Rock mass dilatancy angle in-situ testing device under action of real stress

Abstract

The utility model provides a rock mass dilatancy angle in-situ testing device under the action of real stress, and belongs to the technical field of rock mechanics testing. The device comprises a hydraulic servo module, a lateral pressure loading module, an axial pressure loading module, a deformation measuring module and a control processing module. The hydraulic servo module, the lateral pressure loading module, the axial pressure loading module, the deformation measuring module and the control processing module are mounted at the engineering position of the rock mass test piece, so that the in-situ testing device of the rock mass test piece is obtained, the problem of in-situ testing of the fractured rock mass test piece on the engineering scale is solved, and meanwhile, the in-situ testing efficiency is improved. Through independent pressurization of the axial pressure loading module and the lateral pressure loading module, a true triaxial stress environment is provided for the rock mass test piece, and the problem that in-situ testing is difficult to restore the stress condition of the original rock is solved.

Description

Technical Field

[0001] This utility model relates to the field of rock mechanics testing technology, and in particular to an in-situ testing device for the shear dilatation angle of rock mass under real stress. Background Technology

[0002] As underground engineering projects progress to deeper levels, large-volume collapses caused by the volume expansion resulting from large deformation of rock masses under high stress have become a frequent new type of engineering disaster in recent years. Deep rock masses, under high stress, exhibit significant irreversible volume expansion before failure; this phenomenon is called rock mass expansion. Numerous triaxial tests on indoor rock specimens show that when the external force exceeds the peak strength, the volume of the rock specimen does not decrease but increases significantly, and the rate of increase increases with stress, ultimately leading to expansion failure. Engineering rock masses are in a complex triaxial stress state. After tunnel excavation, the surrounding rock in the near field undergoes principal stress axis rotation and stress path changes. If the original principal stress direction was parallel to the tunnel axis before excavation, the radial stress will be rapidly unloaded after excavation, while the tangential principal stress will increase rapidly. The shear dilatation angle will be affected by the stress path, stress history, and stress state. Therefore, studying the expansion characteristics of rock masses under load is a prerequisite for revealing the deformation and failure mechanism of the loosened and fractured zone of the surrounding rock and the interaction mechanism between the support structure and the surrounding rock. It is of great significance for revealing the deformation and failure mechanism of rock masses under high stress.

[0003] However, rock masses are geological units composed of discontinuous surfaces such as primary or secondary joints, fissures, or structural planes. Generally, a rock mass is considered to be equal to intact rock plus joints. Current technologies for obtaining the dilatation angle of rocks use intact rocks in the laboratory, and there is a lack of engineering-scale in-situ dilatation angle testing equipment for fractured rock masses. At the same time, the measurement process has problems such as difficulty in reproducing the true stress environment and stress path. Utility Model Content

[0004] To address the problems in the prior art, this invention provides an in-situ testing device for the shear dilatation angle of rock mass under real stress. This invention obtains an in-situ testing device for the rock mass specimen by installing a hydraulic servo module, a lateral pressure loading module, an axial pressure loading module, a deformation measurement module, and a control processing module at the engineering location of the rock mass specimen. This solves the problem of in-situ testing of fractured rock mass specimens at the engineering scale. Simultaneously, by independently pressurizing the axial and lateral pressure loading modules, a true triaxial stress environment is provided for the rock mass specimen, solving the problem that in-situ testing cannot accurately reproduce the original rock stress conditions. To achieve the above objectives, the technical solution is as follows:

[0005] An in-situ testing device for the shear dilatation angle of rock mass under real stress, the device comprising: a hydraulic servo module, a lateral pressure loading module, an axial pressure loading module, a deformation measurement module, and a control processing module;

[0006] The hydraulic servo module is connected to the lateral pressure loading module and the axial pressure loading module, and provides hydraulic power to the lateral pressure loading module and the axial pressure loading module.

[0007] The control processing module is connected to the hydraulic servo module via a data cable and controls the pressure of the hydraulic servo module.

[0008] The control processing module is connected to the deformation measurement module via a data cable to collect deformation data of the rock mass specimen.

[0009] Optionally, the hydraulic servo module includes: an oil pump unit, a PLC pressure controller, a pressure regulating device, a pressure sensor, pipelines, and an RS485 hub;

[0010] The oil pump unit consists of three independent motors and oil pumps, providing stable loading pressure in the X, Y and Z directions respectively;

[0011] The PLC pressure controller receives pressure commands from the control processing module via the RS485 hub and sends pressure adjustment commands to the pressure regulating device.

[0012] The pressure regulating device is installed at the output end of the oil pump unit and adjusts the output pressure of the oil pump unit according to the received pressure regulating command;

[0013] The pressure sensor is installed at the front end of the pipeline to monitor the pressure changes in the pipeline in real time and send the data to the pressure control device.

[0014] The pipeline connects the hydraulic servo module to the lateral pressure loading module and the axial pressure loading module.

[0015] Optionally, the lateral pressure loading module includes: an X-direction reaction frame, a Y-direction reaction frame, a hydraulic pillow, an outer rigid pad, an inner rigid pad, and a friction reduction device;

[0016] Both the X-direction reaction frame and the Y-direction reaction frame are rectangular steel frames. The short sides of the X-direction reaction frame and the short sides of the Y-direction reaction frame are in contact with the hydraulic cushion, while the long sides of the X-direction reaction frame and the long sides of the Y-direction reaction frame are not in contact with the hydraulic cushion. The X-direction reaction frames and the Y-direction reaction frames are stacked on top of each other, and the short sides of the X-direction reaction frames and the long sides of the Y-direction reaction frames are arranged at a 90° angle to each other.

[0017] Alternatively, the friction-reducing device is formed by overlapping two plastic plates with lubricant applied between them.

[0018] Optionally, the hydraulic pillow is made of two flexible steel plates welded around the perimeter, with a through hole in the middle. A round tube is inserted into the through hole, and then the round tube is welded firmly to the flexible steel plate. The round tube has axial expansion and contraction properties, and an oil inlet is provided at the bottom of the hydraulic pillow.

[0019] Optionally, the axial pressure loading module includes: a jack, a force transmission column, a leveling ellipsoid, a base plate, and a pad plate;

[0020] The lower end of the jack is connected to the rock mass specimen through the pad, and the upper end is equipped with the force transmission column;

[0021] The base plate is placed on the upper part of the leveling ellipsoid, and the base plate is in contact with the surrounding rock.

[0022] Optionally, the leveling ellipsoid includes a convex ellipsoid and a concave ellipsoid;

[0023] The convex ellipsoid and the concave ellipsoid are connected and can rotate in any direction.

[0024] Optionally, the deformation measurement module includes: a vertical displacement sensor, a horizontal displacement sensor, a bracket, and an L-shaped fixing base;

[0025] The vertical displacement sensor and the horizontal displacement sensor are connected to the bracket via the L-shaped mounting base; the bottom end of the L-shaped mounting base is connected to the bracket via screws.

[0026] One horizontal displacement sensor is arranged at the center of each of the four sides of the rock mass specimen, and one vertical displacement sensor is arranged symmetrically on each side of the upper end of the rock mass specimen.

[0027] The vertical displacement sensor and the horizontal displacement sensor are connected to the RS485 hub, and the data from the vertical displacement sensor and the horizontal displacement sensor are transmitted to the control processing module through the RS485 hub.

[0028] Optionally, the bracket has an elongated hole through which the height of the L-shaped fixing seat can be adjusted.

[0029] Optionally, the L-shaped mounting base has an elongated mounting hole through which the horizontal position of the horizontal displacement sensor is adjusted.

[0030] Compared with the prior art, the technical solution of this utility model has at least the following beneficial effects:

[0031] The above scheme, by installing a hydraulic servo module, a lateral pressure loading module, an axial pressure loading module, a deformation measurement module, and a control processing module at the engineering location of the rock mass specimen, obtains an in-situ testing device for the rock mass specimen. This solves the problem of in-situ testing of fractured rock mass specimens at the engineering scale. Through the independent pressurization of the axial pressure loading module and the lateral pressure loading module, a true triaxial stress environment is provided for the rock mass specimen, solving the problem that in-situ testing is difficult to restore the original rock stress conditions. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the in-situ testing device in an embodiment of the rock mass dilatation angle in-situ testing device under real stress according to this utility model;

[0034] Figure 2 This is a schematic diagram of the hydraulic servo module in an embodiment of the in-situ testing device for rock mass dilatation angle under real stress according to this utility model;

[0035] Figure 3 This is a cross-sectional schematic diagram of the lateral pressure loading module in an embodiment of the in-situ testing device for rock mass dilatation angle under real stress according to this utility model.

[0036] Figure 4 This is a front view schematic diagram of the hydraulic pillow in an embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress according to this utility model;

[0037] Figure 5 This is a left-side view of the hydraulic pillow in an embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress according to this utility model;

[0038] Figure 6 This is a schematic diagram of the axial pressure loading module in an embodiment of the in-situ testing device for rock mass dilatation angle under real stress according to this utility model;

[0039] Figure 7 This is a schematic diagram of the leveling ellipsoid in an embodiment of the in-situ testing device for the shear dilatation angle of rock mass under real stress according to this utility model;

[0040] Figure 8 This is a front view schematic diagram of the deformation measurement module in an embodiment of the in-situ testing device for rock mass dilatation angle under real stress according to this utility model;

[0041] Figure 9 This is a left-side view of the deformation measurement module in an embodiment of the in-situ testing device for rock mass dilatation angle under real stress according to this utility model.

[0042] Explanation of the numbers in the diagram: 1. Hydraulic servo module; 2. Lateral pressure loading module; 3. Axial pressure loading module; 4. Deformation measurement module; 5. Control processing module; 6. Rock mass specimen; 7. Surrounding rock; 8. Oil pump unit; 101. PLC pressure controller 102, pressure regulating device 103, pressure sensor 104, pipeline 105, RS485 hub 106, X-direction reaction frame 201, Y-direction reaction frame 202, hydraulic pillow 203, outer rigid pad 204, inner rigid pad 205, friction reducing device 206, flexible steel plate 2031, through hole 2032, oil inlet hole 2033, jack 301, force transmission column 302, leveling ellipsoid 303, base plate 304, pad 305, convex ellipsoid 3031, concave ellipsoid 3032, vertical displacement sensor 401, horizontal displacement sensor 402, bracket 403, L-shaped fixing seat 404, bracket elongated hole 4031, fixing seat elongated hole 4041. Detailed Implementation

[0043] The technical solution of this utility model will now be described with reference to the accompanying drawings.

[0044] In the embodiments of this utility model, words such as "exemplarily" and "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in this utility model should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in the embodiments of this utility model, the meaning expressed by "and / or" can be both, or it can be either one or the other.

[0045] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0046] like Figure 1 The diagram shown is a schematic of the in-situ testing device in an embodiment of the rock mass dilatation angle testing device under real stress according to this utility model. This utility model provides an in-situ testing device for rock mass dilatation angle under real stress. The device includes: a hydraulic servo module 1, a lateral pressure loading module 2, an axial pressure loading module 3, a deformation measurement module 4, and a control processing module 5.

[0047] Specifically, a rock mass specimen 6 is excavated from the surrounding rock 7 of the underground cavern. The hydraulic servo module 1 is arranged near the rock mass specimen 6, the lateral pressure loading module 2 is installed on the side of the rock mass specimen 6, and the axial pressure loading module 3 is installed on the top of the rock mass specimen 6.

[0048] The hydraulic servo module 1 is connected to the lateral pressure loading module 2 and the axial pressure loading module 3, providing hydraulic power to the lateral pressure loading module 2 and the axial pressure loading module 3.

[0049] The control processing module 5 is connected to the hydraulic servo module 1 via a data cable and controls the pressure of the hydraulic servo module 1.

[0050] The control processing module 5 is connected to the deformation measurement module 4 via a data cable to collect deformation data of the rock mass specimen 6.

[0051] Specifically, such as Figure 2 The schematic diagram shown is of the hydraulic servo module in the embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress of this utility model. The hydraulic servo module 1 includes: oil pump unit 101, PLC pressure controller 102, pressure regulating device 103, pressure sensor 104, pipeline 105, and RS485 hub 106.

[0052] The oil pump unit 101 consists of 3 independent motors and oil pumps, providing stable loading pressure in the X, Y and Z directions respectively.

[0053] The PLC pressure controller 102 receives the pressure command from the control processing module 5 through the RS485 hub 106 and sends a pressure adjustment command to the pressure regulating device 103.

[0054] The pressure regulating device 103 is installed at the output end of the oil pump unit 101 and adjusts the output pressure of the oil pump unit 101 according to the received pressure regulating command.

[0055] The pressure sensor 104 is installed at the front end of the pipeline 105 to monitor the pressure changes of the pipeline 105 in real time and send the data to the pressure regulating device 103.

[0056] The pipeline 105 connects the hydraulic servo module 1 to the lateral pressure loading module 2 and the axial pressure loading module 3.

[0057] Specifically, such as Figure 3 The diagram shows a cross-sectional view of the lateral pressure loading module in an embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress of this utility model. The lateral pressure loading module 2 includes: an X-direction reaction frame 201, a Y-direction reaction frame 202, a hydraulic pillow 203, an outer rigid pad 204, an inner rigid pad 205, and a friction reduction device 20.

[0058] The lateral pressure loading module 2 is arranged in the following order from the inside to the outside: rock mass specimen 6, friction reduction device 206, inner rigid pad 205, hydraulic pillow 203, outer rigid pad 204, X-direction reaction frame 201 and Y-direction reaction frame 202.

[0059] The rock mass specimen 6 has four lateral pressure loading modules 2 arranged on its four sides. The outer size of each hydraulic pad 203 is slightly smaller than the inner rigid pad 205. There is no contact between the four hydraulic pads 203. The pipelines 105 of the two hydraulic pads 203 arranged opposite each other are connected in series.

[0060] Both the X-direction reaction frame 201 and the Y-direction reaction frame 202 are rectangular steel frames. The short sides of the X-direction reaction frame 201 and the Y-direction reaction frame 202 are in contact with the hydraulic cushion 203, while the long sides of the X-direction reaction frame 201 and the Y-direction reaction frame 202 are not in contact with the hydraulic cushion 203. The X-direction reaction frame 201 and the Y-direction reaction frame 202 are stacked on top of each other, and the short sides of the X-direction reaction frame 201 and the long sides of the Y-direction reaction frame 202 are arranged at a 90° angle to each other.

[0061] The friction reduction device 206 is formed by overlapping two plastic plates with lubricating oil applied between them;

[0062] like Figure 4 The diagram shown is a front view of the hydraulic pillow in an embodiment of the in-situ testing device for the rock mass shear dilatation angle under real stress according to this utility model, and the diagram shown is as follows: Figure 5 The diagram shown is a left-side view of the hydraulic pillow in the embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress of this utility model. The hydraulic pillow 203 is made of two flexible steel plates 2031 welded around its perimeter, with a through hole 2032 in the middle. A round tube is inserted into the through hole 2032, and then the round tube is welded firmly to the flexible steel plate 2031. The round tube has axial expansion and contraction properties. An oil inlet hole 2033 is provided at the bottom of the hydraulic pillow 203.

[0063] Specifically, such as Figure 6 The schematic diagram shown is of the axial pressure loading module in the embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress of this utility model. The axial pressure loading module 3 includes: jack 301, force transmission column 302, leveling ellipsoid 303, base plate 304, and pad plate 305.

[0064] The lower end of the jack 301 is connected to the rock mass test piece via the pad 305, and the upper end is equipped with the force transmission column 302.

[0065] The base plate 304 is installed on the upper part of the leveling ellipsoid 303, and the base plate 304 is in contact with the surrounding rock 7.

[0066] like Figure 7The schematic diagram shown is of the leveling ellipsoid in the embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress of this utility model. The leveling ellipsoid 303 includes a convex ellipsoid 3031 and a concave ellipsoid 3032.

[0067] The convex ellipsoid 3031 and the concave ellipsoid 3032 are docked and can rotate in any direction.

[0068] The pad 305 is composed of three steel plates, with the bottom plate having an outer dimension 2 mm smaller than the outer dimension of the upper surface of the rock specimen 6.

[0069] Specifically, such as Figure 8 The diagram shown is a front view of the deformation measurement module in an embodiment of the in-situ testing device for rock mass dilatation angle under real stress according to this utility model. Figure 9 The diagram shown is a left view of the deformation measurement module in the embodiment of the in-situ testing device for rock mass shear dilatation angle under real stress of this utility model. The deformation measurement module 4 includes: a vertical displacement sensor 401, a horizontal displacement sensor 402, a bracket 403, and an L-shaped fixing seat 404.

[0070] The vertical displacement sensor 401 and the horizontal displacement sensor 402 are connected to the bracket 403 via the L-shaped fixing base 404; the bottom end of the L-shaped fixing base 404 is connected to the bracket 403 via screws.

[0071] The horizontal displacement sensor 402 is arranged at the center of each of the four sides of the rock mass specimen 6, and the vertical displacement sensor 401 is arranged symmetrically on both sides of the upper end of the rock mass specimen 6.

[0072] The vertical displacement sensor 401 and the horizontal displacement sensor 402 are connected to the RS485 hub 106. The data from the vertical displacement sensor 401 and the horizontal displacement sensor 402 are transmitted to the control processing module 5 through the RS485 hub 106.

[0073] The bracket 403 has a bracket elongated hole 4031, through which the height position of the L-shaped fixing seat 404 is adjusted.

[0074] The L-shaped mounting base 404 has a mounting base elongated hole 4041, through which the horizontal position of the horizontal displacement sensor 402 is adjusted.

[0075] This invention provides an in-situ testing device for rock mass specimens by installing a hydraulic servo module 1, a lateral pressure loading module 2, an axial pressure loading module 3, a deformation measurement module 4, and a control processing module 5 at the engineering location of the rock mass specimen. This solves the problem of in-situ testing of fractured rock mass specimens at the engineering scale. At the same time, the independent pressurization of the axial pressure loading module 3 and the lateral pressure loading module 2 provides a true triaxial stress environment for the rock mass specimen, solving the problem that in-situ testing is difficult to restore the original rock stress conditions.

[0076] It is understood that the present invention has been described through the above embodiments and should not be construed as limiting the implementation methods or scope of the present invention. Those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the teachings of the present invention, modifications can be made to these features and embodiments to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by the present invention.

Claims

1. A device for in-situ testing of rock mass dilatancy angle under true stress, characterized in that, The device comprises a hydraulic servo module, a lateral pressure loading module, an axial pressure loading module, a deformation measurement module and a control processing module; The hydraulic servo module is connected with the lateral pressure loading module and the axial pressure loading module, and provides hydraulic power for the lateral pressure loading module and the axial pressure loading module; The control processing module is connected with the hydraulic servo module through a data line, and controls the pressure of the hydraulic servo module; The control processing module is connected with the deformation measurement module through a data line, and collects deformation data of the rock mass specimen.

2. The in-situ testing device for rock dilatancy angle under true stress according to claim 1, characterized in that, The hydraulic servo module comprises an oil pump unit, a PLC pressure controller, a pressure regulating device, a pressure sensor, a pipeline and an RS485 concentrator; The oil pump unit is composed of three groups of independent motors and oil pumps, and provides stable loading pressure in X, Y and Z directions respectively; The PLC pressure controller receives the pressure instruction of the control processing module through the RS485 concentrator, and sends a pressure adjustment instruction to the pressure regulating device; The pressure regulating device is installed at the output end of the oil pump unit, and adjusts the output pressure of the oil pump unit according to the received pressure adjustment instruction; The pressure sensor is installed at the front end of the pipeline, and monitors the pressure change of the pipeline in real time, and sends it to the pressure regulating device; The pipeline connects the hydraulic servo module with the lateral pressure loading module and the axial pressure loading module.

3. The in-situ testing device for rock dilatancy angle under true stress according to claim 1, characterized in that, The lateral pressure loading module comprises an X-direction reaction force frame, a Y-direction reaction force frame, a hydraulic pillow, an outer steel pad, an inner steel pad and a friction reduction device; The X-direction reaction force frame and the Y-direction reaction force frame are both rectangular steel frames, the short side of the X-direction reaction force frame and the short side of the Y-direction reaction force frame are in contact with the hydraulic pillow, the long side of the X-direction reaction force frame and the long side of the Y-direction reaction force frame are not in contact with the hydraulic pillow, the X-direction reaction force frame and the Y-direction reaction force frame are stacked and arranged, and the short side of the X-direction reaction force frame and the long side of the Y-direction reaction force frame are arranged at a 90° angle.

4. The in-situ test device for rock dilatancy angle under real stress according to claim 3, characterized in that, The friction reduction device is formed by overlapping two plastic plates with lubricating oil in the middle.

5. The in-situ test device for rock dilatancy angle under true stress according to claim 3, characterized in that, The hydraulic pillow is formed by welding two flexible steel plates around, and has a through hole in the middle, a round pipe is inserted into the through hole, and the round pipe is firmly welded with the flexible steel plate, the round pipe has telescopic performance in the axial direction, and an oil inlet hole is arranged below the hydraulic pillow.

6. The in-situ test device for rock dilatancy angle under real stress according to claim 1, characterized in that, The axial pressure loading module comprises a jack, a force transmission column, a leveling ellipsoid, a bottom plate and a pad; The lower end of the jack is connected with the rock mass specimen through the pad, and the upper end is arranged with the force transmission column; The bottom plate is arranged on the upper part of the leveling ellipsoid, and the bottom plate is in contact with the surrounding rock.

7. The in-situ test device for rock dilatancy angle under real stress according to claim 6, characterized in that, The leveling ellipsoid comprises a convex ellipsoid and a concave ellipsoid; The convex ellipsoid and the concave ellipsoid are connected and can be rotated in any direction.

8. The in-situ test device for rock dilatancy angle under real stress according to claim 2, characterized in that, The deformation measurement module comprises a vertical displacement sensor, a horizontal displacement sensor, a support and an L-shaped fixing seat; The vertical displacement sensor and the horizontal displacement sensor are connected with the support through the L-shaped fixing seat; the bottom end of the L-shaped fixing seat is connected with the support through a screw; The horizontal displacement sensor is arranged at the center of the four side surfaces of the rock mass test piece respectively, and the vertical displacement sensor is arranged symmetrically at the two sides of the upper end of the rock mass test piece respectively; The vertical displacement sensor and the horizontal displacement sensor are connected with the RS485 concentrator, and the data of the vertical displacement sensor and the data of the horizontal displacement sensor are transmitted to the control processing module through the RS485 concentrator.

9. The in-situ test device for rock dilatancy angle under real stress according to claim 8, characterized in that, The support has a support long hole, and the height position of the L-shaped fixing seat is adjusted through the support long hole.

10. The in-situ test device for rock dilatancy angle under real stress according to claim 8, characterized in that, The L-shaped fixing seat has a fixing seat long hole, and the horizontal position of the horizontal displacement sensor is adjusted through the fixing seat long hole.

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