Salt-resistant slurry for slurry shield tunneling and method thereof

Abstract

The invention discloses a salt-resistant slurry for slurry shield tunneling and a preparation method thereof, belonging to the technical field of shield tunneling. The invention makes full use of waste slurry to effectively save resources and costs, reduce environmental pollution, and can prepare high-quality slurry that meets the requirements of viscosity, water separation rate, physical and chemical stability, etc. By adding anti-settling agent to modify tara gum, the Ca content in high-salt slurry is reduced. 2+ Mg 2+ The pressure of plasma increases the stability of clay particles, thereby preventing coagulation or aggregation; the modified tara gum has greater steric hindrance and can be anchored in the mud to form a three-dimensional gel network structure, so that the mud can maintain its overall structure when it comes into contact with high-concentration salt water, preventing the mud from coagulating and losing, and improving the construction efficiency of the shield machine.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunneling, and in particular to a salt-resistant slurry for mud-water shield tunneling and a method thereof. Background Art

[0002] In recent years, with the continuous advancement of urban infrastructure construction, shield technology has played an important role in urban transportation and other fields. In the process of shield tunneling, there is a huge demand for mud, which mainly plays multiple roles in shield operations, such as lubrication, support, and cooling.

[0003] During the shield construction process, mud is usually needed to stabilize the excavation face of the slurry shield and to carry the soil debris out of the ground. The waste mud generated at the same time not only has a large discharge volume, but also causes extremely serious environmental pollution. At present, the conventional treatment methods for waste mud from slurry shields are to transport it out with tank mud trucks and to dry the mud on site, but both treatment methods have serious limitations. Due to the incorporation of groundwater and fine particles during the construction of slurry shields, it is inevitable that waste mud and a large amount of slag that cannot be reused will be generated.

[0004] Chinese patent document CN117342761A discloses a construction method for waste mud modification and recycling, which relates to the technical field of waste mud and discloses a construction method for waste mud modification, treatment and recycling, including taking a set amount of waste mud as a modified sample, measuring the original state index value of the waste mud; using a mud purification separator to screen the waste mud for a set time, measuring the sand content of the screened waste mud, and stopping the screening of the waste mud when the sand content is lower than the set sand content; adding bentonite solution or clean water to the waste mud to make the specific gravity of the waste mud between 1.05 and 1.15; adding A strong acid salt or a weak alkaline salt is used to make the pH value of the waste mud between 7 and 9; a cellulose solution is added to the waste mud to make the water loss, mud skin thickness, colloid rate and viscosity of the waste mud meet the set requirements; the ratio of bentonite solution, clean water, strong acid, weak alkaline salt and cellulose solution is determined as a modified formula; the waste mud generated by the construction is modified according to the modified formula and then recycled. The invention does not disclose which specific cellulose solution is used, and the waste mud modification method of the invention cannot be applied to waste mud with high salt content, which is prone to agglomeration and sinking, resulting in degradation of the mud film-forming function, seriously affecting the construction quality and progress. Summary of the invention

[0005] The main purpose of the invention is to propose a method for preparing mud for slurry shield tunneling using waste mud, and to optimize the components so that the mud has good comprehensive properties.

[0006] To achieve the above objectives, the present invention proposes a salt-resistant mud for slurry shield tunneling, comprising the following components in parts by weight: 1000-1250 parts of waste mud, 100-300 parts of water, 30-50 parts of bentonite, 1-5 parts of thickener, 1-3 parts of anti-settling agent, and 1-3 parts of lubricant.

[0007] Preferably, the density of the waste mud is 1.10 g / cm 3 -1.45g / cm 3 The viscosity of the Soviet funnel is 20-75s, and the 24h water seepage rate is ≤20%; the waste mud is produced when the shield passes through the previous strata. If the density and viscosity of the waste mud are too large, water is added to dilute it. If the mud density is too small, bentonite is added to adjust it. If the mud viscosity is too small or the water seepage rate is too high, thickener is added to adjust it.

[0008] Preferably, the thickener is at least one of hydroxypropyl starch, hydroxyethyl cellulose and sodium carbonate; it can improve the salt resistance, calcium and magnesium resistance, viscosity increase and filtration loss reduction effects of the mud, and effectively adjust the viscosity and physical stability of the mud to meet the excavation requirements of the silty soil stratum.

[0009] Further preferably, the thickener is a mixture of hydroxyethyl cellulose and sodium carbonate, and the mass ratio of the two is 1-3:1.

[0010] Preferably, the anti-settling agent is modified tara gum, and the preparation method thereof is as follows: mixing tara gum with water, heating and dissolving, adding triethylenetetramine and epichlorohydrin, continuing the reaction for 1-2 hours, cooling and filtering, and freeze-drying the solid to obtain ammoniated tara gum; dripping chlorosulfonic acid into humic acid, stirring evenly after the dripping is completed, and then adding it to a sodium hydroxide aqueous solution for reaction, adjusting the pH to 4-6 with a hydrochloric acid aqueous solution, filtering, collecting the solid, washing the solid with water until the filtrate is neutral, and then drying to obtain sulfonated sodium humate; dispersing ammoniated tara gum in ethyl acetate, adding sulfonated sodium humate, adjusting the pH to 8-10, reacting at 50-75°C for 2-4 hours, cooling to room temperature, distilling off the solvent under reduced pressure, and drying the residue to obtain modified tara gum.

[0011] Preferably, the usage ratio of tara gum, triethylenetetramine, epichlorohydrin and sodium sulfonated humate is 20-30:10-18:5-8:5-10.

[0012] The tara gum used in the present invention has the advantages of wide sources, low cost, biodegradability and good biocompatibility, and contains active hydroxyl groups on the surface. Under the action of epichlorohydrin, it can react with triethylenetetramine to generate amino-modified tara gum, and then sulfonated sodium humate is grafted on the surface of the tara gum to obtain modified tara gum. On the one hand, the modified tara gum has better dispersibility and will not agglomerate. On the other hand, the modified tara gum can be ionized in water and can be adsorbed on the surface of clay particles to form a hydration layer, which changes the potential of the clay particles and reduces the Ca in high-salt mud. 2+ Mg 2+ The pressure of plasma increases the stability of clay particles, thereby preventing coagulation or aggregation; the modified tara gum has greater steric hindrance and can be anchored in the mud to form a three-dimensional gelling network structure, so that the mud can maintain its overall structure when it comes into contact with high-concentration salt water, preventing the mud from coagulating and losing; and the tara gum grafted with sodium sulfonated humate can also improve the water retention performance of the mud, prevent segregation, and improve the fluidity of the mud, which is beneficial to improving the construction efficiency of the shield machine.

[0013] Preferably, the lubricant is modified molybdenum disulfide, and its preparation method is as follows:

[0014] Add molybdenum disulfide to sodium hydroxide solution, immerse at room temperature for 5-8 hours, filter, wash and dry after immersion, then add to ethanol aqueous solution, add 3-aminopropyltriethoxysilane, react at 40-60°C for 1-2 hours, filter, wash and dry after the reaction is completed to obtain amino molybdenum disulfide; disperse the amino molybdenum disulfide in N,N-dimethylformamide, add epoxy phenyl silicone oil, adjust the pH value to 4-6, then react at 60-100°C for 3-5 hours, filter, wash and dry after the reaction is completed to obtain modified molybdenum disulfide.

[0015] Preferably, the usage ratio of molybdenum disulfide, 3-aminopropyltriethoxysilane and epoxyphenyl silicone oil is 30-50:1-3:5-8.

[0016] Molybdenum disulfide is a good lubricant. After being added to the mud, it can reduce the resistance between the substances in the system, thereby improving the fluidity of the mud. By modifying it, the dispersibility of molybdenum disulfide in the system can be improved. The evenly dispersed modified molybdenum disulfide has good compression and wear resistance, and epoxy phenyl silicone oil can form a stable lubricating film layer in the mud, further improving the lubrication stability of the mud.

[0017] The present invention also discloses a method for preparing the above-mentioned salt-resistant slurry for slurry shield tunneling, comprising the following steps:

[0018] The waste mud and water generated when the shield passes through the previous strata are placed in a slurry mixing tank, and bentonite, thickener, anti-settling agent and lubricant are added. After sufficient stirring, salt-resistant mud for mud-water shield excavation is obtained.

[0019] Preferably, the stirring conditions are a rotation speed of 700-900 rpm and a stirring time of 20-40 min.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention makes full use of waste mud to effectively save resources and costs, reduce environmental pollution, and can prepare high-quality mud that meets the requirements of density, viscosity, segregation rate, physical and chemical stability, etc. The mud can form a dense mud film on the excavation surface of the silt layer and effectively maintain the stability of the excavation surface. It is an efficient, environmentally friendly and energy-saving method for preparing mud for slurry shield tunneling;

[0022] 2. The present invention adds an anti-settling agent to modify tara gum, which can be ionized in water and adsorbed to the surface of clay particles to form a hydration layer, thereby changing the potential of the clay particles and reducing the Ca content in high-salt water. 2+ Mg 2+ The pressure of plasma increases the stability of clay particles, thereby preventing coagulation or aggregation; the modified tara gum has greater steric hindrance and can be anchored in the mud to form a three-dimensional gel network structure, so that the mud can maintain its overall structure when it contacts high-concentration salt water, preventing the mud from coagulating and losing; and the tara gum grafted with sodium sulfonated humate can also improve the water retention performance of the mud, prevent segregation, and improve the fluidity of the mud, which is conducive to improving the construction efficiency of the shield machine;

[0023] 3. The present invention improves the dispersibility of molybdenum disulfide in the system by adding lubricant to modify molybdenum disulfide. The uniformly dispersed modified molybdenum disulfide has good compression and wear resistance. In addition, the epoxy phenyl silicone oil can form a stable lubricating film layer in the mud, further improving the lubrication stability of the mud. DETAILED DESCRIPTION

[0024] To avoid redundant description, the articles used in the following examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods unless otherwise specified. The technical scheme of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0025] The sources of some raw materials used in the present invention are as follows:

[0026] Bentonite, active ingredient content is 94%, whiteness is 80%, particle size is 50μm, expansion multiple is 10-25, density is 2g / cm3 , purchased from Lingshou County Malin Mineral Products Processing Plant.

[0027] Tara gum, with a content of 99%, was purchased from Jiangsu Caiwei Biotechnology Co., Ltd.

[0028] Molybdenum disulfide, with a purity of 99% and a particle size of 200 nm, was purchased from Xi’an Qiyue Biotechnology Co., Ltd.

[0029] Epoxy phenyl silicone oil, with a viscosity of 30-50 cst, was purchased from Anhui Xinjia Silicone Technology Co., Ltd.

[0030] Example 1

[0031] A method for preparing salt-resistant slurry for slurry shield tunneling comprises the following steps:

[0032] 1140g of waste mud produced when the shield tunneled through the previous strata and 200g of water were placed in a slurry mixing tank, 40g of bentonite, 4g of thickener, 2g of modified tara gum, and 2g of modified molybdenum disulfide were added, and stirred at a speed of 800rpm for 30min to obtain salt-resistant mud for mud shield tunneling; the density of the waste mud was 1.31g / cm 3 , the viscosity of the Sohler funnel is 53s, and the water secretion rate is 18% in 24h; the thickener is a mixture of 2.5g hydroxyethyl cellulose and 1.5g sodium carbonate;

[0033] The preparation method of the modified tara gum is as follows: 26 g of tara gum is mixed with 400 mL of water, and then heated at 80° C. for 15 min to obtain a tara gum aqueous solution; 14 g of triethylenetetramine and 6.6 g of epichlorohydrin are added, and the reaction is continued for 1.5 h, and then cooled and filtered; the solid is freeze-dried at -40° C. for 24 h to obtain an ammoniated tara gum; 10 mL of chlorosulfonic acid is added dropwise to 10 g of humic acid, and after the addition is completed, 10 mL of chlorosulfonic acid is stirred evenly, and then added to 200 mL of The mixture was reacted in a 1 mol / L sodium hydroxide aqueous solution for 15 min, the pH was adjusted to 5 with a 1 mol / L hydrochloric acid aqueous solution, filtered, the solid was collected, the solid was washed with water until the filtrate was neutral, and then dried to obtain sulfonated sodium humate; the ammoniated tara gum was dispersed in 800 mL of ethyl acetate, 8.6 g of sulfonated sodium humate was added, the pH value was adjusted to 9, the mixture was reacted at 65 ° C for 3 h, cooled to room temperature, the solvent was evaporated under reduced pressure, and the residue was freeze-dried at -40 ° C for 24 h to obtain modified tara gum.

[0034] The preparation method of the modified molybdenum disulfide is as follows:

[0035] 43.4 g of molybdenum disulfide was added to 500 mL of 1 mol / L sodium hydroxide solution, immersed at room temperature for 7 h, filtered after the immersion was completed, the solid was collected, washed until the filtrate was neutral, and dried, and then the solid was added to 600 mL of 50 wt% ethanol aqueous solution, 2 g of 3-aminopropyltriethoxysilane was added, and the reaction was carried out at 50 ° C for 1.5 h. After the reaction was completed, the solid was filtered and collected, and the solid was washed with water 3 times and dried at 80 ° C for 6 h to obtain amino molybdenum disulfide; the amino molybdenum disulfide was dispersed in 800 mL of N, N-dimethylformamide, 6.8 g of epoxyphenyl silicone oil was added, the pH value was adjusted to 5, and then reacted at 80 ° C for 4 h. After the reaction was completed, the filter cake was filtered and collected, and the filter cake was washed with ethanol 3 times and dried at 60 ° C for 8 h to obtain modified molybdenum disulfide.

[0036] Example 2

[0037] A method for preparing salt-resistant slurry for slurry shield tunneling comprises the following steps:

[0038] 1000g of waste mud produced when the shield tunneled through the previous strata and 100g of water were placed in a slurry mixing tank, 30g of bentonite, 4g of thickener, 1g of modified tara gum, and 3g of modified molybdenum disulfide were added, and the mixture was stirred at a speed of 700rpm for 40min to obtain salt-resistant mud for mud shield tunneling; the density of the waste mud was 1.10g / cm 3 , the viscosity of the Sohler funnel is 20s, and the water secretion rate is 15% in 24h; the thickener is a mixture of 2g hydroxyethyl cellulose and 2g sodium carbonate;

[0039] The preparation method of the modified tara gum is as follows: 20g of tara gum is mixed with 400mL of water, and then heated at 80°C for 15min to obtain a tara gum aqueous solution, 10.2g of triethylenetetramine and 5g of epichlorohydrin are added, and the mixture is reacted for 1h, then cooled and filtered, and the solid is freeze-dried at -40°C for 24h to obtain an ammoniated tara gum; 10mL of chlorosulfonic acid is added dropwise to 10g of humic acid, and the mixture is stirred evenly after the addition is completed, and then added to 200mL of a 1mol / L sodium hydroxide aqueous solution to react for 15min, and the pH is adjusted to 5 with a 1mol / L hydrochloric acid aqueous solution, filtered, and the solid is collected, and the solid is washed with water until the filtrate is neutral and then dried to obtain sulfonated sodium humate; the ammoniated tara gum is dispersed in 800mL of ethyl acetate, 5g of sulfonated sodium humate is added, the pH value is adjusted to 10, and the mixture is reacted at 55°C for 2h, then cooled to room temperature, the solvent is evaporated under reduced pressure, and the residue is freeze-dried at -40°C for 24h to obtain the modified tara gum.

[0040] The preparation method of the modified molybdenum disulfide is as follows:

[0041] 30.3 g of molybdenum disulfide was added to 500 mL of 1 mol / L sodium hydroxide solution, immersed at room temperature for 5 h, filtered after the immersion was completed, the solid was collected, washed until the filtrate was neutral, and dried, and then the solid was added to 600 mL of 50 wt% ethanol aqueous solution, 1 g of 3-aminopropyltriethoxysilane was added, and the reaction was carried out at 50 ° C for 1 h. After the reaction was completed, the solid was filtered and collected, and the solid was washed with water 3 times and dried at 80 ° C for 6 h to obtain amino molybdenum disulfide; the amino molybdenum disulfide was dispersed in 800 mL of N, N-dimethylformamide, 5.1 g of epoxyphenyl silicone oil was added, the pH value was adjusted to 4, and then reacted at 60 ° C for 3 h. After the reaction was completed, the filter cake was filtered and collected, and the filter cake was washed with ethanol 3 times and dried at 60 ° C for 8 h to obtain modified molybdenum disulfide.

[0042] Example 3

[0043] A method for preparing salt-resistant slurry for slurry shield tunneling comprises the following steps:

[0044] 1250g of waste mud produced when the shield tunneled through the previous strata and 300g of water were placed in a slurry mixing tank, 50g of bentonite, 5g of thickener, 3g of modified tara gum, and 1g of modified molybdenum disulfide were added, and stirred at a speed of 900rpm for 20min to obtain salt-resistant mud for mud shield tunneling; the density of the waste mud was 1.45g / cm 3 , the viscosity of the Sohler funnel is 75s, and the water secretion rate is 13% in 24h; the thickener is a mixture of 3g hydroxyethyl cellulose and 2g sodium carbonate;

[0045] The preparation method of the modified tara gum is as follows: 30g of tara gum is mixed with 400mL of water, and then heated at 80°C for 15min to obtain a tara gum aqueous solution, 18g of triethylenetetramine and 8g of epichlorohydrin are added, and the mixture is reacted for 2h, cooled, filtered, and the solid is freeze-dried at -40°C for 24h to obtain an ammoniated tara gum; 10mL of chlorosulfonic acid is added dropwise to 10g of humic acid, and the mixture is stirred evenly after the addition is completed, and then added to 200mL of a 1mol / L sodium hydroxide aqueous solution to react for 15min, and the pH is adjusted to 5 with a 1mol / L hydrochloric acid aqueous solution, filtered, and the solid is collected, and the solid is washed with water until the filtrate is neutral and then dried to obtain sulfonated sodium humate; the ammoniated tara gum is dispersed in 800mL of ethyl acetate, 10g of sulfonated sodium humate is added, the pH value is adjusted to 8, the mixture is reacted at 75°C for 4h, cooled to room temperature, the solvent is evaporated under reduced pressure, and the residue is freeze-dried at -40°C for 24h to obtain the modified tara gum.

[0046] The preparation method of the modified molybdenum disulfide is as follows:

[0047] 50 g of molybdenum disulfide was added to 500 mL of 1 mol / L sodium hydroxide solution, immersed at room temperature for 8 h, filtered after the immersion was completed, the solid was collected, washed until the filtrate was neutral, and dried, and then the solid was added to 600 mL of 50 wt% ethanol aqueous solution, 3 g of 3-aminopropyltriethoxysilane was added, and the reaction was carried out at 60 ° C for 2 h. After the reaction was completed, the solid was filtered and collected, and the solid was washed with water 3 times and dried at 80 ° C for 6 h to obtain amino molybdenum disulfide; the amino molybdenum disulfide was dispersed in 800 mL of N, N-dimethylformamide, 7.9 g of epoxyphenyl silicone oil was added, the pH value was adjusted to 5, and then reacted at 100 ° C for 3 h. After the reaction was completed, the filter cake was filtered and collected, and the filter cake was washed with ethanol 3 times and dried at 60 ° C for 8 h to obtain modified molybdenum disulfide.

[0048] Comparative Example 1

[0049] A method for preparing salt-resistant slurry for slurry shield tunneling is similar to that of Example 1, except that the anti-settling agent used is tara gum, and specifically comprises the following steps:

[0050] 1140g of waste mud produced when the shield tunneled through the previous strata and 200g of water were placed in a slurry mixing tank, 40g of bentonite, 4g of thickener, 2g of tara gum, and 2g of modified molybdenum disulfide were added, and stirred at a speed of 800rpm for 30min to obtain salt-resistant mud for mud shield tunneling; the density of the waste mud was 1.31g / cm 3 , the viscosity of the Sohler funnel is 53s, and the water secretion rate is 18% in 24h; the thickener is a mixture of 2.5g hydroxyethyl cellulose and 1.5g sodium carbonate;

[0051] The preparation method of the modified molybdenum disulfide is as follows:

[0052] 43.4 g of molybdenum disulfide was added to 500 mL of 1 mol / L sodium hydroxide solution, immersed at room temperature for 7 h, filtered after the immersion was completed, the solid was collected, washed until the filtrate was neutral, and dried, and then the solid was added to 600 mL of 50 wt% ethanol aqueous solution, 2 g of 3-aminopropyltriethoxysilane was added, and the reaction was carried out at 50 ° C for 1.5 h. After the reaction was completed, the solid was filtered and collected, and the solid was washed with water 3 times and dried at 80 ° C for 6 h to obtain amino molybdenum disulfide; the amino molybdenum disulfide was dispersed in 800 mL of N, N-dimethylformamide, 6.8 g of epoxyphenyl silicone oil was added, the pH value was adjusted to 5, and then reacted at 80 ° C for 4 h. After the reaction was completed, the filter cake was filtered and collected, and the filter cake was washed with ethanol 3 times and dried at 60 ° C for 8 h to obtain modified molybdenum disulfide.

[0053] Comparative Example 2

[0054] A method for preparing salt-resistant slurry for slurry shield tunneling is similar to Example 1, except that the lubricant used is molybdenum disulfide, and specifically comprises the following steps:

[0055] 1140g of waste mud produced when the shield tunneled through the previous strata and 200g of water were placed in a slurry mixing tank, 40g of bentonite, 4g of thickener, 2g of modified tara gum, and 2g of molybdenum disulfide were added, and stirred at a speed of 800rpm for 30min to obtain salt-resistant mud for mud shield tunneling; the density of the waste mud was 1.31g / cm 3 The viscosity of the Su funnel is 53s, and the water secretion rate is 18% in 24h; the thickener is a mixture of 2.5g hydroxyethyl cellulose and 1.5g sodium carbonate.

[0056] The preparation method of the modified tara gum is as follows: 26 g of tara gum is mixed with 400 mL of water, and then heated at 80° C. for 15 min to obtain a tara gum aqueous solution; 14 g of triethylenetetramine and 6.6 g of epichlorohydrin are added, and the reaction is continued for 1.5 h, and then cooled and filtered; the solid is freeze-dried at -40° C. for 24 h to obtain an ammoniated tara gum; 10 mL of chlorosulfonic acid is added dropwise to 10 g of humic acid, and after the addition is completed, 10 mL of chlorosulfonic acid is stirred evenly, and then added to 200 mL of The mixture was reacted in a 1 mol / L sodium hydroxide aqueous solution for 15 min, the pH was adjusted to 5 with a 1 mol / L hydrochloric acid aqueous solution, filtered, the solid was collected, the solid was washed with water until the filtrate was neutral, and then dried to obtain sulfonated sodium humate; the ammoniated tara gum was dispersed in 800 mL of ethyl acetate, 8.6 g of sulfonated sodium humate was added, the pH value was adjusted to 9, the mixture was reacted at 65 ° C for 3 h, cooled to room temperature, the solvent was evaporated under reduced pressure, and the residue was freeze-dried at -40 ° C for 24 h to obtain modified tara gum.

[0057] Test Case

[0058] Test object: salt-resistant mud for slurry shield tunneling prepared in Examples 1-3 and Comparative Examples 1-2;

[0059] Viscosity test: Use a Soxhlet funnel viscometer with a stopwatch to measure the viscosity of the mud, in seconds;

[0060] Water separation rate: Use a measuring cylinder and a glass plate to measure the water separation rate of the mud, that is, the ratio of the water separated from the slurry within 24 hours after the sample mud is made to the original mud volume. The smaller the value, the better the stability of the mud;

[0061] Filtration: Use an air pump filter loss meter to measure the water loss of the mud;

[0062] Static shear force: The static shear force test of mud was adopted; the test results are shown in Table 1:

[0063] Table 1 Performance test results of salt-resistant slurry for slurry shield tunneling

[0064]

[0065] It can be seen from the experimental results in Table 1 that the comprehensive performance of the salt-resistant slurry for slurry shield tunneling prepared in Examples 1-3 of the present invention is relatively high.

[0066] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A salt-resistant slurry for slurry shield tunneling, characterized in that: The invention comprises the following components in parts by weight: 1000-1250 parts of waste mud, 100-300 parts of water, 30-50 parts of bentonite, 1-5 parts of thickener, 1-3 parts of anti-settling agent, and 1-3 parts of lubricant; The anti-settling agent is modified tara gum, and the preparation method thereof is as follows: mixing tara gum with water, heating and dissolving, adding triethylenetetramine and epichlorohydrin, continuing the reaction for 1-2 hours, cooling, filtering, and freeze-drying the solid to obtain ammoniated tara gum; dripping chlorosulfonic acid into humic acid, stirring evenly after the dripping is completed, and then adding it to a sodium hydroxide aqueous solution for reaction, adjusting the pH to 4-6 with a hydrochloric acid aqueous solution, filtering, collecting the solid, washing the solid with water until the filtrate is neutral, and drying to obtain sulfonated sodium humate; dispersing ammoniated tara gum in ethyl acetate, adding sulfonated sodium humate, adjusting the pH to 8-10, reacting at 50-75° C. for 2-4 hours, cooling to room temperature, distilling off the solvent under reduced pressure, and drying the residue to obtain modified tara gum; The dosage ratio of tara gum, triethylenetetramine, epichlorohydrin and sodium sulfonated humate is 20-30:10-18:5-8:5-10; The lubricant is modified molybdenum disulfide, and its preparation method is as follows: add molybdenum disulfide to a sodium hydroxide solution, immerse at room temperature for 5-8 hours, filter, wash, and dry after the immersion is completed, then add it to an ethanol aqueous solution, add 3-aminopropyltriethoxysilane, react at 40-60°C for 1-2 hours, filter, wash, and dry after the reaction is completed to obtain amination molybdenum disulfide; disperse the amination molybdenum disulfide in N,N-dimethylformamide, add epoxy phenyl silicone oil, adjust the pH value to 4-6, then react at 60-100°C for 3-5 hours, filter, wash, and dry after the reaction is completed to obtain modified molybdenum disulfide; The usage ratio of molybdenum disulfide, 3-aminopropyltriethoxysilane and epoxyphenyl silicone oil is 30-50:1-3:5-8.

2. The salt-resistant mud according to claim 1, characterized in that: The following steps are involved: The density of the waste mud is 1.10 g / cm 3 -1.45g / cm 3 The viscosity of the Soderbergh funnel is 20-75s, and the water seepage rate is ≤20% in 24 hours.

3. The salt-resistant mud according to claim 1, characterized in that: The thickener is a mixture of hydroxyethyl cellulose and sodium carbonate.

4. The salt-resistant mud according to claim 3 is characterized in that: The mass ratio of the hydroxyethyl cellulose to sodium carbonate is 1-3:

1.

5. A method for preparing the salt-resistant slurry according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: placing the waste mud and water generated when the shield passes through the previous strata in a slurry mixing pool, adding bentonite, thickener, anti-settling agent and lubricant, and fully stirring to obtain salt-resistant mud for mud-water shield tunneling.

6. The preparation method according to claim 5, characterized in that: The stirring conditions are a rotation speed of 700-900 rpm and a stirring time of 20-40 min.

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