Test equipment for simulating upward floating of duct piece in tunnel construction and matched measurement method

Abstract

The invention relates to the field of simulation test equipment before shield construction, in particular to test equipment for simulating floating of duct pieces in tunnel construction and a matched measurement method. The problems that in the prior art, preparation is insufficient and operation time is long due to the fact that duct piece floating is usually solved through on-site matching are solved. The device comprises a test base with a plurality of rotational degrees of freedom and a simulation box mounted on the test base, the simulation box is barrel-shaped, a primary limiting frame for limiting the initial position of a simulation segment is arranged at an opening of the barrel-shaped simulation box, the simulation segment is assembled to form a multilayer simulation segment ring, and the simulation segment ring is connected with the primary limiting frame. A simulation rock stratum is filled between a simulation segment ring and the simulation box, and a grouting opening facing the simulation rock stratum is formed in the simulation segment ring; and the transparent observation plate is arranged at the opening of the simulation box. The device has the advantages that simulation is carried out from the fundamental principle of segment floating, and the real construction is simulated in advance.

Description

A test device and a matching measurement method for simulating the floating of tunnel segments during tunnel construction. Technical Field

[0001] This invention relates to the field of simulation test equipment before shield tunneling, and in particular to a test device and a matching measurement method for simulating the floating of tunnel segments during tunnel construction. Background Technology

[0002] Segment floating is a common technical problem in tunnel construction, especially in soft soil strata or under high water pressure conditions. Specifically, segment floating is defined as the phenomenon where, after segment assembly, the entire or partial segment ring deviates from the design axis and shifts upwards due to external loads (such as groundwater pressure, grouting pressure, etc.) or construction factors. In severe cases, it can lead to tunnel axis deviation, joint leakage, or even structural damage.

[0003] Currently, the main technical solutions to this problem are: 1. Using anchoring structures to measure and adjust the tunnel segments to prevent them from floating; 2. Using wireless measuring devices to perform measurements and transmit data simultaneously for backend processing.

[0004] However, the applicant argues that current technologies are based on a problem-solving approach, where solutions are often limited to finding a suitable force range within a general framework. This approach is ineffective in handling diverse geological conditions and often results in issues such as insufficient anchoring device strength or mismatch between the grouting process and anti-buoyancy equipment, requiring on-site adjustments. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems and provide a test device that can accurately simulate buoyancy conditions in advance, simulate technical solutions in advance, and observe the effectiveness of the solutions.

[0006] The specific solution of this invention is as follows: A test device for simulating the floating of tunnel segments during construction is designed, comprising a test base with multiple degrees of rotational freedom, a simulation box mounted on the test base, the simulation box being barrel-shaped, with a primary limiting frame at the opening of the barrel defining the initial position of the simulated tunnel segments, the simulated tunnel segments being assembled into a multi-layered simulated tunnel segment ring, simulated rock layers being filled between the simulated tunnel segment ring and the simulation box, and grouting ports facing the simulated rock layers being provided inside the simulated tunnel segment ring; a transparent observation plate is also installed at the opening of the simulation box; the simulation box is also connected to a liquid flow simulation mechanism simulating water ripples in a water-rich area; multiple pressure plates applying force towards the center of the simulation box are provided inside the simulation box, on the surface where the outlet of the liquid flow simulation mechanism is located, and gaps for liquid flow are provided on the pressure plates.

[0007] In specific implementation, the liquid flow simulation mechanism includes water permeable holes provided on the body of the simulation tank, and a pressurized water source is provided outside the simulation tank to form a pressurized liquid flow channel through each water permeable hole.

[0008] In practice, mounting bases are provided on two adjacent bottom surfaces and the rear of the simulation chamber, and the mounting bases are snapped onto the test base.

[0009] In specific implementation, the area inside the simulation box that does not interfere with the simulated tunnel segment is provided with a grid to form a rock layer support, and the spacing of the grid is not less than 0.1 times the inner diameter of the simulated tunnel segment ring.

[0010] In practice, the simulated tube segment ring includes a multi-ring combination of tube rings, and the tube rings are connected by clamping, fitting, or riveting.

[0011] In specific implementation, the outer contour of the transparent observation plate corresponds to the opening of the barrel shape, the transparent observation plate is provided with an inner hole with a diameter smaller than the inner diameter of the simulated tube segment, and an inner cylinder for preventing overflow is provided along the edge of the inner hole.

[0012] In a specific implementation, the transparent observation plate includes a base plate with a through hole, a sleeve coaxially mounted outside the through hole, and an annular baffle coaxially mounted on the other side of the sleeve. The inner diameter of the sleeve is larger than the outer diameter of the simulated tube segment ring, and the inner diameter of the annular baffle is smaller than the inner diameter of the simulated tube segment ring.

[0013] In specific implementation, the components that form the multiple degrees of rotational automation are adjustment components. The adjustment components include four lifting mechanisms installed below the test base. The power source of the lifting mechanisms includes hydraulic control elements or lead screw and nut control elements.

[0014] In specific implementation, a secondary limit frame is also installed at the center of the primary limit frame. The secondary limit frame is clamped in the central hole of the primary limit frame. The structure of the secondary limit frame includes a clamping bracket for clamping the simulated inner diameter of the tube segment, and a support rod located between the clamping bracket and the primary limit frame.

[0015] The present invention also relates to a measurement method using a test device for simulating the floating of tunnel segments during tunnel construction. The method is characterized by the following steps: (1) Data acquisition: According to the construction design manual, collect and organize the surrounding rock conditions and overall pressure, the enrichment of underground water flow, and the tilting of the shield tunneling cutter head in the construction area; (2) Establish a simulation test platform: According to the data information collected in step (1), determine the installation position of the simulated shield tunnel segments, fill the simulation box with sand and gravel to simulate the surrounding rock, establish a water flow layer on the side of the simulation box to simulate the enriched water flow, and install the simulated shield tunnel segments in the simulation box with the help of a first-level limit frame and a second-level limit frame; (3) Establish a simulation experiment: Grout from the inside of the simulated tunnel segment ring to the outside with the on-site grouting material, and after removing the second-level limit frame, apply pressure to the sand and gravel simulated surrounding rock towards the simulated shield tunnel segments with a pressure plate, and then observe and measure the deformation of the simulated tunnel segment ring by simulating the floating state of the inner wall of the simulated shield tunnel segments during the solidification period of the grouting material.

[0016] The beneficial effects of this invention are as follows: it simulates the fundamental principle of segment floating, achieving a pre-simulation of actual construction; the secondary limiting frame facilitates installation during the assembly stage and provides floating margin for the testing stage; combined with the transparent observation plate, it achieves a technical structure that allows for observation and measurement without restricting floating after fixation; the overlapping form of the simulated segments maintains the continuity and integrity of the assembly while ensuring floating, effectively guaranteeing the stability of the testing equipment; the grid further fixes the simulated rock strata, resulting in good simulation effect; the pressure plate can pressurize the simulated rock and soil, further simulating the pressure conditions within the strata, and its waterproof sealing jacket extends its service life; the outlet design further improves the waterproof effect without affecting measurement accuracy; the transparent observation plate facilitates observation of the final solidification range of the grout flow and also facilitates the loading and unloading of the grouting pipe and the entry and exit of the measuring mechanism; the simulation box can simulate both horizontal and clear floating states of the tunnel, with a wide range of applications. Attached Figure Description

[0017] Figure 1 is a perspective view of the structure of the present invention; Figure 2 is a front view of the structure of the present invention; Figure 3 is a top view of the structure of the present invention; Figure 4 is a rear view of the structure of the present invention; Figure 5 is a left view of the structure of the present invention; Figure 6 is a right view of the structure of the present invention; Figure 7 is an enlarged schematic diagram of the limiting frame part; Figure 8 is a structural schematic diagram of the simulated tube segment ring; Figure 9 is a perspective view of the structure from another angle; Figure 10 is a perspective view of the structure from yet another angle; The names of the components in the figures are as follows: 1. Test base; 2. Primary limiting frame; 3. Secondary limiting frame; 4. Simulated tube segment; 5. Simulation box; 6. Grouting port; 7. Water permeable hole; 8. Water source; 9. Water flow channel; 10. Mounting seat; 11. Hydraulic rod assembly for controlling the displacement of the pressure plate; 12. Base plate; 13. Sleeve; 14. Annular baffle; 15. Fixing component between simulated tube segment rings; 16. Pressure plate; For clarity of view representation, the transparent observation plate in Figure 1 is drawn using an exploded view. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Embodiment 1

[0019] A test device for simulating the floating of tunnel segments during tunnel construction, as shown in Figure 1, includes a test base 1 with multiple degrees of rotational freedom, a simulation box 5 mounted on the test base 1, the simulation box 5 being barrel-shaped, and a primary limiting frame 2 at the opening of the barrel to limit the initial position of the simulated tunnel segments 4. The simulated tunnel segments 4 are assembled into a multi-layer simulated tunnel segment ring, and simulated rock layers are filled between the simulated tunnel segment ring and the simulation box 5. The simulated tunnel segment ring has a grouting port 6 facing the simulated rock layers inside. It also includes a transparent observation plate installed at the opening of the simulation box 5; the simulation box 5 is also connected to a liquid flow simulation mechanism that simulates water ripples in a water-rich area.

[0020] Inside the simulation chamber 5, on the surface where the outlet of the liquid flow simulation mechanism is located, there are multiple pressure plates 16 that apply force toward the center of the simulation chamber 5, and the pressure plates 16 have gaps through which the liquid flows.

[0021] The function of the pressure plate 16 is to simulate the pressure of the underground rock layer without affecting the flow of water.

[0022] The liquid flow simulation mechanism includes water permeable holes 7 provided on the body of the simulation tank 5, and a pressurized water source 8 provided outside the simulation tank 5 to form a pressurized liquid flow channel through each water permeable hole 7.

[0023] Mounting bases 10 are provided on two adjacent bottom surfaces and the rear of the simulation chamber 5, and the mounting bases 10 are snapped onto the test base 1. During operation, different test bases 1 can be snapped on according to different test scenarios to meet the requirements of different test positions.

[0024] Inside the simulation chamber 5, in the area that does not interfere with the simulated tunnel segment 4, a grid is provided to form a rock layer support. The spacing of the grid is not less than 0.1 times the inner diameter of the simulated tunnel segment. This design ensures that there are no excessively large gaps between the simulated rock layers, thus guaranteeing the relative accuracy of the experiment.

[0025] The simulated tube segment rings include multi-ring combinations, and the tube rings are connected by snap-fit, set, or riveting.

[0026] In this embodiment, the outer contour of the transparent observation plate corresponds to the opening of the barrel shape. The transparent observation plate has an inner hole with a diameter smaller than the inner diameter of the simulated tube segment 4, and an overflow-preventing inner cylinder is provided along the edge of the inner hole. In this embodiment, the length of the simulated tube segment ring is equal to the depth of the simulated box 5. During operation, the transparent observation plate forms a cover on one side of the simulated box 5, achieving complete coverage of the material between the simulated tube segment ring and the simulated box 5. In this example, the transparent observation plate can be fixed by a snap-fit ​​or clip-on method, or by using a moving track.

[0027] The components that form the multiple degrees of rotational automation are adjustment components. The adjustment components include four lifting mechanisms installed below the test base 1. The power source of the lifting mechanisms includes hydraulic control elements or lead screw and nut control elements.

[0028] The primary limiting frame 2 is further equipped with a secondary limiting frame 3, which is fitted into the central hole of the primary limiting frame 2. The secondary limiting frame 3 includes a clamping bracket for accommodating the inner diameter of the simulated tube segment 4, and a support rod located between the clamping bracket and the primary limiting frame 2. The purpose of this design is to achieve accurate positioning during installation, while not interfering with the movement of components during testing, and without unnecessary additional pressure.

[0029] A measurement method using a test device for simulating the floating of tunnel segments during tunnel construction includes the following steps: (1) Data acquisition: According to the construction design manual, collect and organize the surrounding rock conditions and overall pressure, underground water accumulation, and shield tunneling cutter head tilt of the construction area; (2) Establish a simulation test platform: Based on the data information collected in step (1), determine the installation position of the simulated shield tunnel segments, fill the simulation box 5 with sand and gravel to simulate the surrounding rock, establish a water flow layer on the side of the simulation box 5 to simulate the water accumulation, and install the simulated shield tunnel segments in the simulation box 5 with the help of the first-level limiting frame 2 and the second-level limiting frame 3; (3) Establish a simulation experiment: Grout from the inside of the simulated tunnel segment ring to the outside with the on-site grouting material, and after removing the second-level limiting frame 3, apply pressure plate 16 to the sand and gravel simulated surrounding rock towards the simulated shield tunnel segments, and then, during the solidification period of the grouting material, observe and measure the deformation of the simulated tunnel segment ring by simulating the floating state of the inner wall of the shield tunnel segment using the detection equipment.

[0030] Specifically, in the working process of this embodiment, the preliminary information is first surveyed and mapped. Then, a simulation environment is established in the laboratory based on the preliminary information. Before the test begins, the simulated segment ring is fixed. When the test begins, the circumferential degree of freedom constraint of the simulated segment ring is removed. Then, the simulated grouting process is started. At the same time, the timing is started and the water ripple simulation is turned on. As the grout gradually solidifies after grouting, the floating of the simulated segment ring is repeatedly measured to simulate the effect of on-site construction. Finally, the on-site construction plan is adjusted to achieve the technical objective of simulating the optimal value in advance and optimizing the on-site construction process.

[0031] The tilt angle of the test base 1 is designed primarily to simulate tests on tilted paths or at the bottom layer.

[0032] The device for measuring segment float is a testing device. The testing device uses a built-in probe and a fixing device with a degree of freedom of movement to fix the built-in probe. The fixing device can adjust the position of the probe, that is, the probe is always fixed at the axis of the simulated segment ring installation position and can only move laterally. When the simulated segment ring is initially positioned, the probe moves into the interior of the simulated segment ring for the first time to establish initial coordinates and references. When the float test ends, the probe enters the interior of the simulated segment ring again to measure the relative movement data of the internal points, thereby realizing the measurement of float.

[0033] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Example 2

[0034] The principle of this embodiment is the same as that of Embodiment 1. The specific difference is that when the water pressure and water flow direction are opposite to the direction set by this equipment, the equipment remains unchanged, but the test equipment is mirrored to obtain the measurement result in reverse. Embodiment 3

[0035] The principle of this embodiment is the same as that of Embodiment 1, the specific difference being that when the layers of each simulated tube segment are overlapped in a fish-scale pattern, it is easier to ensure assembly stability while deforming. Embodiment 4

[0036] The principle of this embodiment is the same as that of Embodiment 1, with the specific difference being that the transparent observation plate includes a base plate 12 with a through hole, a sleeve 13 coaxially mounted outside the through hole, and an annular baffle 14 coaxially mounted on the other side of the sleeve 13. The inner diameter of the sleeve 13 is larger than the outer diameter of the simulated tunnel segment ring, and the inner diameter of the annular baffle 14 is smaller than the inner diameter of the simulated tunnel segment ring. This embodiment is used to simulate tunnel segment rings where the length is greater than the depth of the simulation box 5, i.e., in real-world long-distance tunneling conditions where the loading is relatively balanced, stable, and unchanging. In this embodiment, the floating of the simulated tunnel segment ring is not interfered with.

Claims

1. A test device for simulating the floating of tunnel segments during tunnel construction, characterized in that: The test base (1) has multiple degrees of rotational freedom, and a simulation box (5) is installed on the test base (1). The simulation box (5) is barrel-shaped, and a first-level limiting frame (2) is provided at the opening of the barrel to limit the initial position of the simulated tube segment (4). The simulated tube segment (4) is assembled into a multi-layer simulated tube segment ring. Simulated rock layers are filled between the simulated tube segment ring and the simulation box (5). The simulated tube segment ring is provided with a grouting port (6) facing the simulated rock layer. The test base (5) also includes a transparent observation plate installed at the opening of the simulation box (5). The simulation box (5) is also connected to a liquid flow simulation mechanism that simulates water ripples in a water-rich area. In the simulation box (5), on the surface where the outlet of the liquid flow simulation mechanism is located, there are multiple pressure plates (16) that apply force towards the center of the simulation box (5). The pressure plates (16) are provided with gaps through which the liquid flows.

2. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 1, characterized in that: The liquid flow simulation mechanism includes water permeable holes (7) provided on the body of the simulation box (5), and a pressurized water source (8) is provided outside the simulation box (5) to form a pressurized liquid flow channel through each water permeable hole (7).

3. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 1, characterized in that: Mounting seats (10) are provided on two adjacent bottom surfaces and the back of the simulation box (5), and the mounting seats (10) are snapped onto the test base (1).

4. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 1, characterized in that: The simulation box (5) is provided with a grid in the area that does not interfere with the simulation segment (4) to form a rock support, and the spacing of the grid is not less than 0.1 times the inner diameter of the simulation segment ring.

5. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 4, characterized in that: The simulated tube segment rings include multi-ring combinations, and the tube rings are connected by snap-fit, set, or riveting.

6. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 1, characterized in that: The outer contour of the transparent observation plate corresponds to the opening of the barrel shape. The transparent observation plate is provided with an inner hole with a diameter smaller than the inner diameter of the simulated tube segment (4), and an inner cylinder for preventing overflow is provided along the edge of the inner hole.

7. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 1, characterized in that: The transparent observation plate includes a base plate (12) with a through hole, a sleeve (13) coaxially mounted outside the through hole, and an annular baffle (14) coaxially mounted on the other side of the sleeve (13). The inner diameter of the sleeve (13) is larger than the outer diameter of the simulated tube ring, and the inner diameter of the annular baffle (14) is smaller than the inner diameter of the simulated tube ring.

8. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 6 or 7, characterized in that: The components that form the multiple degrees of rotational automation are adjustment components. The adjustment components include four lifting mechanisms installed below the test base (1). The power source of the lifting mechanisms includes hydraulic control elements or screw and nut control elements.

9. The test equipment for simulating the floating of tunnel segments during tunnel construction as described in claim 8, characterized in that: The primary limiting frame (2) is also equipped with a secondary limiting frame (3) at its center. The secondary limiting frame (3) is fitted into the central hole of the primary limiting frame (2). The structure of the secondary limiting frame (3) includes a clamping bracket for clamping the inner diameter of the simulated tube segment (4) and a support rod located between the clamping bracket and the primary limiting frame (2).

10. A measurement method using the test equipment for simulating the floating of tunnel segments during construction as described in claim 1, characterized in that, The following steps are included: (1) Data collection: According to the construction design manual, collect and organize the surrounding rock conditions and overall pressure, underground water accumulation, and shield tunneling cutter head tilt of the construction area; (2) Establish a simulation test bench: According to the data information collected in step (1), determine the installation position of the simulated shield tunnel segment, fill the simulation box (5) with sand and gravel to simulate the surrounding rock, establish a water flow layer on the side of the simulation box (5) to simulate the water accumulation, and install the simulated shield tunnel segment in the simulation box (5) with the help of the first-level limit frame (2) and the second-level limit frame (3); (3) Establish a simulation experiment: Grout from the inside of the simulated tunnel segment ring to the outside with the on-site grouting material, and after removing the second-level limit frame (3), apply pressure to the sand and gravel simulated surrounding rock towards the simulated shield tunnel segment with the pressure plate (16), and then observe and measure the deformation of the simulated tunnel segment ring by simulating the floating state of the inner wall of the simulated shield tunnel segment during the solidification period of the grouting material.

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