Brickstone ancient tower interface shear resistance detection device and detection method

Abstract

The invention relates to the technical field of masonry structure shear resistance detection, in particular to a masonry ancient tower interface shear resistance detection device and method. The device comprises a magnetic part and a shearing part, the magnetic part comprises two U-shaped clamping plates symmetrically arranged on the two sides of a masonry test piece, each clamping plate comprises a main plate and side plates installed on the two sides of the main plate, and the groove length direction of a U-shaped groove in each clamping plate is parallel to the shearing direction of the masonry test piece; the two clamping plates are oppositely combined to form a cuboid clamping cavity, and a masonry test piece is placed in the clamping cavity. Electromagnetic components are mounted on two side plates of the clamping plates, the electromagnetic components on the opposite side plates on the two clamping plates magnetically attract each other, so that the two main plates are driven by the magnetic attraction force to apply clamping force for clamping the masonry test piece from two sides of the masonry test piece, and the clamping force is normal stress. The normal stress is applied to the two sides of the masonry test piece to simulate the extruded condition of the masonry test piece, so that the accuracy of the shear resistance detection of the masonry test piece is improved.

Description

Technical Field

[0001] The invention relates to the technical field of shear resistance detection of masonry structures, and in particular to a device and method for detecting shear resistance of an interface of a masonry ancient tower. Background Art

[0002] Masonry structures are widely used in low-rise buildings, ancient dwellings, and ancient towers. The masonry structure in the building mainly relies on the block and mortar interface bonding and friction connection as a whole to build various supporting structures of the building. Compared with the "strong node" connection of modern building structures, the building masonry structure mainly relies on the interface bonding and friction connection as a whole. Once damaged under the action of static force, it has an irreversible and continuously accumulated state. Therefore, the shear resistance of the block and mortar connection interface has a great influence on the overall bearing capacity and stability of the structure. Therefore, the shear resistance of the block and mortar connection interface is often a key issue for cultural relics protection staff. The higher the bond friction strength of the block and mortar connection interface, the better the shear strength of the masonry structure and the more stable the building; conversely, the worse the stability of the building. It can be seen that the bond friction strength of the block and mortar connection interface is crucial to the stability of the building.

[0003] In the actual construction process, the shear strength of the masonry structure is usually used to characterize the bond friction strength of the block and mortar connection interface, and thus reflects the stability of the building. Patent CN111257136B discloses a masonry quasi-static horizontal shear test method and equipment, which can detect the shear performance of masonry structures under different loads.

[0004] During actual use, masonry structures are usually subjected to normal stress on both sides due to the compression of other masonry structures. However, the above-mentioned method and device cannot provide clamping normal stress on both sides of the masonry structure during use, resulting in a large difference between the experimental conditions of the masonry structure and the actual conditions, which in turn leads to a large error in the test results of the shear performance.

[0005] It can be seen that the current testing methods and equipment for the shear resistance of masonry structures need to be improved and upgraded. Summary of the invention

[0006] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a device and method for detecting the shear resistance of masonry ancient tower interfaces. The present invention applies normal stress on both sides of the masonry specimen to truly simulate the extrusion of the masonry specimen, thereby improving the accuracy of the shear resistance detection of the masonry specimen.

[0007] To achieve the above object, the present invention provides the following technical solutions: A device for detecting the shear resistance of the interface of an ancient masonry tower comprises a magnetic part for sequentially applying different normal stresses on both sides of a masonry specimen, and a shear part for simultaneously applying shear force along the shear direction of the masonry specimen; the magnetic part comprises two U-shaped clamping plates symmetrically arranged on both sides of the masonry specimen, the clamping plates comprising a main plate and side plates installed on both sides of the main plate, and the groove length direction of the U-shaped groove in the clamping plate is parallel to the shear direction of the masonry specimen; the two clamping plates are matched to form a rectangular open-loop clamping cavity, and the masonry specimen is placed in the clamping cavity; electromagnetic components that can generate magnetic force are installed on both side plates of the clamping plates, and the electromagnetic components on the side plates of the two clamping plates arranged opposite to each other are magnetically attracted to each other, so as to drive the two main plates to apply a clamping force to clamp the masonry specimen from both sides of the masonry specimen through the magnetic attraction force, and the clamping force is the normal stress.

[0008] As a further solution of the present invention: the electromagnetic assembly includes a plurality of spaced-apart strong magnetic bars installed side by side in sequence along the length direction of the U-shaped groove in the clamping plate, the length direction of each strong magnetic bar is parallel to the notch direction of the U-shaped groove, and an electromagnetic coil is coaxially sleeved on the outer side of each strong magnetic bar; two strong magnetic bars facing each other in two groups of electromagnetic assemblies that are magnetically attracted to each other are coaxially arranged, and four strong magnetic bars located in the same plane perpendicular to the shear direction of the masonry specimen constitute a magnetic bar group.

[0009] As a further solution of the present invention: the clamping force applied by the two clamping plates in the magnetic part to the masonry specimen is calculated as follows: ; ; In the formula, It represents the clamping force applied by the two clamping plates in the magnetic part to the masonry specimen; Indicates the total number of magnetic bar groups; Indicates i The magnetic attraction generated by the group of magnetic rods; represents the vacuum permeability; Indicates i The diameter of each strong magnetic bar in the group of magnetic bars; Indicates i The current in each electromagnetic coil in the group of magnetic bars; Indicates i The number of coil turns in each electromagnetic coil in the group of magnetic rods; Indicates i The magnetic attraction distance between two strong magnetic bars arranged opposite to each other in a group of magnetic bars.

[0010] As a further solution of the present invention: in the same magnetic bar group, the current in each electromagnetic coil is the same, and the number of turns of each electromagnetic coil is the same.

[0011] As a further solution of the present invention: the sizes of the strong magnetic bars are the same, and the magnetic attraction distance between the two strong magnetic bars facing each other is the same. As a further solution of the present invention: it is characterized in that the shearing part includes a workbench with a horizontally arranged table top, a support frame is fixedly installed on the workbench, a telescopic rod is installed on the support frame, and the telescopic direction of the telescopic rod is perpendicular to the table top of the workbench; a shearing space for placing the masonry specimen is formed between the telescopic end of the telescopic rod and the table top of the workbench.

[0012] As a further solution of the present invention: the telescopic rod is a hydraulic cylinder, and a pad for abutting against the masonry specimen is fixedly connected to the telescopic end of the hydraulic cylinder; a sinking hole is opened on the table top of the workbench, and the masonry specimen is mounted on the sinking hole so that the masonry specimen can bend downward when the pad is pressed downward.

[0013] A method for detecting the shear resistance of an ancient masonry tower interface, the method using the above-mentioned device for detecting the shear resistance of an ancient masonry tower interface, is characterized in that it includes the following detection steps: S1. Construct the corresponding masonry structure according to the corresponding construction standard, and directly use the constructed masonry structure as a masonry specimen, or use a cutting machine to cut the masonry structure into masonry specimens of preset sizes; S2, using the magnetic unit to apply different normal stresses on both sides of the masonry specimen in sequence; S3. Under each normal stress, use the shear part to apply shear force along the shear direction of the masonry specimen, and record the maximum shear force when the masonry specimen is sheared and damaged. The maximum shear force represents the peak shear load of the masonry specimen under the current normal stress.

[0014] As a further solution of the present invention: the specific content of step S2 is as follows: S21. Place the masonry specimen on the workbench surface and directly below the hydraulic cylinder; S22, placing two clamping plates on the workbench surface and symmetrically arranged on both sides of the masonry specimen, and the height of the rectangular clamping cavity formed between the two clamping plates is the same as the height of the masonry specimen; S23, making the current in the electromagnetic coils of each group of magnetic rods in the magnetic part, the size of the strong magnetic rods, the magnetic attraction distance and the number of turns of the electromagnetic coils all the same; S24. Change the current in each electromagnetic coil simultaneously according to the same rule so that the masonry specimen is subjected to different clamping forces.

[0015] As a further solution of the present invention: the specific content of step S3 is as follows: S31, under the current clamping force, start the hydraulic cylinder and make the pad press against the masonry specimen, then continue to increase the pressure of the hydraulic cylinder along the shear direction of the masonry specimen until the masonry specimen breaks in the shear direction, and the pressure of the hydraulic cylinder at this time is the maximum shear force when the masonry specimen is sheared; S32. Under each clamping force, the masonry specimen is sheared according to the content of step S31, and the corresponding maximum shear force is obtained, and the maximum shear force is proportional to the peak shear load of the masonry specimen.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention can scientifically evaluate the shear resistance of masonry structures by systematically applying different levels of normal stress to masonry specimens of masonry ancient pagoda materials and measuring their maximum ability to resist shear failure under these stresses. This is crucial to ensure the stability and safety of buildings or structures under shear forces such as wind loads and earthquakes.

[0017] 2. The electromagnetic assembly of the present invention is composed of a plurality of strong magnetic rods and electromagnetic coils arranged at intervals. This design allows the magnitude of the normal stress to be flexibly controlled by adjusting the current in the electromagnetic coil, thereby meeting the requirements under different experimental conditions. In addition, the uniformity and consistency of the magnetic force can also be ensured by optimizing the specifications of the magnetic rods, the magnetic attraction distance and the number of turns of the electromagnetic coil.

[0018] 3. The design of the U-shaped clamping plate of the present invention cleverly adapts to the shape of the rectangular masonry specimen, so that the specimen can be coaxially placed in the clamping cavity, ensuring the uniformity of stress application. At the same time, the electromagnetic components installed on the clamping plate are magnetically attracted to each other, which not only simplifies the clamping mechanism, but also improves the stability and reliability of the structure.

[0019] 4. The present invention uses magnetic force instead of mechanical force for clamping, avoiding the noise, vibration and friction heat problems that may be generated by the traditional clamping method, and improving the safety of the experimental process. At the same time, the use of electromagnetic components is also in line with modern environmental protection concepts, reducing the environmental pollution that may be caused by traditional mechanical clamping methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a detection flow chart of the present invention.

[0021] Figure 2 It is a schematic diagram of the overall structure of the device in the present invention.

[0022] Figure 3 It is a structural schematic diagram of the magnetic part in the present invention.

[0023] Figure 4 It is a schematic diagram of the disassembled structure of the electromagnetic component in the present invention.

[0024] In the figure: 1, shearing part; 11, supporting frame; 111, base; 112, vertical plate; 113, horizontal plate; 12, workbench; 121, supporting plate; 122, column; 123, sinking hole; 2, masonry specimen; 3, telescopic rod; 31, pad; 4, magnetic part; 41, clamping plate; 411, main board; 412, side plate; 42, clamping cavity; 43, electromagnetic assembly; 431, packaging box; 4311, box cavity; 4312, mounting hole; 4313, magnetic isolation plate; 432, electromagnetic coil; 433, strong magnetic rod. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 to Figure 4 In the embodiment of the present invention, the shearing part 1 includes a support frame 11 and a workbench 12. The support frame 11 includes a base 111 supported and arranged on the ground, and a gantry is arranged on the base 111. The gantry includes two vertical plates 112 symmetrically arranged on the base 111, and the top ends of the two vertical plates 112 arranged vertically on the plate surface are fixed to each other through a horizontal plate 113 arranged horizontally on the plate surface, thereby forming a gantry. The workbench 12 includes four columns 122 axially symmetrically arranged in the gantry. Each column 122 is arranged vertically in the length direction, the bottom end of the column 122 is fixed on the base 111, and the top end of the column 122 is fixed on the horizontal plate 113. The support plate 121 is fixedly connected to the four columns 122 at the same time, and is used to support the masonry specimen 2. And the upper plate surface of the support plate 121 constitutes the horizontal working surface of the workbench 12. A telescopic rod 3 is fixedly installed at the middle position of the lower plate surface of the horizontal plate 113, which can apply shear force to the masonry specimen 2 along the shear direction of the masonry specimen 2, and the telescopic rod 3 is usually a hydraulic cylinder. In order to apply uniformly distributed shear force to the masonry specimen 2, a pad 31 with a horizontal plate surface is fixed at the front end of the hydraulic cylinder, and the lower plate surface of the pad 31 can fit with the upper end surface of the masonry specimen 2 to apply shear force. In order to facilitate the measurement of the shear resistance of the masonry specimen 2, a sinking hole 123 is opened on the surface of the workbench 12, and the masonry specimen 2 is mounted on the sinking hole 123, so that when the hydraulic cylinder is pressed down, the masonry specimen 2 directly below the pad 31 loses the support of the workbench 12 surface, so that the masonry specimen 2 can bend downward and break when the pad 31 is pressed down, and finally the corresponding shear force is measured.

[0027] The magnetic part 4 includes two U-shaped clamping plates 41 that can be symmetrically arranged on both sides of the masonry specimen 2. The clamping plates 41 include a main board 411 and side boards 412 installed on both sides of the main board 411. When applying normal stress, the length direction of the U-shaped groove in the clamping plate 41 is parallel to the shear direction of the masonry specimen 2 along the vertical direction. The two clamping plates 41 are matched to form a rectangular open-loop clamping cavity 42, that is, the opposite side boards 412 do not contact each other and form a magnetic attraction distance, and the masonry specimen 2 is coaxially placed in the clamping cavity 42. Electromagnetic components 43 that can generate magnetic force are installed on the two side boards 412 of the clamping plate 41, and the electromagnetic components 43 on the side boards 412 arranged opposite to each other on the two clamping plates 41 are magnetically attracted to each other, so as to drive the two main boards 411 to apply a clamping force to clamp the masonry specimen 2 from both sides of the masonry specimen 2 through magnetic attraction, and the clamping force is the normal stress. In order to improve the accuracy of the measurement, a plurality of compression type sensors are installed between the clamping plate 41 and the masonry specimen 2 to detect the normal stress applied by the clamping plate 41 and compare it with the calculated normal stress, thereby playing the role of correcting the electromagnetic component 43 in real time, thereby improving the accuracy of the calculation. That is, before the formal test, a preliminary inspection is first performed to compare the difference between the compression type sensor and the calculated normal stress, so as to timely adjust the position and size of each component in the magnetic part 4, so as to make the calculated value and the measured value within the set error, and then use the magnetic part 4 to apply the normal stress.

[0028] like Figure 4 As shown, the electromagnetic assembly 43 includes a packaging box 431, and a hollow box cavity 4311 is formed inside the packaging box 431. A plurality of mounting holes 4312 are sequentially arranged side by side along the slot length direction of the U-shaped slot in the clamping plate 41 on the box body of the packaging box 431, and each strong magnetic rod 433 is coaxially inserted in each mounting hole 4312 in turn, and the rod body of each strong magnetic rod 433 is located in the box cavity 4311. The part of the strong magnetic rod 433 located in the box cavity 4311 is wound with an electromagnetic coil 432, and different currents can be passed through the electromagnetic coil 432. The electromagnetic coils 432 located in the same packaging box 431 can be sequentially connected in series in the same circuit so that the currents in each electromagnetic coil 432 are the same. At the same time, the electromagnetic coils 432 in the same packaging box 431 can also be independent of each other, and the magnitude of their respective currents can be controlled through their respective circuits. In order to further reduce the interference between adjacent strong magnetic bars 433, magnetic isolation plates 4313 are installed between adjacent strong magnetic bars 433 in the box cavity 4311, thereby dividing the box cavity 4311 into a plurality of small chambers that are not magnetically connected to each other. The size of the packaging box 431 is adapted to the side plate 412, and the packaging box 431 is fixed to the outer surface of the side plate 412 by welding or gluing.

[0029] During the entire detection process, the clamping plate 41 is made of a material with a relatively high bending strength to prevent it from being deformed under the action of magnetic force and thus affecting the accuracy of the detection result.

[0030] Two strong magnetic bars 433 facing each other in two groups of mutually attracted electromagnetic components 43 are coaxially arranged, and four strong magnetic bars 433 located in the same plane perpendicular to the shear direction of the masonry specimen 2 constitute a group of magnetic bars. In the same magnetic bar group, the current in each electromagnetic coil 432 is the same, the size of each strong magnetic bar 433 is the same, the magnetic attraction distance between the two strong magnetic bars 433 facing each other is the same, and the number of turns of each electromagnetic coil 432 is the same. The masonry specimen 2 is usually made of bricks and cement mortar, so when the shear force is realized, the shear force will propagate downward along the brick joints in the plumb direction. In this case, the shear resistance of the masonry specimen 2 will be slightly weaker. When the masonry specimen 2 is made of reinforced concrete, there is no brick joint, and the shear resistance of the masonry specimen 2 will be stronger at this time.

[0031] The clamping force applied by the two clamping plates 41 in the magnetic part 4 to the masonry specimen 2 is calculated as shown in formula (1) and formula (2): (1); ; In the formula, It represents the clamping force applied by the two clamping plates 41 in the magnetic part 4 to the masonry specimen 2; Indicates the total number of magnetic bar groups; Indicates i The magnetic attraction generated by the group of magnetic rods; represents the vacuum permeability; Indicates i The diameter of each strong magnetic bar 433 in the magnetic bar group; Indicates i The current in each electromagnetic coil 432 in the group of magnetic bars; Indicates i The number of coil turns in each electromagnetic coil 432 in the group of magnetic rods; Indicates i The magnetic attraction distance between two strong magnetic bars 433 arranged opposite to each other in the magnetic bar group.

[0032] The detection process of the present invention is specifically as follows: 1. Construct the corresponding masonry structure according to the corresponding construction standards.

[0033] 2. Directly use the masonry structure of the constructed ancient brick and stone tower material as the masonry specimen 2, or use a cutting machine to cut the masonry structure into masonry specimens 2 of preset sizes.

[0034] 3. Place the masonry specimen 2 on the workbench 12 and directly below the pad 31 on the hydraulic cylinder.

[0035] 4. Place two clamping plates 41 on the workbench 12 and arrange them symmetrically on both sides of the masonry specimen 2 , and the height of the rectangular clamping cavity 42 formed between the two clamping plates 41 is the same as the height of the masonry specimen 2 .

[0036] 5. Make the current in the electromagnetic coil 432 in each group of magnetic rods in the magnetic part 4, the size of the strong magnetic rod 433, the magnetic attraction distance and the number of turns of the electromagnetic coil 432 all the same.

[0037] 6. According to the same rule, the current in each electromagnetic coil 432 is changed at the same time, and the corresponding clamping force is calculated using formula (1) and formula (2), so that the masonry specimen 2 is subjected to different clamping forces.

[0038] 7. Under the current clamping force, start the hydraulic cylinder and press the pad 31 against the masonry specimen 2. Then continue to increase the pressure of the hydraulic cylinder along the shear direction of the masonry specimen 2 until the masonry specimen 2 breaks in the shear direction. At this time, the pressure of the hydraulic cylinder is the maximum shear force that causes shear damage to the masonry specimen.

[0039] 8. Shear the masonry specimen 2 according to the above steps under various clamping forces, and obtain the corresponding maximum shear force, and the maximum shear force is proportional to the peak shear load of the masonry specimen 2.

[0040] In order to further demonstrate the shear resistance of the masonry specimen 2, image recognition technology is used. A matte black and white speckle pattern is sprayed on the front face of the rectangular masonry specimen 2, and the thickness of the speckle pattern should not be too large. Then a camera is installed in front of the masonry specimen 2 using a lifting bracket. The optical axis of the camera is perpendicular to the front face of the masonry specimen 2 and passes through the center point of the front face, so that the camera can shoot the area at the center of the front face through the gap between the two side panels 412. The shear resistance of the masonry specimen 2 is characterized by the change in the coordinates of the points on the front face. The shear resistance is expressed as shown in Formula 3. During the camera shooting process, since the position of the camera and the distance between the masonry specimen 2 are determined, the imaging size of the camera is determined, and the imaging area is also determined. Therefore, a circle can be drawn with the center point of the front face of the masonry specimen 2 as the center and a set radius, and the circle is defined as the area M . Annotate the area in the pixel coordinate system of the photo taken by the camera M The coordinates of each pixel point in the image are obtained, and the grayscale value of each pixel point is calculated through the grayscale value calculation function.

[0041] (3); In the formula, Characterization in the region M The shear performance of masonry specimen 2 when the coordinates of each pixel point change. Indicates in the area M The coordinates of the pixel points are The gray value at Indicates in the area M Inside, the coordinates of the pixel Due to the displacement caused by extrusion The gray value after Represents the gray value calculation function. B Indicates the area during the integration process M The boundary value is used to define the gray value integral when calculating x and y The range of coordinate values, that is, the area M When the gray value of the inner pixel is integrated, x and y The upper limit of points is B , the lower limit is 0.

[0042] Formula (3) can reflect the displacement change of the pixel coordinates under the action of shear force. The larger the calculated result is, the better the shear resistance of masonry specimen 2 is.

[0043] Embodiments of the present invention are as follows: The calculation formula for the shear bearing capacity of masonry specimen 2 is shown in formula (4): ; Where: is the shear bearing capacity of masonry specimen 2 during the shear process, that is, the shear force. is the shear strength of masonry specimen 2. It is the contact area between the masonry specimen 2 when the clamping plate 41 clamps the masonry specimen 2. is the correction factor, is the influence coefficient of shear-compression combined force. It represents the normal pressure on one side of the masonry specimen 2 when the two clamping plates 41 clamp the masonry specimen 2. Represents the shear stress area of ​​masonry specimen 2.

[0044] The length of a masonry specimen 2 L =240mm, width B =115mm, height H =53mm, the block material in masonry specimen 2 is MU15, and the compressive strength of the block material is The bonding material in masonry specimen 2 is M5 mortar, and the compressive strength of the bonding material is It is 5.91MPa.

[0045] Compressive strength of masonry specimen 2: ; In the formula, Represents the compressive strength of masonry specimen 2. Represents the influence coefficient of block material on compressive strength. Represents the influence coefficient of bonding material on compressive strength. Indicates the correction factor of the compressive strength of the block material.

[0046] Shear strength of masonry specimen 2: ; In the formula, Represents the material shear coefficient of the bonding material.

[0047] All strong magnetic bars 433 are selected with diameter R The current in the electromagnetic coil 432 is I The number of turns of each electromagnetic coil 432 is 34A. N There are four sets of magnetic rods in total, and the magnetic attraction distance between the two relatively arranged strong magnetic rods is 433. d Both are 53mm, shear stress area .

[0048] The normal stress is calculated as follows: ; The normal pressure calculation can be provided as follows: ; Therefore, the shear bearing capacity of the masonry specimen is as follows: ; It can be seen that the peak shear load of the current masonry specimen 2 is N.

[0049] The detection device and detection method of the present invention have broad application prospects, not only limited to masonry ancient towers, but can be widely used in the performance evaluation and detection of various masonry structures. Through continuous optimization and innovation, it is expected to provide more accurate and efficient solutions for the fields of building safety, cultural relics protection, scientific research and teaching.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for detecting the shear resistance of the interface of a masonry ancient tower, characterized in that: The invention comprises a magnetic part (4) for sequentially applying different normal stresses on both sides of a masonry specimen (2), and a shearing part (1) for simultaneously applying a shearing force along the shearing direction of the masonry specimen (2); the magnetic part (4) comprises two U-shaped clamping plates (41) symmetrically arranged on both sides of the masonry specimen (2); the clamping plates (41) comprise a main plate (411) and side plates (412) mounted on both sides of the main plate (411); and the groove length direction of the U-shaped groove in the clamping plate (41) is parallel to the shearing direction of the masonry specimen (2); and the two The clamping plates (41) are matched to form a rectangular open-loop clamping cavity (42), and the masonry specimen (2) is placed in the clamping cavity (42); electromagnetic components (43) capable of generating magnetic force are installed on both side plates (412) of the clamping plate (41), and the electromagnetic components (43) on the side plates (412) arranged opposite to each other on the two clamping plates (41) are magnetically attracted to each other, so that the two main plates (411) are driven by the magnetic attraction force to apply a clamping force to clamp the masonry specimen (2) from both sides of the masonry specimen (2), and the clamping force is the normal stress.

2. A masonry ancient tower interface shear performance detection device according to claim 1, characterized in that: The electromagnetic assembly (43) comprises a plurality of spaced strong magnetic bars (433) which are sequentially and side by side mounted on the side plate (412) along the groove length direction of the U-shaped groove in the clamping plate (41), the length direction of each strong magnetic bar (433) being parallel to the groove opening direction of the U-shaped groove, and an electromagnetic coil (432) is coaxially sleeved on the outer side of each strong magnetic bar (433); two strong magnetic bars (433) facing each other in two groups of mutually magnetically attracted electromagnetic assemblies (43) are coaxially arranged, and four strong magnetic bars (433) located in the same plane perpendicular to the shear direction of the masonry specimen (2) constitute a magnetic bar group.

3. A masonry ancient tower interface shear performance detection device according to claim 2, characterized in that: The clamping force applied by the two clamping plates (41) in the magnetic part (4) to the masonry specimen (2) is calculated as follows: ； ； In the formula, represents the clamping force applied by the two clamping plates (41) in the magnetic part (4) to the masonry specimen (2); Indicates the total number of magnetic bar groups; Indicates i The magnetic attraction generated by the group of magnetic rods; represents the magnetic permeability of vacuum; Indicates i The diameter of each strong magnetic bar (433) in the group of magnetic bars; Indicates i The current in each electromagnetic coil (432) in the group of magnetic bars; Indicates i The number of coil turns in each electromagnetic coil (432) in the group of magnetic rods; Indicates i The magnetic attraction distance between two strong magnetic bars (433) arranged opposite to each other in the magnetic bar group.

4. A device for detecting shear resistance of masonry ancient tower interface according to claim 3, characterized in that: In the same magnetic bar group, the current in each electromagnetic coil (432) is the same, and the number of turns of each electromagnetic coil (432) is the same.

5. A device for detecting shear resistance of masonry ancient tower interface according to claim 4, characterized in that: The sizes of the strong magnetic bars (433) are the same, and the magnetic attraction distance between two strong magnetic bars (433) facing each other is the same.

6. A device for detecting shear resistance of masonry ancient tower interface according to claim 5, characterized in that: The shearing portion (1) comprises a workbench (12) with a horizontally arranged tabletop, a support frame (11) being fixedly mounted on the workbench (12), a telescopic rod (3) being mounted on the support frame (11) and capable of applying a shearing force to the masonry specimen (2) along a shearing direction of the masonry specimen (2), and the telescopic direction of the telescopic rod (3) is perpendicular to the tabletop of the workbench (12); a shearing space for placing the masonry specimen (2) is formed between the telescopic end of the telescopic rod (3) and the tabletop of the workbench (12).

7. A device for detecting shear resistance of masonry ancient tower interface according to claim 6, characterized in that: The telescopic rod (3) is a hydraulic cylinder, and a backing plate (31) for abutting against the masonry specimen (2) is fixedly connected to the telescopic end of the hydraulic cylinder; a sinking hole (123) is provided on the table surface of the workbench (12), and the masonry specimen (2) is mounted on the sinking hole (123), so that the masonry specimen (2) can bend downward when the backing plate (31) is pressed downward.

8. A method for detecting the shear resistance of an ancient masonry tower interface, the method using the device for detecting the shear resistance of an ancient masonry tower interface as claimed in claim 7, characterized in that: The following detection steps are included: S1. constructing a corresponding masonry structure according to a corresponding construction standard, and using the constructed masonry structure as a masonry test piece (2), or using a cutting machine to cut the masonry structure into masonry test pieces (2) of a preset size; S2, using the magnetic unit (4) to sequentially apply different normal stresses on both sides of the masonry specimen (2); S3. Under each normal stress, use the shearing portion (1) to apply shear force along the shear direction of the masonry specimen (2), and record the maximum shear force that causes shear failure of the masonry specimen (2). The maximum shear force represents the peak shear load of the masonry specimen (2) under the current normal stress.

9. A method for detecting shear resistance of masonry ancient tower interface according to claim 8, characterized in that: The specific content of step S2 is as follows: S21, placing the masonry test piece (2) on the workbench (12) and directly below the hydraulic cylinder; S22, placing two clamping plates (41) on the workbench (12) and symmetrically arranged on both sides of the masonry specimen (2), and the height of the rectangular clamping cavity (42) formed between the two clamping plates (41) is the same as the height of the masonry specimen (2); S23, making the current in the electromagnetic coil (432) in each group of magnetic rods in the magnetic part (4), the size of the strong magnetic rod (433), the magnetic attraction distance and the number of turns of the electromagnetic coil (432) all the same; S24. The currents in the electromagnetic coils (432) are changed simultaneously according to the same rule, so that the masonry specimen (2) is subjected to different clamping forces.

10. A method for detecting shear resistance of masonry ancient tower interface according to claim 9, characterized in that: The specific content of step S3 is as follows: S31, under the current clamping force, start the hydraulic cylinder and make the pad (31) press against the masonry specimen (2), then continue to increase the pressure of the hydraulic cylinder along the shear direction of the masonry specimen (2) until the masonry specimen (2) breaks in the shear direction, and the pressure of the hydraulic cylinder at this time is the maximum shear force when the masonry specimen (2) breaks in shear; S32. Under each clamping force, the masonry specimen (2) is sheared according to the content of step S31, and the corresponding maximum shear force is obtained, and the maximum shear force is proportional to the peak shear load of the masonry specimen (2).

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