High-pressure water-rich stratum shield synchronous grouting water and land condensation time difference measuring method and shield synchronous grouting component regulating and controlling method

Abstract

The invention discloses a high-pressure water-rich stratum shield synchronous grouting water and land condensation time difference determination method and a shield synchronous grouting component regulation and control method, and relates to the technical field of material detection. According to the measuring method, the land forming test piece and the water forming test piece are prepared respectively, the environment of shield synchronous grouting in land and high-pressure water-rich strata can be simulated, and the condensation characteristic of shield synchronous grouting slurry in actual construction can be accurately reflected. By simulating the real working condition, parameters more conforming to the actual condition can be provided for shield construction in the high-pressure water-rich environment, the construction efficiency can be accelerated, and the construction quality and safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of material detection, and in particular to a method for measuring the water-land setting time difference of shield synchronous grouting in a high-pressure water-rich stratum and a method for regulating the components of shield synchronous grouting. Background Art

[0002] With the acceleration of urbanization and the deepening of underground space development, the shield method has become the mainstream technology for the construction of underground projects such as subway tunnels, urban integrated pipeline corridors, high-speed railways, highways, and municipal roads due to its advantages such as high efficiency and safety. Synchronous grouting is a key link in the construction of shield tunnels in high-pressure water-rich strata. By timely filling the gaps at the shield tail, it plays a decisive role in controlling stratum deformation, preventing surface subsidence, and ensuring the stability of the tunnel structure. In actual construction, the synchronous grouting slurry needs to be injected into an annular gap filled with groundwater. Its performance must not only meet the setting time requirements of land construction, but also adapt to the complex underwater environment, ensuring strong resistance to water dispersion and water scouring under high water pressure conditions, and achieving rapid setting and hardening after injection into the water.

[0003] Currently, the differences in the setting time of synchronous grouting slurries between water and land environments significantly impact project quality and construction safety. Furthermore, commonly used synchronous grouting materials for shield tunneling in high-pressure, water-rich strata exhibit different setting properties in water and land environments due to their composition and properties. Furthermore, the difficulty of controlling setting time is further exacerbated by factors such as differences in raw material quality and irrational slurry mix ratios. However, within the existing performance evaluation system for synchronous grouting slurries for shield tunneling in high-pressure, water-rich strata, traditional land-based setting time determination methods struggle to accurately reflect the true setting characteristics of slurries in high-pressure, water-rich environments.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for measuring the water-land coagulation time difference of shield synchronous grouting in high-pressure water-rich strata and a method for regulating the components of shield synchronous grouting. The method is scientific and accurate, which is conducive to optimizing the design of synchronous grouting slurry mix ratio, ensuring the quality and safety of shield engineering construction, and promoting the development of underground engineering technology.

[0006] The present invention is achieved in that: In a first aspect, the present invention provides a method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata, comprising: S1. Preparation of synchronous grouting slurry: Cement, fly ash, river sand, water and anti-dispersant are mixed to form shield synchronous grouting slurry; S2. Testing the Land Setting Time: Take the shield synchronous grouting slurry and put it into a land mortar container, and put it 10mm below the upper edge of the container. Knock the land mortar container and smooth it out to form a land forming test piece. Test the land setting time t of the land forming test piece according to the provisions of the "Setting Time Test" in the current industry standard "Standard for Test Methods of Basic Properties of Building Mortar" JGJ / T 70. 陆 ; S3. Test the setting time in water: completely place the underwater mortar container into the water container, with the distance from the upper opening of the water container to the upper opening of the underwater mortar container being 65-75mm; fill the water container and the underwater mortar container with water, and point the caulking gun filled with the shield synchronous grouting slurry vertically downward, with the round mouth of the caulking gun close to the water surface, aimed at the underwater mortar container, and push the piston of the caulking gun to uniformly inject the shield synchronous grouting slurry into the underwater mortar container, so that the shield synchronous grouting slurry penetrates the water layer and falls into the underwater mortar container and accumulates to form a small hill; let it stand for 5min~10min, gently take out the underwater mortar container filled with slurry from the water, knock the underwater mortar container, and scrape off the upper slurry with a spatula. The slurry should be 10mm below the upper opening of the container as an underwater molding test piece. The underwater molding test piece is tested according to the current industry standard "Standard for Test Methods for Basic Properties of Building Mortar" JGJ / T The coagulation time specified in the "Coagulation Test" in 70 is the coagulation time of the test specimen formed in water, referred to as the coagulation time in water. 水 ; S4. Calculation of the time difference between land and water condensation: According to Δt= t 水 -t 陆 Calculate the time difference between land and water condensation, where Δt is the time difference between land and water condensation; Δt is less than 60 minutes.

[0007] In an optional embodiment, the caulking gun is provided with a pressure sensor for detecting the extrusion pressure of the caulking gun and a driving mechanism for driving the piston, and the pressure sensor is connected to the driving mechanism for signal connection.

[0008] In an optional embodiment, the pressure driving the piston is maintained at 0.5-1.5 kPa.

[0009] In an optional embodiment, before detecting the setting time, the method further includes testing the expansion degree of the shield synchronous grouting slurry, and the expansion degree meets the requirements of 400mm-500mm.

[0010] In an optional embodiment, the caulking gun may inject the shield synchronous grouting slurry into the underwater mortar container in multiple injections, with the interval between each injection not exceeding 2 minutes.

[0011] In an optional embodiment, the cement shall comply with the provisions of Appendix A of GB 8076 or the strength grade 42.5 silicate or ordinary silicate engineering cement specified in GB 175; the fly ash shall comply with the provisions of Grade II fly ash in GB / T 1596, with a water requirement ratio of 100±2; the river sand shall comply with the medium sand requirements of Zone II in GB / T 14684, with a fineness modulus of 2.6-2.9 and a mud content of less than 1%.

[0012] In an optional embodiment, the land condensation time, the water condensation time, and the difference between the water and land condensation time are all accurate to 1 minute.

[0013] In an optional embodiment, a layer of clean sand is laid inside the water container to adjust the distance from the upper opening of the water container to the upper opening of the mortar container in water.

[0014] In an optional embodiment, the determination of the land setting time and the water setting time of the shield synchronous grouting slurry should be carried out by taking two samples of the shield synchronous grouting slurry in the same dish, and the average value of the two test results should be used as the setting time value of the mortar. The error of the secondary test results should not be greater than 30 minutes, otherwise it should be re-measured.

[0015] In the second aspect, the present invention provides a method for regulating the composition of shield synchronous grouting, which includes a method for determining the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata as described in any of the above embodiments; when Δt does not meet the requirement of less than 60 minutes, adjust the composition ratio of the shield synchronous grouting slurry, and perform detection again according to the above method until Δt meets the requirement of less than 60 minutes.

[0016] The present invention has the following beneficial effects: The present invention provides a method for measuring the difference in setting time between land and water for shield simultaneous grouting in high-pressure, water-rich strata. The method involves preparing land-molded specimens and underwater-molded specimens, respectively. This method can simulate shield simultaneous grouting in land and high-pressure, water-rich strata environments, accurately reflecting the setting characteristics of shield simultaneous grouting slurry during actual construction. By simulating real-world working conditions, parameters more in line with actual conditions can be provided for shield construction in high-pressure, water-rich environments, helping to accelerate construction efficiency and improve construction quality and safety. The present invention uses the penetration resistance method of the "setting time test" in the current industry standard "Standard for Test Methods for Basic Properties of Building Mortar" JGJ / T 70 to measure the setting time, and can more accurately record the setting time achieved by specimens formed in different environments. The penetration resistance method is a mature method for determining setting time, with high accuracy and reliability. Furthermore, various influencing factors are strictly controlled and measured during the test process, further improving detection accuracy and ensuring accurate assessment of the slurry setting time. The present invention takes into account the influence of multiple factors such as the material composition, type and dosage of water-resistant dispersant, water-cement ratio, etc. in cement-based single-liquid grouting materials on the setting time difference. Through comprehensive analysis of multiple factors, the interaction and influence rules between various factors can be fully understood, which is helpful to optimize the mix ratio of synchronous grouting slurry and shorten the setting time of slurry in water. The present invention considers the reasonable determination of the limit value of the water-land setting time difference of cement-based single-liquid as a means of evaluating the water-dispersion resistance and water-scouring resistance of shield synchronous grouting slurry. After a large number of tests and verifications, it was determined that the limit value of the water-land setting time difference is 60 minutes. When the setting time difference of a certain shield cement-based single-liquid synchronous grouting slurry is less than 60 minutes, it is characterized as having high-quality water-dispersion resistance and water-scouring resistance. DETAILED DESCRIPTION

[0017] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0018] This study found that the difference in the setting time of synchronous grouting slurry in water and land environments significantly affects the quality of the project and construction safety. If the difference in the setting time between water and land is too large, it means that the slurry is easily washed and diluted in the water, resulting in delayed setting time, increased water-cement ratio, insufficient strength development, and causing serious accidents such as stratum collapse and tunnel leakage; on the contrary, reasonable control of the difference in the setting time between water and land can make the slurry quickly set and harden underwater to form an effective support structure and maintain the stability of the stratum. However, in the existing performance evaluation system of synchronous grouting slurry for shield tunneling in high-pressure water-rich strata, there is a lack of standardized measurement methods for the difference in setting time between water and land. The traditional land setting time measurement method is difficult to accurately reflect the true setting characteristics of the slurry in a high-pressure water-rich environment. To this end, the present invention provides a method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata, which comprises the following steps: S1. Preparation of synchronous grouting slurry.

[0019] Cement, fly ash, river sand, water and anti-dispersant are mixed to form shield synchronous grouting slurry.

[0020] Among them, cement shall comply with the provisions of Appendix A of GB 8076 or silicate or ordinary silicate engineering cement with strength grade 42.5 specified in GB 175; fly ash shall comply with the provisions of Grade II fly ash in GB / T 1596, with a water requirement ratio of 100±2, uniform color, and no impurities such as oil or dirt. When mixed with cement and water, no obvious irritating gas shall be released, and it shall have good adaptability with other materials and little loss of flow properties; river sand shall comply with the medium sand requirements of Zone II in GB / T 14684, with a fineness modulus of 2.6-2.9 and a mud content of less than 1%.

[0021] Before testing the setting time, the shield tunneling grouting slurry's expansion is also tested, with the expansion required to meet the 400mm-500mm standard. This expansion test is conducted in accordance with the "Slump Expansion Test" in the current national standard, GB / T50448, Technical Specification for the Application of Cement-Based Grouting Materials.

[0022] The mixing method for the cement, fly ash, river sand, water, and anti-dispersant mentioned above follows the current "Standard for Test Methods for Basic Properties of Building Mortar" (JGJ / T 70). Specifically, wet the mixing pot and add the river sand first. If the anti-dispersant is a powder, it should be premixed with the cement and fly ash before adding it together. Dry mix for 30 seconds. Slowly add 80% of the mixing water and continue stirring for 120 seconds. Test the slurry's spread. If the spread exceeds the specified range, adjust the mixing water until the specified spread is achieved. If the anti-dispersant is an aqueous solution, it should be added simultaneously with the mixing water. The mixing time after adding the anti-dispersant can be extended by 1 to 2 minutes.

[0023] S2. Test the land setting time.

[0024] Take the shield synchronous grouting slurry and put it into the land mortar container, and put it 10mm below the upper edge of the container. Knock the land mortar container and smooth it out to make it a land forming test piece. The land forming test piece is tested for the land setting time t according to the provisions of the "Setting Time Test" in the current industry standard "Standard for Test Methods of Basic Properties of Building Mortar" JGJ∕T 70. 陆 , accurate to 1 minute.

[0025] S3. Test the condensation time in water.

[0026] Lay a layer of clean sand inside the water container, place the underwater mortar container into the water container, and the distance from the upper end of the water container to the upper end of the underwater mortar container is 65-75mm; fill the water container and the underwater mortar container with water, and point the caulking gun filled with shield synchronous grouting slurry vertically downward, with the round mouth of the caulking gun close to the water surface, aim at the underwater mortar container, and push the piston of the caulking gun to inject the shield synchronous grouting slurry into the underwater mortar container at a uniform speed, so that the shield synchronous grouting slurry penetrates the water layer and falls into the underwater mortar container and accumulates to form a small hill; let it stand for 5min~10min, gently take out the underwater mortar container filled with slurry from the water, knock on the underwater mortar container, and scrape off the upper slurry with a spatula. The slurry should be 10mm lower than the upper end of the container as an underwater molding specimen. The underwater molding specimen is tested according to the current industry standard "Standard for Test Methods for Basic Properties of Building Mortar" JGJ∕T The setting time test stipulated in 70 is the setting time of the molded specimen in water, referred to as the setting time in water, t 水 , accurate to 1 minute.

[0027] In the present invention, the actual construction environment is simulated. When the test piece is formed in water, the round nozzle of the caulking gun is close to the water surface. When the shield synchronous grouting slurry is injected into the underwater mortar container, the shield synchronous grouting slurry meets the water as soon as it comes out of the round nozzle of the caulking gun. The shield synchronous grouting slurry will penetrate the entire water layer, which is consistent with the actual construction environment.

[0028] In actual construction, when the synchronous grouting slurry is poured behind the shield segments, it is pumped at a certain pressure. In order to simulate the actual construction environment, in the present invention, the caulking gun used for the underwater molding test piece is equipped with a pressure sensor for detecting the extrusion pressure of the caulking gun and a driving mechanism for driving the piston. The pressure sensor can display and adjust the pressure. The pressure sensor is connected to the driving mechanism signal, and the pressure sensor transmits the pressure signal to the driving mechanism, so that the driving mechanism pressurizes and drives the piston at a certain pressure, thereby generating pressure for the synchronous grouting slurry of the shield. The pressure of the driving piston is maintained at 0.5-1.5kPa. Through the above pressure simulation, the synchronous grouting slurry of the shield is ejected from the round nozzle of the caulking gun and injected into the underwater mortar container.

[0029] When injecting shield synchronous grouting slurry into the underwater mortar container with a caulking gun, the injection can be done in multiple times, with the interval between each injection not exceeding 2 minutes. By controlling the interval time, it is possible to avoid long intervals affecting the curing parameters of the underwater molded specimens.

[0030] It should be understood that for the determination of the land setting time and the water setting time of the shield synchronous grouting slurry, two shield synchronous grouting slurry samples should be taken from the same plate respectively, and the average value of the two test results should be used as the setting time value of the mortar. The error of the secondary test results should not be greater than 30 minutes, otherwise it should be re-measured.

[0031] S4. Calculation of the time difference between water and land condensation.

[0032] According to Δt= t 水 -t 陆 Calculate the time difference between land and water condensation: where Δt is the time difference between land and water condensation, accurate to 1 minute; Δt must be less than 60 minutes.

[0033] The present invention provides a method for measuring the difference in setting time between land and water for shield simultaneous grouting in high-pressure, water-rich strata. The method prepares land-molded specimens and underwater-molded specimens, respectively, and can simulate shield simultaneous grouting in land and high-pressure, water-rich strata environments, accurately reflecting the setting characteristics of shield simultaneous grouting slurry during actual construction. By simulating real working conditions, it can provide parameters that are more in line with actual conditions for shield construction in high-pressure, water-rich environments, helping to accelerate construction efficiency and improve construction quality and safety. The present invention uses the penetration resistance method of the "setting time test" in the current industry standard "Standard for Test Methods for Basic Properties of Building Mortar" JGJ / T 70 to measure the setting time, and can more accurately record the setting time achieved by specimens formed in different environments. The penetration resistance method is a mature method for determining setting time, with high accuracy and reliability. At the same time, various influencing factors are strictly controlled and measured during the test process, further improving the detection accuracy and providing a guarantee for the accurate assessment of the slurry setting time. The present invention takes into account the influence of multiple factors such as the material composition, type and dosage of water-resistant dispersant, water-cement ratio, etc. in cement-based single-liquid grouting materials on the setting time difference. Through comprehensive analysis of multiple factors, the interaction and influence rules between various factors can be fully understood, which is helpful to optimize the mix ratio of synchronous grouting slurry and shorten the setting time of slurry in water. The present invention considers the reasonable determination of the limit value of the water-land setting time difference of cement-based single-liquid as a means of evaluating the water-dispersion resistance and water-scouring resistance of shield synchronous grouting slurry. After a large number of tests and verifications, it was determined that the limit value of the water-land setting time difference is 60 minutes. When the setting time difference of a certain shield cement-based single-liquid synchronous grouting slurry is less than 60 minutes, it is characterized as having high-quality water-dispersion resistance and water-scouring resistance.

[0034] It should be understood that the present invention can be used to test conventional grouting slurries currently available on the market. The composition of grouting slurries is not limited to the above-mentioned components. The present invention can determine whether conventional grouting slurries need to be adjusted based on the test results, and then retest after adjustment until the requirements of the present invention for the difference in water-land setting time are met, thereby obtaining grouting slurries with good performance. In response to this, the present application provides a method for regulating the components of shield synchronous grouting, which tests the grouting slurry to be tested according to the above-mentioned method. When Δt does not meet the requirement of less than 60 minutes, the component ratio of the shield synchronous grouting slurry is adjusted, and the test is performed again according to the above-mentioned method.

[0035] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0036] Example 1 This embodiment provides a method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata, which includes: S1. Shield Tunneling Grouting: Mix 200kg of cement (PO4 2.5%), 400kg of fly ash (fineness 20, water requirement ratio 99%), 1000kg of river sand (Sichuan region river sand fineness modulus 1.9), water (adjust water amount based on cement-based single-liquid expansion), and 6kg or 8kg of water-resistant dispersant (polyacrylamide) to prepare the shield tunneling grouting slurry. The expansion of the grouting slurry is set at 400mm-500mm.

[0037] S2. Take the shield synchronous grouting slurry and put it into the land mortar container, and put it 10mm below the upper edge of the container. Knock the land mortar container and smooth it. Use it as a land forming test piece. Test the land forming test piece according to the "setting time test" in the current industry standard "Standard for Test Methods of Basic Properties of Building Mortar" JGJ / T 70. 陆 , accurate to 1 minute.

[0038] S3. Lay a layer of clean sand inside the water container, place the underwater mortar container into the water container, and the distance from the upper end of the water container to the upper end of the underwater mortar container is 70mm; fill the water container and the underwater mortar container with water, and point the caulking gun filled with shield synchronous grouting slurry vertically downward, with the round mouth of the caulking gun close to the water surface, aiming at the underwater mortar container, push the piston of the caulking gun, and keep the pressure of the driving piston at 1kPa, so that the shield synchronous grouting slurry is injected into the underwater mortar container at a uniform speed, so that the shield synchronous grouting slurry penetrates the water layer and falls into the underwater mortar container and accumulates to form a small hill; let it stand for 10 minutes, gently take out the underwater mortar container filled with slurry from the water, knock on the underwater mortar container, and scrape off the upper slurry with a spatula. The slurry should be 10mm lower than the upper end of the container as an underwater molding test piece. The underwater molding test piece is tested according to the current industry standard "Standard for Test Methods for Basic Properties of Building Mortar" JGJ∕T The setting time test stipulated in 70 is the setting time of the molded specimen in water, referred to as the setting time in water, t 水 , accurate to 1 minute.

[0039] S4, press Δt= t 水 -t 陆 Calculate the time difference between the condensation of water and land.

[0040] Table 1. Calculation of the difference in time between the water and land setting of a cement-based single-liquid in Example 1.

[0041] As can be seen from the table above, for mixes 1-6 and 6kg of water-resistant dispersant, the difference in water-land setting time is greater than 1 hour, indicating that the cement-based single liquid has weak water-dispersion and water-scouring resistance, and cannot meet the safety and quality requirements for shield grouting in high-pressure, water-rich strata. For mixes 7-12 and 8kg of water-resistant dispersant, the difference in water-land setting time is less than 1 hour, indicating that the cement-based single liquid has strong water-dispersion and water-scouring resistance, meeting the requirements for shield grouting in high-pressure, water-rich strata to better control segment floating and displacement, better control stratum settlement, and achieve safe, reliable, fast, and efficient construction.

[0042] Example 2 This embodiment provides a method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata, which includes: S1. Shield Tunneling Grouting: Mix 200kg of cement (PO4 2.5%), 400kg of fly ash (fineness 20, water requirement ratio 99%), 1000kg of manufactured sand (fineness modulus 2.9 in Sichuan), water (adjust water amount based on cement-based single-liquid expansion), and 6kg or 8kg of water-resistant dispersant (polyacrylamide) to prepare the shield tunneling grouting slurry. The expansion of the grouting slurry is set at 400mm-500mm.

[0043] S2-S4 are the same as in Example 1.

[0044] Table 2. Data related to the calculation of the difference in setting time between water and land for cement-based single-liquid in Example 2

[0045] As can be seen from the table above, for mixes 13-18 and 6kg of water-resistant dispersant, the difference in water-land setting time is greater than 1h, indicating that the cement-based single liquid has weak water-dispersion and water-scouring resistance, and cannot meet the safety and quality requirements for shield grouting in high-pressure, water-rich strata. For mixes 19-24 and 8kg of water-resistant dispersant, the difference in water-land setting time is less than 1h, indicating that the cement-based single liquid has strong water-dispersion and water-scouring resistance, meeting the requirements for shield grouting in high-pressure, water-rich strata to better control segment floating and displacement, better control stratum settlement, and achieve safe, reliable, fast, and efficient construction.

[0046] Example 3 This embodiment shows the comparison before and after the synchronous grouting construction of a shield tunnel in a high-pressure water-rich stratum of a certain subway project.

[0047] The actual test results of the shield synchronous grouting slurry mix ratio and the water-land setting time difference originally used in this project are as follows: Table 3. Test results of the original shield synchronous grouting mix ratio and water-land setting time difference of a subway project

[0048] The above-mentioned shield synchronous grouting mix ratio is a traditional mix ratio. In the shield section constructed using the above mix ratio, due to the large difference in the setting time between water and land, the synchronous grouting slurry takes too long to set in water in the high-pressure water-rich stratum environment, resulting in the slurry failing to set and harden within a reasonable time, and having poor water dispersion and water scouring resistance, resulting in serious water leakage and floating misalignment of the pipe segments.

[0049] In response to the above problem, the shield synchronous grouting mix ratio was optimized and adjusted to keep the difference in water and land setting time within a reasonable range. See Table 4 for details.

[0050] Table 4 Optimized shield synchronous grouting mix ratio and water-land setting time difference test results for a subway project

[0051] The optimized shield tunneling grouting mix eliminated the bentonite used in the traditional mix and incorporated a water-resistant dispersant, keeping the time difference between the grout's water and land setting within a reasonable range. Subsequent shield tunneling sections using this mix significantly improved segment leakage and floating misalignment.

[0052] In summary, the present invention provides a method for determining the difference in setting time between land and water for shield synchronous grouting in high-pressure water-rich strata, by preparing land-molded specimens and water-molded specimens respectively, which can simulate the environment of shield synchronous grouting in land and high-pressure water-rich strata, and accurately reflect the setting characteristics of shield synchronous grouting slurry in actual construction. By simulating real working conditions, it is possible to provide parameters that are more in line with actual conditions for shield construction in a high-pressure water-rich environment, which helps to speed up construction efficiency, improve construction quality and safety. The present invention adopts the penetration resistance method of the "setting time test" in the current industry standard "Standard for Test Methods for Basic Properties of Building Mortar" JGJ / T70 to determine the setting time, and can more accurately record the setting time achieved by specimens formed in different environments. The penetration resistance method is a mature method for determining setting time, with high accuracy and reliability. At the same time, various influencing factors are strictly controlled and measured during the test process, which further improves the detection accuracy and provides a guarantee for the accurate evaluation of the slurry setting time. The present invention takes into account the influence of multiple factors such as the material composition, type and dosage of water-resistant dispersant, water-cement ratio, etc. in cement-based single-liquid grouting materials on the setting time difference. Through comprehensive analysis of multiple factors, the interaction and influence rules between various factors can be fully understood, which is helpful to optimize the mix ratio of synchronous grouting slurry and shorten the setting time of slurry in water. The present invention considers the reasonable determination of the limit value of the water-land setting time difference of cement-based single-liquid as a means of evaluating the water-dispersion resistance and water-scouring resistance of shield synchronous grouting slurry. After a large number of tests and verifications, it was determined that the limit value of the water-land setting time difference is 60 minutes. When the setting time difference of a certain shield cement-based single-liquid synchronous grouting slurry is less than 60 minutes, it is characterized as having high-quality water-dispersion resistance and water-scouring resistance.

[0053] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for measuring the difference in water-land setting time during shield synchronous grouting in high-pressure water-rich strata, characterized in that: It includes: S1. Preparation of synchronous grouting slurry: Cement, fly ash, river sand, water and anti-dispersant are mixed to form shield synchronous grouting slurry; S2. Testing the Land Setting Time: Take the shield synchronous grouting slurry and put it into a land mortar container, and put it 10mm below the upper edge of the container. Knock the land mortar container and smooth it out to form a land forming test piece. Test the land setting time t of the land forming test piece according to the provisions of the "Setting Time Test" in the current industry standard "Standard for Test Methods of Basic Properties of Building Mortar" JGJ / T 70. 陆 ; S3. Test the setting time in water: completely place the underwater mortar container into the water container, with the distance from the upper opening of the water container to the upper opening of the underwater mortar container being 65-75mm; fill the water container and the underwater mortar container with water, and point the caulking gun filled with the shield synchronous grouting slurry vertically downward, with the round mouth of the caulking gun close to the water surface, aimed at the underwater mortar container, and push the piston of the caulking gun to uniformly inject the shield synchronous grouting slurry into the underwater mortar container, so that the shield synchronous grouting slurry penetrates the water layer and falls into the underwater mortar container and accumulates to form a small hill; let it stand for 5min~10min, gently take out the underwater mortar container filled with slurry from the water, knock the underwater mortar container, and scrape off the upper slurry with a spatula. The slurry should be 10mm below the upper opening of the container as an underwater molding test piece. The underwater molding test piece is tested according to the current industry standard "Standard for Test Methods for Basic Properties of Building Mortar" JGJ / T The "setting time test" in 70 stipulates that the setting time is the setting time of the test piece formed in water, referred to as the setting time in water. 水 ; S4. Calculation of the time difference between land and water condensation: According to Δt= t 水 -t 陆 Calculate the time difference between land and water condensation, where Δt is the time difference between land and water condensation; Δt is less than 60 minutes.

2. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 1 is characterized in that: The caulking gun is provided with a pressure sensor for detecting the extrusion pressure of the caulking gun and a driving mechanism for driving the piston, and the pressure sensor is connected to the driving mechanism for signal transmission.

3. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 2 is characterized in that: The pressure driving the piston was maintained at 0.5-1.5 kPa.

4. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 1, characterized in that: Before detecting the setting time, the expansion degree of the shield synchronous grouting slurry is also tested, and the expansion degree meets the requirements of 400mm-500mm.

5. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 1 is characterized in that: The caulking gun can inject the shield synchronous grouting slurry into the underwater mortar container in multiple times, and the interval between each injection does not exceed 2 minutes.

6. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 1, characterized in that: The cement shall comply with the provisions of Appendix A of GB 8076 or the strength grade 42.5 silicate or ordinary silicate engineering cement specified in GB 175; the fly ash shall comply with the provisions of Grade II fly ash in GB / T 1596, with a water requirement ratio of 100±2; the river sand shall comply with the medium sand requirements of Zone II in GB / T 14684, with a fineness modulus of 2.6-2.9 and a mud content of less than 1%.

7. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 1, characterized in that: The land condensation time, the water condensation time, and the difference between the water and land condensation time are all accurate to 1 minute.

8. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 1, characterized in that: A layer of clean sand is laid inside the water container to adjust the distance from the upper opening of the water container to the upper opening of the mortar container in water.

9. The method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to claim 1, characterized in that: To determine the setting time on land and in water of the shield synchronous grouting slurry, two samples of the shield synchronous grouting slurry should be taken from the same dish, and the average value of the two test results should be used as the setting time value of the mortar. The error of the secondary test results should not be greater than 30 minutes, otherwise it should be re-measured.

10. A method for controlling the components of shield synchronous grouting, characterized in that: The method comprises the method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata according to any one of claims 1 to 9; When Δt does not meet the requirement of less than 60 min, the composition ratio of the shield synchronous grouting slurry is adjusted, and the test is performed again according to the above method until Δt meets the requirement of less than 60 min.

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