A test device and test method for testing the filling property of double-liquid slurry

Abstract

The present invention relates to the technical field of synchronous grouting of shield tunnels, and in particular to a test device and test method for testing the filling properties of dual-liquid slurry. The test device includes: a shield tail gap model, an air compressor, and a camera; the shield tail gap model is a circular ring structure made according to specific working conditions, including an inner ring, an outer ring, a front face, and a rear face, wherein the front face is made of a transparent material, and the camera is arranged toward the front face of the shield tail gap model; the shield tail gap model is provided with grouting holes and air pressure holes, and the grouting holes are arranged on the inner ring of the shield tail gap model for grouting into the shield tail gap model; the air pressure holes are connected to the air compressor for adjusting the pressure inside the shield tail gap model. The test device can reflect the dynamic process of dual-liquid slurry filling in the shield tail gap based on different working conditions, and can be used as a basis for judging the filling performance of dual-liquid slurry under specific working conditions.

Description

Technical Field

[0001] The invention relates to the technical field of synchronous grouting of shield tunnels, and in particular to a test device and a test method for testing the filling property of dual-liquid slurry. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] With rapid economic development and the continuous expansion of urban scale, the utilization rate of urban underground space has gradually increased. Synchronous grouting, as one of the most important processes in tunnel construction, has a significant impact on controlling surface settlement, segment stress, and tunnel stability.

[0004] Currently, simultaneous grouting materials primarily consist of single-liquid slurry and dual-liquid slurry. Single-liquid slurry has been widely adopted due to its advantages, including low cost, simple preparation, and widespread availability of raw materials. However, since it is liquid upon injection into the shield tail gap and has a long setting time (4-10 hours), the segments are subjected to slurry buoyancy forces far exceeding their own weight for extended periods. Consequently, severe segment flotation often occurs during construction, leading to risks such as segment cracking, segment misalignment, and inter-ring water leakage, seriously compromising construction safety. To address the slow setting time and low initial strength of single-liquid slurry, dual-liquid slurries with additives such as industrial sodium silicate and phosphate water glass have emerged. These additives accelerate the hydration reaction of cement, resulting in a short setting time (less than 30 minutes) and high early strength. This stabilizes the segments and significantly reduces flotation during construction. However, due to its rapid setting rate, dual-liquid slurries often lose fluidity before the space behind the wall is completely filled, preventing them from completely filling the space behind the wall and resulting in poor filling results. Due to the lack of protection from the grouting layer, water in the stratum will seep into the gaps at the joints of the pipe segments, easily causing construction risks such as water leakage in the tunnel, which is not conducive to the normal progress of construction.

[0005] To address the shortcomings of dual-liquid slurry during construction, research is needed to investigate the effects of different additives on its filling properties. While existing tests, such as consistency tests and setting time tests, can reflect its filling properties to a certain extent, they cannot fundamentally reflect the filling effect of dual-liquid slurry in the space behind the wall under actual working conditions, and thus remain limited in their ability to provide a thorough understanding of its filling properties. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the embodiment of the present invention is to provide a test device for testing the filling properties of dual-liquid slurry, which can reflect the dynamic process of dual-liquid slurry filling in the shield tail gap based on different working conditions and can serve as a basis for judging the dual-liquid slurry filling performance under specific working conditions.

[0007] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0008] A test device for testing the filling properties of dual-liquid slurry comprises: a shield tail gap model, an air compressor and a camera; the shield tail gap model is a circular structure made according to specific working conditions, comprising an inner ring, an outer ring, a front face and a rear face, wherein the front face is made of a transparent material, and the camera is arranged toward the front face of the shield tail gap model; the shield tail gap model is provided with grouting holes and air pressure holes, the grouting holes are arranged on the inner ring of the shield tail gap model, and are used for grouting into the shield tail gap model; the air pressure holes are connected to the air compressor for adjusting the pressure inside the shield tail gap model.

[0009] In another preferred embodiment of the present invention, a flow rate sensor is provided on the shield tail gap model for monitoring the diffusion rate of the dual-liquid slurry after being injected into the shield tail gap model.

[0010] In another preferred embodiment of the present invention, the flow velocity sensor is a non-contact sensor.

[0011] In another preferred embodiment of the present invention, the grouting holes of the shield tail gap model are connected to a grouting pump, and the grouting pump is used to simulate the actual construction process of the double-liquid slurry.

[0012] In another preferred embodiment of the present invention, a slurry discharge pipe is provided at the bottom of the outer ring of the shield tail gap model, and the slurry discharge pipe is connected to a waste slurry barrel at its lower end.

[0013] In another preferred embodiment of the present invention, a fixed stand is further included, a column is installed on the fixed stand, and the shield tail gap model is fixed to the column by fasteners.

[0014] In another preferred embodiment of the present invention, the front end surface of the shield tail gap model is made of acrylic material.

[0015] An embodiment of the present invention also provides a test method for the above-mentioned test device for testing the filling properties of the dual-liquid slurry: adjusting the pressure in the shield tail gap model to a predetermined value, turning on the camera to record data, injecting the pre-configured dual-liquid slurry into the pipe segment gap model, and the camera obtains the diffusion of the dual-liquid slurry through the transparent front end surface.

[0016] In another preferred embodiment of the present invention, the pressure in the shield tail gap model is adjusted to a predetermined value according to different buried depths of the segments.

[0017] In another preferred embodiment of the present invention, the interval between two consecutive photos taken by the camera is 0.2s.

[0018] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0019] Before the test, the test device of the present invention makes a shield tail gap model according to the specific working conditions, so that the inner and outer rings and the front and rear end faces form a closed cavity to simulate the specific shield tail gap. Grouting holes are opened at corresponding positions on the shield tail gap model according to the number and position of grouting points in the actual project. By setting an air pressure hole on the model to connect to an air compressor, the air pressure in the shield tail gap model is controlled and changed to simulate the filling of the double liquid slurry in the space behind the wall at different tunnel burial depths. The diffusion process of the double liquid slurry in the shield tail gap is recorded by a camera, and the actual process of the double liquid slurry filling effect in the shield tail is restored by analyzing the pictures taken during the test. This can more intuitively and deeply reflect the diffusion of the double liquid slurry in the space behind the wall under different grouting pressures and different tunnel burial depths. Compared with existing theoretical test methods such as consistency and setting time, it is more in line with the specific working conditions in practice and provides a more efficient test platform for double liquid slurry optimization research.

[0020] Additional advantages of the present invention will be given in the description which follows, and in part will be obvious from the description which follows, or may be learned through practice of the present invention.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 1 is an overall schematic diagram of a test device according to an embodiment of the present invention;

[0024] Figure 2 2. This is a schematic diagram of the back side of the shield tail gap model according to an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of a fastener according to an embodiment of the present invention;

[0026] Figure: 1. Shield tail gap model; 2. Flow rate sensor; 3. Air pressure hole; 4. Grouting hole; 5. Slurry discharge valve; 6. Waste slurry drum; 7. Fixed stand; 8. Camera; 9. Computer; 10. Grouting pump; 11. Air compressor; 12. Fasteners;

[0027] In order to show the positions of various parts, the distances or sizes between them are exaggerated. The schematic diagram is for reference only. DETAILED DESCRIPTION

[0028] 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.

[0029] Explanation of Terminology: Terms such as "installed," "connected," "connect," and "fixed" in this disclosure should be interpreted broadly. For example, they may refer to fixed connections, detachable connections, or integrated connections. They may refer to mechanical connections, direct connections, indirect connections through an intermediate medium, internal connections between two components, or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances. In the description of this disclosure, "multiple" or "plurality" means two or more.

[0030] As introduced in the background technology, although existing tests for testing slurry properties, such as viscosity and setting time tests, can reflect the fluidity and filling properties of the slurry to a certain extent, they are more inclined to theoretical research tests, divorced from the specific working conditions in practice, and cannot directly reflect the filling conditions of the pipe segments in the space behind the wall under actual circumstances. Therefore, it is impossible to accurately judge the filling properties of the dual-liquid slurry, and it has certain limitations. In order to solve the above technical problems, the present invention proposes a test device for testing the filling properties of the dual-liquid slurry.

[0031] like Figure 1-Figure 3 As shown, an embodiment of the present invention records a test device for testing the filling properties of dual-liquid slurry, including: a shield tail gap model 1, an air compressor 11 and a camera 8; the shield tail gap model 1 is a circular structure made according to specific working conditions, including an inner ring, an outer ring, a front face and a rear face, wherein the front face is made of a transparent material, and the camera 8 is arranged toward the front face of the shield tail gap model 1; the shield tail gap model 1 is provided with a grouting hole 4 and an air pressure hole 3, the grouting hole 4 is arranged on the inner ring of the shield tail gap model 1, and is used for grouting into the shield tail gap model 1; the air pressure hole 3 is connected to the air compressor 11 for adjusting the pressure in the shield tail gap model 1.

[0032] The inner ring, outer ring, front face, and rear face of the shield tail gap model form a closed cavity. The difference in diameter between the inner and outer rings represents the width of the space behind the wall, which is used to simulate the shield tail gap. At least the front face of the shield tail gap model should be transparent, and acrylic can be selected. The remaining inner ring, outer ring, and rear face can be made of metal to ensure the strength of the shield tail gap model.

[0033] The grouting holes are set in the inner ring of the shield tail gap model, and the air pressure holes can be set on the front face of the shield tail gap model. It should be noted that the openings mentioned above should be kept airtight to prevent the double liquid slurry from flowing out of the opening gap and to ensure that the subsequent air compressor can normally adjust and maintain the air pressure in the model.

[0034] The camera is a high-speed camera fixed in front of the shield tail gap model. Before the test, the shooting height and angle are adjusted so that the shield tail gap model can be fully captured. It is mainly used to record the diffusion process of the dual slurry in the shield tail gap. Before the test, the interval between the two shots of the high-speed camera is set to 0.2 seconds.

[0035] Due to varying tunnel depths, the pressure in the shield tail gap varies significantly in actual projects. By connecting an air compressor to an air pressure port on the model, the air pressure within the shield tail gap model can be controlled and varied to simulate the filling of the space behind the wall with a dual-liquid slurry at different tunnel depths.

[0036] Flow rate sensors 2 are installed on the shield tail gap model 1 at a predetermined angle. Specifically, they can be located on the front face of the model, with each sensor spaced 36 degrees apart. These sensors can be used to monitor the flow rate changes at specified locations during the dual-liquid slurry filling process. After the test, the flow rate data can be exported via a computer 9. This flow rate data can be used as an important indicator for subsequent evaluation of the fillability of the gap.

[0037] The flow velocity sensor 2 is non-contact and installed outside the shield tail gap model 1. It can measure the flow velocity without contacting the liquid, thereby reducing the impact on the dual-liquid slurry flow and improving the test accuracy.

[0038] The grouting pump 10 is connected to the grouting hole 4 reserved on the shield tail gap model 1. The dual-liquid slurry is injected into the shield tail gap model 1 through the grouting pump. The grouting pump is mainly used to simulate the actual construction process of the dual-liquid slurry. The specific operation process is as follows: the grouting pump is filled with pre-configured dual-liquid slurry, and the grouting pump is turned on to allow the dual-liquid slurry to be injected into the shield tail gap model. In order to better simulate the actual filling situation of the dual-liquid slurry, the configuration ratio of the dual-liquid slurry must be the same as in actual construction. The injection pressure of the grouting pump can be adjusted to simulate the working conditions of different grouting pressures in actual engineering.

[0039] A slurry discharge pipe is provided at the bottom of the outer ring of the shield tail gap model 1, and the slurry discharge pipe is connected to the waste slurry tube 6 at the bottom. The main function of the slurry discharge pipe is to collect the test waste slurry after the test is completed, so as to facilitate the next test. A slurry discharge valve 5 is provided on the slurry discharge pipe, and the waste slurry is allowed to flow into the waste slurry tube 6 by opening the slurry discharge valve.

[0040] The test device also includes a fixed stand 7, on which a column is installed, and the shield tail gap model 1 is vertically installed on the column through a fastener 12. The fixed stand, column and fastener are all made of metal, and the shape of the fastener is as follows: Figure 3 As shown, the middle part has a groove to accommodate the column. The fasteners and the shield tail gap model can be connected by screws or welded. The stability of the shield tail gap model during the test is maintained by fixing the stand and the column.

[0041] The test method for the test device for testing the filling property of the dual-liquid slurry:

[0042] First, air is ventilated into the shield tail gap model 1 via an air compressor 11 to adjust the pressure within the shield tail gap model 1 to a predetermined value, depending on the different buried depths of the segments. Secondly, the pre-configured dual-liquid slurry is injected into the segment gap model 1 via a grouting pump 10. At this point, the flow rate sensor 2 and high-speed camera 8 are turned on to record data. The grouting pump is turned off when the volume of the injected dual-liquid slurry matches the volume of the shield tail gap model cavity. Then, the flow rate changes and actual diffusion of the dual-liquid slurry within the shield tail gap model during the test are derived via a computer 9 and high-speed camera 8. Finally, the slurry discharge valve 5 is opened to allow the test waste slurry to flow into the waste slurry drum 6 to facilitate the subsequent test.

[0043] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A test device for testing the filling property of a double-liquid slurry, characterized in that: include: Shield tail gap model, air compressor and camera; The shield tail gap model is a circular structure made according to specific working conditions, including an inner ring, an outer ring, a front face and a rear face, wherein the front face is made of a transparent material, and the camera is set toward the front face of the shield tail gap model; The shield tail gap model is provided with grouting holes and air pressure holes. The grouting holes are provided on the inner ring of the shield tail gap model for grouting into the shield tail gap model; the air pressure holes are connected to the air compressor for adjusting the pressure in the shield tail gap model; A flow rate sensor is provided on the shield tail gap model for monitoring the diffusion rate of the dual-liquid slurry after being injected into the shield tail gap model.

2. The test device for testing the filling property of dual-liquid slurry according to claim 1, characterized in that: The flow rate sensor is a non-contact sensor.

3. The test device for testing the filling property of dual-liquid slurry according to claim 1, characterized in that: The grouting holes of the shield tail gap model are connected to a grouting pump, and the grouting pump is used to simulate the actual construction process of the double-liquid slurry.

4. The test device for testing the filling property of dual-liquid slurry according to claim 1, characterized in that: A slurry discharge pipe is provided at the bottom of the outer ring of the shield tail gap model, and the slurry discharge pipe is connected to a waste slurry barrel at the bottom.

5. The test device for testing the filling property of dual-liquid slurry according to claim 1, characterized in that: It also includes a fixed stand, on which a column is installed, and the shield tail gap model is fixed to the column through fasteners.

6. The test device for testing the filling property of dual-liquid slurry according to claim 1, characterized in that: The front end surface of the shield tail gap model is made of acrylic material.

7. The test method for testing the filling property of a dual-liquid slurry test device according to any one of claims 1 to 6, characterized in that: Adjust the pressure in the shield tail gap model to a predetermined value, turn on the camera to record data, inject the pre-configured dual-liquid slurry into the segment gap model, and use the camera to obtain the dual-liquid slurry diffusion through the transparent front face.

8. The test method according to claim 7, wherein The pressure in the shield tail gap model is adjusted to a predetermined value according to the different buried depths of the segments.

9. The test method according to claim 7, wherein The interval between the two shots taken by the camera is 0.2s.

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