Shield grouting layer degradation simulation device and method

Abstract

The invention discloses a shield grouting layer degradation simulation device and method, and relates to the field of grouting layer degradation simulation tests.The shield grouting layer degradation simulation device comprises a test box, an anti-seismic patch and a water pressure loading device.The test box comprises a bottom plate, fixed side plates are fixed to the two sides of the bottom plate, movable side plates are arranged at the two ends of the bottom plate, and the movable side plates are connected with a horizontal loading device; the upper side of the test box is provided with a cover plate, the cover plate is provided with a through hole for arranging a vibrated plate, and the vibrated plate is connected with a dynamic and static loading device; the diversion trench is pre-fixed on the inner side of the test box, so that the diversion trench is externally attached to the surface of the test block under the action of the horizontal loading device to form a seepage channel; the flow guide groove is provided with a cooling capacity conduction module and a heat conduction module and is used for carrying out freeze thawing simulation; the water pressure loading device is used for supplying water to the water filling nozzle of the test box. According to the device, the scouring and erosion effects of seepage water in a rock stratum on a grouting layer are simulated through the closed flow guide groove, the common influence of permeable scouring and vibration effects is simulated, and seepage water freezing and thawing simulation can be achieved.

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] Metro tunnels are mostly constructed using the shield method. There is a grouting layer between the shield tunnel segments and the surrounding rock. During the operation of the tunnel, the surrounding rock-grouting layer-segment is a stable force system. For hard rock shield tunnels, the strength difference between the grouting layer and the segments and surrounding rock is large, and it is a weak layer. During the operation of the tunnel, the grouting layer often faces a complex service environment, including stress environment, groundwater environment, freeze-thaw cycle and train vibration. The grouting layer is most likely to deteriorate, which leads to stress concentration on the segments, cracking, breakage, opening and other diseases, affecting the safety of tunnel operation. It is of great significance to explore the degradation of the grouting layer and its influence on the stress of the segments. The experimental method can vividly demonstrate the degradation process and degradation law of the grouting layer and its influence on the service performance of the segments, which can effectively guide 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 effects 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 prior art, 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 seepage water in the rock strata 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 devices.

[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 is used to place the test block, the test box comprises a bottom plate, fixed side plates are fixed on both sides of the bottom plate, movable side plates are arranged at both ends of the bottom plate, and the movable side plates are connected to the horizontal loading device; a cover plate is arranged on the upper side of the test box, and a through hole is opened on the cover plate for setting a shock-absorbing plate, and the shock-absorbing plate is connected to the dynamic and static loading devices;

[0007] The guide groove is pre-fixed inside the test box 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;

[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 earthquake-resistant patches are provided on the inner wall of the test box, and the earthquake-resistant 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, 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 by 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 shield grouting layer degradation simulation method, 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 anti-seismic patch on the inner wall of the test box;

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

[0021] Adjust the water pressure to perform seepage simulation; adjust the vibration frequency to perform vibration simulation; 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 effect of seepage water, and can simulate various seepage channels with different test requirements by changing the trajectory of the diversion trough; the diversion trough is inlaid with a cold conduction module and a heat conduction module to simulate the freeze-thaw effect of the seepage channel; the integrated cold and heat adjustment module is combined with the seepage channel to simplify the test operation process. In addition, the present invention can realize the soil pressure simulation environment through the dynamic and static loading device and the horizontal loading device; by adjusting the water tank pressure in the water pressure loading device to adjust the water head of the seepage water in the rock formation, it can simulate the effect of the joint action of the seepage water and the vehicle vibration under the water head distribution of different rock formations. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, 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 the arrangement of seismic patches according to one or more embodiments of the present invention;

[0029] Figure 5 is a schematic diagram of the structure 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] Fig. 9 It is a schematic diagram of the structure 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 box, 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 descriptions are illustrative and 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 meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] Embodiment 1:

[0037] This embodiment provides a shield grouting layer degradation simulation device, such as Figure 1-Figure 3 As shown, it includes a test box 6, a dynamic and static loading device 2, a horizontal loading device 5, a freeze-thaw control device 3 and a water pressure loading device 4. The dynamic and static loading device 2 and the horizontal loading device 5 constitute a soil pressure simulation system, wherein the dynamic and static loading device 2 is installed on the top of the reaction frame 1 to provide vertical pressure; the horizontal loading device 5 is provided with two groups, connected to the reaction frame 1 and arranged symmetrically relative to the test box 6. The dynamic and static loading device 2 and the horizontal loading device 5 are both loaded by hydraulic clamps (hydraulic jacks); they play a role in fixing the test block 7 during the vibration and seepage test, and at the same time, by adjusting the force output of the three hydraulic clamps, the soil pressure simulation of different test environments is realized.

[0038] The test box 6 is made of metal, and includes a bottom plate 24, a fixed side plate (not shown in the figure) and a movable side plate 23. The fixed side plates are installed on both sides of the bottom plate 24, and the movable side plates 23 are connected to the horizontal loading device 5. Under the action of the horizontal loading device 5, the movable side plates 23 can move relative to the bottom plate 24; the two fixed side plates, the two movable side plates 23 and the bottom plate 24 constitute a rectangular test block 7 cavity, and the volume of the cavity is variable. Two bases 22 are provided on the upper side of the bottom plate 24. The bases 22 are arranged close to the fixed side plates, and the bases 22 extend a certain length along the length direction of the bottom plate 24. The bases 22 are provided to simulate the actual bending moment of the pipe segment.

[0039] After placing the test block 7 in the test box 6, a cover plate 10 is arranged on the top of the test block 7; in order to adapt to the test box 6, the cover plate 10 is a rectangular plate. A through hole is opened in the middle of the cover plate 10, and the through hole is used to set 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 is in direct contact with the top surface of the test block 7. The through hole is adapted to the shape of 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 seismic patch 12, which is a rubber patch, so that the test block 7 is evenly subjected to vibration. In this embodiment, the seismic patches 12 are arranged in multiple rows on the inner wall of the test box 6, and the seismic patches 12 can be evenly distributed, and the seismic patches 12 corresponding to the fixed side plate and the movable side plate 23 are of 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, so that the guide groove 13 and the test block 7 are pressed tightly, and the seepage channel is efficiently installed. Figure 5 As shown, the main material is made of a refrigeration-resistant strong magnetic material with a certain degree of ductility, and a layer of rubber material is coated on the outside to improve the airtightness of the guide groove 13 to avoid falling off or cracking due to uneven vibration force. Specifically, the cross section of the guide groove 13 is U-shaped, and the guide groove 13 includes a magnet frame 16, and the outside of the magnet frame 16 is wrapped with a rubber protective layer 19.

[0043] The movable side plate 23 fixes the guide groove 13 and the test block 7 at the time of squeezing, so as to simulate the seepage scouring of the test block 7 in the form of an external seepage channel. Since the bottom plate 24 of the test box 6 is provided with a water outlet 15 and the fixed side plate is provided with a water injection port 14, the flowing water is guided through the guide groove 13 and flows from the water injection port 14 through the test block 7. The guide groove 13 can realize the customization of the seepage channel trajectory on the surface of the test block 7 in the form of splicing, that is, the setting trajectory of the guide groove 13 can be adaptively adjusted according to the test requirements.

[0044] like Figure 8As shown, the interface between the guide groove 13 and the water injection port 14 is connected by a sealing adapter 17, and the sealing adapter 17 is implemented by covering the water injection port 14 with a waterproof glue. The pressurized water tank water in the hydraulic loading device 4 is connected to the water injection port 14 from the outside through a water pipe, and the seepage simulation of different osmotic pressures of the grouting layer can be realized with the hydraulic loading device 4.

[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 leaking 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 the 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 Fig. 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 groove 13 to simulate the effect of seepage water. The trajectory of the diversion groove 13 can be changed to simulate various seepage channels with different test requirements. The diversion groove 13 is embedded with a cold conduction module 20 and a heat conduction module 21 to simulate the freeze-thaw effect of the seepage channel. The integrated cold and heat adjustment module is combined with the seepage channel to simplify the test operation process. In addition, the soil pressure simulation environment can be realized through the dynamic and static loading device 2 and the horizontal loading device 5. By adjusting the water head of the seepage water in the rock formation by adjusting the water tank pressure in the water pressure loading device 4, the effect of the joint action of the seepage water and the vehicle vibration under the different rock formation head distribution can be simulated.

[0047] Embodiment 2:

[0048] This embodiment provides a shield grouting layer degradation simulation method, 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 track and install the wire of the freeze-thaw control device 3. The guide groove 13 is pre-adsorbed on the inner side of the test box 6, and the anti-seismic patch 12 is pasted on the inner wall of the test box 6.

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

[0051] (3) Adjust the water pressure of the water tank in 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 vibration exciter 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 only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A shield grouting layer degradation simulation device, characterized in that: include: A test box is used to place the test block, the test box comprises a bottom plate, fixed side plates are fixed on both sides of the bottom plate, movable side plates are arranged at both ends of the bottom plate, and the movable side plates are connected to the horizontal loading device; a cover plate is arranged on the upper side of the test box, and a through hole is opened on the cover plate for setting 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 box 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 freeze-thaw simulation; 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 comprises 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 2, characterized in that: The cold conduction module and the heat conduction module are connected to the freeze-thaw control device through wires.

4. 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.

5. 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.

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

7. A 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 arranged at the bottom of the test box.

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

9. A 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.

10. A method for simulating shield grouting layer degradation, characterized in that: A simulation device as claimed in any one of claims 1 to 9, comprising: Place the test block in the test box, pre-fix the guide groove in the test box, and stick the anti-seismic patch on the inner wall of the test box; Start the horizontal loading device to fix the guide groove and the outer wall of the test block to form a seepage channel; Adjust the water pressure to perform seepage simulation; adjust the vibration frequency to perform vibration simulation; start the freeze-thaw control device to simulate the freeze-thaw cycle of the seepage channel.

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