A method for determining the time difference of water-land coagulation of high-pressure water-rich stratum shield synchronous grouting and a method for regulating the composition of shield synchronous grouting

Abstract

The application discloses a kind of high-pressure water-rich stratum shield synchronous grouting water-land setting time difference determination method and the regulation method of shield synchronous grouting component, and it is related to material detection technical field.The determination method respectively prepares land forming test piece and water forming test piece, can simulate shield synchronous grouting in land and high-pressure water-rich stratum environment, accurately reflects the setting characteristics of shield synchronous grouting slurry in actual construction.Through simulating real working condition, it can provide more actual situation parameters for shield construction in high-pressure water-rich environment, help to speed up construction efficiency, improve construction quality and safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material detection, in particular to a method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata and a method for regulating the composition of shield synchronous grouting. BACKGROUND

[0002] With the acceleration of urbanization and the deepening of underground space development, shield method has become the mainstream technology for underground engineering construction such as subway tunnels, urban comprehensive pipe galleries, high-speed railways, highways, and municipal roads, due to its efficiency and safety. As a key link in shield construction in high-pressure water-rich strata, synchronous grouting plays a decisive role in controlling stratum deformation, preventing ground settlement, and ensuring the stability of tunnel structure by timely filling the shield tail gap. In actual construction, synchronous grouting slurry needs to be injected into the annular gap filled with underground water, and its performance not only needs to meet the requirements of land construction on setting time, but also needs to adapt to the complex underwater environment to ensure strong resistance to water dispersion and water erosion under high water pressure, and realize rapid setting and hardening in water.

[0003] Currently, the difference in setting performance of synchronous grouting slurry under water-land environment significantly affects the engineering quality and construction safety. At the same time, the commonly used synchronous grouting materials for high-pressure water-rich strata are limited by their own composition and performance, and show different setting performances in water-land environment. Moreover, due to factors such as differences in raw material quality and unreasonable slurry mix ratio, the difficulty of setting time control is further increased. However, in the existing performance evaluation system of synchronous grouting slurry for high-pressure water-rich strata, the traditional land setting time measurement method cannot accurately reflect the real setting characteristics of the slurry in high-pressure water-rich environment.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The present application aims to provide a method for measuring the water-land setting time difference of synchronous grouting in high-pressure water-rich strata and a method for regulating the composition of shield synchronous grouting, which is scientific and precise, and is beneficial to optimizing the design of synchronous grouting slurry mix ratio, ensuring the quality and safety of shield construction, and promoting the development of underground engineering technology.

[0006] The present application is implemented as follows:

[0007] In a first aspect, the present application provides a method for measuring the water-land setting time difference of synchronous grouting in high-pressure water-rich strata, which comprises:

[0008] S1, preparation of synchronous grouting slurry: mixing cement, fly ash, river sand, water, and anti-dispersant to form shield synchronous grouting slurry;

[0009] S2, test the land setting time: take the shield synchronous grouting slurry into the land mortar container, and lower the container upper opening by 10mm, knock the land mortar container, and smooth it, as 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 "building mortar basic performance test method standard" JGJ / T 70 陆 ;

[0010] S3, test the water setting time: put the water mortar container completely into the water container, the distance from the water container upper opening to the water mortar container upper opening is 65-75mm; fill the water container and the water mortar container with water, vertically downwardly inject the caulk gun filled with the shield synchronous grouting slurry, the round nozzle of the caulk gun is close to the water surface, aligns the water mortar container, pushes the piston of the caulk gun, makes the shield synchronous grouting slurry uniformly inject into the water mortar container, makes the shield synchronous grouting slurry penetrate the water layer and fall into the water mortar container and form a small hill shape; stand for 5min-10min, gently take out the water mortar container filled with the slurry from the water, knock the water mortar container, scrape the upper slurry with a spatula, the slurry should be lower than the container upper opening by 10mm, as a water forming test piece, test the setting time of the water forming test piece according to the provisions of the "setting test" in the current industry standard "building mortar basic performance test method standard" JGJ / T 70, which is the water setting time t of the water forming test piece 水 ;

[0011] S4, calculate the water-land setting time difference: calculate the water-land setting time difference according to Δt=t 水 -t 陆 , in the formula: Δt is the water-land setting time difference; the Δt satisfies less than 60min.

[0012] In the optional implementation, the caulk gun is provided with a pressure sensor for detecting the extrusion pressure of the caulk gun and a driving mechanism for driving the piston, and the pressure sensor is signal connected with the driving mechanism.

[0013] In the optional implementation, the pressure for driving the piston is kept at 0.5-1.5kPa.

[0014] In the optional implementation, before detecting the setting time, further include testing the spread of the shield synchronous grouting slurry, and the spread satisfies 400mm-500mm.

[0015] In the optional implementation, the caulk gun can inject the shield synchronous grouting slurry into the water mortar container in multiple times, and the interval time of each injection is not more than 2min.

[0016] In an optional embodiment, the cement should meet the requirements of GB 8076 Appendix A or the strength grade 42.5 Portland or ordinary Portland engineering cement specified in GB 175; the fly ash should meet the requirements of Grade II fly ash in GB / T 1596, the water demand ratio being 100±2; and the river sand should meet the requirements of medium sand in Zone II in GB / T 14684, the fineness modulus being 2.6-2.9, and the clay content being less than 1%.

[0017] In an optional embodiment, the land setting time, the water setting time and the water-land setting time difference are accurate to 1 min.

[0018] In an optional embodiment, the distance from the upper opening of the water container to the upper opening of the water mortar container is adjusted by laying a layer of clean sand in the water container.

[0019] In an optional embodiment, for the determination of the land setting time and the water setting time of the shield synchronous grouting slurry, two samples of the shield synchronous grouting slurry are taken in the same tray, and the average of the two test results is taken as the setting time value of the mortar. The error of the two test results should not be greater than 30 min, otherwise the determination should be redone.

[0020] In a second aspect, the application provides a method for regulating the components of shield synchronous grouting, which comprises the high-pressure water-rich stratum shield synchronous grouting water-land setting time difference determination method according to any one of the above embodiments. When Δt does not meet the requirement of being less than 60 min, the component ratio of the shield synchronous grouting slurry is adjusted, and the above method is used again for detection until Δt meets the requirement of being less than 60 min.

[0021] The application has the following beneficial effects:

[0022] The application provides a high-pressure water-rich stratum shield synchronous grouting water-land setting time difference measuring method, land forming test pieces and water forming test pieces are prepared respectively, the shield synchronous grouting in the land and the high-pressure water-rich stratum environment can be simulated, and the setting characteristics of the shield synchronous grouting slurry in actual construction can be accurately reflected. Through simulation of the real working condition, more actual parameters can be provided for the shield construction in the high-pressure water-rich environment, which is helpful to speed up the construction efficiency, improve the construction quality and safety. The application adopts the penetration resistance method of the setting time test in the current industry standard JGJ / T 70, i.e., the standard for the basic performance test method of building mortar, to measure the setting time, and the setting time of the test piece in different environments can be accurately recorded. The penetration resistance method is a mature setting time measuring method, and has high accuracy and reliability. Meanwhile, various influencing factors are strictly controlled and measured in the test process, and the detection accuracy is further improved, thereby providing guarantee for accurate evaluation of the slurry setting time. The application considers the influence of multiple factors, such as the material composition of the cement-based single liquid grouting material, the type and content of the water resistance dispersant, and the water-binder ratio, on the setting time difference. Through comprehensive analysis of multiple factors, the interaction and influence law among the factors can be comprehensively understood, which is helpful to optimize the synchronous grouting slurry mix proportion, and shorten the water setting time of the slurry. The application considers that the limit value of the cement-based single liquid water-land setting time difference should be reasonably determined as the evaluation of the water dispersion resistance and water scouring resistance of the shield synchronous grouting slurry. Through a large number of test verifications, the limit value of the water-land setting time difference is determined as 60 min. When the setting time difference of a certain kind of shield cement-based single liquid synchronous grouting slurry is less than 60 min, the slurry has excellent water dispersion resistance and water scouring resistance. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application will be clearly and completely described below. If the specific conditions are not indicated in the embodiments, the conventional conditions or the conditions recommended by the manufacturers are adopted. If the reagents or instruments are not indicated by the manufacturers, they are all conventional products that can be purchased in the market.

[0024] The application researches and finds that the setting performance difference of the synchronous grouting slurry setting time in the water-land environment significantly influences the engineering quality and construction safety. If the water-land setting time difference is too large, the slurry is easy to be washed and diluted in water, which leads to delayed setting time, increased water-binder ratio, insufficient strength development, and causes serious accidents such as stratum collapse and tunnel leakage; on the contrary, the water-land setting time difference is reasonably controlled, the slurry can be quickly set and hardened to form an effective supporting structure under water, and the stratum stability is maintained. However, in the existing high-pressure water-rich stratum shield synchronous grouting slurry performance evaluation system, there is a lack of a standardized measuring method for the water-land setting time difference, and the traditional land setting time measuring method cannot accurately reflect the real setting characteristics of the slurry in the high-pressure water-rich environment.

[0025] To this end, the application provides a high-pressure water-rich stratum shield synchronous grouting water-land setting time difference determination method, which comprises the following steps:

[0026] S1, preparation of synchronous grouting slurry.

[0027] The cement, fly ash, river sand, water and anti-dispersant are mixed to form the shield synchronous grouting slurry.

[0028] The cement should meet the requirements of GB 8076 Appendix A or the strength grade 42.5 Portland or ordinary Portland engineering cement specified in GB 175; the fly ash should meet the requirements of II-grade fly ash in GB / T 1596, the water demand ratio is 100±2, the color is uniform, no impurities such as oil stains are contained, no obvious irritating gas is released when mixed with cement and water, good adaptability to other materials, and small loss of flow performance; the river sand should meet the requirements of II-zone medium sand in GB / T 14684, the fineness modulus is 2.6-2.9, and the clay content is less than 1%.

[0029] Before detecting the setting time, the spread of the shield synchronous grouting slurry is also tested, and the spread meets 400mm-500mm. The spread test is performed according to the relevant provisions of the current national standard “Cement-based Grouting Material Application Technical Specification” GB / T50448 “Slump Spread Test”.

[0030] The mixing mode of the above cement, fly ash, river sand, water and anti-dispersant refers to the provisions of the current “Building Mortar Basic Performance Test Method Standard” JGJ / T 70, and the specific steps are as follows: wet the mixing pot, first add the river sand, when the water-repellent dispersant is a powder, it is added together with the cement and fly ash, dry mixing for 30s, slowly add 80% of the mixing water and continue to stir for 120s to test the spread of the slurry. If the spread exceeds the specified range, the amount of mixing water should be adjusted until the specified spread is reached. When the water-repellent dispersant is a water agent, it is added synchronously with the mixing water. The stirring time of the water-repellent dispersant can be appropriately extended by 1min-2min.

[0031] S2, test the land setting time.

[0032] The shield synchronous grouting slurry is taken into the land mortar container and is 10mm lower than the upper opening of the container, the land mortar container is knocked and is smoothed to form a land forming test piece, and the land setting time t 陆 is tested according to the provisions of the current industry standard “Building Mortar Basic Performance Test Method Standard” JGJ / T 70 “Setting Time Test” for the land forming test piece, and is accurate to 1min.

[0033] S3, test the water setting time.

[0034] A layer of clean sand is laid in the water container, the water-sand mortar container is placed in the water container, the distance from the upper opening of the water container to the upper opening of the water-sand mortar container is 65-75 mm, the water container and the water-sand mortar container are filled with water, the caulking gun filled with shield synchronous grouting slurry is vertically downward, the round nozzle of the caulking gun is close to the water surface, the caulking gun is aimed at the water-sand mortar container, the piston of the caulking gun is pushed, the shield synchronous grouting slurry is uniformly injected into the water-sand mortar container, the shield synchronous grouting slurry penetrates the water layer and falls into the water-sand mortar container and forms a small hill, the water-sand mortar container filled with the slurry is gently taken out from the water after 5-10 min, the water-sand mortar container is knocked, the upper slurry is scraped off with a spatula, the slurry should be lower than the upper opening of the container by 10 mm, the water-sand molded test piece is obtained, the setting time of the water-sand molded test piece is tested according to the setting time test in the current industry standard JGJ / T 70, that is, the setting time of the water-sand molded test piece, referred to as the water setting time t 水 , accurate to 1 min.

[0035] In the application, the actual construction environment is simulated, the round nozzle of the caulking gun is close to the water surface when the water-sand molded test piece is formed, the shield synchronous grouting slurry meets the water as soon as it is injected into the water-sand mortar container from the round nozzle of the caulking gun, and the shield synchronous grouting slurry penetrates the entire water layer, so that the actual construction environment is consistent.

[0036] In actual construction, the shield synchronous grouting slurry is pumped with a certain pressure when it is injected into the back of the shield segment. In order to simulate the actual construction environment, the caulking gun used for the water-sand molded test piece is provided 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 size of the pressure, the pressure sensor is signal connected with the driving mechanism, and the pressure sensor transmits the pressure signal to the driving mechanism, so that the driving mechanism drives the piston under a certain pressure to form pressure on the shield synchronous grouting slurry. The pressure for driving the piston is kept at 0.5-1.5 kPa. Through the simulation of the above pressure, the shield synchronous grouting slurry is injected into the water-sand mortar container from the round nozzle of the caulking gun.

[0037] The shield synchronous grouting slurry can be injected into the water-sand mortar container in multiple times, and the interval time of each injection is not more than 2 min. By controlling the interval time, the solidification parameters of the water-sand molded test piece are avoided from being affected by too long interval.

[0038] It should be understood that the determination of the land setting time and the water setting time of the shield synchronous grouting slurry should be respectively taken two shield synchronous grouting slurry samples in the same tray, and the average value of the two test results is taken as the setting time value of the mortar, and the error of the two test results should not be greater than 30 min, otherwise the determination should be re-determined.

[0039] S4, water-land setting time difference calculation.

[0040] According to Δt = t 水 -t 陆 The water-land setting time difference is calculated, wherein: Δt is the water-land setting time difference, accurate to 1 min; Δt satisfies less than 60 min.

[0041] The high-pressure water-rich stratum shield synchronous grouting water-land setting time difference determination method provided by the application can simulate the shield synchronous grouting in the land and the high-pressure water-rich stratum environment, and accurately reflect the setting characteristics of the shield synchronous grouting slurry in the actual construction. Through simulation of the real working condition, more actual parameters can be provided for the shield construction in the high-pressure water-rich environment, which helps to speed up the construction efficiency, improve the construction quality and safety. The application adopts the penetration resistance method of the "setting time test" in the current industry standard "Building mortar basic performance test method standard" JGJ / T 70 to determine the setting time, which can more accurately record the setting time of the test piece formed in different environments. The penetration resistance method is a mature setting time determination method, which has 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 application considers the influence of multiple factors such as material composition, water resistance dispersant type and dosage, and water-cement ratio in cement-based single liquid grouting material on the setting time difference. Through comprehensive analysis of multiple factors, the interaction and influence law between various factors can be comprehensively understood, which helps to optimize the synchronous grouting slurry mix proportion and shorten the water setting time of the slurry. The application considers that the limit value of the cement-based single liquid water-land setting time difference should be reasonably determined as the evaluation of the water dispersion resistance and water scouring resistance of the shield synchronous grouting slurry. A large number of test verifications show that the limit value of the water-land setting time difference is 60 min. When the setting time difference of a certain kind of shield cement-based single liquid synchronous grouting slurry is less than 60 min, it indicates that the slurry has excellent water dispersion resistance and water scouring resistance.

[0042] It should be understood that the present application can detect the conventional grouting slurry on the market, and the composition of the grouting slurry is not limited to the above-mentioned ingredients. The present application can further determine whether the conventional grouting slurry needs to be adjusted through the detection result, and then detect again after adjustment until the requirement of the water-land setting time difference in the present application is met, so as to obtain a grouting slurry with good performance. In this regard, the present application provides a method for adjusting the composition of shield synchronous grouting, which detects the grouting slurry to be detected according to the above-mentioned method. When Δt does not satisfy less than 60 min, the composition ratio of the shield synchronous grouting slurry is adjusted, and the detection is performed again according to the above-mentioned method.

[0043] The features and performances of the present application are further described in detail below in combination with embodiments.

[0044] Embodiment 1

[0045] The present embodiment provides a method for determining the water-land setting time difference of high-pressure water-rich stratum shield synchronous grouting, which comprises:

[0046] S1, the mixing ratio of the shield synchronous grouting slurry is: 200 kg of cement (P·O42.5), 400 kg of fly ash (fineness 20 water demand ratio 99), 1000 kg of river sand (Sichuan river sand fineness modulus 1.9), water (adjusting water quantity according to cement-based single liquid expansion degree) and 6 kg or 8 kg of water-resistant dispersant (polyacrylamide), and the shield synchronous grouting slurry is prepared by mixing. The expansion degree of the synchronous grouting slurry is determined to be 400 mm-500 mm.

[0047] S2, the shield synchronous grouting slurry is taken and filled into a land mortar container, and is lower than the upper opening of the container by 10 mm. The land mortar container is knocked and smoothed, and is used as a land forming test piece. The land forming test piece is tested according to the provisions of the “setting time test” in the current industry standard “building mortar basic performance test method standard” JGJ / T 70 to test the land setting time t 陆 , accurate to 1 min.

[0048] S3, a layer of clean sand is laid in the water container, the water-in-sand slurry container is put into the water container, the distance from the upper opening of the water container to the upper opening of the water-in-sand slurry container is 70 mm; the water container and the water-in-sand slurry container are filled with water, the filling gun filled with shield synchronous grouting slurry is vertically downward, the round nozzle of the filling gun is close to the water surface, the filling gun is aligned with the water-in-sand slurry container, the piston of the filling gun is pushed, the pressure of the piston is kept at 1 kPa, the shield synchronous grouting slurry is uniformly injected into the water-in-sand slurry container, the shield synchronous grouting slurry penetrates the water layer and falls into the water-in-sand slurry container and forms a small hill; after 10 minutes, the water-in-sand slurry container filled with slurry is gently taken out from the water, the water-in-sand slurry container is knocked, the upper slurry is scraped off with a spatula, the slurry should be lower than the upper opening of the container by 10 mm, which is used as a water-formed test piece, the water-formed test piece is tested according to the provisions of the "setting time test" in the current industry standard "building mortar basic performance test method standard" JGJ / T 70, the setting time is the setting time of the water-formed test piece, which is referred to as the water setting time t 水 , accurate to 1 min.

[0049] S4, the water-land setting time difference is calculated according to Δt = t 水 -t 陆 .

[0050] Table 1. Water-land setting time difference calculation related data of cement-based single liquid in example 1

[0051]

[0052] From the above table, it can be seen that when the water-repellent dispersant is 6 kg, the water-land setting time difference of the cement-based single liquid of the proportions 1-6 is greater than 1 h, indicating that the water-repellent dispersing and water-washing resistance of the cement-based single liquid is weak, which cannot meet the construction requirements of safety and quality of shield synchronous grouting in high-pressure water-rich strata. When the water-repellent dispersant is 8 kg, the water-land setting time difference of the proportions 7-12 is less than 1 h, indicating that the water-repellent dispersing and water-washing resistance of the cement-based single liquid is strong, which can meet the construction requirements of better control of segment floating and error table, better control of strata settlement, safe and reliable, fast and efficient construction in high-pressure water-rich strata.

[0053] Example 2

[0054] The embodiment provides a method for measuring the water-land setting time difference of shield synchronous grouting in high-pressure water-rich strata, which comprises:

[0055] S1, the synchronous grouting slurry of shield has the mixing ratio of 200 kg of cement (P·O42.5), 400 kg of fly ash (fineness 20, water demand ratio 99), 1000 kg of machine-made sand (the fineness modulus of machine-made sand in Sichuan area is 2.9), water (the water quantity is adjusted according to the cement-based single liquid extension degree) and 6 kg or 8 kg of water-resistant dispersant (polyacrylamide), and is mixed to prepare the synchronous grouting slurry of shield. The extension degree of the synchronous grouting slurry is 400 mm-500 mm.

[0056] S2-S4, same as example 1.

[0057] Table 2. The calculation of the water-land setting time difference of the cement-based single liquid in example 2

[0058]

[0059] As can be seen from the above table, when the water-resistant dispersant is 6 kg, the water-land setting time difference of the mixing ratio No. 13-18 is greater than 1 h, which represents that the water-resistant dispersion and water washing resistance of the cement-based single liquid are weak, and cannot meet the construction requirements of safety and quality of synchronous grouting of shield in high-pressure water-rich stratum. When the water-resistant dispersant is 8 kg, the water-land setting time difference of the mixing ratio No. 19-24 is less than 1 h, which represents that the water-resistant dispersion and water washing resistance of the cement-based single liquid are strong, and can meet the construction requirements of better control of segment floating and paneling, better control of stratum settlement, safe and reliable, fast and efficient construction in high-pressure water-rich stratum.

[0060] Example 3

[0061] This example is a comparison before and after the synchronous grouting construction of shield in high-pressure water-rich stratum of a certain subway project.

[0062] The actual detection results of the synchronous grouting slurry mixing ratio and the water-land setting time difference of the project are as follows:

[0063] Table 3. The detection results of the synchronous grouting mixing ratio and the water-land setting time difference of a certain subway project

[0064]

[0065] The above synchronous grouting mixing ratio is a traditional mixing ratio. The shield interval constructed by using the above mixing ratio has the problems of too large water-land setting time difference, too long water setting time of synchronous grouting slurry in high-pressure water-rich stratum, poor water-resistant dispersion and water washing resistance of the slurry, and serious water leakage and floating and paneling of the segment.

[0066] In view of the above problems, the synchronous grouting mixing ratio of shield is optimized and adjusted so that the water-land setting time difference is within a reasonable range, and details are shown in Table 4.

[0067] Table 4 Detection results of the mixing proportion of a certain subway project after optimization and the water-land setting time difference

[0068]

[0069] The mixing proportion of the slurry after optimization cancels the bentonite used in the traditional mixing proportion and adds a water-resistant dispersant, so that the water-land setting time difference of the slurry is controlled within a reasonable range. The subsequent shield interval construction using the mixing proportion greatly improves the problems of pipe leakage and floating error.

[0070] In summary, the method for determining the water-land setting time difference of the high-pressure water-rich stratum synchronous grouting provided by the present application can simulate the synchronous grouting of the shield in the land and the high-pressure water-rich stratum environment, accurately reflect the setting characteristics of the synchronous grouting slurry in the actual construction, and provide more actual parameters for the shield construction in the high-pressure water-rich environment, which helps to speed up the construction efficiency, improve the construction quality and safety. The present application uses the penetration resistance method of the "setting time test" in the current industry standard "Standard for Testing the Basic Performance of Building Mortar" JGJ / T70 to determine the setting time, which can accurately record the setting time of the test piece formed in different environments. The penetration resistance method is a mature method for determining the setting time, which has high accuracy and reliability. At the same time, various influencing factors are strictly controlled and measured during the test, which further improves the detection accuracy and provides a guarantee for the accurate evaluation of the setting time of the slurry. The present application considers the influence of multiple factors such as the composition of the cement-based single liquid grouting material, the type and amount of water-resistant dispersant, and the water-cement ratio on the setting time difference. Through comprehensive analysis of multiple factors, the interaction and influence law between various factors can be comprehensively understood, which helps to optimize the mixing proportion of the synchronous grouting slurry and shorten the water setting time of the slurry. The present application considers that the limit value of the water-cement setting time difference of the cement-based single liquid should be reasonably determined as an evaluation of the water-resistant dispersion and water erosion resistance of the synchronous grouting slurry of the shield. Through a large number of test verifications, it is determined that the limit value of the water-land setting time difference is 60 minutes. When the setting time difference of a certain synchronous grouting slurry of the shield cement-based single liquid is less than 60 minutes, it indicates that the slurry has excellent water-resistant dispersion and water erosion resistance.

[0071] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for determining the time difference between the water-land setting time of high-pressure water-rich stratum shield synchronous grouting, characterized in that, It comprises: S1, preparation of synchronous grouting slurry: cement, fly ash, river sand, water and anti-dispersant are mixed to form shield synchronous grouting slurry; S2, test the land condensation time: take the shield synchronous grouting slurry into the land mortar container, and lower the container upper opening by 10 mm, knock the land mortar container, and smooth it, as a land forming test piece, and test the land condensation time t according to the provisions of the "condensation time test" in the current industry standard "building mortar basic performance test method standard" JGJ / T 70 陆 ; S3, test the condensation time in water: the water mortar container is completely put into the water container, the distance from the upper opening of the water container to the upper opening of the water mortar container is 65-75 mm; the water container and the water mortar container are filled with water, the caulking gun filled with the shield synchronous grouting slurry is vertically downward, the round nozzle of the caulking gun is close to the water surface, the caulking gun is aligned with the water mortar container, the piston of the caulking gun is pushed, the shield synchronous grouting slurry is uniformly injected into the water mortar container, the shield synchronous grouting slurry penetrates the water layer and falls into the water mortar container and forms a small hill shape; after 5 min-10 min, the water mortar container filled with the slurry is gently taken out from the water, the water mortar container is knocked, the upper slurry is scraped off by a spatula, the slurry should be lower than the upper opening of the container by 10 mm, which is a water forming test piece, the water forming test piece is tested according to the "condensation time test" in the current industry standard "building mortar basic performance test method standard" JGJ / T 70, the condensation time is the condensation time of the water forming test piece, which is referred to as the condensation time in water t 水 ; S4, water-land condensation time difference calculation: according to Δt = t 水 -t 陆 The water-land condensation time difference is calculated, wherein: Δt is the water-land condensation time difference; the Δt satisfies less than 60 min, when the Δt does not satisfy less than 60 min, the component ratio of the shield synchronous grouting slurry is adjusted, and the above method is detected again until the Δt satisfies less than 60 min.

2. The method according to claim 1, wherein, 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 signal connected with the driving mechanism.

3. The method according to claim 2, wherein, The pressure for driving the piston is kept at 0.5-1.5kPa.

4. The method according to claim 1, wherein, Before detecting the setting time, the spread of the shield synchronous grouting slurry is also tested, and the spread is 400-500mm.

5. The method for determining the synchronous grouting water-land setting time difference of high-pressure water-rich formation shield according to claim 1, characterized in that, When the caulking gun injects the shield synchronous grouting slurry into the water mortar container, the injection is carried out in multiple times, and the interval time of each injection is not more than 2min.

6. The method for determining the synchronous grouting water-land setting time difference of high-pressure water-rich formation shield according to claim 1, characterized in that, The land setting time, the water setting time and the water-land setting time difference are all accurate to 1min.

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

8. The method for determining the synchronous grouting water-land setting time difference of high-pressure water-rich formation shield according to claim 1, characterized in that, The land setting time and the water setting time of the shield synchronous grouting slurry are measured by taking two shield synchronous grouting slurry samples in the same tray respectively, and the average of the two test results is taken as the setting time value of the mortar. The error of the two test results should not be more than 30min, otherwise the measurement should be re-measured.

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