A shield tunnel ground interface in-situ grouting test device

Abstract

The utility model discloses a kind of shield ground butt extracorporal grouting test devices, it is related to shield grouting test technical field, the shield ground butt extracorporal grouting test device, including waist test box and bottom test box, one side of waist test box is the arc panel made according to shield waist, to simulate shield shell waist position, water inlet one and pumping outlet are set in waist test box upper portion, multiple groups of grouting holes are provided at arc panel, relief valve is installed in one side of waist test box, bottom test box is independently arranged in one side of waist test box, bottom test box is made of steel plate welding, multiple groups of openings are set in bottom test box, bottom test box and ground embedded steel plate are connected.The utility model utilizes waist pressure test box, simulates about 5m range above lane board with pressure environment, bottom test box, further verifies the test results of upper stage, so that the whole test device can be stably operated under the pressure condition of simulating actual construction environment.

Description

Technical Field

[0001] This utility model relates to the field of shield tunneling grouting test technology, and in particular to an external grouting test device for shield tunneling underground docking. Background Technology

[0002] During shield tunnel construction, curtain grouting reinforcement is a crucial step in ensuring tunnel structural stability and preventing water leakage. However, it faces numerous challenges and risks in actual construction.

[0003] For example, strata at different depths exhibit different physical and mechanical properties, such as significant differences in water content and permeability coefficient. Especially when grouting operations are carried out in confined aquifers, the high water head pressure (approximately 60-76 meters) and high water pressure (reaching 0.6-0.76 MPa) increase the difficulty and risk of construction. To ensure the safety and effectiveness of the grouting process, advanced equipment and techniques are required. For instance, effective anti-surge measures must be taken during drilling; during grouting, the sealing of the grouting hole must be ensured to prevent media leakage or grout overflow along the drill pipe.

[0004] To verify and optimize grouting processes and parameters, full-scale model tests are typically conducted under laboratory conditions. These tests not only require the ability to simulate the pressure conditions of actual formations but also need to possess good sealing performance and stable structural strength to ensure the reliability and repeatability of experimental results. However, traditional test chamber structures are not robust enough and are prone to deformation or damage due to external pressure; the sealing design of grouting holes is not perfect, which can easily lead to media leakage or grout surge. Utility Model Content

[0005] This utility model provides a test device for external grouting of shield tunneling underground docking, including a waist test box and a bottom test box. One side of the waist test box is an arc-shaped panel made according to the waist of the shield body to simulate the waist position of the shield shell. A water injection port and an exhaust port are opened at the top of the waist test box. Multiple sets of grouting holes are provided at the arc-shaped panel. A pressure relief valve is installed on one side of the waist test box. The bottom test box is independently set on one side of the waist test box. The bottom test box is welded from steel plates. Multiple sets of openings are opened on the bottom test box. The bottom test box is embedded in the ground with steel plates.

[0006] Preferably, the outer side of the waist test chamber is reinforced with square hollow steel pipes, and reinforced supports are provided on all sides except the side of the arc panel.

[0007] Preferably, pressure gauges are installed on one side of both the water inlet and the outlet.

[0008] Preferably, the waist test chamber is provided with multiple sets of inner plates with through holes, and the waist test chamber is filled with fine sand.

[0009] Preferably, multiple sets of earth pressure gauges are installed on the inner wall of the waist test chamber, and the earth pressure gauges are fixed by cross-shaped steel bar grooves.

[0010] Preferably, the cable of the earth pressure gauge is protected by a junction box installed on the inner wall of the waist test chamber.

[0011] Preferably, a one-way valve is installed on the grouting hole.

[0012] Preferably, the end of the grouting hole is connected to the connecting pipe via a flange, and the connecting pipe is connected to the drill rod via a flange.

[0013] Preferably, a grout stopper is installed inside the connecting pipe, and the uninserted portion of the grout stopper is wrapped with a steel pipe sleeve.

[0014] Preferably, the bottom test chamber has symmetrical pressure ports on one side, and the chamber body between the pressure ports has a second water inlet and a pressure relief port, and ball valves are installed on the pressure ports, the second water inlet and the pressure relief port.

[0015] This utility model provides a shield tunneling underground docking external grouting test device, which, compared with the prior art, has the following advantages:

[0016] 1. This utility model reinforces the outer side of the waist-shaped test chamber with square hollow steel pipes, and reinforced supports are provided on all sides except for the curved panel side. This not only enhances the overall rigidity of the chamber but also effectively prevents deformation or damage caused by external pressure. Furthermore, pressure gauges are installed on one side of the water inlet and the outlet to monitor water pressure changes within the chamber in real time, ensuring safety during pressurization. The bottom test chamber is independently located on one side of the waist-shaped test chamber, constructed of welded steel plates and connected to pre-embedded steel plates in the ground, ensuring its stability and meeting the requirements of the foundation bearing capacity. These designs allow the waist-shaped pressurized test chamber to simulate a pressurized environment within approximately 5 meters above the roadway slab, enabling grouting tests under pressure conditions. The bottom test chamber further verifies the results of the previous stage of testing, ensuring the entire test device can operate stably under pressure conditions simulating actual construction environments, providing a solid foundation for subsequent experiments.

[0017] 2. This utility model prevents the medium from flowing out of the drill rod by installing a one-way valve on the grouting hole, ensuring the safety and effectiveness of the grouting process. The end of the grouting hole is connected to the connecting pipe via a flange, and then to the drill rod via another flange. This design simplifies the assembly and disassembly process and improves work efficiency. The uninserted portion of the grout stop plug installed inside the connecting pipe is wrapped with a steel pipe sleeve, further enhancing the sealing performance and preventing grout surge. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0020] Figure 2 This is a schematic diagram of the waist test chamber structure according to an embodiment of the present utility model;

[0021] Figure 3 This is a side view of the waist test chamber according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the fine sand structure filling in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the connecting pipe and other structures in an embodiment of the present utility model;

[0024] Figure 6 This is a schematic diagram showing the disassembled structure of the grout stopper and connecting pipe according to an embodiment of the present utility model;

[0025] Figure 7 This is a schematic diagram of the bottom test chamber structure according to an embodiment of the present invention;

[0026] Figure 8 This is a top view of the bottom test chamber structure according to an embodiment of the present invention.

[0027] Figure label:

[0028] 1. Waist test chamber; 2. Hollow steel pipe; 3. Reinforcing support; 4. Inner plate; 5. Earth pressure gauge; 6. Wiring protection box; 7. Water inlet one; 8. Grouting hole; 9. Pressure relief valve; 10. Fine sand; 11. Check valve; 12. Connecting pipe; 13. Grout stop plug; 14. Steel pipe sleeve; 15. Bottom test chamber; 16. Opening; 17. Pressurization port; 18. Pressure relief port; 19. Water inlet two; 20. Pressure gauge. Detailed Implementation

[0029] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] Please refer to Figures 1-8This utility model embodiment provides a test device for external grouting of shield tunneling underground docking, including a waist test box 1 and a bottom test box 15. The overall dimensions of the waist test box 1 are 10m × 2.46m × 5m (length × minimum width of top surface × height). One side has an arc-shaped panel made according to the waist of the shield body at a 1:1 scale, which is used to simulate the waist position of the shield shell, that is, the arc-shaped area within 5m above the lane plate elevation. The thickness is 80mm, and the thickness of the other plates is 50mm. The outer side of the waist test box 1 is reinforced with square hollow steel pipes 2. Except for the side of the arc-shaped panel, all sides are equipped with reinforcing supports 3. The box material is Q355B low alloy high strength steel.

[0031] The steel plate welding meets the 10.9MPa water pressure sealing test of the waist test chamber. The upper part of the waist test chamber 1 has an 800mm diameter hole, which is the water inlet 7 and the exhaust port. The hole is sealed with a rubber plate and tightened with bolts. A pressure gauge 20 is installed on one side of the water inlet 7 and the exhaust port to monitor the water pressure change in the chamber in real time and ensure safety.

[0032] Multiple earth pressure gauges 5 are installed on the inner wall of the waist test chamber 1. The earth pressure gauges 5 are fixed by cross steel bar grooves. The cables of the earth pressure gauges 5 are protected by the wiring protection box 6 installed on the inner wall of the waist test chamber 1. The wiring protection box 6 is sealed with cement grout to ensure the sealed environment of the chamber. The earth pressure gauges 5 monitor the pressure changes at the shield position during the grouting process.

[0033] The waist test chamber 1 is equipped with multiple sets of inner plates 4 with through holes, and is filled with fine sand 10. Water is injected to provide a pressurized environment for the waist test chamber 1 to reach the design pressure of 0.8MPa. The pressure is released by the pressure relief valve 9 installed on one side of the waist test chamber 1 to maintain the internal pressure balance of the waist test chamber 1.

[0034] Multiple grouting holes 8 are provided on the arc-shaped panel to simulate the actual grouting process. One-way valves 11 are installed on the grouting holes 8 to prevent the medium from flowing out of the drill rod during the disassembly and reassembly of the drill rod.

[0035] The end of the grouting hole 8 is connected to the connecting pipe 12 via a flange. The connecting pipe 12 is connected to the drill rod via a flange. A grout stop plug 13 is installed inside the connecting pipe 12. The grout stop plug 13 is a frustum-shaped pure rubber material, 400mm long, with an inner diameter of 58mm, an outer diameter of 146mm at the large end and 116mm at the small end. The steel pipe sleeve 14 is 400mm long, with an inner diameter of 126mm and a wall thickness of 10mm. The grout stop plug 13 is inserted into the steel pipe sleeve 14. The part that is not inserted is wrapped with a 15cm long independent steel pipe sleeve 14. The outside is squeezed by bolts and flanges to achieve a sealing effect and prevent grout from gushing out.

[0036] Using the waist test chamber 1, a pressurized environment was simulated within a range of about 5m above the lane slab, and a grouting test was conducted under the pressure condition of the waist.

[0037] The bottom test chamber 15 is independently set on one side of the waist test chamber 1. The bottom test chamber 15 is welded from steel plates. Multiple sets of openings 16 are opened on the bottom test chamber 15 and sealed with rubber plates. The bolts are tightened. The bottom test chamber 15 is embedded with steel plates in the ground to ensure the stability of the chamber. The bearing capacity of the foundation meets the bearing requirement of 0.18MPa.

[0038] The bottom test chamber 15 has symmetrical pressure ports 17 on one side. The chamber between the pressure ports 17 has a water inlet 19 and a pressure relief port 18 respectively. Ball valves are installed on the pressure ports 17, water inlet 19 and pressure relief port 18.

[0039] The bottom test chamber 15 was used to further verify the test results of the waist test chamber 1.

[0040] In summary, both the waist test chamber 1 and the bottom test chamber 15 are welded from steel plates and need to meet design pressure resistances of 0.9MPa and 1.0MPa respectively. A water pressure sealing test is required before the formal testing. The performance of the chamber sealing, internal water pressure bearing capacity, and the stability of the safety pressure gauge and safety valve are verified. Before the test, residual sand inside the waist test chamber 1 and the bottom test chamber 15 is cleaned by draining through water inlet 7, water inlet 2 19, the exhaust port, and the pressure relief valve 9. The solidified double-liquid slurry at the bottom is also cleaned by manual chiseling. After cleaning the residual sand, fine sand 10 is filled into the waist test chamber 1 and the bottom test chamber 15 according to the test design. After filling, water is injected through water inlet 7 and water inlet 2 19, and the pressure gauge 20 is observed. The pressure reaches the design requirements. When the pressure in the waist box 1 is 0.9 MPa and the pressure in the bottom box 15 is 1.0 MPa, stop water injection and maintain the pressure for 30 minutes. If the pressure drop does not exceed 0.05 MPa, and at the same time check that there is no water leakage, the pressure test of the box is completed. During the test, the internal pressure of the box is initially set to 0.75 MPa, and the safety valve pressures of the waist and top boxes are set to 0.9 MPa and 1.0 MPa, respectively. Grouting is done at a single point. The internal pressure of the box increases slowly. When the safety valve setting value is reached, the safety valve releases water to ensure safety and grouting is carried out. Grouting of this hole and section can be ended when the grouting volume reaches the designed grouting volume.

[0041] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A test device for external grouting of shield tunnel underground docking, characterized in that: The test chamber includes a waist test chamber (1) and a bottom test chamber (15). One side of the waist test chamber (1) is an arc-shaped panel made according to the waist of the shield body to simulate the waist position of the shield shell. A water injection port (7) and a drainage port are opened on the upper part of the waist test chamber (1). Multiple sets of grouting holes (8) are provided at the arc-shaped panel. A pressure relief valve (9) is installed on one side of the waist test chamber (1). The bottom test chamber (15) is independently set on one side of the waist test chamber (1). The bottom test chamber (15) is made of welded steel plate. Multiple sets of openings (16) are opened on the bottom test chamber (15). The bottom test chamber (15) is embedded with a steel plate on the ground.

2. The external grouting test device for shield tunneling underground docking according to claim 1, characterized in that: The outer side of the waist test chamber (1) is reinforced with square hollow steel pipe (2), and reinforced supports (3) are provided on all sides except the side of the arc panel.

3. The external grouting test device for shield tunneling underground docking according to claim 2, characterized in that: Pressure gauges (20) are installed on one side of the water inlet (7) and the drain outlet.

4. The external grouting test device for shield tunneling underground docking according to claim 3, characterized in that: The waist test chamber (1) is provided with multiple sets of inner plates (4) with through holes, and the waist test chamber (1) is filled with fine sand (10).

5. The external grouting test device for shield tunneling underground docking according to claim 4, characterized in that: Multiple sets of earth pressure gauges (5) are installed on the inner wall of the waist test box (1), and the earth pressure gauges (5) are fixed by cross steel bar grooves.

6. The external grouting test device for shield tunneling underground docking according to claim 5, characterized in that: The cable of the earth pressure gauge (5) is protected by a wiring protection box (6) installed on the inner wall of the waist test chamber (1).

7. The external grouting test device for shield tunneling underground docking according to claim 1, characterized in that: A one-way valve (11) is installed on the grouting hole (8).

8. The external grouting test device for shield tunneling underground docking according to claim 7, characterized in that: The end of the grouting hole (8) is connected to the connecting pipe (12) via a flange, and the connecting pipe (12) is connected to the drill rod via a flange.

9. The external grouting test device for shield tunneling underground docking according to claim 8, characterized in that: A grout stopper (13) is installed inside the connecting pipe (12), and the uninserted part of the grout stopper (13) is wrapped by a steel pipe sleeve (14).

10. The external grouting test device for shield tunneling underground docking according to claim 1, characterized in that: The bottom test chamber (15) has symmetrical pressure ports (17) on one side. The chamber between the pressure ports (17) has a water inlet (19) and a pressure relief port (18) respectively. Ball valves are installed on the pressure ports (17), water inlet (19) and pressure relief port (18).

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