Bidirectional constant stiffness constraint rock shear testing device and method based on multi-source information

Abstract

A bidirectional constant stiffness constraint rock shear testing device includes; a base 1; a fixed component, including an L-shaped shearing plate 2 and a fixed pressure head 8 connected with each ot

Description

The disclosure relates to the technical field of rock mass engineering, and in particular to a bidirectional constant stiffness constraint rock shear testing device and a method based on multi-source information. Shear fracture is a typical failure mode of rock materials, which will lead to large-scale deformation or even collapse of surrounding rock in underground engineering. The shear strength of surrounding rock is an important parameter in the design and construction of civil engineering and underground engineering. Previous studies mainly focused on the shear characteristics of rock under the constraint of equal normal force. In this case, the normal force remains constant and the expansion of rock shear fracture surface is not limited, but for underground engineering, the expansion of rock shear fracture surface is always restricted by surrounding rock. Due to the "climbing effect", the normal force on the rock shear fracture surface is increasing. The boundary constraint conditions of constant normal stiffness and constant normal force have completely different effects on the shear mechanical properties of rock, and there are significant differences in the shear properties of rock under these two boundary conditions. At present, there are many studies on the shear mechanical properties of rock under the boundary constraint conditions of constant normal stiffness, but only limited to the constraint of constant normal stiffness in a single direction, and the direction perpendicular to the single direction is a free surface, which is obviously different from the constraint conditions in the process of rock shear failure in underground engineering, so the experimental results obtained from this are also quite different from the actual rock shear mechanical properties. Moreover, since the direction perpendicular to the normal stiffness constraint direction is the free surface, the rock sample may peel off on the free surface under the condition of large normal force at the beginning or during the test, causing unnecessary deviation of the test results. Therefore, it is urgent to develop a test device and test method for rock shear mechanical properties under the constraint of bidirectional constant normal stiffness based on multi-source information. An objective of the disclosure is to provide a bidirectional constant stiffness constraint rock shear testing device and a method based on multi-source information, so as to solve problems existing in the prior art, and the bidirectional constant stiffness measurement of the sample is realized by bidirectionally loading the sample through a pair of first force applying members. In order to achieve the above objective, the disclosure provides a following scheme. The disclosure provides a bidirectional constant stiffness constraint rock shear testing device based on multi-source information, including a base; a fixed component, including an L-shaped shearing plate and a fixed pressure head connected with each other, where the L-shaped shearing plate and the fixed pressure head are arranged on the base, and an accommodating space for accommodating a sample is formed between the L-shaped shearing plate and the fixed pressure head; a pair of first force applying members arranged on the base, where force applying directions of the pair of the first force applying members are perpendicular, and force applying ends of the pair of the first force applying members are used to abut against a pair of adjacent side surfaces of the sample, and the force applying ends of the force-applying members are provided with first sensors for acquiring acoustic and electromagnetic change data generated after the sample is stressed and second sensors for acquiring stroke data of movement stroke of the force applying ends; and a second force applying member, where a force applying end of the second force applying member is used for abutting against a top surface of the sample. Further, the device also includes bearing plates for abutting against the sample, where the bearing plates are used for abutting against the force applying ends of the first force applying members, a surface of each of the bearing plates is provided with grooves, and the first sensors are arranged in the grooves. Further, the device also includes first balls arranged on the bearing plates, and the first balls are in frictional contact with the force applying ends of the first force applying members. Further, the device also includes a bracket, where the bracket is in sliding fit with the base; one of the second sensors is arranged on the bracket, and the one of second sensors is connected with one of the force applying ends of the first force applying members, and the one of the force applying ends of the first force applying members slides relative to the base, so that the bracket slides relative to the base and the one of second sensors obtains the stroke data. Further, the bracket is provided with second balls, and the second balls are in frictional contact with the base. Further, the device also includes a pair of second baffles arranged on the base, and the pair of the first force applying members are respectively arranged on the pair of the second baffles. Further, the device also includes a first baffle arranged on the base; a plurality of first pull rods arranged between one of the second baffles and the first baffle; and a plurality of second pull rods arranged between an other second baffle and the L-shaped shearing plate, and the first pull rods are perpendicular to the second pull rods. Further, the base is provided with a pair of guide rails, and the pair of the second baffles are respectively slidably connected with the pair of the guide rails. Further, the L-shaped shear plate, the first baffles and the pair of the second baffles are all provided with fastening chucks for fixing the first pull rods and the second pull rods. A bidirectional constant stiffness constraint rock shear testing method based on multi-source information, including following steps: placing the sample in the accommodating space, and making the force applying ends of the pair of the first forcing members abut against the pair of the adjacent side surfaces of the sample, and the force applying end of the second force applying member abuts against the top surface of the sample; controlling the force applying ends of the first force applying members and the force applying end of the second force applying member to apply pressure to the sample; and acquiring the acoustic and electromagnetic change data generated after the sample is stressed and the stroke data of the movement stroke of the force applying ends of the first force applying members. The disclosure discloses the following technical effects. The device is provided with the L-shaped shearing plate and the fixed pressure head for fixing the sample, where the pair of the first force applying members are respectively arranged on the adjacent side surfaces of the sample, and the first sensors and the second sensors are arranged at the force applying ends of the first force applying members, so as to facilitate the measurement of the acoustic and electromagnetic change data generated by the sample under the force application of the pair of the force applying members and the stroke data of the pair of the first force applying members during the force application process, and facilitate the measurement of the bidirectional constant normal stiffness shearing mechanical characteristics of the sample. The device breaks through the technical limitation that the traditional shear test may only realize the unidirectional constant normal stress boundary, and is closer to the actual stress state of underground engineering rock mass structure, so the authenticity and reliability of the rock mechanics research are improved. Based on the processing of multi-source physical information data, the deformation and failure process of samples may be better analyzed. In order to explain the embodiments of the disclosure or the technical scheme in the prior art more clearly, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the disclosure, and other drawings may be obtained according to these drawings without creative work for ordinary people in the field. Figure 1 is a schematic diagram of an overall structure of the disclosure. Figure 2 is a plan view of the whole disclosure. Figure 3 is a schematic diagram of a horizontal pressurization process of a sample in the disclosure. Figure 4 is a schematic diagram of a pressurizing process in another horizontal direction of a sample in the disclosure. Figure 5 is a schematic structural diagram of a bearing plate in the disclosure. Figure 6 is a schematic structural diagram of a bracket in the disclosure. Figure 7 is a flowchart of the whole disclosure. Wherein, 1. base; 111. guide rail; 2. L-shaped shearing plate; 3. fixed baffle; 4. baffle; 5. first force applying member; 6. second sensor; 7. first ball; 8. fixed pressure head; 9. second force applying member 9; 10. fastening chuck; 11. second pull rod; 12. sample; 13. bearing plate; 1311. groove; 14. data collector; 15. processing system; 16. bracket; 17. lock; 18. nut; 19. perforation; 20. second ball; 21. first pull rod. In the following, the technical scheme in the embodiment of the disclosure will be clearly and completely described with reference to the attached drawings. Obviously, the described embodiment is only a part of the embodiment of the disclosure, but not the whole embodiment. Based on the embodiment in the disclosure, all other embodiments obtained by ordinary technicians in the field without creative labor belong to the scope of protection of the disclosure. In order to make the above objects, features and advantages of the disclosure more obvious and easier to understand, the disclosure will be further described in detail with the attached drawings and the specific embodiment. As shown in Figure 1-Figure 6, the disclosure provides a bidirectional constant stiffness constraint rock shear testing device based on multi-source information, including a fixed component, where the fixed component is arranged on a base 1, and the fixed component includes an L-shaped shearing plate 2 and a fixed pressure head 8; the fixed pressure head 8 has an inverted L-shaped structure; the fixed pressure head 8 is fixedly connected to a top of the L-shaped shearing plate 2, and a space for placing a sample 12 is formed between the L-shaped shearing plate 2 and the fixed pressure head 8. A bottom of the L-shaped shearing plate 2 is fixed on the base 1, and an exposed width of a top end of the bottom is half of a bottom width of the sample 12, so as to ensure that half of the sample 12 is suspended and the sample 12 may be sheared under the action of a second force applying member 9; a top of the sample 12 is provided with the fixed pressure head 8 and the second force applying member 9, a bottom of the second force applying member 9 abuts against the sample 12, and one side of the second force applying member 9 abuts against the fixed pressure head 8; the fixed pressure head 8 is inverted L-shaped, and is provided with two through holes at a top, and is fixed on the top of the L-shaped shearing plate 2 by nuts 18 to prevent the sample 12 from rotating in a shearing process; and the L-shaped shearing plate 2 is provided with a plurality of perforations 19, where the perforations 19 are distributed on two adjacent sides of the L-shaped shearing plate 2. The device also includes a pair of first force applying members 5. In this embodiment, the first force applying members 5 are mechanical jacks, and the pair of the first force applying members 5 are located on the base 1. The force applying directions of the pair of the first force applying members 5 are perpendicular, and force applying ends of the pair of the first force applying members 5 are used to abut against a pair of adjacent side surfaces of the sample 12, and the force applying ends of the force-applying members 5 are provided with first sensors for acquiring acoustic and electromagnetic change data generated after the sample 12 is stressed and second sensors 6 for acquiring stroke data of movement stroke of the force applying ends. The two adjacent side surfaces of the sample 12 are each abutted against a bearing plate 13, and one side of the bearing plate 13 abutting against the sample 12 is provided with grooves 1311, and the grooves 1311 are internally provided with the first sensors, and in this embodiment, there are three grooves 1311; the first sensors are probes of acoustic emission, parallel electrical method and electromagnetic radiation monitoring instruments respectively, that is, the probes of acoustic emission, parallel electrical method and electromagnetic radiation monitoring instruments are respectively put into the three grooves 1311. A data collector 14 collects the evolution law of multi-source physical information such as sound, electricity and magnetism in the deformation and failure process of different samples 12, and analyzes the deformation and failure process of the different samples 12. An other side of the bearing plate 13 is provided with first balls 7, where the first balls 7 are in frictional contact with the bearing plate 13 and each of the first force applying members 5, respectively, for reducing friction. One of the second sensors 6 is arranged on a bracket 16, where the bracket 16 is in sliding fit with the base 1. The one of second sensors 6 is connected with the one of the force applying ends of the first force applying members 5, and the one of the force applying ends of the first force applying members 5 slides relative to the base 1, so that the bracket slides relative to the base and the one of second sensors 6 may obtain the stroke data of the one of the first force applying members. In this embodiment, the second sensors 6 are pressure displacement sensors, and the second sensors 6 are used to measure the pressure and displacement data of the each of the first force applying members during the process of applying force to the sample by the each of the first force applying members. As shown in Figure 6, the bracket 16 has a swastika structure, which may support the one of first sensors 6 and ensure that the height of the one of first sensors 6 is consistent with the sample 12. The bracket 16 is arranged in a swastika structure, so the support is more stable. Second balls 20 are arranged at a bottom of the bracket 16 to reduce the friction between the bracket 16 and the base 1, so that the bracket 16 and the base 1 are in sliding fit. The base is also provided with a pair of second baffles 4, and the pair of the first force applying members 5 are respectively arranged on the pair of second baffles 4. The base is provided with guide rails 111, where the guide rails 111 are groove guide rails, and bottoms of the pair of the second baffles 4 are provided with convex guide rails matched with the guide rails 111, so as to ensure that the baffles 4 are flush in the testing process, so that the second baffles 4 are slidably connected with the base 1, and one side of each of the second baffles 4 facing the sample 12 is connected with a corresponding first force applying member 5. The base 1 is also provided with a first baffle 3, where the first baffle 3 is fixed on the base 1. A plurality of first pull rods 21 are arranged between one of the second baffles 4 and the first baffle 3, and a plurality of second pull rods 11 are arranged between the other second baffle 4 and the L-shaped shearing plate 2, and the first pull rods 21 and the second pull rods 11 are perpendicular to each other. The tensile stiffness of the first pull rods 21 and the second pull rods 11 is related to the elastic modulus and cross-sectional area of the materials of the first pull rods 21 and the second pull rods 11. According to the test requirements, the number of the first pull rods 21 and the second pull rods 11 may be changed, and the test stiffness may be changed to realize the test under different normal restraint stiffness conditions. As shown in Figure 3, one end of each of the second pull rods 11 passes through the L-shaped shearing plate 2 through a corresponding perforation 19 and is fixed by a fastening chuck 10, and an other end passes through the baffle plate 4 and is fixed by a fastening chuck 10. The fastening chuck 10 is provided with a plurality of holes, and each hole is fixed with one second pull rod 11, so that the plurality of second pull rods 11 may be fixed to ensure that the internal second pull rods 11 do not slip when being pulled. A lock 17 is arranged on an outer side of the fastening chuck 10, and each of the second pull rods 11 is fixed by the lock 17, so as to resist the reverse force when one of the first force applying members 5 applies force and avoid the displacement of the one of the second baffles 4. As shown in Figure 4, one end of a first pull rod 21 passes through the L-shaped shearing plate 2 through a corresponding perforation 19 and continues to extend through the fixed baffle 3, and is fixed by the fastening chuck 10 and the lock 17, while an other end of the first pull rod 21 passes through the baffle 4 and is fixed by the fastening chuck 10 and the lock 17. Similarly, the first pull rods 21 are used to resist the directional force when the other first force applying member 5 applies force and avoid the displacement of the other second baffle 4. A top surface of the sample 12 is provided with a second force applying member 9. In this embodiment, the second force applying member 9 is a loading pressure head, which is used for connecting with a press to provide vertical pressure. A bidirectional constant stiffness constraint rock shear testing method based on multi-source information, including following steps: as shown in Figure 7, placing the sample 12 in the accommodating space, and making the force applying ends of the pair of the first forcing members 5 abut against the pair of the adjacent side surfaces of the sample 12, and the force applying end of the second force applying member 9 abut against the top surface of the sample 12; controlling the force applying ends of the first force applying members 5 and the force applying end of the second force applying member 9 to apply pressure to the sample 12; and acquiring acoustic and electromagnetic change data generated after the sample 12 is stressed and the stroke data of the movement stroke of the force applying ends of the first force applying members 5. Firstly, an uniaxial test is carried out on the sample 12 to measure the stress and strain. If the sample 12 is a heterogeneous material, the stress and strain in two directions need to be measured, and the stiffness is a ratio of stress and strain. The sample 12 is put into the L-shaped shearing plate 2, and the nuts 18 at the top of the fixed pressure head 8 are tightened to fix the sample 12; the bearing plates 13 into which the acoustic, electric and magnetic probes are placed are closely attached to the sample 12, and then the balls 7, the pressure displacement sensors 6, the mechanical jacks and the baffles 4 are put respectively; the normal stiffness required for testing is determined by step SI, and different numbers of the pull rods 21 are selected and fixed by the fastening chucks 10 and locks 17; the bidirectional jacks are started to load, and confining pressures (Fnl, Fn2) are read at the same time, and when the confining pressures reach a predetermined value, the loading is stopped and locked; a shear stress second force applying member 9 is installed, the shear stress loading is started in the press, and the shear stress loading is performed at the top of the sample 12; the data collector 14 collects shear force (Fs), confining pressures (Fnl, Fn2) on both sides of the sample 12, and acoustic, electrical and magnetic data, and transmits the data to a processing system 15 for processing. The data input by the processing system 15 include the data obtained by the testing device itself shear force (Fs), confining pressures (Fnl, Fn2) on both sides of the sample 12, and acoustic electromagnetism. The data that need to be measured by other instruments include lithology, mineral composition and particle size. Through the integration of these data, samples 12 with different lithology are continuously tested, and through the intelligent processing of the processing system 15, a database is finally formed, and a multi-source information system for deformation and failure of the samples 12 is established. In this embodiment, two adjacent sides of the sample 12 are respectively provided with the jacks of the first force applying members 5 to test the shear force on both sides of the sample 12, so as to measure the bidirectional constant stiffness of the sample 12. The force applying ends of the first force applying members 5 are each provided with the first sensors and the second sensors 6, which facilitates the measurement of acoustic and electromagnetic change data generated after the the sample 12 is stressed as well as the acquisition of stroke data of the movement stroke of the force applying ends of the first force applying members 5, breaks through the technical limitation that the traditional shear test may only realize the unidirectional constant normal stress boundary, and is closer to the actual force state of the rock structure, so the authenticity and reliability of the rock mechanics research are improved. This device has the characteristics of variable stiffness, and the stiffness of the pull rod depends on the pull rod material itself and the cross-sectional area of the pull rod. This device changes the number of pull rods, that is changes the cross-section and thus the stiffness. This device may collect and process multi-source information, and combine all the collected data to establish a comprehensive database for analyzing and understanding the deformation and failure characteristics of sample 12 under different conditions. In the description of the disclosure, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, only for the 5 convenience of describing the disclosure, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore may not be understood as a limitation of the disclosure. The above-mentioned embodiments only describe the preferred mode of the disclosure, and do not limit the scope of the disclosure. Under the premise of not departing from the design spirit of 10 the disclosure, various modifications and improvements made by ordinary technicians in the field to the technical scheme of the disclosure shall fall within the protection scope determined by the claims of the disclosure.

Claims

1. A bidirectional constant stiffness constraint rock shear testing device based on multi-source information, comprising:a base (1);a fixed component, comprising an L-shaped shearing plate (2) and a fixed pressure head (8) connected with each other, wherein the L-shaped shearing plate (2) and the fixed pressure head (8) are arranged on the base (1), and an accommodating space for accommodating a sample (12) is formed between the L-shaped shearing plate (2) and the fixed pressure head (8);a pair of first force applying members (5) arranged on the base (1), wherein force applying directions of the pair of the first force applying members (5) are perpendicular, and force applying ends of the pair of the first force applying members (5) are used to abut against a pair of adjacent side surfaces of the sample (12), and the force applying ends of the force-applying members (5) are provided with first sensors for acquiring acoustic and electromagnetic change data generated after the sample (12) is stressed and second sensors (6) for acquiring stroke data of movement stroke of the force applying ends; anda second force applying member (9), wherein a force applying end of the second force applying member (9) is used for abutting against a top surface of the sample (12).

2. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 1, further comprising bearing plates (13) for abutting against the sample, wherein the bearing plates (13) are used for abutting against the force applying ends of the first force applying members (5), a surface of each of the bearing plates (13) is provided with grooves (1311), and the first sensors are arranged in the grooves.

3. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 2, further comprising first balls (7) arranged on the bearing plates (13), and the first balls (7) are in frictional contact with the force applying ends of the first force applying members (5).

4. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 1, further comprising a bracket (16), wherein the bracket (16) is in sliding fit with the base (1); one of the second sensors (6) is arranged on the bracket (16), andthe one of second sensors (6) is connected with one of the force applying ends of the first force applying members (5), and the one of the force applying ends of the first force applying members (5) slides relative to the base (1), so that the bracket (16) slides relative to the base (1) and the one of second sensors (6) obtains the stroke data.

5. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 4, wherein the bracket (16) is provided with second balls (20), and the second balls (20) are in frictional contact with the base (1).

6. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 1, further comprising a pair of second baffles (4) arranged on the base (1), and the pair of the first force applying members (5) are respectively arranged on the pair of the second baffles (4).

7. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 6, further comprising:a first baffle (3) arranged on the base (1);a plurality of first pull rods (21) arranged between one of the second baffles (4) and the first baffle (3); anda plurality of second pull rods (11) arranged between an other second baffle (4) and the L-shaped shearing plate (2), and the first pull rods (21) are perpendicular to the second pull rods (11).

8. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 6, wherein the base (1) is provided with a pair of guide rails (111), and the pair of the second baffles (4) are respectively slidably connected with the pair of the guide rails (111).

9. The bidirectional constant stiffness constraint rock shear testing device based on multi-source information according to claim 7, wherein the L-shaped shear plate (2), the first baffles (3) and the pair of the second baffles (4) are all provided with fastening chucks (10) for fixing the first pull rods (21) and the second pull rods (11).

10. Abidirectional constant stiffness constraint rock shear testing method based on multi-source information, based on the bidirectional constant stiffness constraint rock shear testing devicebased on multi-source information according to any one of claims 1-9, comprising following steps:placing the sample (12) in the accommodating space, and making the force applying ends of the pair of the first forcing members (5) abut against the pair of the adjacent side surfaces of the 5 sample (12), and the force applying end of the second force applying member (9) abuts against the top surface of the sample (12);controlling the force applying ends of the first force applying members (5) and the force applying end of the second force applying member (9) to apply pressure to the sample (12); and acquiring the acoustic and electromagnetic change data generated after the sample (12) is 10 stressed and the stroke data of the movement stroke of the force applying ends of the first force applying members (5).IntellectualPropertyOfficeApplication GB2415045.0Search report under Section 17 of the Patents Act 1977Date search completed: 15 May 2025Claims searched: 1-10International classificationSubclass and subgroup Valid from GO 1N 3 / 02 01 / 01 / 2006 GO 1N 3 / 04 01 / 01 / 2006 GO 1N 3 / 24 01 / 01 / 2006Field of searchWorldwide search of patent documents classified in the following areas of the IPC:G01NDatabases used in the preparation of this search report:SEARCH-PATENTDocuments considered to be relevantPatent literatureCategory Relevant claims Document of relevance P — CN 118150367 A (CHINA UNIVERSITY OF MINING AND TECHNOLOGY)Intellectual Property Office is an operating name of the Patent Officewww.gov.uk / ipoA — CN 114659908 A (CHINESE MINING UNIVERSITY) A — CN 105651671 A (BEIJING UNIVERSITY OF TECHNOLOGY) A — CN 105973722 A (SHANDONG UNIVERSITY SCI &TECH) A — CN 105891018 A (SICHUAN WATER CONSERVANCY) Non-patent Category iterature Relevant claims Document of relevance Categories Letter or symbol Description X Document indicating lack of novelty or inventive step.Document indicating lack of inventive step, if combined with another document of the same category.& Member of the same patent family. A Document indicating technological background. P Document published on or after the priority date but before the fling date of the present application.Letter or symbol Description E Earlier application published on or after the filing date of the present application.

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