Synchronous double-liquid slurry with non-attenuated initial fluidity and application of synchronous double-liquid slurry

Abstract

The invention belongs to the technical field of shield grouting construction, and particularly relates to synchronous double-liquid slurry with the initial fluidity not attenuated and application thereof.On-site single-liquid hard slurry is adopted as a liquid A, a coagulant is adopted as a liquid B, and the liquid A and the liquid B are pumped through different pipelines and mixed at the position close to a shield tail grouting hole to form the synchronous double-liquid slurry. The gelling time of the synchronous double-liquid slurry is greatly shortened, a segment ring just coming out of a shield tail can be stabilized in time, and the quality problems of floating, slab staggering, leakage, even cracking and the like of the segment ring are reduced; and moreover, the initial fluidity is almost not lost, the risk of pipe blockage is reduced, and the method has a relatively high popularization value under the existing construction management level in China.

Description

Technical Field

[0001] The invention belongs to the field of shield grouting construction, and particularly relates to a synchronous double-liquid slurry with non-attenuated initial fluidity and application thereof. Background Art

[0002] The shield construction method has been widely used in China for its advantages of safety, environmental protection and speed. Synchronous grouting, as an indispensable key auxiliary construction method in the shield construction process, plays an important role in ensuring the stability of the excavation face and the effective filling of the shield tail gap. The synchronous grouting slurry of the shield tunnel can be roughly divided into two categories: single-liquid type and double-liquid type. The single-liquid slurry can be divided into inert slurry and hard slurry. The double-liquid slurry can be divided into slow-setting type, plastic type and instant setting type according to the initial setting time. The main cementing materials of the single-liquid inert slurry are fly ash and slaked lime. It has good pumpability and low cost, but low strength and long setting time. It is not suitable for projects with high surface settlement control. The single-liquid hard slurry is a single-liquid inert slurry with cement added. Compared with the single-liquid inert slurry, it has better strength. In order to ensure pumpability, its setting time is generally greater than 10h. Under such a long setting time, it is easy to produce a large floating amount of the pipe segment. Double liquid slurry is usually composed of liquid A and liquid B. Liquid A is generally a cement-based material, and liquid B is generally a hardener, usually water glass. The two are pumped from different pipes and mixed to form double liquid slurry when they are about to be injected into the gap of the shield tail. Traditional synchronous double liquid slurry is rarely used in China because of its complex construction process, easy to cause pipe blockage, and easy to cause aging of the shield tail brush. Some scholars have improved the traditional synchronous double liquid slurry by adding retarding components to delay the rapid reaction of cement and water glass, but this method is relatively complicated and has strict requirements on the ratio control. Too much retarder will make the slurry difficult to coagulate for a long time, and too little retarder will not achieve the appropriate retarding effect, and it is difficult to mix on site.

[0003] There is a contradiction between the filling property of the shield tail gap and the pumpability of the slurry during injection in synchronous grouting. Especially when the shield is excavated in the full-section surrounding rock formation, the single-liquid hard slurry in the shield tail gap is easy to flow to the excavation surface along the gap between the shield shell and the formation, resulting in the slurry being unable to fill the shield tail gap. At present, the initial setting time of the single-liquid hard slurry is too long and difficult to control. After being injected into the shield tail gap, it is easy to cause slurry leakage and loss, which cannot meet the filling requirements. The initial setting time of the traditional cement-water glass double-liquid slurry is too short, which is easy to cause pipe blockage and cannot meet the pumpability requirements. Therefore, it is of great significance to study a new type of synchronous double-liquid slurry whose initial fluidity does not decay after the A and B liquids are mixed. Summary of the invention

[0004] In order to solve the problems of long gelation time and high risk of pipe blocking in the prior art, the present invention provides a synchronous dual-liquid slurry with no attenuation of initial fluidity. The specific scheme is as follows:

[0005] A synchronous double-liquid slurry with no attenuation of initial fluidity comprises liquid A and liquid B, wherein the liquid A is a single-liquid hard slurry containing cement-based materials; and the liquid B is a composite accelerator.

[0006] Furthermore, the B liquid includes a coagulant component, a retarding component and a strengthening component.

[0007] Furthermore, the accelerating component includes one or more of aluminum sulfate, silicate or calcium chloride; the retarding component includes one or more of sodium gluconate, aluminum chloride or phosphate; and the strengthening component includes one or two of triethanolamine or silica fume.

[0008] Furthermore, the liquid B includes, by weight, 1 to 5 parts of accelerating component, 0.5 to 1.5 parts of retarding component and 0.15 to 0.25 parts of strengthening component.

[0009] Furthermore, the density of the B liquid is 1.4-1.6 g / cm3, and the solid content is 40-60%.

[0010] Furthermore, the mixing ratio of the B liquid is 0.5-2.5% of the mass of the A liquid.

[0011] Furthermore, the gel time is 4 to 60 minutes.

[0012] Furthermore, the strength of the stone body at 7 days was 1.5-2.0 MPa, and the strength at 28 days was 2.8-3.5 MPa.

[0013] A construction method of the above-mentioned synchronous double-liquid slurry with no attenuation of initial fluidity is as follows: according to the mixing ratio, liquid A and liquid B are pumped from different pipelines, mixed near the shield tail grouting hole, and synchronous double-liquid slurry is formed after mixing.

[0014] An application of the above-mentioned synchronous dual-liquid slurry with unattenuated initial fluidity in shield construction.

[0015] By adopting the above scheme, the method of the present invention has the following advantages:

[0016] 1. The gelling time of the synchronous double-liquid slurry of the present invention is adjustable, which is significantly shorter than that of the single-liquid slurry. When applied on site, it can control the floating of the pipe segments and improve the assembly quality of the pipe segments. While reducing the risk of pipe blockage, its later strength does not decay.

[0017] 2. Compared with the traditional cement-water glass double liquid slurry, the synchronous double liquid slurry of the present invention does not lose its initial fluidity, and the pumpable time accounts for about 75% of the total gelling time, which coordinates the contradiction between the filling property of the shield tail gap and the pumpability during slurry injection.

[0018] 3. The synchronous dual-liquid slurry of the present invention has been verified by field tests, and monitoring data show that it has a good control effect on the posture of the pipe segment, and the number of leakage points in the pipe segment annular seam is significantly reduced, which is conducive to reducing the subsequent plugging costs.

[0019] 4. The present invention creatively combines accelerating setting components, retarding setting components and strengthening components, and the range of the amount that can be added is large and easy to control. It overcomes the technical prejudice that adding retarding components will make the ratio control requirements strict and the on-site mixing difficult. Under the current domestic construction management level, it has great promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a photo of Solution B of the present invention.

[0021] Figure 2 This is a graph showing how the gelling time of the synchronous dual-liquid slurry of the present invention changes with the amount of liquid B added.

[0022] Figure 3 This is a graph showing the relationship between the initial fluidity of the synchronous dual-liquid slurry of the present invention and the amount of B liquid added.

[0023] Figure 4 This is a graph showing how the fluidity of the new synchronous dual-liquid slurry changes with time when the B liquid dosage is 1.5%.

[0024] Figure 5 This is a graph showing the effect of the amount of liquid B on the compressive strength of the slurry. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1:

[0027] According to the mass ratio of 4:1:0.2, aluminum sulfate, sodium gluconate and triethanolamine are taken, dispersed with water, and liquid B with a solid content of 48% is prepared. Liquid B and liquid A are mixed at a ratio of 1.5% of the mass of liquid A to prepare the synchronous double liquid slurry of the rear wall of the shield tail. The slurry gels after 20 minutes.

[0028] Embodiment 2:

[0029] According to the mass ratio of 4:1:0.2, aluminum sulfate, sodium gluconate and triethanolamine are taken, dispersed with water, and liquid B with a solid content of 48% is prepared. Liquid B and liquid A are mixed at a ratio of 0.5% of the mass of liquid A to prepare the synchronous double liquid slurry for the rear wall of the shield tail. The slurry gels after 60 minutes.

[0030] Embodiment 3:

[0031] According to the mass ratio of 4:1:0.2, aluminum sulfate, sodium gluconate and triethanolamine were taken, dispersed with water, and liquid B with a solid content of 48% was prepared. Liquid B and liquid A were mixed at a ratio of 1.0% of the mass of liquid A to prepare the synchronous double liquid slurry of the rear wall of the shield tail. The slurry gelled after 30 minutes.

[0032] Embodiment 4:

[0033] According to the mass ratio of 4:1:0.2, aluminum sulfate, sodium gluconate and triethanolamine were taken, dispersed with water, and liquid B with a solid content of 48% was prepared. Liquid B and liquid A were mixed at a ratio of 2.0% of the mass of liquid A to prepare the synchronous double liquid slurry for the rear wall of the shield tail. The slurry gelled after 5 minutes.

[0034] Embodiment 5:

[0035] According to the mass ratio of 4:1:0.2, aluminum sulfate, sodium gluconate and triethanolamine are taken, dispersed with water, and liquid B with a solid content of 48% is prepared. Liquid B and liquid A are mixed at a ratio of 2.5% of the mass of liquid A to prepare the synchronous double liquid slurry of the rear wall of the shield tail. The slurry will gel after 3 to 4 minutes.

[0036] Example sample test:

[0037] 1. Use the inverted cup method to conduct a gel time test to explore the influence of liquid B on the gel time. The test results are as follows Figure 2 As shown in the figure, the gel time of the slurry gradually decreases with the increase of the amount of liquid B. Adding 2.5% of liquid B can reduce the gel time of the slurry from 180 minutes to 3-4 minutes, a decrease of 97.8%. Adding only 2.5% of liquid B can reduce the gel time by two-thirds. The gel time of the slurry is positively correlated with the amount of liquid B. In practical applications, the reasonable amount of addition can be determined based on the working conditions and the gel time curve to ensure that the gel time meets the pumpability requirements of the construction team for back-wall grouting.

[0038] 2. Use a jumping table to conduct a fluidity test to explore the influence of liquid B on fluidity. The initial fluidity of the slurry changes with the amount of liquid B. Figure 3 As shown in the figure, the amount of liquid B has little effect on the initial fluidity of the slurry. When the amount of liquid B is large, the fluidity of the slurry even increases slightly, indicating that as long as the fluidity of the single-liquid hard slurry meets the requirements, the new synchronous dual-liquid slurry can meet the initial fluidity requirements.

[0039] 3. Under the condition of 1.5% B liquid dosage in Example 1, the fluidity of the synchronous dual-liquid slurry was further observed. The change of fluidity with time is shown as follows: Figure 4The gelling time of the synchronous dual-liquid slurry of Example 1 is 20 minutes. It can be seen from the figure that the fluidity of the slurry is almost not lost in the first 10 minutes, and it starts to decrease rapidly after 10 minutes. The pumpability requirements can be met before 15 minutes, and the pumpable time accounts for only 75% of the total.

[0040] 4. Use an unconfined compressive strength instrument to test the compressive strength of the stone body and explore the influence of liquid B on the compressive strength of the stone body. The change of the compressive strength of the stone body with the amount of liquid B is as follows: Figure 5 As shown in the figure, the B liquid dosage has little effect on the compressive strength of the slurry in general, and the compressive strength of the slurry shows an upward trend with the B liquid dosage. The 7d strength when the B liquid dosage is 2.5% is 10% higher than that of the pure A liquid without addition. The B liquid can slightly improve the strength of the A liquid slurry, and the strength of the synchronous dual liquid slurry of the present invention meets the requirements of 7d strength greater than 0.7MPa and 28d strength greater than 2.5MPa in practical applications.

[0041] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims

1. A synchronous dual-liquid slurry with no initial fluidity attenuation, characterized in that: It comprises liquid A and liquid B, wherein the liquid A is a single-liquid hard slurry containing cement-based materials; and the liquid B is a composite accelerator.

2. The synchronous dual-liquid slurry with non-attenuated initial fluidity according to claim 1, characterized in that: The B liquid comprises a coagulant component, a retarding component and a strengthening component.

3. The synchronous dual-liquid slurry with non-attenuated initial fluidity according to claim 2, characterized in that: The accelerating component includes one or more of aluminum sulfate, silicate or calcium chloride; the retarding component includes one or more of sodium gluconate, aluminum chloride or phosphate; and the strengthening component includes one or two of triethanolamine or silica fume.

4. The synchronous dual-liquid slurry with non-attenuated initial fluidity according to claim 1, characterized in that: In parts by mass, the liquid B includes 1 to 5 parts of accelerating component, 0.5 to 1.5 parts of retarding component and 0.15 to 0.25 parts of strengthening component.

5. The synchronous dual-liquid slurry with non-attenuated initial fluidity according to claim 1, characterized in that: The density of the B liquid is 1.4-1.6 g / cm 3 , solid content is 40-60%.

6. The synchronous dual-liquid slurry with non-attenuated initial fluidity according to claim 1, characterized in that: The mixing ratio of the B liquid is 0.5-2.5% of the mass of the A liquid.

7. The synchronous dual-liquid slurry with non-attenuated initial fluidity according to claim 1, characterized in that: The gelation time is 4 to 60 minutes.

8. The synchronous dual-liquid slurry with non-attenuated initial fluidity according to claim 1, characterized in that: The strength of the stone body is 1.5-2.0 MPa at 7 days and 2.8-3.5 MPa at 28 days.

9. A construction method of synchronous dual-liquid slurry with no attenuation of initial fluidity according to any one of claims 1 to 8, characterized in that: According to the mixing ratio, liquid A and liquid B are pumped through different pipelines and mixed near the shield tail grouting hole to form a synchronous double-liquid slurry.

10. Use of the synchronous dual-liquid slurry with unattenuated initial fluidity as claimed in any one of claims 1 to 8 in shield construction.

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