Water-rich sand layer pipe-jacking construction anti-drag anti-seepage agent and preparation method thereof

Abstract

The invention discloses a water-rich sand layer pipe-jacking construction resistance-reducing seepage-proofing agent and a preparation method thereof. The resistance-reducing seepage-proofing agent comprises seepage-proofing slurry and resistance-reducing slurry, the anti-seepage slurry comprises the following raw materials: 30-40 parts of a polyurethane component, 2-5 parts of epoxy resin and 5-15 parts of an inorganic material; the anti-drag slurry is prepared from the following raw materials: 10 to 15 parts of graphite, 10 to 15 parts of sodium carbonate and 2 to 5 parts of polyacrylamide; respectively dispersing an anti-seepage slurry raw material and a drag reduction slurry raw material in water to obtain an anti-seepage slurry with the mass concentration of 30-50% and a drag reduction slurry with the mass concentration of 5-20%; and uniformly mixing the anti-seepage slurry and the anti-drag slurry according to the mass ratio of (1-99): (99-1) to obtain the anti-drag anti-seepage agent. The anti-drag anti-seepage agent has high water-retaining property, anti-permeability, stability and controllable thixotropic property, can meet the requirements of complex stratums in the long-distance pipe-jacking construction process, and particularly can effectively control seepage and reduce the frictional resistance of the pipe wall in a water-rich sand layer environment.

Description

Technical Field

[0001] The invention relates to the technical field of drag reducing and anti-seepage agent and construction, and in particular to a drag reducing and anti-seepage agent for pipe jacking construction in a water-rich sand layer, a preparation method thereof, and a pipe jacking system construction method. Background Art

[0002] With the development of urbanization in my country, urban land in the Yangtze River Delta region is becoming increasingly scarce, and a large number of urban power infrastructure needs to be buried underground. Pipe jacking is a construction method widely used in urban cable tunnels. As one of the main methods of trenchless technology, the application of pipe jacking is becoming more and more common. In the past, pipe jacking was mostly used to build urban underground pipe galleries or small-diameter, short-distance pipe trench projects. Now, in municipal projects with other functions such as subway tunnels and station ancillary structures, pipe jacking is increasingly used to build tunnels. Using the pipe jacking method to build tunnels in prosperous urban areas can ensure smooth ground traffic during construction, reduce construction land, and avoid various problems caused by demolition.

[0003] However, water-rich sand layers are a unique and complex stratum in the Yangtze River Delta region. Urban power pipe jacking construction faces many problems such as difficulty in anti-seepage control when crossing water-rich sand layers. In long-distance pipe jacking construction, there is excessive friction resistance of the pipe wall, and traditional drag reducers do not have anti-seepage function. The squeezing and friction of the pipe wall in the water-rich sand layer causes local ultra-high pore water pressure, which will lead to serious leakage problems at pipe joints, pipe joints and working well interfaces, and equipment wall holes.

[0004] In the existing pipe jacking construction, in order to reduce the friction between the overlying soil and the pipe segment, the mud material is injected into the gap outside the pipe segment through the grouting hole inside the pipe segment. First, it plays a lubricating role. During the jacking construction process, the mud is subjected to external disturbances such as pumping and flow. The slurry lubricates the friction between the pipe segment structure and the soil in a fluid form, thereby reducing the propulsion resistance; second, it plays a filling and supporting role. The slurry becomes a gel after standing still, which can effectively fill the gap between the supporting pipe segment structure and the surrounding soil, reduce the stratum disturbance and settlement deformation, and ensure the safety and controllability of the surrounding environment. At present, in the preparation process of drag reduction mud, most of the cases still rely on traditional empirical rules to determine. The accuracy of the addition cannot be ensured each time the mud is mixed, which often leads to the instability of the prepared mud in performance. This phenomenon will have an impact that cannot be ignored in construction applications. Therefore, it is very important to study the proportion and construction method of grouting materials in the process of pipe jacking construction.

[0005] Invention CN 112851216A discloses a high water retention and low viscosity thixotropic mud for pipe jacking, which contains the following components and the mass proportions of each component: 4-8 parts of sodium bentonite, 0.2-0.3 parts of soda ash, 1-4 parts of fly ash microspheres, 0.05-0.2 parts of warm wheel glue, and 85.5-94.75 parts of water. The invention has high water retention at a lower dosage of bentonite and admixtures, and is suitable for complex formations such as groundwater-rich strata and sandy soils. The design of the thixotropic mud pursues high water retention and low viscosity to adapt to complex formations. However, in long-distance pipe jacking construction, low viscosity will cause the slurry to flow too fast, making it difficult to form a stable slurry layer in the pipeline, and then loss or accumulation in certain parts will occur. This imbalance in fluidity makes it difficult to evenly distribute the mud.

[0006] Invention CN107858150A discloses a thixotropic mud, which comprises 30-40 parts of bentonite, 6-8 parts of soda ash, 1-2 parts of sodium hydroxymethylcellulose, 3-5 parts of polyacrylamide, 5-6 parts of modified graphite, 4-6 parts of modified water-retaining gel, 2-3 parts of retarder, 3-6 parts of polyethylene oxide and 60-70 parts of water, in order by weight. Although the thixotropic mud improves the water retention and impermeability of the mud by adding polyacrylamide, the thixotropic performance of the mud is greatly limited because the main body of the mud is bentonite, and the natural difference of the bentonite component is large, so it is difficult to accurately control the effective component ratio in the thixotropic mud.

[0007] Therefore, how to provide a highly adaptable drag-reducing and anti-seepage mud with high water retention, impermeability and controllable thixotropic properties to meet the needs of complex formations during long-distance pipe jacking construction, especially in water-rich sand layer environments, effectively control leakage, reduce pipe wall friction resistance, and maintain the stability of the mud's performance during transportation and standing, has become a problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0008] In view of the defects existing in the above-mentioned prior art, the present invention provides a drag-reducing and anti-seepage agent for jacking pipe construction in water-rich sand layers, a preparation method thereof, and a jacking pipe system construction method. The drag-reducing and anti-seepage agent is designed to include an anti-seepage slurry and a drag-reducing slurry in an appropriate proportion. It has the advantages of high water retention, impermeability, controllable thixotropy, stable performance and high adaptability. It can meet the needs of complex formations during long-distance jacking pipe construction, especially in a water-rich sand layer environment, effectively controlling leakage and reducing pipe wall friction resistance.

[0009] In a first aspect, the present invention provides a drag reducing and anti-seepage agent for pipe jacking construction in a water-rich sand layer, comprising an anti-seepage slurry and a drag reducing slurry;

[0010] The raw materials of the anti-seepage slurry include, by mass:

[0011] Polyurethane component 30-40 parts

[0012] Epoxy resin 2-5 parts

[0013] 5-15 parts of inorganic materials;

[0014] The raw materials of drag reducing slurry include:

[0015] Graphite 10-15 parts

[0016] Soda ash 10-15 parts

[0017] Polyacrylamide 2-5 parts;

[0018] Dispersing the raw materials of the anti-seepage slurry in water to obtain an anti-seepage slurry with a mass concentration of 30-50%;

[0019] Dispersing the raw materials of the drag-reducing slurry in water to obtain a drag-reducing slurry with a mass concentration of 5-20%;

[0020] The anti-seepage slurry and the drag-reducing slurry are uniformly mixed in a mass ratio of (1-99): (99-1) to obtain the drag-reducing and anti-seepage agent.

[0021] The existing technology mostly uses bentonite as the main material of thixotropic mud, which has good water absorption, expansion and certain thixotropy, and can form a high viscosity structure when standing, preventing mud loss, and playing a supporting and lubricating role. However, due to the large natural differences in bentonite components, it is difficult to accurately control. At the same time, the thixotropic properties formed in the mud are relatively single, and the shear thinning ability is limited, making it difficult to adapt to various rheological requirements under different working conditions.

[0022] The present invention obtains a highly adaptable drag-reducing and anti-seepage agent by combining organic and inorganic components. In the anti-seepage slurry, the aqueous polyurethane component, epoxy resin and inorganic material can form a dense network structure in the mud system, thereby significantly enhancing the slurry's impermeability and water resistance, and is particularly suitable for high-permeability formations such as water-rich sand layers. In addition, the fluidity and viscosity of the slurry can be more accurately regulated by adding the aqueous polyurethane component, epoxy resin and inorganic material in a proportion, thereby avoiding the risk of loss of effective components due to low viscosity of the existing mud, or blocking the pipeline due to high viscosity. In the drag-reducing slurry, graphite is used to provide lubrication and filling, soda ash maintains the overall dispersibility of the drag-reducing slurry and adjusts the pH value, and polyacrylamide thickens and provides thixotropy. This combination not only ensures the fluidity of the drag-reducing slurry during transportation, but also ensures its lubrication and support at the pipe wall, effectively reducing the friction resistance in long-distance pipe jacking construction.

[0023] Preferably, the polyurethane component comprises the following raw materials by mass:

[0024] Isocyanate 50-100 parts

[0025] Polyol 10-50 parts

[0026] 1-5 parts of terminal hydroxyl compound,

[0027] The polyol and the terminal hydroxyl compound are firstly mixed uniformly, and then the isocyanate and the optional auxiliary agent are added to mix and prepare the water-based polyurethane component containing the polyurethane prepolymer.

[0028] The isocyanate includes one or more of phenylene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), polymethylene polyphenyl polyisocyanate (PAPI), and diphenylmethane diisocyanate (MDI);

[0029] The polyol includes at least one of polyester polyol, polyether polyol, oligomeric polyol containing unsaturated bonds, and glycerol;

[0030] The terminal hydroxyl compounds include terminal hydroxyl polyethylene oxide polymers, polyoxyethylene-polyoxypropylene monools or mixtures thereof;

[0031] The auxiliary agent includes one or more of a catalyst, a curing agent, a stabilizer, and a coupling agent, and the total amount of the auxiliary agent accounts for about 2-10% of the mass of the isocyanate;

[0032] Among them, the catalyst is preferably DBTDL, the curing agent is preferably DMP-30, the foam stabilizer is preferably AK8805, and the coupling agent can be a silane coupling agent, preferably KH560.

[0033] Preferably, the epoxy resin comprises porous epoxy resin particles with an average particle size of 30-100 μm and an average pore size of 10 to 2000 nm;

[0034] The inorganic material includes one or more of cement, controllable clay, and water glass;

[0035] The porous epoxy resin particles and / or the inorganic material are pre-treated with a silane coupling agent, wherein the silane coupling agent contains an isocyanate reactive group.

[0036] The silane coupling agent used for the pretreatment is, for example, a silane coupling agent represented by the formula AR-Si-(B)3, wherein A can be an isocyanate reactive group selected from at least one of an amine group, a hydroxyl group or a thiol group, B can be an alkoxy group, and R is selected from an aromatic or aliphatic ester group. When the anti-seepage slurry is prepared, the porous epoxy resin particles and / or inorganic materials pretreated with the silane coupling agent are mixed with the waterborne polyurethane component containing the polyurethane prepolymer. Due to the excess of isocyanate in the waterborne polyurethane component, the reactive group can react with the waterborne polyurethane component to form a hydrophilic core-shell structure in which the epoxy particles and / or inorganic particles are coated with the waterborne polyurethane, thereby improving the hydrophilic stability of the anti-seepage slurry.

[0037] Preferably, the polyacrylamide includes one or more of cationic polyacrylamide, anionic polyacrylamide and nonionic polyacrylamide;

[0038] Graphite is compounded by mixing micro-nano graphite powder with a particle size of 1-10 μm and expanded graphite with a particle size of 20-50 μm, and the mass ratio of the micro-nano graphite powder to the expanded graphite is (10-20):(1-5).

[0039] The long chain structure and polar groups (amide groups) of polyacrylamide enable it to play the role of thickening, water retention, anti-seepage and rheological regulation in the drag reduction slurry. It forms a gel network with elasticity and toughness in the drag reduction slurry system by means of physical entanglement and chemical adsorption. This network can adapt to changes in external forces under different construction conditions, thereby improving the stability, lubricity and support effect of the drag reduction slurry. The present invention further improves the lubrication effect of the drag reducer while improving the thixotropy and viscosity of the drag reducer by adding polyacrylamide and graphite to the drag reduction slurry.

[0040] Furthermore, the use of graphite with different particle sizes and morphologies can better play a supporting and lubricating role. Expanded graphite (EG) is a new type of functional carbon material. It is a loose and porous worm-like substance obtained by intercalation, washing, drying, and high-temperature expansion of natural graphite. In addition to the excellent properties of natural graphite itself, such as resistance to cold and heat, corrosion resistance, and self-lubrication, expanded graphite also has better softness, compression resilience, adsorption, ecological environment coordination, biocompatibility, radiation resistance and other characteristics.

[0041] Preferably, polyacrylamide and expanded graphite are pre-formed into an intercalated composite structure, comprising the following steps:

[0042] S1-1, ultrasonically dispersing expanded graphite in an ethanol aqueous solution to obtain a graphite dispersion;

[0043] S1-2, adding polyacrylamide to the graphite dispersion, stirring and ultrasonically treating, to obtain a polyacrylamide-graphite intercalation composite structure.

[0044] In order to better play the advantages of expanded graphite, a multi-layered composite structure of polymer inserted into expanded graphite is formed through ultrasonic assisted pretreatment, so that expanded graphite is dispersed more stably and evenly in the polymer matrix. Compared with the intercalation structure of natural graphite, the expanded graphite with a larger and more diverse layered structure can be more effectively inserted into polymer macromolecules under relatively mild conditions.

[0045] More preferably, polyacrylamide and expanded graphite are preformed into a composite gel, comprising the following steps:

[0046] S2-1, disperse expanded graphite in water, add acrylamide monomer and ammonium persulfate (APS), and perform ultrasonic treatment for 10-20 minutes;

[0047] S2-2, adding tetramethylethylenediamine (TEMED) and ultrasonic treatment for 2-5 min;

[0048] S2-3, react at 40-60°C for 2-24h to obtain an aqueous polyacrylamide-graphite composite gel.

[0049] By mixing and polymerizing expanded graphite with acrylamide monomer and initiator, not only can the polymer penetrate into the expanded graphite to form a better filling intercalation structure, but the expanded graphite has a richer loose porous structure than ordinary natural graphite, which can provide a physical cross-linking method for polyacrylamide - topological cross-linking. In the water-based polyacrylamide-graphite composite gel with expanded graphite as the cross-linking point, the polymerized monomer will form a molecular chain that passes through these holes during the polymerization process, and these holes will not produce too much "locking force" with the molecular chain. The free sliding of the molecular chain produces a pulley-like effect, which improves the drag reduction performance of the drag reduction slurry.

[0050] In a second aspect, the present invention further provides a method for preparing the aforementioned drag reducing and anti-seepage agent for pipe jacking construction in a water-rich sand layer, comprising the following steps:

[0051] S1. Prepare anti-seepage slurry:

[0052] Weigh the raw materials of the anti-seepage slurry according to the preset proportions;

[0053] Dispersing the raw materials of the anti-seepage slurry in water and mixing them evenly to form an anti-seepage slurry with a mass concentration of 30-50%;

[0054] S2. Prepare drag reduction slurry:

[0055] Weigh the raw materials of the drag reduction slurry according to the preset proportions;

[0056] Dispersing the raw materials of the drag reduction slurry in water and mixing them evenly to form a drag reduction slurry with a mass concentration of 5-20%;

[0057] S3. Mix the anti-seepage slurry and the drag-reducing slurry in a mass ratio of (1-99):(99-1) to obtain the drag-reducing and anti-seepage agent.

[0058] In a third aspect, the present invention further provides a method for constructing a pipe jacking system using the aforementioned water-rich sand layer to construct a drag-reducing and anti-seepage agent, wherein the pipe jacking system comprises a head pipe segment and a plurality of body pipe segments connected in sequence, and the construction method comprises the following steps:

[0059] Step 1: prepare an anti-seepage compounding agent and a drag-reducing compounding agent respectively according to the use position of the drag-reducing and anti-seepage agent in the pipe jacking system;

[0060] The anti-seepage compounding agent is a mixture of the anti-seepage slurry and the drag-reducing slurry in a mass ratio of (65-90): (10-35);

[0061] The drag reducing agent is a mixture of the anti-seepage slurry and the drag reducing slurry in a mass ratio of (10-35): (65-90);

[0062] Step 2: Determine the laying path of the pipe sections of the jacking system and dig the tunnel;

[0063] Step 3: Install the jacking device and the excavation device in the tunnel, and push the excavation device through the jacking device;

[0064] Step 4: Arrange a machine head pipe joint in the tunnel, and apply the anti-seepage compound at the port of the machine head pipe joint;

[0065] Step 5: Push in the fuselage tube segments one by one, and connect the fuselage tube segments end to end until all the fuselage tube segments are installed, wherein the drag reducing compound is applied between the fuselage tube segments.

[0066] The tunnels dug according to the pipe segment laying path of the jacking system include but are not limited to the launch pit and the receiving pit. A jacking device is installed in the launch pit, and the excavation device is hoisted into the launch pit, so that the jacking device pushes the excavation device. The subsequent head pipe segment and fuselage pipe segment can be lowered to the launch pit by hoisting.

[0067] During the construction of the jacking system, the drag-reducing and anti-seepage agent for jacking in water-rich sand layers can flexibly adjust the ratio of anti-seepage slurry and drag-reducing slurry according to the specific use location, which can effectively enhance the anti-seepage property of the head pipe section and reduce the jacking resistance of the fuselage pipe section. Specifically, the proportion of drag-reducing slurry can be appropriately increased in the pipe body section to improve the lubrication performance and effectively reduce the friction resistance between the pipe wall and the surrounding soil layer. This flexible regulation allows the jacking to remain stable during the advancement process, helps to reduce the workload of the equipment, reduce construction costs, and extend the service life of the construction equipment. In the head pipe section and special formation areas, increasing the proportion of anti-seepage slurry can form a dense anti-seepage layer between the pipe sections, effectively preventing water or mud leakage. This regulation enables the pipe section interface, working well interface, and wall hole to remain stable under high pressure and water-rich environments, avoiding structural damage due to leakage and ensuring construction safety.

[0068] Flexible control of the ratio of anti-seepage slurry and drag-reducing slurry helps to reasonably use anti-seepage and drag-reducing materials in different locations and working conditions to avoid material waste. By adding anti-seepage or drag-reducing components when needed, unnecessary material consumption can be reduced, which helps to reduce construction costs and improve resource utilization efficiency.

[0069] Preferably, in step five, both ends of each fuselage pipe segment respectively include a plug end and a socket end, and the plug ends and socket ends of adjacent fuselage pipe segments are plugged together to form an installation gap, and a steel pipe sleeve and a sealing ring are arranged at the installation gap. The sealing ring is inflated to push out a liquid injection gap between the pipe segment wall and the steel pipe sleeve, and the drag reduction compound is applied to the liquid injection gap, and then the inflated sealing ring is deflated and shrunk.

[0070] Preferably, the shrinkage outer diameter of the sealing ring when not inflated or deflated is less than or equal to the outer diameter of the pipe segment wall;

[0071] The amount of compression of the sealing ring after inflation is less than or equal to half of the inflated outer diameter of the sealing ring. Preferably, the contact pressure of the sealing ring is above 0.3 MPa.

[0072] Preferably, the sealing ring is an inflatable rubber sealing ring, which surrounds the socket end of the sleeved fuselage pipe section; the inflatable rubber sealing ring more preferably comprises chloroprene rubber with high sealing performance.

[0073] When adjacent fuselage pipe sections are connected, the spigot end of one fuselage pipe section is inserted into the socket end of another fuselage pipe section, and the spigot end and the socket end are plugged and matched, connected to each other and forming the installation gap. The rubber sealing ring is set in the installation gap. After the high-pressure gas is filled into the rubber sealing ring, its elastic deformation pushes up the steel pipe sleeve at the end of the socket to form an effective support structure, and the injection gap is pushed out between the pipe section wall and the steel pipe sleeve, which facilitates the injection of the drag reduction compounding agent into the attention gap. At the same time, after the rubber sealing ring is inflated, the gap between the pipe sections is sealed, which helps to block the injected drag reduction and anti-seepage agent, and ensure that the drag reduction and anti-seepage agent forms the desired effect at the corresponding position.

[0074] During the process of pipe jacking, the inflated state of the rubber seal ring also closes the gap between the pipe jacking and the steel pipe sleeve, exerting axial restraint on the spigot to prevent the spigot from slipping due to internal pressure of the pipe or external force. Before the pipe jacking, the high-pressure gas in the rubber ring is released to further release the gap between the formation and the pipe wall, reducing frictional resistance. This controllable friction adjustment function effectively reduces the workload of the equipment, extends the service life of the equipment, and reduces construction costs.

[0075] The present invention has at least the following beneficial effects:

[0076] (1) The drag-reducing and anti-seepage agent of the present invention adopts organic / inorganic material composite components, as well as a compounding method of anti-seepage slurry and drag-reducing slurry, so that the drag-reducing and anti-seepage agent has excellent anti-seepage and drag-reducing properties in the construction of jacking pipes in water-rich sand layers. The polyurethane component and epoxy resin in the anti-seepage slurry provide extremely high sealing and anti-permeability properties, forming a dense waterproof layer to resist the osmotic pressure of water-rich formations; the inorganic material further enhances the pressure resistance, allowing the slurry to remain stable under high pressure conditions. At the same time, the graphite and polyacrylamide in the drag-reducing slurry interact with each other. The graphite provides lubrication to reduce the friction between the pipeline and the soil, and the polyacrylamide improves the water retention and thixotropy of the mud, ensuring that the slurry forms a uniform drag-reducing layer around the pipe wall, thereby effectively reducing the propulsion resistance.

[0077] (2) The present invention adopts a composite graphite component, and through the porous worm-like structure of expanded graphite and the high water absorption and thixotropy of polyacrylamide, a stable intercalated composite structure or composite gel is formed, which not only provides excellent self-lubrication and compression resilience, but also produces a "pulley effect" through a topological cross-linked structure, enhancing the resilience and pressure resistance and drag reduction effect of the composite material. In long-distance pipe jacking construction, this composite material can flexibly adjust the drag reduction performance under different working conditions, achieving the dual effects of high viscosity support when static and good flow under shear force, providing more stable and efficient drag reduction and anti-seepage support for complex formation conditions.

[0078] (3) In the anti-seepage slurry of the present invention, the porous epoxy resin particles and / or inorganic materials are pretreated with a silane coupling agent containing an isocyanate reactive group, which can react and connect with the excess isocyanate in the aqueous polyurethane component containing the polyurethane prepolymer, which is not only beneficial to improve the hydrophilic stability of the anti-seepage slurry, but also can enhance the bonding strength between the slurry and the substrate, which is beneficial to the rapid cessation of leakage and seepage control of the drag-reducing and anti-seepage agent provided by the present invention during pipe jacking construction in water-rich sand layers.

[0079] (4) The drag-reducing and anti-seepage agent prepared by the present invention can be flexibly proportioned according to the requirements of different parts of the jacking system. The proportion of the anti-seepage agent is increased in the pipe head section to enhance the anti-seepage effect, while the proportion of the drag-reducing agent is increased in the pipe body section to reduce friction resistance and improve the smoothness of the jacking advancement and construction efficiency. This zoning can effectively reduce construction costs while ensuring structural safety.

[0080] (5) The pipe jacking system disclosed in the present invention has rubber sealing rings added between the pipe sections, which can seal the gaps between the pipe sections, making the coating range of the drag-reducing and anti-seepage agent more comprehensive, ensuring that key parts and potential leakage points are evenly covered without omission, thereby improving the overall sealing and anti-seepage performance. At the same time, the inflation function of the rubber ring can temporarily close the gap between the pipe jacking and the formation when the pipe jacking is advanced, reducing friction resistance, significantly reducing the load of the equipment, and extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 It is a structural schematic diagram of the pipe jacking system of the present invention;

[0082] Figure 2 It is an axial schematic diagram of the pipe joint connection structure of the pipe jacking system of the present invention;

[0083] Figure 3 It is a schematic diagram of the construction method of the pipe jacking system of the present invention.

[0084] Explanation of the accompanying drawings: 1-liquid injection gap, 2-steel casing, 3-sealing ring, 4-socket end, 5-plug end. DETAILED DESCRIPTION

[0085] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the specification and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0086] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0087] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0088] The following will be combined with the attached Figure 1-3 The drag reducing and anti-seepage agent, pipe jacking system and preparation method for pipe jacking construction in water-rich sand layer provided by the present invention are further described:

[0089] A drag reducing and anti-seepage agent for pipe jacking construction in a water-rich sand layer, specifically comprising:

[0090] (1) Anti-seepage slurry, in parts by mass, including:

[0091] 1.1) 30-40 parts of polyurethane component

[0092] 1.2) 2-5 parts of epoxy resin

[0093] 1.3) 5-15 parts of inorganic materials;

[0094] Wherein, 1.1) the polyurethane component comprises the following raw materials:

[0095] Isocyanate 50-100 parts

[0096] Polyol 10-50 parts

[0097] 1-5 parts of terminal hydroxyl compound;

[0098] Firstly, the polyol and the terminal hydroxyl compound are uniformly mixed, and then isocyanate (excessive amount) and optional auxiliary agents are added to mix and prepare a water-based polyurethane component containing a polyurethane prepolymer;

[0099] 1.2) The epoxy resin includes porous epoxy resin particles having an average particle size of 30-100 μm and an average pore size of 10 to 2,000 nm;

[0100] 1.3) The inorganic material includes one or more of cement, controlled clay and water glass;

[0101] The porous epoxy resin particles and / or inorganic materials are pretreated with a silane coupling agent, wherein the silane coupling agent contains an isocyanate reactive group and can react and connect with excess isocyanate in a waterborne polyurethane component containing a polyurethane prepolymer to form a hydrophilic core-shell structure in which the waterborne polyurethane encapsulates the epoxy particles and / or inorganic particles;

[0102] The raw materials of the anti-seepage slurry are dispersed in water to obtain an anti-seepage slurry with a mass concentration of 30-50%.

[0103] (2) Drag-reducing slurry, in parts by mass, comprising:

[0104] 2.1) 10-15 parts of graphite

[0105] 2.2) 10-15 parts of soda ash

[0106] 2.3) 2-5 parts of polyacrylamide;

[0107] Wherein, 2.1) graphite is compounded by mixing micro-nano graphite powder with a particle size of 1-10 μm and expanded graphite with a particle size of 20-50 μm, and the mass ratio of the micro-nano graphite powder to the expanded graphite is (10-20):(1-5);

[0108] 2.2) Polyacrylamide includes one or more of cationic polyacrylamide, anionic polyacrylamide and nonionic polyacrylamide;

[0109] Preferably, polyacrylamide and expanded graphite are pre-formed into an intercalated composite structure or a composite gel:

[0110] ① The intercalation composite structure includes the following preparation steps:

[0111] S1-1, ultrasonically dispersing expanded graphite in an ethanol aqueous solution to obtain a graphite dispersion;

[0112] S1-2, adding polyacrylamide to the graphite dispersion, stirring and ultrasonically treating, to obtain a polyacrylamide-graphite intercalation composite structure.

[0113] ② The composite gel comprises the following preparation steps:

[0114] S2-1, disperse graphite in water, add acrylamide monomer and ammonium persulfate (APS), and perform ultrasonic treatment for 10-20 minutes;

[0115] S2-2, adding tetramethylethylenediamine (TEMED) and ultrasonic treatment for 2-5 min;

[0116] S2-3, react at 40-60°C for 2-24h to obtain an aqueous polyacrylamide-graphite composite gel.

[0117] The raw materials of the drag-reducing slurry are dispersed in water to obtain a drag-reducing slurry with a mass concentration of 5-20%.

[0118] The anti-seepage slurry and the drag-reducing slurry are mixed uniformly in a mass ratio of (1-99): (99-1) to obtain a drag-reducing anti-seepage agent. The drag-reducing anti-seepage agent is used in a pipe jacking system, and the ratio of the anti-seepage slurry and the drag-reducing slurry in the drag-reducing anti-seepage agent is adjusted according to the use location and requirements to obtain an anti-seepage compounding agent and a drag-reducing compounding agent, respectively.

[0119] A method for constructing a pipe jacking system using the aforementioned water-rich sand layer to construct a drag-reducing and anti-seepage agent, the pipe jacking system comprising a head pipe segment and a plurality of body pipe segments connected in sequence, the construction method comprising the following steps:

[0120] Step 1: prepare an anti-seepage compounding agent and a drag-reducing compounding agent respectively according to the use position of the drag-reducing and anti-seepage agent in the pipe jacking system;

[0121] The anti-seepage compounding agent is a mixture of the anti-seepage slurry and the drag-reducing slurry in a mass ratio of (65-90): (10-35);

[0122] The drag reducing agent is a mixture of the anti-seepage slurry and the drag reducing slurry in a mass ratio of (10-35): (65-90);

[0123] Step 2: Determine the laying path of the pipe sections of the jacking system and dig the launching pit and receiving pit;

[0124] Step 3: Install the jacking device in the launch pit, hoist the excavation device into the launch pit, and push the excavation device through the jacking device;

[0125] Step 4: hoist the machine head pipe section to the inside of the launch pit, and apply the anti-seepage compounding agent at the port of the machine head pipe section;

[0126] Step 5: Place and push in the fuselage tube sections one by one, connecting each fuselage tube section end to end until all fuselage tube sections are installed.

[0127] When adjacent fuselage tube sections are connected, the spigot end 5 of one fuselage tube section is inserted into the socket end 4 of another fuselage tube section, and the spigot end 5 and the socket end 4 are plugged and matched, connected to each other and forming an installation gap;

[0128] An uninflated sealing ring 3 (made of chloroprene rubber) is sleeved in the installation gap. After high-pressure gas is filled into the rubber sealing ring 3, it elastically deforms and lifts up the steel pipe sleeve 2 at the end of the socket to form an effective supporting structure, and a liquid injection gap 1 is pushed out between the pipe segment wall and the steel pipe sleeve 2, and a drag reduction compound is injected into the liquid injection gap 1;

[0129] Before pushing the pipe jacking system, the inflated sealing ring 3 is deflated and shrunk. The shrinkage outer diameter of the sealing ring 3 when not inflated or deflated is less than or equal to the outer diameter of the pipe segment wall, and the compression amount of the sealing ring 3 after inflation is less than or equal to half of the inflated outer diameter of the sealing ring, and its contact pressure is above 0.3MPa.

[0130] Anti-seepage slurry A1

[0131] The anti-seepage slurry A1 of this preparation example, in parts by mass, specifically comprises the following raw materials:

[0132] Polyurethane component 40 parts

[0133] 4 parts porous epoxy resin particles

[0134] 6 parts of water glass;

[0135] The polyurethane component is a water-based polyurethane component containing a polyurethane prepolymer. By weight, 18 parts of polyether polyol 303 and 2 parts of polyethylene oxide with terminal hydroxyl groups are uniformly mixed, and then 60 parts of diphenylmethane diisocyanate are added to obtain the prepolymer.

[0136] The porous epoxy resin particles have an average particle size of 60±5 μm and an average pore size of 1000±100 nm; the porous epoxy resin particles are pretreated with bis(trimethoxysilylpropyl)amine;

[0137] The polyurethane component, porous epoxy resin particles and water glass are mixed evenly, and the above raw materials are dispersed in water to obtain an anti-seepage slurry with a mass concentration of 50%. The isocyanate in the polyurethane component reacts with the active groups of the porous epoxy resin particles to obtain a water-soluble and uniform anti-seepage slurry A1.

[0138] Anti-seepage slurry A2

[0139] The anti-seepage slurry A2 of this preparation example is different from the anti-seepage slurry A1 in that the raw material ratio is different. In parts by mass, the raw materials of A2 specifically include:

[0140] Polyurethane component 30 parts

[0141] 5 parts of porous epoxy resin particles

[0142] 15 parts of water glass.

[0143] Anti-seepage slurry A3

[0144] The anti-seepage slurry A3 of this preparation example is different from the anti-seepage slurry A1 in that the raw material ratio is different. In parts by mass, the raw materials of A3 specifically include:

[0145] Polyurethane component 35 parts

[0146] 3 parts porous epoxy resin particles

[0147] 12 parts of water glass.

[0148] The material proportions of anti-seepage slurry A1-A3 are shown in Table 1:

[0149] Table 1 Material ratio of anti-seepage slurry A1-A3

[0150]

[0151]

[0152] Drag Reduction Slurry B1

[0153] The drag reduction slurry B1 of this preparation example, in parts by mass, specifically comprises the following raw materials:

[0154] 15 parts of micro-nano graphite powder

[0155] 10 parts of soda ash

[0156] 5 parts of nonionic polyacrylamide;

[0157] The average particle size of micro-nano graphite powder is 5±1μm.

[0158] The raw materials of the drag-reducing slurry are dispersed in water to obtain a drag-reducing slurry B1 with a mass concentration of 20%.

[0159] Drag Reduction Slurry B2

[0160] The drag reducing slurry B2 of this preparation example is different from the drag reducing slurry B1 in that the graphite in the raw materials is compound graphite. The specific raw materials include, by weight:

[0161]

[0162] The average particle size of micro-nano graphite powder is 5±1μm.

[0163] Expanded graphite, with an average particle size of 35±5 μm, polyacrylamide and expanded graphite are pre-formed into an intercalated composite structure, comprising the following steps:

[0164] S1-1, ultrasonically dispersing expanded graphite in an ethanol aqueous solution for 15 minutes to obtain a graphite dispersion;

[0165] S1-2, adding polyacrylamide to the graphite dispersion, stirring and ultrasonically treating for 15 minutes to obtain a polyacrylamide-graphite intercalation composite structure.

[0166] All raw materials of the drag-reducing slurry are dispersed in water to obtain a drag-reducing slurry with a mass concentration of 20%.

[0167] Drag Reduction Slurry B3

[0168] The drag reducing slurry B3 of this preparation example is different from the drag reducing slurry B2 in that polyacrylamide and expanded graphite are pre-formed into a composite gel, which includes the following steps:

[0169] S2-1, disperse graphite in water, add acrylamide monomer and ammonium persulfate (APS), and treat with ultrasound for 10 min;

[0170] S2-2, add tetramethylethylenediamine (TEMED) and treat with ultrasound for 3 min;

[0171] S2-3, react at 50°C for 12 hours to obtain an aqueous polyacrylamide-graphite composite gel.

[0172] All raw materials of the drag-reducing slurry are dispersed in water to obtain a drag-reducing slurry with a mass concentration of 20%.

[0173] Drag Reduction Slurry B4

[0174] The drag reducing slurry B4 of this preparation example is different from the drag reducing slurry B3 in that the raw material ratios are different, and the raw materials are calculated by weight:

[0175]

[0176] The material ratio of drag reduction slurry B1-B4 is shown in Table 2:

[0177] Table 2 Material ratio of drag reduction slurry B1-B4

[0178]

[0179] Example 1

[0180] The anti-seepage slurry A1 and the drag-reducing slurry B1 are used to prepare the anti-seepage compounding agent 1 and the drag-reducing compounding agent 1 respectively.

[0181] Anti-seepage compound 1: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A1 and drag reduction slurry B1 is 80:20;

[0182] Drag reduction compound 1: Applied between two pipe sections of the pipe body, the mass ratio of anti-seepage slurry A1 and drag reduction slurry B1 is 30:70.

[0183] The anti-seepage compound 1 and the drag-reducing compound 1 in this embodiment 1 are used to carry out a pipe jacking system construction method, wherein the pipe jacking system comprises a head pipe segment and a plurality of fuselage pipe segments connected in sequence, and the construction method comprises the following steps:

[0184] Step 1: prepare an anti-seepage compounding agent and a drag-reducing compounding agent respectively according to the use position of the drag-reducing and anti-seepage agent in the pipe jacking system;

[0185] The anti-seepage compounding agent 1 is applied to the port of the machine head pipe joint, and the anti-seepage slurry adopts the anti-seepage slurry A1 and the drag-reducing slurry adopts the drag-reducing slurry B1, which are mixed at a mass ratio of 80:20;

[0186] Drag reduction compounding agent 1 is applied to the injection gap between adjacent fuselage tube sections, and the anti-seepage slurry is the anti-seepage slurry A1, and the drag reduction slurry is the drag reduction slurry B1, which is mixed at a mass ratio of 30:70;

[0187] Step 2: Determine the laying path of the pipe sections of the jacking system and dig the launching pit and receiving pit;

[0188] Step 3: Install the jacking device in the launch pit, hoist the excavation device into the launch pit, and push the excavation device through the jacking device;

[0189] Step 4: hoist the machine head pipe section to the inside of the launch pit, and apply the anti-seepage compound 1 at the port of the machine head pipe section;

[0190] Step 5: Place and push in the fuselage tube segments one by one, and connect the fuselage tube segments end to end until all fuselage tube segments are installed. When adjacent fuselage tube segments are connected, the spigot end of one fuselage tube segment is inserted into the socket end of another fuselage tube segment, and the spigot end and the socket end are plugged and matched, connected to each other and forming an installation gap, and the uninflated chloroprene rubber sealing ring is set in the installation gap. After the high-pressure gas is filled into the rubber sealing ring, its elastic deformation pushes up the steel pipe sleeve at the socket end, and pushes out the injection gap between the tube segment wall and the steel pipe sleeve, and the drag reduction compound 1 is injected into the injection gap.

[0191] Example 2

[0192] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this embodiment is the same as that in Example 1, except that this embodiment adopts anti-seepage slurry A2 and drag reducing slurry B1 to respectively configure anti-seepage compounding agent 2 and drag reducing compounding agent 2.

[0193] Anti-seepage compound 2: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A2 and drag-reducing slurry B1 is 80:20;

[0194] Drag reduction compound 2: Applied between two pipe sections of the pipe body, the mass ratio of anti-seepage slurry A2 and drag reduction slurry B1 is 30:70.

[0195] Example 3

[0196] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this embodiment is the same as that in Example 1, except that this embodiment adopts anti-seepage slurry A3 and drag reducing slurry B1 to respectively configure anti-seepage compounding agent 3 and drag reducing compounding agent 3.

[0197] Anti-seepage compound 3: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A3 and drag-reducing slurry B1 is 80:20;

[0198] Drag reduction compound 3: Applied between two pipe sections of the pipe body, the mass ratio of anti-seepage slurry A3 and drag reduction slurry B1 is 30:70.

[0199] Example 4

[0200] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this embodiment is the same as that in Example 1, except that this embodiment adopts anti-seepage slurry A3 and drag reducing slurry B2 to respectively configure anti-seepage compounding agent 4 and drag reducing compounding agent 4.

[0201] Anti-seepage compound 4: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A3 and drag-reducing slurry B2 is 80:20;

[0202] Drag reduction compound 4: Applied between two pipe sections of the pipe body, the mass ratio of the anti-seepage slurry A3 and the drag reduction slurry B2 is 30:70.

[0203] Example 5-1

[0204] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this embodiment is the same as that in Example 1, except that this embodiment adopts anti-seepage slurry A3 and drag reducing slurry B3 to respectively configure anti-seepage compounding agent 5-1 and drag reducing compounding agent 5-1.

[0205] Anti-seepage compound 5-1: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A3 and drag reduction slurry B3 is 80:20;

[0206] Drag reduction compound 5-1: Applied between two pipe sections of the pipe body, the mass ratio of anti-seepage slurry A3 and drag reduction slurry B3 is 30:70.

[0207] Example 5-2

[0208] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this embodiment is the same as that in Example 1, except that this embodiment adopts anti-seepage slurry A3 and drag reducing slurry B3 to respectively configure anti-seepage compounding agent 5-2 and drag reducing compounding agent 5-2.

[0209] Anti-seepage compound 5-2: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A3 and drag-reducing slurry B3 is 90:10;

[0210] Drag reduction compound 5-2: Applied between two pipe sections of the pipe body, the mass ratio of anti-seepage slurry A3 and drag reduction slurry B3 is 35:65.

[0211] Example 5-3

[0212] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this embodiment is the same as that in Example 1, except that this embodiment adopts anti-seepage slurry A3 and drag reducing slurry B3 to respectively configure anti-seepage compounding agent 5-3 and drag reducing compounding agent 5-3.

[0213] Anti-seepage compound 5-3: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A3 and drag reduction slurry B3 is 65:35;

[0214] Drag reduction compound 5-3: Applied between two pipe sections of the pipe body, the mass ratio of the anti-seepage slurry A3 and the drag reduction slurry B3 is 10:90.

[0215] Example 6

[0216] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this embodiment is the same as that in Example 1, except that this embodiment adopts anti-seepage slurry A3 and drag reducing slurry B4 to respectively configure anti-seepage compounding agent 6 and drag reducing compounding agent 6.

[0217] Anti-seepage compound 6: applied between the pipe sections of the nose section, the mass ratio of anti-seepage slurry A3 and drag-reducing slurry B4 is 80:20;

[0218] Drag reducing compound 6: Applied between two pipe sections of the pipe body, the mass ratio of the anti-seepage slurry A3 and the drag reducing slurry B4 is 30:70.

[0219] The material ratios of Examples 1-6 are shown in Table 3 below:

[0220] Table 3 Material ratio of Examples 1-6

[0221]

[0222] In Table 3, anti-seepage refers to anti-seepage compounding agent, and drag reduction refers to drag reducing compounding agent. For example, anti-seepage 1 refers to anti-seepage compounding agent 1, and drag reduction 1 refers to drag reducing compounding agent 1.

[0223] Comparative Example 1

[0224] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this comparative example is the same as that in Example 1, except that this comparative example only uses the anti-seepage slurry A3, and the anti-seepage slurry A3 is applied at the port of the head pipe segment and in the gap between adjacent fuselage pipe segments.

[0225] Comparative Example 2

[0226] The construction method of the jacking system of the water-rich sand layer jacking construction drag reducing and anti-seepage agent in this comparative example is the same as that in Example 1, except that this comparative example only uses the drag reducing slurry B3, and the drag reducing slurry B3 is placed at the port of the head pipe segment and in the gap between adjacent fuselage pipe segments.

[0227] Performance test and results:

[0228] The following performance tests were performed on the drag reduction and anti-seepage agent samples of Examples 1-6 and Comparative Examples 1 and 2:

[0229] (1) Specific gravity:

[0230] Specific gravity is also called relative density. The specific gravity of a mud sample is the ratio of the mud density to the water density. This test uses a mud hydrometer to measure the specific gravity of the mud sample.

[0231] (2) Filtration loss:

[0232] After the mud sample is prepared, put it into a container of a certain volume (filtration area is 45.8±0.6cm 2 ), set a pressure difference (690±35kpa) at both ends of the container, and part of the water in the slurry will be pressed into the soil. This property is called filtration loss or water loss. The water loss of the slurry is generally not more than 25ml / 30min during construction.

[0233] (3) Funnel viscosity:

[0234] Funnel viscosity can also be called viscosity, which refers to the resistance of a fluid to flow. When a fluid (gas or liquid) flows, when one part flows over another part, it encounters resistance, which is the internal friction of the fluid. Viscosity refers to the fluidity of the mud. When using a Marsh funnel viscometer, when measuring, plug the lower outlet of the funnel with your finger, pour the evenly stirred mud into the funnel to the bottom of the screen; release your finger and start the stopwatch at the same time. When the mud flows to the edge of the measuring cup and reaches its edge, stop the stopwatch. The time shown on the stopwatch is the mud viscosity, in seconds (s).

[0235] (4) Water separation rate:

[0236] After the mud is prepared, place it in a measuring cylinder for 24 hours. The ratio of the volume of water precipitated from the original mud to the volume of the original drag-reducing mud is called the water precipitation rate. This index reflects the stability of the drag-reducing mud. Place 1000ml of the stirred experimental mud in a stoppered measuring cylinder covered with a glass stopper and place it in a constant temperature room for 24 hours. Read the amount of precipitated water and convert it into the water precipitation rate. The smaller the water precipitation rate of the thixotropic mud, the better the stability of the slurry.

[0237] In engineering applications, the anti-seepage drag reducing agent must meet certain basic performance indicators. The parameter ranges of the performance indicators are shown in Table 4. The test results of Examples 1-6 of the present invention and Comparative Examples 1 and 2 are shown in Table 5:

[0238] Table 4 Reference values ​​of technical parameters of performance indicators

[0239] Technical Parameters <![CDATA[Specific gravity (g / cm 3 )]]> Filtration loss (ml / 30min) Funnel viscosity(s) Water separation rate (%) Reference value 1.1～1.6 ≤25 ≥30 Towards 0

[0240] Table 5 Test results of drag reduction and anti-seepage agent performance index test

[0241]

[0242]

[0243] Referring to Table 4, it can be seen from the data in Table 5 that the drag-reducing and anti-seepage agents in the embodiments of the present invention are configured according to the requirements of different use positions, and the performance is flexibly adjustable within a certain range, and the comprehensive performance index is good. For example, each embodiment shows a low filtration loss, especially the filtration loss of the anti-seepage compound is below 7.5ml / 30min, and the filtration loss of the drag-reducing compound is also below 25ml / 30min, which effectively curbs the abnormal penetration of water inside the mud sleeve into the surrounding soil. At the same time, under the coordination of the anti-seepage slurry and the drag-reducing slurry, the specific gravity and viscosity are properly adjusted, showing good thixotropy; the water separation rate of the samples in each embodiment is below 5%, especially the water separation rate of the anti-seepage compound is further reduced to below 3%, reflecting its good stability, can be well applied to large-diameter pipe jacking construction, can save materials and reduce costs, and is pollution-free to the environment. On the whole, by modifying and formulating the materials of the anti-seepage slurry and the drag-reducing slurry, and proposing a reasonable formulation of the anti-seepage slurry and the drag-reducing slurry according to different usage requirements, the obtained anti-seepage and drag-reducing agent exhibits flexible configuration adaptability, including high viscosity, better fluidity, dispersibility and lower water loss, and the drag reduction and anti-seepage performances are better and easier to control.

[0244] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A drag reducing and anti-seepage agent for pipe jacking construction in water-rich sand layers, characterized in that: The drag-reducing and anti-seepage agent includes an anti-seepage slurry and a drag-reducing slurry; The raw materials of the anti-seepage slurry include, by weight: Polyurethane component 30-40 parts Epoxy resin 2-5 parts 5-15 parts of inorganic materials; The raw materials of the drag reducing slurry include, by weight: Graphite 10-15 parts Soda ash 10-15 parts Polyacrylamide 2-5 parts; Dispersing the raw materials of the anti-seepage slurry in water to obtain an anti-seepage slurry with a mass concentration of 30-50%; Dispersing the raw materials of the drag-reducing slurry in water to obtain a drag-reducing slurry with a mass concentration of 5-20%; The anti-seepage slurry and the drag-reducing slurry are mixed in a mass ratio of (1-99):(99-1) to obtain the drag-reducing and anti-seepage agent.

2. The drag reducing and anti-seepage agent according to claim 1, characterized in that: The polyurethane component comprises the following raw materials in parts by mass: Isocyanate 50-100 parts Polyol 10-50 parts 1-5 parts of terminal hydroxyl compound, The polyol and the terminal hydroxyl compound are firstly mixed evenly, and then the isocyanate and optional auxiliary agents are added to mix and prepare a water-based polyurethane component containing a polyurethane prepolymer.

3. The drag reducing and anti-seepage agent according to claim 2, characterized in that: The epoxy resin comprises porous epoxy resin particles with an average particle size of 30-100 μm and an average pore size of 10 to 2,000 nm; The inorganic material includes one or more of cement, controllable clay, and water glass; The porous epoxy resin particles and / or inorganic material are pre-treated with a silane coupling agent, wherein the silane coupling agent contains an isocyanate reactive group.

4. The drag reducing and anti-seepage agent according to any one of claims 1 to 3, characterized in that: The polyacrylamide comprises: One or more of cationic polyacrylamide, anionic polyacrylamide, and nonionic polyacrylamide; Graphite is compounded by mixing micro-nano graphite powder with a particle size of 1-10 μm and expanded graphite with a particle size of 20-50 μm, wherein the mass ratio of the micro-nano graphite powder to the expanded graphite is (10-20):(1-5).

5. The drag reducing and anti-seepage agent according to claim 4, characterized in that: The polyacrylamide and the expanded graphite are pre-formed into an intercalated composite structure, comprising the following steps: S1-1, ultrasonically dispersing the expanded graphite in an ethanol aqueous solution to obtain a graphite dispersion; S1-2, adding the polyacrylamide into the graphite dispersion, stirring and ultrasonically treating, to obtain a polyacrylamide-graphite intercalation composite structure.

6. The drag reducing and anti-seepage agent according to claim 4, characterized in that: The polyacrylamide and the expanded graphite are preformed into a composite gel, comprising the following steps: S2-1, disperse graphite in water, add acrylamide monomer and ammonium persulfate, and perform ultrasonic treatment for 10-20 minutes; S2-2, add tetramethylethylenediamine and treat with ultrasound for 2-5 min; S2-3, react at 40-60°C for 2-24h to obtain an aqueous polyacrylamide-graphite composite gel.

7. A method for preparing the drag reducing and anti-seepage agent according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Prepare anti-seepage slurry: Weigh the raw materials of the anti-seepage slurry according to the preset proportions; Dispersing the raw materials of the anti-seepage slurry in water and mixing them evenly to form an anti-seepage slurry with a mass concentration of 30-50%; S2. Prepare drag reduction slurry: Weigh the raw materials of the drag-reducing slurry according to the preset proportions; Dispersing the raw materials of the drag reduction slurry in water and mixing them evenly to form a drag reduction slurry with a mass concentration of 5-20%; S3. Mix the anti-seepage slurry and the drag-reducing slurry in a mass ratio of (1-99):(99-1) to obtain the drag-reducing and anti-seepage agent.

8. A method for constructing a pipe jacking system using the drag reducing and anti-seepage agent according to any one of claims 1 to 6, characterized in that: The pipe jacking system comprises a head pipe section and a plurality of fuselage pipe sections connected in sequence, and the construction method comprises the following steps: Step 1: prepare an anti-seepage agent and a drag-reducing agent respectively according to the use position of the drag-reducing and anti-seepage agent in the pipe jacking system; The anti-seepage compounding agent is a mixture of the anti-seepage slurry and the drag-reducing slurry in a mass ratio of (65-90): (10-35); The drag reducing agent is a mixture of the anti-seepage slurry and the drag reducing slurry in a mass ratio of (10-35): (65-90); Step 2: Determine the laying path of the pipe sections of the pipe jacking system and dig the tunnel; Step 3: Install the jacking device and the excavation device in the tunnel, and push the excavation device through the jacking device; Step 4: Arrange a machine head pipe joint in the tunnel, and apply the anti-seepage compound at the port of the machine head pipe joint; Step 5: Push in the fuselage tube segments one by one, and connect the fuselage tube segments end to end until all the fuselage tube segments are installed, wherein the drag reducing compound is applied between the fuselage tube segments.

9. The pipe jacking system construction method according to claim 8, characterized in that: In step five, both ends of each fuselage pipe segment include a plug end and a socket end respectively, and the plug ends and socket ends of adjacent fuselage pipe segments are plugged together to form an installation gap, and a steel pipe sleeve and a sealing ring are arranged at the installation gap. The sealing ring is inflated to push out a liquid injection gap between the pipe segment wall and the steel pipe sleeve, and the drag reduction and anti-seepage agent is applied to the liquid injection gap, and then the inflated sealing ring is deflated and shrunk.

10. The pipe jacking system construction method according to claim 9, characterized in that: The shrinkage outer diameter of the sealing ring when not inflated or deflated is less than or equal to the outer diameter of the pipe segment wall; The compression amount of the sealing ring after inflation is less than or equal to half of the inflated outer diameter of the sealing ring.

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