Double-liquid water stop slurry material for shield synchronous hoop and application method of double-liquid water stop slurry material

Abstract

The invention discloses a double-liquid water stop slurry material for a shield synchronous hoop and an application method thereof, the slurry material comprises a liquid A and a liquid B. The liquid A comprises the following raw materials by weight: 300-350 parts of cement; 2-8 parts of caustic soda; 1 to 5 parts of cellulose; 0.5 to 3 parts of a retarder; 300 to 350 parts of water; the liquid B is prepared from the following raw materials in parts by weight: 1 part of water glass; and 1 to 1.5 parts of water. By means of the optimized formula and technology, the problems that traditional single-liquid slurry is too slow in condensation and traditional double-liquid slurry cannot be transported in a plant mixing mode are solved, long-distance transportation stability of the liquid A and instantaneous reaction condensation of the double-liquid behind the segment wall are achieved, and therefore the dense and firm hoop water stop structure is efficiently constructed.

Description

Technical Field

[0001] This invention relates to the field of grouting materials technology, and in particular to a double-liquid water-stopping grout material for shield tunnel synchronous ring hoop and its application method. Background Technology

[0002] During shield tunneling, after the shield tail separates from the tunnel lining segments, a ring-shaped void (referred to as the "backwall void") is formed between the segments and the soil. During tunneling, groundwater can seep through this void, creating a concentrated seepage channel and seriously threatening construction safety. Synchronous ring grouting is an effective method for addressing this problem. It aims to create a closed, ring-shaped solidified body (i.e., a "water-stopping ring") in the water-bearing section, thereby cutting off the water flow.

[0003] However, existing technologies have inherent limitations in achieving efficient ring grouting: Limitations of traditional single-component slurries: To ensure stability during long-distance transport, retarders need to be added, but this delays their setting in the annulus and makes them easily dispersed in a flowing water environment, making rapid setting difficult. If rapid setting is desired, the transport stability of the plant-mixed slurry cannot be guaranteed, requiring extremely high on-site mixing capabilities.

[0004] Limitations of traditional two-component grouts: Although the cement-water glass system can achieve rapid setting, it has traditionally been used mostly for emergency leak sealing. Its A-component (cement-based) can hardly remain stable for a long time after plant mixing, and must be mixed on-site or used for a very short time, which cannot meet the needs of large-scale, long-distance synchronous ring grouting.

[0005] Therefore, developing a synchronous ring grouting system that balances the long-term stability of plant-mixed grout with the rapid setting and instantaneous response on-site has become a key innovative approach to solving the leakage problem in shield tunneling in water-rich strata. Summary of the Invention

[0006] The main objective of this invention is to provide a double-liquid water-stopping grout material for shield tunneling synchronous rings and its application method, aiming to solve at least one of the above-mentioned technical problems.

[0007] To achieve the above objectives, the present invention provides a dual-liquid water-stopping grout material for shield tunneling synchronous rings, comprising liquid A and liquid B, wherein liquid A, by weight, comprises the following raw materials: Cement: 300-350 parts; Caustic soda: 2-8 parts; Cellulose: 1-5 parts; Retarder: 0.5–3 parts; Water: 300-350 parts; Liquid B, by weight, comprises the following raw materials: Water glass: 1 part; Water: 1 to 1.5 parts.

[0008] Furthermore, the amount of liquid B is 40-60% of the volume of liquid A, and the modulus of the water glass is 2.2-3.0.

[0009] Furthermore, the caustic soda (sodium hydroxide) is industrial-grade flake caustic soda or soda ash, and its function is to pre-adjust the alkalinity of the cement paste, provide an optimized environment for rapid reaction with water glass (liquid B), and help improve the stability of liquid A.

[0010] Furthermore, the cement in liquid A is ordinary Portland cement of grade P.O42.5 or higher.

[0011] Furthermore, the cellulose in the A solution is hydroxypropyl methylcellulose (HPMC) with a viscosity range of 80,000–150,000 mPa·s. Its core function is to ensure the uniformity, water retention, and thixotropy of the plant-mixed A solution during long-term transportation and storage, and to prevent segregation and bleeding.

[0012] Furthermore, the retarder in liquid A is sodium gluconate, citric acid, or sodium tripolyphosphate. Its key function is to deeply inhibit cement hydration during transportation and waiting, ensuring its workability, and this inhibitory effect can be quickly overcome after mixing with liquid B.

[0013] Water glass is diluted with 1 to 1.5 parts water to precisely adjust the gelation time and flowability, ensuring uniform and efficient mixing with liquid A in the mixer.

[0014] The present invention also provides a method for applying the above-mentioned double-liquid water-stopping grout material for shield tunnel synchronous rings, comprising the following steps: (1) Raw material preparation 1.1) Mixing and transportation of liquid A: The homogenized liquid A is centrally mixed at the mixing plant, loaded into mixer trucks, and transported to the construction site; 1.2) On-site preparation of solution B: At the construction site, water glass and water are mixed in proportion to prepare solution B for later use; (2) Simultaneous grouting with two liquids 2.1) Pump liquid A and liquid B through independent pipelines to the tunnel boring machine's synchronous grouting system; 2.2) The two grouts, liquid A and liquid B, are thoroughly mixed in a static mixer near the outlet of the shield tail grouting pipe to obtain a two-liquid grout; 2.3) The double-liquid slurry is injected into the voids behind the pipe segment wall, and after gelation, it forms a ring-shaped water-stop structure.

[0015] The beneficial effects of this invention are reflected in: This invention solves the problems of slow coagulation of traditional single-liquid slurry and inability to plant mix and transport traditional two-liquid slurry by optimizing the formula and process. It achieves stable long-distance transportation of liquid A and instantaneous reaction and coagulation of the two liquids behind the pipe wall, thereby efficiently constructing a dense and robust ring-shaped water-stop structure.

[0016] This invention is particularly suitable for synchronous ring grouting in water-rich strata such as sand layers and fractured rock layers, using a combination of plant-mixed liquid A and on-site liquid B to quickly construct an efficient water-stop barrier, achieving immediate sealing of water inflow and stabilizing tunnel segments. It is applicable to shield tunneling in high-pressure, water-rich strata where grouting sites are far apart, site conditions are limited, and the speed and effectiveness of water inflow sealing are extremely critical. Specific advantages are as follows: Solving the problem of plant mixing and rapid setting: The design of "plant-mixed stabilized liquid A + on-site activated liquid B" ensures both long-term stability and instantaneous reactivity. Liquid A can be stably stored for several hours, and its slow-setting state is instantly broken when mixed with liquid B, achieving immediate sealing.

[0017] Ring forming and water-stopping performance: The two-component grout sets quickly in the voids and has high early strength, which can effectively resist groundwater erosion and quickly form a complete, dense, and high-strength ring, with a water-stopping effect far superior to that of the single-component grout.

[0018] Improving construction quality, efficiency, and standardization: Plant-mixed A-grade solution ensures stable and uniform quality, overcoming the problems of insufficient on-site mixing capacity and quality fluctuations. The entire process is highly standardized, significantly improving construction efficiency and reliability. Detailed Implementation

[0019] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0020] Unless otherwise specified, the raw materials, reagents or devices used in the following embodiments can be obtained from conventional commercial sources or by existing known methods; unless otherwise specified, the methods used in the embodiments of the present invention are methods mastered by those skilled in the art.

[0021] Example 1 Preparation of a two-liquid water-stopping grout material for shield tunnel synchronous rings The formula for liquid A by weight is as follows: 330 parts water, 3 parts caustic soda, 2.5 parts sodium gluconate, 1 part hydroxypropyl methylcellulose (viscosity 150,000 mPa·s), and 300 parts ordinary silicate cement (P.O42.5R). All raw materials are mixed evenly to obtain liquid A.

[0022] The formula for solution B by weight is: 1 part water glass (modulus 2.8) and 1.5 parts water; mix all raw materials evenly to obtain solution B.

[0023] The volume of solution B is 40% of the volume of solution A. Performance indicators: Initial fluidity of liquid A is 280 mm, and ≥260 mm after standing for 6 hours; initial coagulation of the two liquids is 50-70 seconds, and the strength is ≥0.8 MPa after 1 hour.

[0024] Example 2 Preparation of a two-liquid water-stopping grout material for shield tunnel synchronous rings The formula for liquid A by weight is as follows: 320 parts water, 8 parts caustic soda, 0.5 parts citric acid, 5 parts hydroxypropyl methylcellulose (viscosity 80,000 mPa·s), and 350 parts ordinary silicate cement. All raw materials are mixed evenly to obtain liquid A.

[0025] The formula for solution B by weight is: 1 part water glass (modulus 2.4) and 1 part water; mix all raw materials evenly to obtain solution B.

[0026] The volume of solution B is 50% of the volume of solution A; Performance indicators: Initial fluidity of liquid A is 250 mm, and ≥230 mm after standing for 4 hours; initial coagulation of the two liquids after mixing is 20-40 seconds, and the strength is ≥1.5 MPa after 1 hour.

[0027] Example 3 Preparation of a two-liquid water-stopping grout material for shield tunnel synchronous rings The formula for liquid A by weight is as follows: 325 parts water, 5 parts caustic soda, 1.5 parts sodium tripolyphosphate, 3 parts hydroxypropyl methylcellulose (viscosity 100,000 mPa·s), and 320 parts ordinary silicate cement. All raw materials are mixed evenly to obtain liquid A.

[0028] The formula for solution B by weight is: 1 part water glass (modulus 2.6) and 1.2 parts water; mix all raw materials evenly to obtain solution B.

[0029] The volume of solution B is 60% of the volume of solution A; Performance indicators: Initial fluidity of liquid A is 270 mm, and ≥250 mm after standing for 4 hours; initial coagulation of the two liquids after mixing is 30-50 seconds, and the strength is ≥1.2 MPa after 1 hour.

[0030] Example 4 Synchronous double-liquid ring-hoop water-stop grouting The grouts prepared in Examples 1-3 were injected using the following method: (1) Pump liquid A and liquid B through independent pipelines to the synchronous grouting system of the tunnel boring machine; (2) The two slurries, A and B, are fully mixed in a static mixer near the outlet of the shield tail grouting pipe to obtain a two-liquid slurry; (3) The double liquid slurry is injected into the gap behind the pipe segment wall and solidified to form a ring-shaped water-stop structure.

[0031] Grouting pressure control: Normal pressure 0.2~0.4MPa, maximum pressure ≤0.5MPa. A strategy of initially low pressure (0.2~0.25MPa) and gradually increasing to the working pressure as the grout ring forms is adopted.

[0032] Grouting volume calculation: According to the formula Q=π×(D2) d2)×L×λ / 4Q=π×(D2 The theoretical quantity is calculated using d2)×L×λ / 4, and the construction is carried out using the "pressure-flow" dual control principle.

[0033] in: D: Shield excavation diameter (m) d: Outer diameter of the tunnel segment (m) L: Length of the grouting section (m) λ: Grouting rate, taken as 1.2-1.8 (upper limit for water-rich strata). Grouting hole layout: Utilize the existing synchronous grouting system of the shield machine, and add a water glass grouting system. The two pipes are connected in parallel at the tail of the shield and fully mixed in a static mixer before being injected synchronously into the soil layer to fill the construction gaps between the shield machine excavation and the segments. The specific injection volume is controlled by the grouting pipe reserved at the tail of the shield, with the grouting volume controlled according to the ratio of 80% for the upper part and 20% for the lower part.

[0034] Comparative Example 1 Traditional single-liquid slurry system Formula: Cement: Water: Retarder = 1:1:0.01 (by weight).

[0035] Grouting process: After mixing at the plant, the mixture is transported to the site and injected directly through a single-liquid grouting system.

[0036] Comparative Example 2 Traditional cement-water glass two-component grouting system Formula for Liquid A: Pure cement slurry, water-cement ratio = 1:1.

[0037] Solution B formulation: Uses water glass with a modulus of 2.8, for direct use.

[0038] Grouting process: Liquid A is mixed on-site and injected with Liquid B through a simple mixing device.

[0039] Experimental Example 1 The performance of the grouting materials of Example 3 and Comparative Examples 1 and 2 was tested, and the results are shown in Table 1 below: Table 1 Comparison of Performance and Process Parameters

[0040] Based on the above comparison, the following conclusions can be drawn: 1. Compared to traditional single-liquid slurries: This invention resolves the contradiction between setting rate and stability. Traditional single-liquid slurries sacrifice setting rate for pumpability, resulting in ineffectiveness in water-rich formations; while this invention, through a two-liquid system, achieves the ideal state of stability during transportation and rapid setting after injection, thus improving water-stopping performance.

[0041] 2. Compared to traditional two-component slurries: This invention solves the problem of their inability to adapt to modern, large-scale, long-distance shield tunneling construction. The A-component (pure cement slurry) of traditional two-component slurries lacks stability for long-distance transportation, greatly limiting its application range. This invention, by introducing cellulose (water-retaining and thickening agent) and a retarder (for precise hydration control), ensures the stability of the A-component's performance, allowing for both plant mixing and long-distance transportation.

[0042] 3. Improved performance and reliability: Traditional two-component slurry gelation time is too fast and difficult to control, easily leading to pipe blockage, and the resulting solidified body is brittle and prone to shrinkage and cracking. This invention, through pre-adjusting alkalinity with caustic soda and dilution with water glass, achieves a milder and more controllable reaction, resulting in a denser and more durable ring structure.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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.

Claims

1. A dual-liquid water-stopping grout material for shield tunneling synchronous rings, comprising liquid A and liquid B, characterized in that, Liquid A comprises, by weight, the following raw materials: Cement: 300-350 parts; Caustic soda: 2-8 parts; Cellulose: 1-5 parts; Retarder: 0.5–3 parts; Water: 300-350 parts; Liquid B, by weight, comprises the following raw materials: Water glass: 1 part; Water: 1 to 1.5 parts.

2. The double-liquid water-stopping grout material for shield tunneling synchronous rings as described in claim 1, characterized in that, The amount of liquid B is 40-60% of the volume of liquid A, and the modulus of the water glass is 2.2-3.

0.

3. The double-liquid water-stopping grout material for shield tunneling synchronous rings as described in claim 1 or 2, characterized in that, The cement in liquid A is ordinary Portland cement of grade P.O42.5 or higher.

4. The double-liquid water-stopping grout material for shield tunneling synchronous rings as described in claim 1 or 2, characterized in that, The cellulose in solution A is hydroxypropyl methylcellulose with a viscosity range of 80,000 to 150,000 mPa·s.

5. The double-liquid water-stopping grout material for shield tunneling synchronous rings as described in claim 1 or 2, characterized in that, The retarder in solution A is sodium gluconate, citric acid, or sodium tripolyphosphate.

6. The application method of the double-liquid water-stopping grout material for shield tunnel synchronous ring as described in any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Raw material preparation 1.1) Mixing and transportation of liquid A: The homogenized liquid A is centrally mixed at the mixing plant, loaded into mixer trucks, and transported to the construction site; 1.2) On-site preparation of solution B: At the construction site, water glass and water are mixed in proportion to prepare solution B for later use; (2) Simultaneous grouting with two liquids 2.1) Pump liquid A and liquid B through independent pipelines to the tunnel boring machine's synchronous grouting system; 2.2) The two grouts, liquid A and liquid B, are thoroughly mixed in a static mixer near the outlet of the shield tail grouting pipe to obtain a two-liquid grout; 2.3) The double-liquid slurry is injected into the voids behind the pipe segment wall, and after gelation, it forms a ring-shaped water-stop structure.

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