 can smoothly perform the axial compression test operation on sample 5.

[0092] In addition, combined Figure 9 As shown, the container shell 2 includes a shell body 21 and two end covers 22. The two end covers 22 are respectively installed on the shell body 21 along the two ends of the container body. The end covers 22 are threadedly connected to the shell body 21 or connected by other fasteners.

[0093] Combine Figure 8 As shown, another embodiment of the present invention provides a testing system, including a press 6, a confining pressure system 8, a pore pressure system 9 and the three-axis compensation pressure experimental device as described above, and also including a rotating device 7, the rotating device 7 including a support frame 71, a rotating shaft 72 and a mounting frame 73, the container body of the three-axis compensation pressure experimental device can be detachably mounted on the mounting frame 73, the mounting frame 73 is mounted on the support frame 71 through the rotating shaft 72, and the mounting frame 73 is used to drive the container body to rotate around the rotating shaft 72.

[0094] It should be noted that the rotating device 7 is used to replace manual labor to more easily rotate the container body 180 degrees. Specifically, the container body of the three-axis compensation pressure experimental device is detachably mounted on the mounting frame 73, and the mounting frame 73 is mounted on the support frame 71 through the rotating shaft 72, so that the container body can be rotated 180 degrees manually. Figure 9 After the container body in the embodiment is rotated 180 degrees, the axial pressure compensation chamber of the axial pressure rod structure 32 and the first container plug 37 is located above the sample 5 (see Figure 8As shown), the triaxial compensation pressure test device is then installed on the press 6, and the relevant components on the triaxial compensation pressure test device are connected to the confining pressure system 8 and the pore pressure system 9 respectively, as preliminary preparations for the triaxial test of sample 5.

[0095] in, Figure 9 The state of the container body after installing the sample 5 and assembling the relevant components of the triaxial pressure assembly 3 in sequence, Figure 10 The diagram is a schematic diagram of the explosion structure when the container body in the triaxial compensation pressure experimental device is placed on the rotating device 7. Figure 11 FIG. 1 is a structural diagram of a state in which the container body is successfully installed on the mounting bracket 73 of the rotating device 7. Figure 8 A schematic diagram of the structure of the state in which the container body is rotated 180 degrees by the rotating device 7 and the protective cover 1 is installed on the outside of the container body to assemble a three-axis compensation pressure experimental device, and the three-axis compensation pressure experimental device is installed on the press 6 and connected with the confining pressure system 8 and the pore pressure system 9.

[0096] Another embodiment of the present invention provides a testing method, based on the above-mentioned testing system, comprising the following steps:

[0097] S1. Install the container body on the rotating device 7, assemble the sample 5 and the three-axial pressure assembly 3 of the container body in the container shell 2 of the container body, and rotate the container body 180 degrees through the rotating device 7 so that the axial pressure compensation chamber and the axial pressure rod structure 32 of the container body are above the sample 5.

[0098] It should be noted that the container body is first mounted on the rotating device 7, and then the sample 5 and the relevant components of the triaxial pressure assembly 3 are mounted in the container shell 2 according to a certain assembly sequence to form the container body. At this time, the axial pressure rod structure 32 in the container body and the axial pressure compensation chamber in the second container plug 38 are located below the sample 5 (see FIG. Figure 9 As shown), then you can manually Figure 9 After the container body in the embodiment is rotated 180 degrees, the axial pressure compensation chamber of the axial pressure rod structure 32 and the first container plug 37 is located above the sample 5 (see Figure 8 shown).

[0099] S2. Install the rotated container body on a press 6, and apply axial pressure to the triaxial pressure assembly 3 through the press 6 to perform an axial pressure test, and collect first axial pressure data in real time.

[0100] It should be noted that after the rotated container body is installed on the press 6, the protective cover 1 can be installed on the container shell 2 of the container body to form a three-axis compensation pressure test device, and then the press 6 can be used to apply axial downward pressure to the axial pressure rod structure 32 in the three-axis pressure assembly 3 to perform an axial pressure test on the sample 5, and collect the first axial pressure data of the sample 5 in real time, wherein the first axial pressure data at least includes the descending height of the axial pressure rod structure 32 and the axial pressure value of the press 6 on the sample 5.

[0101] S3. Control the confining pressure system 8 to fill the second cavity of the container body and the axial pressure compensation chamber with confining pressure fluid so that the axial pressure on the sample 5 in the axial direction is the same as the confining pressure in the circumferential direction, so that the container body is in a static pressure state.

[0102] It should be noted that the confining pressure system 8 is used to output confining pressure fluid, wherein the confining pressure fluid output by the confining pressure system 8 is diverted after passing through the confining pressure inlet 381 of the second container plug 38. A portion of the fluid enters the second cavity along the confining pressure flow channel 383 and flows to the sample chamber to apply confining pressure to the sample sheath 31 as the confining pressure of the sample 5, while the other portion enters the axial pressure compensation chamber along the axial pressure compensation flow channel 382 to compensate for the confining pressure fluctuation caused by the axial pressure rod structure 32 entering and exiting the main cavity when the press 6 is axially loaded, so that the axial pressure on the sample 5 in the axial direction is the same as the confining pressure in the circumferential direction, so that the container body is in a static pressure state. The confining pressure system 8 can use a plunger pump 91 in combination with a supercharger to achieve high-pressure confining pressure loading on the sample.

[0103] S4. Control the heating device 4 to heat the sample 5, and collect the temperature of the sample 5 when the temperature of the sample 5 is close to equilibrium or equilibrium; control the pore pressure system 9 to input pore fluid into the sample 5, increase the flow rate of the confining pressure fluid multiple times, apply axial pressure to the triaxial pressure assembly 3 of the container body multiple times, and collect and record the mechanical data of the sample 5; wherein the mechanical data includes the current pore pressure data, current confining pressure data, and current axial pressure data corresponding to the sample 5 each time the flow rate of the pore fluid, the flow rate of the confining pressure fluid, and the axial pressure of the sample 5 are increased.

[0104] It should be noted that the test system also includes a temperature control device, wherein the thermocouple is electrically connected to the signal end of the temperature control device, and the temperature control device is electrically connected to the heating device 4, for controlling the operation or stop of the heating device 4 according to the working temperature of the sample 5. Figure 8As shown, the pore pressure system 9 may include a plunger pump 91, a pore fluid container 92, a pressure sensor 93 and a vacuum pump 94. The pore fluid container 92 is connected to the liquid inlet 342 of the first sample plug 34 through the fluid inlet pipeline 301. The plunger pump 91 is connected to the pore fluid container 92 to pump out the pore fluid in the pore fluid container 92 and enter the sample 5 along the fluid inlet pipeline 301 through the liquid inlet 342 and the first guide channel 343. The pressure sensor 93 can be set on the fluid inlet pipeline 301 to detect the pressure of the pore fluid in the fluid inlet pipeline 301. The vacuum pump 94 can be set on the fluid inlet pipeline 301 to vacuum the pipeline in the pore pressure system 9.

[0105] Before performing the pore pressure test, the fluid inlet pipeline 301 can be evacuated by the vacuum pump 94, and then a certain pore pressure (lower than the confining pressure) is loaded by the plunger pump 91, and then the pressure sensor 93 collects and records the pressure of the pore fluid.

[0106] S5. Save the mechanical data, unload the pore pressure, the confining pressure fluid and the axial pressure, rotate the container body 180 degrees through the rotating device 7 so that the sample 5 is above the axial pressure compensation chamber and the axial pressure rod structure 32, and take out the sample 5.

[0107] After collecting the mechanical data of sample 5 under the triaxial pressure condition, the experiment ends, at which time the mechanical data is first saved, and then the confining pressure fluid and pore fluid are unloaded;

[0108] The container body can then be rotated 180 degrees by operating the rotating device 7 so that the container body is in the posture before installing the sample 5. In other words, the sample 5 is located above the axial pressure compensation chamber and the axial pressure rod structure 32. Finally, the container shell 2 and the relevant components in the three-axial pressure assembly 3 are disassembled and the sample 5 is taken out.

[0109] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A triaxial compensating pressure experimental device, applied to a test system, characterized in that: The container body comprises a container shell (2), a triaxial pressure assembly (3) and a heating device (4); the container shell (2) is provided with an annular groove structure (211) between its two axial ends; the central axis of the annular groove structure (211) coincides with the central axis of the container body; a main cavity is provided inside the container shell (2); the triaxial pressure assembly (3) is installed in the main cavity; a sample chamber for installing a sample (5) is provided inside the triaxial pressure assembly (3); the annular groove structure (211) is arranged around the sample chamber; the heating device (4) is sleeved on the annular groove structure (211) and connected to the container shell (2); The triaxial pressure assembly (3) comprises an axial pressure rod structure (32), a first heat insulating member (33), a first sample plug (34), a second sample plug (35), a second heat insulating member (36) and a first container plug (37) arranged in the main cavity and arranged in sequence along the axial direction of the container body, wherein the sample chamber is formed between the first sample plug (34) and the second sample plug (35); The triaxial pressure assembly (3) further includes a second container plug (38), the main cavity includes a second cavity, and the first sample plug (34) and the second sample plug (35) are both arranged in the second cavity; The triaxial pressure assembly (3) further comprises a sample sheath (31), the sample sheath (31) being sleeved on at least a portion of the first sample plug (34) and the second sample plug (35) and the sample (5); the second container plug (38) is provided with a confined pressure inlet (381) and a confined pressure flow channel (383), the confined pressure inlet (381) being used to connect to the confined pressure system (8), and the confined pressure flow channel (383) being respectively connected to the confined pressure inlet (381); the second cavity is connected to the confined pressure flow channel (383) to guide the confined pressure fluid provided by the confined pressure system (8) and passing through the confined pressure flow channel (383) to the sample sheath (31); A first sealing ring is installed between the first container plug (37) and the container shell (2) at a position adjacent to the second thermal insulation member (36); a first water cooling chamber (373) for cooling the first sealing ring is provided inside the first container plug (37); a first liquid inlet cooling channel (374) and a first liquid outlet cooling channel (375) communicating with the first water cooling chamber (373) are also provided inside the first container plug (37).

2. The triaxial compensation pressure test device according to claim 1, characterized in that: The heating device (4) comprises a plurality of heating covers arranged in a ring shape, and the plurality of heating covers are used to surround and wrap around the annular groove structure (211); the heating cover comprises a cover body (41) and two connecting parts (42), the two connecting parts (42) are respectively arranged at two ends of the cover body (41) along the central axis direction of the container body, and the connecting parts (42) are used to connect with a portion of the container shell (2) adjacent to the annular groove structure (211).

3. The triaxial compensation pressure test device according to claim 1, characterized in that: It also includes a protective cover (1), which is sleeved on at least a portion of the container shell (2) and is used to provide heat insulation and safety protection for the heating device (4).

4. The triaxial compensation pressure test device according to any one of claims 1 to 3, characterized in that: The first container plug (37) is used to connect to the platform of the press (6) of the test system, and the end of the axial pressure rod structure (32) away from the first thermal insulation component (33) is connected to the telescopic rod of the press (6).

5. The triaxial compensation pressure test device according to claim 4, characterized in that: The triaxial pressure assembly (3) further includes a limiting sleeve (39), the main cavity includes a first cavity, a second cavity, and a third cavity distributed along the axial direction of the container body and connected in sequence, and the second container plug (38) and the first container plug (37) are respectively correspondingly arranged in the first cavity and the third cavity; The axial pressure rod structure (32) includes a coaxially arranged axial pressure rod body (321) and an annular protrusion (322), the annular protrusion (322) is sleeved on the circumferential outer wall of the axial pressure rod body (321), and the interior of the second container plug (38) is provided with a fourth cavity and a fifth cavity that are sequentially connected along the axial direction of the axial pressure rod body (321), the annular protrusion (322) is located in the fourth cavity, and the limiting sleeve (39) is sleeved on the axial pressure rod body (321) and is located in the fifth cavity.

6. The triaxial compensation pressure test device according to claim 5, characterized in that: An axial pressure compensation flow channel (382) is also provided on the second container plug (38), and the axial pressure compensation flow channel (382) is connected to the surrounding pressure inlet (381). An axial pressure compensation chamber is formed between the top of the annular protrusion (322) and the inner top wall of the fourth cavity. The axial pressure compensation flow channel (382) is connected to the axial pressure compensation chamber and is used to compensate for the surrounding pressure fluctuation caused by the axial pressure rod structure (32) entering and exiting the main cavity when the press (6) is axially loaded.

7. The triaxial compensation pressure test device according to claim 4, characterized in that: The triaxial pressure assembly (3) further includes a plurality of connecting parts, wherein a plurality of spaced connecting holes (341) are provided at relative positions of the first sample plug (34) and the second sample plug (35), and the connecting parts sequentially pass through the connecting holes (341) on the first sample plug (34) and the second sample plug (35), the second thermal insulation member (36), and are connected to the first container plug (37).

8. The triaxial compensation pressure test device according to claim 7, characterized in that: The triaxial pressure assembly (3) further comprises a fluid inlet pipeline (301) and a fluid outlet pipeline (302); the first container plug (37) is provided with a fluid inlet flow channel (371) and a fluid outlet flow channel (372); a plurality of installation grooves (351) arranged at intervals are provided on the circumferential edge of the second sample plug (35); the first sample plug (34) is further provided with a liquid inlet (342) and a first flow guide channel (343) that are interconnected; one end of the fluid inlet pipeline (301) is connected to the pore pressure system (9); the other end of the fluid inlet pipeline (301) is sequentially passed through the fluid inlet pipeline (301), the second thermal insulation member (36), the installation groove (35), and the like. 1) is connected to the liquid inlet (342), the first diversion channel (343) is used to uniformly guide the pore fluid provided by the pore pressure system (9) and entering through the fluid inlet pipeline (301) through the liquid inlet (342) to the surface of the sample (5), the second sample plug (35) is also provided with a second diversion channel (352) and a return liquid port (353) that are interconnected, the second diversion channel (352) is located below the sample (5), one end of the fluid discharge pipeline (302) is connected to the return liquid port (353), and the other end of the fluid discharge pipeline (302) is sequentially passed through the second thermal insulation component (36) and the fluid discharge channel (372).

9. The triaxial compensation pressure test device according to claim 8, characterized in that: The fluid inlet pipeline (301) is wound around the outside of the sample (5) at a location between the second sample plug (35) and the liquid inlet (342).

10. A testing system, characterized in that: The invention comprises a press (6), a confining pressure system (8), a pore pressure system (9) and a triaxial compensation pressure experimental device as described in any one of claims 1 to 9, and further comprises a rotating device (7), wherein the rotating device (7) comprises a support frame (71), a rotating shaft (72) and a mounting frame (73), and the container body of the triaxial compensation pressure experimental device is detachably mounted on the mounting frame (73), the mounting frame (73) is mounted on the support frame (71) through the rotating shaft (72), and the mounting frame (73) is used to drive the container body to rotate around the rotating shaft (72).

11. A testing method, based on the testing system according to claim 10, characterized in that: The steps include: The container body is mounted on a rotating device (7), the sample (5) and the three-axis pressure assembly (3) of the container body are assembled in the container shell (2) of the container body, and the container body is rotated 180 degrees by the rotating device (7) so that the axial pressure compensation chamber and the axial pressure rod structure (32) of the container body are located above the sample (5); The rotated container body is mounted on a press (6), and an axial pressure is applied to the triaxial pressure assembly (3) by the press (6) to perform an axial pressure test, and first axial pressure data is collected in real time; The confining pressure system (8) is controlled to fill the second cavity of the container body and the axial pressure compensation chamber with confining pressure fluid, so that the axial pressure on the sample (5) in the axial direction is the same as the confining pressure on the circumferential direction, so that the container body is in a static pressure state; the heating device (4) is controlled to work to heat the sample (5), and when the temperature of the sample (5) is close to equilibrium or equilibrium, the temperature of the sample (5) is collected; the pore pressure system (9) is controlled to input pore fluid into the sample (5), increase the flow rate of the confining pressure fluid multiple times, apply axial pressure to the triaxial pressure assembly (3) of the container body multiple times, and collect and record the mechanical data of the sample (5); wherein the mechanical data includes the current pore pressure data, current confining pressure data and current axial pressure data corresponding to the sample (5) each time the flow rate of the pore fluid, the flow rate of the confining pressure fluid and the axial pressure are increased; The mechanical data is saved, the pore pressure, the confining pressure fluid and the axial pressure are unloaded, the container body is rotated 180 degrees by the rotating device (7) so that the sample (5) is located above the axial pressure compensation chamber and the axial pressure rod structure (32), and the sample (5) is taken out.

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