A multifunctional triaxial loading test device

Abstract

The present invention discloses a multifunctional triaxial loading test device, which includes an outer frame and an inner frame. The inner frame is installed within the outer frame through a three-dimensional moving mechanism and can be driven by the three-dimensional moving mechanism to move relative to the outer frame in the X, Y, and Z directions. A triaxial loading device is provided on the inner frame; the triaxial loading device includes a square loading groove provided on the inner frame, confining pressure jacks provided on the four side walls of the square loading groove, reaction frames provided on both sides of the inner frame in the X direction, and axial pressure jacks provided on the reaction frames. Among them, the confining pressure jacks include Y-direction confining pressure jacks horizontally provided on the left and right inner side walls of the square loading groove and Z-direction loading flat jacks vertically provided on the upper and lower inner side walls. The present invention can not only conduct traditional triaxial loading tests, but also simulate triaxial loading tests under vibration environments or seismic environments, so as to study the influence of seismic or vibration environments on the safety of test blocks.

Description

Technical Field

[0001] The present invention belongs to the technical research field of geotechnical engineering equipment, and particularly relates to a multifunctional triaxial loading test device for triaxial loading tests of test blocks (such as concrete test blocks, rock test blocks, soil test blocks, etc.). Background Technique

[0002] The triaxial loading test confines the test block within the loading space and loads the test block to simulate defined stress conditions. Concrete structures are the most main structural forms in modern construction projects. Due to the complexity of the concrete forming process, any problem in each link will affect its quality and endanger the safety of the entire structure. Therefore, strengthening the quality monitoring and control of concrete has become an important research field in the current construction engineering technology field. Traditional research mainly focuses on uniaxial tests, but concrete structures are usually under multi-axial stress states more often. The multi-axial strength and deformation characteristics of concrete are very different from those of uniaxial ones. Therefore, it is necessary to use multi-axial loading tests to study the mechanical behavior of concrete; in addition, the research on the mechanical properties of rock test blocks, soil test blocks, etc. in civil engineering is also required by actual projects.

[0003] In the prior art for triaxial loading, generally it is in a static environment, and there is no triaxial loading test in a vibration environment or an earthquake environment. Therefore, the seismic resistance of the test block cannot be simulated.

[0004] The present invention proposes a multi-degree-of-freedom test bench for this problem, which can meet the requirements of applying loads to the test block in all directions, truly realizes three-way independent loading without interference, conforms to the stress characteristics in actual projects, and the test process is easy to control. Summary of the Invention

[0005] To solve the above problems, the present invention designs a multi-degree-of-freedom test bench that can be used for triaxial loading tests of test blocks, can meet the loading of test blocks with different sizes, can meet the application of loads to the test block in all directions, and can effectively detect the stress and deformation conditions of the test block in all directions at the same time, so as to further explore the stress characteristics such as the compressive strength of the test block. At the same time, it can also restore its initial state at any time and continue to simulate new stress conditions to explore other stress action laws.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A multifunctional triaxial loading test device, comprising

[0008] An outer frame, serving as the load-bearing frame of the test device;

[0009] The inner frame is installed within the outer frame through a three-dimensional movement mechanism and can be driven by the three-dimensional movement mechanism to move relative to the outer frame in the X, Y, and Z directions. A three-axis loading device is provided on the inner frame.

[0010] The three-axis loading device includes a square loading groove provided on the inner frame, confining pressure jacks provided on the four side walls of the square loading groove, reaction frames provided on both sides of the inner frame in the X direction, and axial pressure jacks provided on the reaction frames. Among them, the confining pressure jacks include Y-direction confining pressure jacks horizontally arranged on the inner side walls of the left and right sides of the square loading groove and Z-direction loading flat jacks vertically arranged on the inner side walls of the upper and lower sides.

[0011] Further, the confining pressure jacks are all installed on the inner wall of the square loading groove through axial sliding pairs.

[0012] Further, loading heads installed through spherical hinges are provided at the front ends of the X-direction horizontal jacks, Y-direction horizontal jacks, and Z-direction vertical flat jacks.

[0013] Further, 1 - 10 confining pressure jacks are provided on each side of the square loading groove.

[0014] Further, a plurality of confining pressure jacks are provided in the X-direction sliding pairs on the inner wall of the square loading groove.

[0015] Further, the three-dimensional movement mechanism includes an intermediate frame, an X-direction jack, a Y-direction jack, and a Z-direction jack; the inner frame is installed within the intermediate frame, and both left and right sides of the inner frame are connected to the intermediate frame through a number of horizontally arranged Y-direction jacks. The position of the inner frame relative to the intermediate frame in the Y direction can be adjusted by the expansion and contraction of the Y-direction jacks on both left and right sides;

[0016] The intermediate frame is installed within the outer frame, and both upper and lower sides of the intermediate frame are connected to the outer frame through a number of vertically arranged Z-direction jacks; the position of the intermediate frame relative to the outer frame in the Z direction can be adjusted by the expansion and contraction of the Z-direction jacks on both upper and lower sides;

[0017] The Z-direction jacks are connected to the intermediate frame or the outer frame through X-direction sliding pairs;

[0018] A number of horizontally installed X-direction jacks that can freely expand and contract in the X direction are further provided between the intermediate frame and the outer frame. The position of the intermediate frame relative to the outer frame in the X direction can be adjusted by the expansion and contraction of the X-direction jacks; the X direction is the same as the axial direction of the square loading groove, and the X-direction jacks are connected to the intermediate frame or the outer frame through Z-direction sliding pairs.

[0019] Further, a number of second rolling bodies that can reduce the frictional force of Y-direction movement are provided between the upper and lower sides of the inner frame and the intermediate frame.

[0020] Further, a number of third rolling bodies capable of reducing the frictional force of Z-direction movement are provided between the left and right sides of the intermediate frame and the inner wall of the outer frame.

[0021] Further, the outer frame is composed of two rectangular frames fixedly connected in parallel at intervals. The left and right sides of the intermediate frame are provided with bearing parts extending outward. The X-direction jack is arranged between the bearing part of the intermediate frame and the corresponding rectangular frame, and the X-direction jack is connected to the rectangular frame or the intermediate frame through a Z-direction sliding pair.

[0022] Further, the inner frame is a cubic frame made of reinforced concrete structure or steel structure; the intermediate frame is a rectangular frame made of steel structure; the rectangular frames of the outer frame are composed of four cross-shaped reinforced concrete columns.

[0023] Further, the reaction frame is a T-shaped reaction beam.

[0024] The basic principle of the device of the present invention is as follows: First, adjust the position of the test block model to the center of the theoretical test space by controlling the XYZ-axis acting direction jacks of the outer frame, and then anchor the T-shaped reaction beam frame to the two sides of the test bench. Apply the load in the Y direction by increasing the anchored reaction beam. The same specification jacks are fixed on the inner side of the reaction beam. So far, the loading work in the three-axis direction of the test block is completed. Use the three-axis direction jacks of the inner frame loading system to apply the corresponding direction load to the model to simulate its working condition stress and simultaneously conduct dynamic deformation monitoring. After the test, continue to control the XYZ-axis acting jacks of the outer frame to adjust the test block to return to the center of the test space, and continue to conduct the stress study of other working conditions. The loading heads are installed at the loading ends of the jacks, which is convenient for being closely connected with the surface of the test block and also makes the force evenly distributed. The realization of the deformation monitoring is because the three-axis direction jack devices inside the inner frame are all closely connected with the surface of the test block. When the test block deforms, the jacks will conduct dynamic adjustment, actively extend / compress, so as to observe and record the deformation data through wired or wireless means. The three-way independent loading can independently and automatically control the application of axial and lateral loads respectively, which not only avoids the mutual influence between the two, but also can coordinate with each other, can simulate the true stress state of soil such as the deflection of the principal stress axis and the rotation stress path, and can conduct the true triaxial test of various stress paths.

[0025] Advantages of the present invention

[0026] A multifunctional triaxial loading test device designed by the present invention has significant advantages and social and economic benefits. The following lists four main beneficial effects thereof:

[0027] (1) The test bench device is relatively easy to assemble and splicing, and has strong operability.

[0028] (2) It meets the load application on the test block in three axial directions, truly realizing three-way independent loading without interference.

[0029] (3) The jacks inside have a built-in deformation monitoring function in the three axial directions. The stress state is real, the strain test is accurate, and the data can be controlled, observed, and saved through wired or wireless means, greatly reducing the manual work intensity and work cost.

[0030] (4) Through the three-dimensional mobile loading system device, it is more convenient to adjust the position of the test block model in the XYZ directions. And by setting slide rails along the edges of the outer frame and inner frame, the position of the test block can be finely adjusted, and the experimental process is easy to control. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a three-dimensional schematic diagram of the three-axis loading test device capable of multi-dimensional movement of the present invention;

[0032] Figure 2 It is a front view of the test block three-axis loading test device of the present invention;

[0033] Figure 3 It is a left view of the test block three-axis loading test device of the present invention;

[0034] Figure 4 It is a top view of the test block three-axis loading test device of the present invention;

[0035] Figure 5 It is a schematic diagram of the inner frame and three-dimensional movement mechanism of the test block three-axis loading test device of the present invention;

[0036] Figure 6 It is a schematic diagram of the outer frame and three-dimensional movement mechanism of the test block three-axis loading test device of the present invention.

[0037] In the figure: 1 - test block, 110 - model box, 111 - fixed plate, 112 - side plate, 120 - landslide soil, 130 - designed landslide, 2 - confining pressure jack, 21 - Y-direction confining pressure jack, 22 - Z-direction loading flat jack, 3 - axial pressure jack, 4 - inner frame, 41 - square loading groove, 42 - reaction frame, 5 - intermediate frame, 51 - load-bearing part, 6 - outer frame, 61 - rectangular frame, 7 - loading head, 8 - axial sliding pair, 9 - three-axis loading space, 10 - X-direction jack, 11 - Y-direction jack, 12 - Z-direction jack, 13 - second rolling body, 14 - third rolling body, 15 - X-direction sliding pair, 16 - Z-direction sliding pair. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following further describes in detail the embodiments of the present invention with reference to the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0039] To better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the technical solution of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0041] As Figures 1 to 6 shown, the present invention provides a three-axis loading test device capable of multi-dimensional movement, including

[0042] an outer frame 6, serving as the load-bearing frame of the test device;

[0043] an inner frame 4, installed in the outer frame 6 through a three-dimensional moving mechanism and capable of being driven by the three-dimensional moving mechanism to move relative to the outer frame 6 in the X, Y, and Z directions. A three-axis loading device is provided on the inner frame 4;

[0044] The three-axis loading device includes a square loading groove 41 provided on the inner frame 4, confining pressure jacks 2 provided on the four side walls in the square loading groove 41, reaction frames 42 provided on both sides of the inner frame 4, and axial pressure jacks 3 provided on the reaction frames 42. Among them, the confining pressure jack 2 includes a Y-direction confining pressure jack 21 horizontally provided on the inner side walls of the left and right sides of the square loading groove 41 and a Z-direction loading flat jack 22 vertically provided on the inner side walls of the upper and lower sides.

[0045] The space enclosed by the confining pressure jacks 2 on the upper, lower, left, and right four sides in the square loading groove 31 and the axial pressure jacks 3 on the reaction frames 42 is a three-axis loading space 9 for placing the test block 1.

[0046] The present invention can adjust the position of the test block 1 through the three-dimensional moving mechanism, so that the axis of the test block 1 is exactly on the designed axis line, that is, located at the theoretical center, or simulate the influence of earthquake or vibration environment on the three-axis loading test through the three-dimensional moving mechanism.

[0047] As a preferred embodiment, as Figure 2 and Figure 5As shown in the figure, the confining pressure jack 2 is installed on the inner wall of the square loading groove 31 through an axial sliding pair 8 to avoid mutual interference between confining pressure loading and axial pressure loading. In this embodiment, the axial sliding pair 8 includes an axial dovetail chute provided on the side wall of the square loading groove 31 and an axial dovetail slider provided on the confining pressure jack 2 and mating with the axial dovetail chute.

[0048] As a more preferred embodiment, as Figure 5 shown, multiple confining pressure jacks 2 can be arranged in the direction of each axial sliding pair 8, that is, multiple axial dovetail sliders can be arranged in one axial dovetail chute, and one confining pressure jack 2 is installed on each axial dovetail slider, so as to simulate the segmented confining pressure on the test block 1.

[0049] The present invention realizes triaxial loading by arranging a number of evenly distributed confining pressure jacks in the square loading groove 31 of the triaxial loading test device to simulate the confining pressure, and arranging axial pressure jacks on the reaction frame 42 to simulate the axial pressure.

[0050] As a preferred embodiment, a loading head 7 installed through a spherical hinge is provided at the front end of the confining pressure jack 2 and the axial pressure jack 3, and is adapted through the spherical hinge so that when the test block 1 undergoes a micro-deformation, the confining pressure jack 2 can still apply a uniform acting force normally.

[0051] As a preferred embodiment, a telescopic amount sensor or a distance sensor is further provided on the jack to independently detect the loading amount of each jack.

[0052] As a preferred embodiment, a pressure sensor is provided at the front end of each jack to detect the accurate loading force of each jack.

[0053] As a preferred embodiment, the number of the confining pressure jacks 2 is related to the actual size of the test block 1 and the type of test to be carried out. Generally, 1-10 confining pressure jacks 2 are provided on each side of the square loading groove 31.

[0054] As a preferred embodiment, as Figures 1 to 6 shown, the three-dimensional moving mechanism includes an intermediate frame 5, an X-direction jack 10, a Y-direction jack 11, and a Z-direction jack 12; the outer side of the inner frame 4 is a square frame and is installed in the intermediate frame 5. The left and right sides of the inner frame 4 are respectively connected to the intermediate frame 5 through a number of horizontally arranged Y-direction jacks 11 ( Figure 2 two on each side in the figure), and the position of the inner frame 4 relative to the intermediate frame 5 in the Y direction can be adjusted by the telescoping of the Y-direction jacks 11 on the left and right sides;

[0055] The middle frame 5 is installed inside the outer frame 6. The upper and lower sides of the middle frame 5 are respectively connected to the outer frame 6 through a number of Z-direction jacks 12 in the vertical direction (5 jacks on each side); the position of the middle frame 5 relative to the outer frame 6 in the Z direction can be adjusted by the expansion and contraction of the Z-direction jacks 12 on the upper and lower sides;

[0056] The Z-direction jack 12 is connected to the middle frame 5 or the outer frame 6 through an X-direction sliding pair 15;

[0057] A number of X-direction jacks 10 that are horizontally installed and can freely expand and contract in the X direction are also provided between the middle frame 5 and the outer frame 6. The position of the middle frame 5 relative to the outer frame 6 in the X direction can be adjusted by the expansion and contraction of the X-direction jacks 10; the X-direction jack 10 is connected to the middle frame 5 or the outer frame 6 through a Z-direction sliding pair 16.

[0058] As a preferred embodiment, telescopic sensors or distance sensors are provided on the X-direction jacks 10, Y-direction jacks 11, and Z-direction jacks 12 for independently detecting the loading amount of each jack, and pressure sensors are provided at the front ends for detecting the precise loading force of each jack.

[0059] As a preferred embodiment, a number of second rolling bodies 13 that can reduce the frictional force of Y-direction movement are provided between the upper and lower sides of the inner frame 4 and the middle frame 5; the middle frame 5 and the outer frame 6 are both square frames, and a number of third rolling bodies 14 that can reduce the frictional force of Z-direction movement are provided between the left and right sides of the middle frame 5 and the inner wall of the outer frame 6. The second rolling bodies 13 and the third rolling bodies 14 are both ball bearings or rollers.

[0060] As a preferred embodiment, as Figure 1 and Figure 6 shown, the outer frame 6 is composed of two spaced and parallel rectangular frames 61 fixedly connected or two rectangular frames 61 are fixed on the test bench (the connection part between the rectangular frames 61 is not shown in the figure). The left and right sides of the middle frame 5 are provided with bearing parts 51 extending outward. The X-direction jack 10 is arranged between the bearing part 51 of the middle frame 5 and the corresponding rectangular frame 61, and the X-direction jack 10 is connected to the rectangular frame 61 or the middle frame 5 through a Z-direction sliding pair 16.

[0061] As a preferred embodiment, as Figure 1 shown, the inner frame 4 is a cubic frame made of reinforced concrete structure or steel structure; the middle frame 5 is a rectangular frame made of steel structure; the rectangular frame of the outer frame 6 is composed of four cross-shaped reinforced concrete columns.

[0062] As a preferred embodiment, the triaxial loading test device further includes a controller for receiving the detection data of each sensor and controlling the actions of each jack.

[0063] For the usage method of the triaxial loading test device of the present invention, a triaxial loading test of the test block 1 under a simulated vibration environment is as Figure 1 shown, and the specific operation steps are as follows:

[0064] S1: Place the test block 1: Control the confining pressure jack 2 inside the inner frame 4 to retract so as to reserve enough space to place the test block 1. After placing it, extend the inner confining pressure jack 2 to just contact the test block 1 to play a temporary fixing role.

[0065] S2: Installation of the axial pressure jack 3. Anchor and install a reaction frame 42 on each side of the inner frame 4, install opposite axial pressure jacks 3 inside the two reaction frames 42, and extend the axial pressure jack 3 so that its front end is close to but not in contact with the test block.

[0066] S3: Adjust the position of the test block 1: Through the three-dimensional movable mechanism, continuously adjust the elongation of each side jack so that the test block 1 moves in the X, Y, and Z directions until the position of the test block 1 is at the theoretical center.

[0067] S2: Installation and startup of monitoring equipment: Layout and start the strain sensors in the research field in the test block 1, and turn on the confining pressure jack 2 and the strain monitoring system. In order to hold the test block 1, and at the same time the test block 1 itself has gravity. At this time, there is an initial force for several confining pressure jacks 2, which is assumed to be zero during the test, and the loading end force is the force increment.

[0068] S3: Apply the corresponding working condition force: Start the triaxial loading device. First, load the confining pressure jack 2 to fix the position of the test block 1, and then load the axial pressure jack 3 to conduct a triaxial loading test. The specific loading force magnitude and time sequence of the test are determined according to the specific requirements of the triaxial loading test. Judge the loading degree through the strain sensor. At this time, the test block 1 will generate corresponding stress deformation. At this time, each confining pressure jack 2 is dynamically monitoring and recording data. During the loading process, start the three-dimensional movable mechanism to simulate vibrations or seismic waves in each direction until the triaxial loading test is completed.

[0069] S4: Adjust and return the device to its original position: After the test, the monitoring data is automatically saved, and the deformation characteristics of the test block 1 under this working condition can be obtained through later analysis.

[0070] It should be noted that according to different research objects, the above strain sensors can be replaced with stress sensors, or stress sensors can be added for relevant research.

[0071] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should all be covered within the scope of the claims of the present invention.

Claims

1. A multifunctional triaxial loading test device, characterized in that including an outer frame, serving as a load-bearing frame of the test device; an inner frame, installed inside the outer frame through a three-dimensional moving mechanism and capable of being driven by the three-dimensional moving mechanism to move relative to the outer frame in the X, Y, and Z directions, and a triaxial loading device is provided on the inner frame; the triaxial loading device includes a square loading groove provided on the inner frame, confining pressure jacks provided on the four side walls of the square loading groove, reaction frames provided on the two sides of the inner frame in the X direction, and axial pressure jacks provided on the reaction frames. Among them, the confining pressure jacks include Y-direction confining pressure jacks horizontally provided on the inner side walls of the left and right sides of the square loading groove and Z-direction loading jacks vertically provided on the inner side walls of the upper and lower sides; the three-dimensional moving mechanism includes an intermediate frame, an X-direction jack, a Y-direction jack, and a Z-direction jack; the inner frame is installed inside the intermediate frame, and the left and right sides of the inner frame are respectively connected to the intermediate frame through a plurality of horizontally arranged Y-direction jacks. By the expansion and contraction of the Y-direction jacks on the left and right sides, the position of the inner frame relative to the intermediate frame in the Y direction can be adjusted; the intermediate frame is installed inside the outer frame, and the upper and lower sides of the intermediate frame are respectively connected to the outer frame through a plurality of vertically arranged Z-direction jacks; by the expansion and contraction of the Z-direction jacks on the upper and lower sides, the position of the intermediate frame relative to the outer frame in the Z direction can be adjusted; the Z-direction jack is connected to the intermediate frame or the outer frame through an X-direction sliding pair; a plurality of X-direction jacks are horizontally installed between the intermediate frame and the outer frame and can freely expand and contract in the X direction. By the expansion and contraction of the X-direction jacks, the position of the intermediate frame relative to the outer frame in the X direction can be adjusted; the X direction is the same as the axial direction of the square loading groove, and the X-direction jack is connected to the intermediate frame or the outer frame through a Z-direction sliding pair.

2. The triaxial loading test device according to claim 1, wherein: All the confining pressure jacks are installed on the inner wall of the square loading groove through axial sliding pairs.

3. The triaxial loading test device according to claim 2, wherein: Loading heads are provided at the front ends of the X-direction horizontal jack, the Y-direction horizontal jack, and the Z-direction vertical jack, which are installed through spherical hinges.

4. The triaxial loading test device according to claim 2, characterized in that: 1-10 confining pressure jacks are provided on each side of the square loading groove.

5. The triaxial loading test device according to claim 2, characterized in that: A plurality of confining pressure jacks are provided in the X-direction sliding pair on the inner wall of the square loading groove.

6. The triaxial loading test device according to claim 1, wherein: A plurality of second rolling bodies capable of reducing the frictional force of Y-direction movement are provided between the upper and lower sides of the inner frame and the intermediate frame.

7. The triaxial loading test device according to claim 1, characterized in that: A plurality of third rolling bodies capable of reducing the frictional force of Z-direction movement are provided between the left and right sides of the intermediate frame and the inner wall of the outer frame.

8. The triaxial loading test device according to claim 1, characterized in that: The outer frame is composed of two spaced and parallel rectangular frames fixedly connected. Bearing parts extending outward are provided on the left and right sides of the intermediate frame. The X-direction jacks are arranged between the bearing parts of the intermediate frame and the corresponding rectangular frames, and the X-direction jacks are connected to the rectangular frames or the intermediate frame through Z-direction sliding pairs.

9. The triaxial loading test device according to claim 1, characterized in that: The inner frame is a cubic frame made of reinforced concrete structure or steel structure; the intermediate frame is a rectangular frame made of steel structure; the rectangular frames of the outer frame are composed of four cross-shaped reinforced concrete columns.

Images