A shield grouting layer degradation simulation device and method

Abstract

The present invention discloses a shield grouting layer degradation simulation device and method, relating to the field of grouting layer degradation simulation testing. The device comprises a test box, a seismic patch, and a hydraulic loading device. The test box comprises a bottom plate, fixed side plates fixed on both sides of the bottom plate, and movable side plates at both ends of the bottom plate, which are connected to a horizontal loading device. A cover plate is provided on the upper side of the test box, which has a through hole for installing a seismic plate, which is connected to a dynamic and static loading device. A diversion trough is pre-fixed inside the test box so that under the action of the horizontal loading device, the diversion trough is attached to the surface of the test block to form a seepage channel. The diversion trough is provided with a cold conduction module and a heat conduction module for performing freeze-thaw simulation. The hydraulic loading device is used to supply water to the water injection port of the test box. The present invention simulates the scouring and erosion effects of seepage water in the rock stratum on the grouting layer through the closed diversion trough, simulates the combined effects of water seepage scouring and vibration, and can simulate the freeze-thaw of the seepage water.

Description

Technical Field

[0001] The invention relates to the field of grouting layer degradation simulation test, and in particular to a shield grouting layer degradation simulation device and method. Background Art

[0002] Subway tunnels are mostly constructed using the shield method. A grouting layer exists between the shield tunnel segments and the surrounding rock. During tunnel operation, the surrounding rock-grouting layer-segment system forms a stable load-bearing system. For hard rock shield tunnels, the grouting layer, the segments, and the surrounding rock have significant strength differences, making it a weak layer. During tunnel operation, the grouting layer often faces a complex service environment, including stress environments, groundwater conditions, freeze-thaw cycles, and train vibration. The grouting layer is most susceptible to deterioration, which in turn leads to stress concentration in the segments, cracking, damage, and opening, affecting tunnel operation safety. Therefore, it is of great significance to investigate the degradation of the grouting layer and its impact on the stress of the segments. The experimental method can vividly demonstrate the degradation process and deterioration patterns of the grouting layer and its impact on the service performance of the segments, effectively guiding the maintenance of shield tunnels. However, the degradation of the grouting layer is a very complex process, with many influencing factors, including structural stress, train vibration, groundwater scouring, seepage path, freeze-thaw cycles, etc. The existing simulation test equipment for testing degradation does not consider the combined influence of vehicle vibration effect and seepage water scouring, and does not consider the impact of freeze-thaw in cold regions on the experimental results. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a shield grouting layer degradation simulation device and method, which can simulate the scouring and erosion of the grouting layer by the leakage water in the rock stratum through the diversion groove, simulate the combined influence of the seepage scouring and vibration, and can realize the simulation of the freezing and thawing of the seepage water; overcome the problems of complex operation and low efficiency of the existing test device.

[0004] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0005] In a first aspect, an embodiment of the present invention provides a shield grouting layer degradation simulation device, comprising:

[0006] A test box for placing test blocks, comprising a bottom plate, fixed side plates fixed on both sides of the bottom plate, movable side plates at both ends of the bottom plate, and the movable side plates connected to the horizontal loading device; a cover plate is provided on the upper side of the test box, and the cover plate has a through hole for arranging a shock-absorbing plate, and the shock-absorbing plate is connected to the dynamic and static loading devices;

[0007] The guide trough is pre-fixed inside the test chamber so that the guide trough is attached to the surface of the test block under the action of the horizontal loading device to form a seepage channel; the guide trough is provided with a cold conduction module and a heat conduction module for performing freeze-thaw simulation;

[0008] The water pressure loading device is used to supply water to the water inlet of the test chamber.

[0009] As a further implementation, the guide groove includes a magnet frame, and the outer side of the magnet frame is wrapped with a rubber protective layer;

[0010] The cold conduction module and the heat conduction module are distributed on the surface of the rubber protective layer.

[0011] As a further implementation, the cold conduction module and the heat conduction module are connected to the freeze-thaw control device via wires.

[0012] As a further implementation, a base is provided on the upper side of the bottom plate, and the base is used to support the test block to simulate the bending moment.

[0013] As a further implementation method, a plurality of anti-seismic patches are provided on the inner wall of the test box, and the anti-seismic patches are used to fill the gap between the test block and the test box to avoid scratches between the test block and the frame during vibration.

[0014] As a further implementation, the gap between the cover plate and the shock-absorbing plate is filled with rubber.

[0015] As a further implementation method, the water inlet is connected to the guide groove, and a water outlet is also provided at the bottom of the test box.

[0016] As a further implementation method, the guide groove and the water injection port are connected using a sealed adapter.

[0017] As a further implementation, the vibration-receiving plate is connected to the vibration exciter via a vibration rod.

[0018] In a second aspect, an embodiment of the present invention further provides a method for simulating degradation of a shield grouting layer, using the simulation device, comprising:

[0019] Place the test block in the test box, pre-fix the guide groove in the test box, and stick the seismic patch on the inner wall of the test box;

[0020] Start the horizontal loading device to make the guide groove fit the outer wall of the test block to form a seepage channel;

[0021] Adjust the water pressure to simulate seepage; adjust the vibration frequency to simulate vibration; start the freeze-thaw control device to simulate the freeze-thaw cycle of the seepage channel.

[0022] The beneficial effects of the present invention are as follows:

[0023] The present invention uses a closed diversion trough to simulate the effects of seepage water. By varying the diversion trough's trajectory, it can simulate diverse seepage channels for different test requirements. The diversion trough incorporates a cooling and heat conduction module, simulating the freeze-thaw effects of the seepage channel. The integrated cooling and heat regulation module, combined with the seepage channel, simplifies the test process. Furthermore, the present invention utilizes dynamic and static loading devices and a horizontal loading device to simulate soil pressure. By adjusting the water head of seepage water in the rock formation by adjusting the water tank pressure in the hydraulic loading device, it can simulate the combined effects of seepage water and vehicle vibration under different rock formation head distributions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 is a front view of a simulation device according to one or more embodiments of the present invention;

[0026] Figure 2 is a schematic diagram of test block installation according to one or more embodiments of the present invention;

[0027] Figure 3 is a perspective view of a simulation device according to one or more embodiments of the present invention;

[0028] Figure 4 is a schematic diagram of an arrangement of seismic patches according to one or more embodiments of the present invention;

[0029] Figure 5 is a schematic structural diagram of an anti-seismic patch according to one or more embodiments of the present invention;

[0030] Figure 6 is a schematic diagram of a connection of a shock-absorbing plate according to one or more embodiments of the present invention;

[0031] Figure 7 is a partial schematic diagram of an anti-seismic patch according to one or more embodiments of the present invention;

[0032] Figure 8 is a schematic diagram of a sealing adapter according to one or more embodiments of the present invention;

[0033] Figure 9 It is a schematic structural diagram of a wire plug according to one or more embodiments of the present invention.

[0034] Among them, 1. reaction frame, 2. dynamic and static loading device, 3. freeze-thaw control device, 4. water pressure loading device, 5. horizontal loading device, 6. test chamber, 7. test block, 8. exciter, 9. vibration rod, 10. cover plate, 11. shock-absorbing plate, 12. anti-seismic patch, 13. guide groove, 14. water inlet, 15. water outlet, 16. magnet frame, 17. sealing adapter, 18. wire plug, 19. rubber protective layer, 20. cold conduction module, 21. heat conduction module, 22. base, 23. movable side panel, 24. bottom plate. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0036] Example 1:

[0037] This embodiment provides a shield grouting layer degradation simulation device, such as Figure 1-Figure 3 As shown, the test chamber 6, a dynamic and static loading device 2, a horizontal loading device 5, a freeze-thaw control device 3, and a hydraulic loading device 4 are included. The dynamic and static loading device 2 and the horizontal loading device 5 constitute an earth pressure simulation system. The dynamic and static loading device 2 is installed on the top of the reaction frame 1 to provide vertical pressure. Two sets of horizontal loading devices 5 are connected to the reaction frame 1 and arranged symmetrically relative to the test chamber 6. Both the dynamic and static loading devices 2 and the horizontal loading device 5 are loaded using hydraulic clamps (hydraulic jacks). During the vibration and seepage tests, they secure the test block 7. At the same time, by adjusting the force output of the three hydraulic clamps, earth pressure simulation can be achieved for different test environments.

[0038] The test chamber 6 is made of metal and includes a base plate 24, fixed side plates (not shown), and movable side plates 23. Fixed side plates are mounted on either side of the base plate 24. The movable side plates 23 are connected to the horizontal loading device 5 and can move relative to the base plate 24 under the action of the horizontal loading device 5. The two fixed side plates, the two movable side plates 23, and the base plate 24 form a rectangular chamber for the test block 7, and the volume of this chamber is variable. Two bases 22 are located on the upper side of the base plate 24. The bases 22 are located near the fixed side plates and extend a certain length along the length of the base plate 24. The bases 22 are provided to simulate the actual bending moment experienced by the segment.

[0039] After placing the test block 7 in the test chamber 6, a cover plate 10 is installed on top of the test block 7. To accommodate the test chamber 6, the cover plate 10 is a rectangular plate. A through hole is provided in the center of the cover plate 10 for mounting a shock-absorbing plate 11. The shock-absorbing plate 11 is connected to the end of the dynamic and static loading device 2. Under the action of the dynamic and static loading device 2, the shock-absorbing plate 11 directly contacts the top surface of the test block 7. The through hole is shaped to match the shock-absorbing plate 11. In this embodiment, the shock-absorbing plate 11 is a rectangular plate, and the through hole is a rectangular opening.

[0040] In order to make the vibration effect on the top of the test block 7 uniform, the gap between the cover plate 10 and the vibration plate 11 is filled with rubber; Figure 4 As shown, the gap between the test box 6 and the test block 7 is filled with a rubber patch 12, which ensures that the entire test block 7 is evenly affected by vibration. In this embodiment, the patch 12 is arranged in multiple rows on the inner wall of the test box 6. The patch 12 can be evenly distributed, and the patch 12 corresponding to the fixed side panel and the movable side panel 23 is the same length.

[0041] like Figure 6 As shown, the dynamic and static loading device 2 includes a hydraulic jack, a vibrator 8 and a vibration rod 9. The vibration rod 9 is nested in the cylindrical hydraulic rod of the hydraulic jack. The top end of the vibration rod 9 is connected to the vibrator 8, and the bottom end passes through the vibration plate 11 to directly act on the test block 7.

[0042] The guide groove 13 is pre-fixed on the inner side of the test box 6 by the magnetic effect. When the movable side plates 23 on both sides are squeezed, the test block 7 is deformed, which can press the guide groove 13 and the test block 7 tightly, thereby realizing the efficient installation of the seepage channel. The structural form of the guide groove 13 is as follows: Figure 5 As shown, the main body is made of a ductile, antifreeze, strong magnetic material, with a rubber layer on the outside to enhance the tightness of the guide groove 13 and prevent it from falling off or cracking due to uneven vibration. Specifically, the cross-section of the guide groove 13 is U-shaped and includes a magnet frame 16, which is wrapped with a rubber protective layer 19 on the outside.

[0043] The movable side panels 23 secure the guide grooves 13 to the test block 7 during compression, simulating seepage erosion on the test block 7 by creating an external seepage channel. Because the bottom plate 24 of the test chamber 6 is provided with a water outlet 15 and the fixed side panels are provided with a water inlet 14, water is guided through the guide grooves 13 and flows from the inlet 14 through the test block 7. The guide grooves 13 can be spliced ​​together to customize the seepage channel trajectory on the surface of the test block 7. This allows the guide grooves 13 to be adjusted to meet test requirements.

[0044] like Figure 8As shown, the interface between the diversion channel 13 and the water inlet 14 is connected by a sealed adapter 17. This is achieved by covering the water inlet 14 with the adapter and then sealing it with waterproof glue. The pressurized water tank in the hydraulic loading device 4 is connected to the water inlet 14 from the outside via a water pipe. This, in conjunction with the hydraulic loading device 4, enables simulation of seepage at different osmotic pressures in the grouting layer.

[0045] The anti-seismic patch 12 and the closed side of the guide groove 13 are affixed with a cold conduction module 20 and a heat conduction module 21, and the leaked parts of the two are in contact with the running water to realize the simulation of the freezing and melting processes. In this embodiment, the cold conduction module 20 and the heat conduction module 21 are aluminum metal blocks, which are only used for conduction; the cold conduction module 20 and the heat conduction module 21 are connected to the freeze-thaw control device 3 through wires, and cooling and heating are generated by the freeze-thaw control device 3; the refrigeration principle of the freeze-thaw control device 3 is based on the Peltier effect, and the heating principle is based on resistance heating, which are all existing technologies and will not be repeated here. The wire installation adopts a plug-type design, and the material of the wire plug 18 is consistent with that of the conduction module, such as Figure 9 As shown, the connection terminal of the wire plug 18 is prefabricated with a rubber protection plate, and the conductive module is reserved with a groove of the same size to prevent water from entering the gap during the seepage test.

[0046] This embodiment uses a closed diversion trough 13 to simulate the effects of seepage water. By varying the trajectory of the diversion trough 13, it is possible to simulate various seepage channels for different test requirements. A cooling conduction module 20 and a heat conduction module 21 are embedded within the diversion trough 13, simulating the freeze-thaw effect of the seepage channel. The integrated cooling and heat regulation modules are integrated with the seepage channel, simplifying the test operation process. Furthermore, the dynamic and static loading device 2 and the horizontal loading device 5 enable a simulated soil pressure environment. By adjusting the water head of the seepage water in the rock formation by adjusting the water tank pressure in the hydraulic loading device 4, it is possible to simulate the combined effects of seepage water and vehicle vibration under different rock formation head distributions.

[0047] Example 2:

[0048] This embodiment provides a method for simulating degradation of a shield grouting layer, based on the simulation device described in the first embodiment, including the following steps:

[0049] (1) Place the test block 7 in the test box 6, and paste the surface guide groove 13 and install the wire of the freeze-thaw control device 3. The guide groove 13 is pre-adsorbed on the inside of the test box 6, and the anti-seismic patch 12 is attached to the inner wall of the test box 6.

[0050] (2) Start the hydraulic clamp of the horizontal loading device 5 and adjust the soil pressure value and bending moment used in the test. Under the action of the movable side plate 23, the guide groove 13 is squeezed to form a closed seepage channel.

[0051] (3) Adjust the water pressure in the water tank of the water pressure loading device 4 and start injecting water from the reserved water injection port 14 to perform seepage simulation.

[0052] (4) Adjust the parameters of the vibrator 8 to reach the vibration frequency used in the test and start the vibration simulation; start the freeze-thaw control device 3 to simulate the freeze-thaw cycle of the seepage channel.

[0053] (5) Take out the test block 7 for testing and obtain the test results.

[0054] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A shield grouting layer degradation simulation device, characterized in that: include: A test box for placing test blocks, comprising a bottom plate, fixed side plates fixed on both sides of the bottom plate, movable side plates at both ends of the bottom plate, and the movable side plates connected to the horizontal loading device; a cover plate is provided on the upper side of the test box, and the cover plate has a through hole for arranging a shock-absorbing plate, and the shock-absorbing plate is connected to the dynamic and static loading devices; The guide groove is pre-fixed inside the test chamber so that the guide groove is attached to the surface of the test block under the action of the horizontal loading device to form a seepage channel; the guide groove is provided with a cold conduction module and a heat conduction module for performing freeze-thaw simulation; the cold conduction module and the heat conduction module are connected to the freeze-thaw control device through wires; The water pressure loading device is used to supply water to the water inlet of the test chamber.

2. A shield grouting layer degradation simulation device according to claim 1, characterized in that: The guide groove includes a magnet frame, and the outer side of the magnet frame is wrapped with a rubber protective layer; The cold conduction module and the heat conduction module are distributed on the surface of the rubber protective layer.

3. A shield grouting layer degradation simulation device according to claim 1, characterized in that: A base is provided on the upper side of the bottom plate, and the base is used to support the test block to simulate the bending moment.

4. A shield grouting layer degradation simulation device according to claim 1, characterized in that: The inner wall of the test box is provided with a plurality of anti-seismic patches, and the anti-seismic patches are used to fill the gap between the test block and the test box.

5. A shield grouting layer degradation simulation device according to claim 1 or 4, characterized in that: The gap between the cover plate and the shock-absorbing plate is filled with rubber.

6. The shield grouting layer degradation simulation device according to claim 1, characterized in that: The water inlet is connected to the guide groove, and a water outlet is also provided at the bottom of the test box.

7. A shield grouting layer degradation simulation device according to claim 6, characterized in that: The guide groove and the water injection port are connected by a sealed adapter.

8. The shield grouting layer degradation simulation device according to claim 1, characterized in that: The vibration receiving plate is connected to the vibration exciter via a vibration rod.

9. A shield grouting layer degradation simulation method, characterized in that: The simulation device according to claim 4 comprises: Place the test block in the test box, pre-fix the guide groove in the test box, and stick the seismic patch on the inner wall of the test box; Start the horizontal loading device to fix the guide groove to the outer wall of the test block to form a seepage channel; Adjust the water pressure to simulate seepage; adjust the vibration frequency to simulate vibration; start the freeze-thaw control device to simulate the freeze-thaw cycle of the seepage channel.

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