A soft soil penetration solidification material, preparation method and use method thereof

Abstract

The invention belongs to the field of engineering construction materials, and specifically provides a soft soil penetration solidification material, a preparation method and a use method thereof. The soft soil penetration solidification material comprises the following components in parts by weight: 5-20 parts of an organic salt; 5-20 parts of a surfactant; 15-80 parts of a curing agent; each component is a water-soluble material; the organic salt is an organic salt containing a non-polar group; the surfactant is a surfactant containing a non-polar group, and the curing agent comprises a silicate, an aluminate, an organosilicon and an activator; the activator is selected from at least one of sodium hydroxide or potassium hydroxide; or the activator is selected from EDTA, EDTA-Na 2 , gluconic acid or citric acid. The soft soil permeable solidification material of the present invention can achieve the purpose of radial and longitudinal migration to the soft soil through permeation, thereby achieving undisturbed soft soil solidification. The present invention also provides a preparation method and a use method of the soft soil permeable solidification material, which can cooperate to achieve the purpose of undisturbed soft soil solidification.

Description

Technical Field

[0001] The invention belongs to the field of engineering construction materials, and in particular relates to a soft soil penetration solidification material, a preparation method and a use method thereof. Background Art

[0002] Soft soil, including silt, silty soil, peaty soil, peat, etc., has the characteristics of high compressibility, low strength, low permeability, etc., which leads to the disadvantages of weak foundation bearing capacity and large deformation. The stratum is prone to deformation and settlement, which has become an important factor restricting the development of engineering. Solidification of soft soil is an important means to solve the above problems of soft soil. The existing soft soil solidification methods are to improve the engineering properties of soft soil by adding specific curing agents to improve its bearing capacity and stability.

[0003] By evenly mixing the curing agent with the soft soil, the curing agent reacts with the moisture in the soil to generate stable chemical products, thereby enhancing the structure and strength of the soil, thereby achieving in-situ curing of the soft soil.

[0004] There are two conventional methods for achieving uniform mixing of curing agent and soft soil in the prior art: one is a curing method of rotary stirring; the other is a curing method of high-pressure grouting.

[0005] For example, patents CN116396024A and CN113912373A disclose a material for solidifying soft soil by stirring and solidifying; among them, patent CN116396024A discloses a nano-modified binary curing agent for sludge solidification and its use method. When implementing the material, the sludge needs to be excavated and then dehydrated, mixed with curing agent, stirred, and backfilled for maintenance, which has a positive effect on improving the strength of the sludge solidified body, reducing permeability, and improving the ability to resist liquefaction. Patent CN113912373A discloses a high-performance curing agent for quickly solidifying high-water content soft soil into roadbed filler. By stirring and mixing the curing agent and soft soil in a mass ratio of 5-15:100 and then curing, the soft soil with high water content can be coated with paste to achieve early strength, high strength and high water stability. This type of solidification method is mostly used in the construction and treatment of soft soil foundations of highways. In-situ solidification equipment such as powerful mixing heads are used to mix the curing agent and soft soil in situ, so that the soil is solidified to form a mixed soil with higher strength, thereby achieving the purpose of in-situ utilization of shallow soft soil. Through in-situ solidification technology, a hard crust layer or plate of a certain thickness can be quickly formed on the surface of the soft soil foundation, which can not only improve the bearing capacity of the soft soil foundation, provide a construction platform, and speed up the construction, but can also be used in conjunction with deep treatment methods such as pile foundations.

[0006] For example, patents CN103437340A and CN116397621A disclose methods or devices for reinforcing soft soil by high-pressure grouting; among them, patent CN103437340A discloses a method for reinforcing soft soil foundation by high-pressure rotary grouting, which arranges holes on the soft soil foundation and drills holes, and injects high-pressure slurry into the holes through a rotating grouting pipe to achieve sufficient mixing of the grouting material and the soft soil; patent CN116397621A discloses a high-pressure grouting treatment equipment and process for soft soil foundation, which improves the effect of high-pressure grouting by compacting the soft soil before grouting and grouting at multiple angles.

[0007] However, neither mixing solidification nor high-pressure splitting grouting is suitable for the repair of subways in operation. This is because such methods have high requirements on the surface construction environment, require construction platforms and large construction machinery, and are difficult to carry out when passing through urban buildings. Moreover, for shield tunnels with great burial depths, surface reinforcement machinery often cannot reach the corresponding depth. When the equipment is working, it will also cause great disturbance to the flexible shield tunnel, and the shield tunnel cannot withstand the reaction force caused by high pressure and rotation.

[0008] Based on this, the prior art has also been applied to the research on the soft soil reinforcement method of subway tunnels in operation. For example, patent CN116291566A discloses a deformation control and recovery method for underground tunnels in soft soil areas, which uses foaming materials to be injected through grouting pipes, and uses the foaming agent to expand and compact the nearby soil, and it is believed that the pores and voids in the stratum are also continuously filled. However, the expansion volume and expansion process of the foaming agent are difficult to control. Once the grouting is excessive, it is very easy to cause excessive expansion, causing irreversible damage to the operating tunnel and the surface structure.

[0009] Another example is the applicant's prior application CN117843316A, which discloses a high-permeability soft soil grouting reinforcement composite material and its preparation method, and studies the use of self-consumable water materials to consume the water in the soft soil so that the water in the soft soil can be solidified, in order to solve the technical problem that the reinforcement material in the prior art has a poor reinforcement effect on high-water-content soft soil. However, this patent still requires the use of a grouting machine to pressure-grout the soft soil solidification material into the soft soil, and there will still be disturbance damage to the operating tunnel due to the high grouting pressure.

[0010] In summary, there is an urgent need to develop a soft soil solidification material and a solidification method with extremely low disturbance or even no disturbance, so as to be suitable for the soft soil solidification in the repair of urban operating tunnels. Summary of the invention

[0011] The first object of the present invention is to provide a soft soil permeable solidification material to achieve undisturbed soft soil solidification.

[0012] The second object of the present invention is to provide a method for preparing the soft soil solidification material, so as to achieve stable preparation of the soft soil solidification material.

[0013] The third object of the present invention is to provide a method for using the soft soil solidification material to achieve undisturbed solidification of soft soil areas.

[0014] In order to achieve the above object, the present invention provides the following specific scheme:

[0015] The present invention first provides a soft soil permeable solidification material, comprising the following components in parts by weight: 5-20 parts of an organic salt; 5-20 parts of a surfactant; and 15-80 parts of a curing agent. All components of the soft soil permeable solidification material are water-soluble materials. The organic salt is an organic salt containing a non-polar group. The surfactant is a surfactant containing a non-polar group. The curing agent comprises silicate, aluminate, organosilicon and an activator. The activator is one of sodium hydroxide and potassium hydroxide. Or the activator is at least one of ethylenediaminetetraacetic acid (EDTA), ethylenediaminetetraacetic acid in the form of disodium salt (EDTA-Na2), gluconic acid or citric acid.

[0016] Preferably, when applied to soft soil rich in alkaline earth metals, the activator is at least one of ethylenediaminetetraacetic acid (EDTA), disodium salt form of ethylenediaminetetraacetic acid (EDTA-Na2), gluconic acid or citric acid; when applied to soft soil free of alkaline earth metals, the activator is one of sodium hydroxide or potassium hydroxide.

[0017] Specifically, in the present invention, the properties of soft soil are defined by the molar ratio of (Ca+Mg) / (Si+Al). When (Ca+Mg) / (Si+Al)≥1, it is called soft soil rich in alkaline earth metals, and when (Ca+Mg) / (Si+Al)<1, it is called soft soil free of alkaline earth metals.

[0018] The present invention creatively proposes the technical concept of "using the infiltration method to achieve the entry of soft soil solidification material into the soft soil to achieve the non-disturbance solidification of the soft soil area". In order to realize the technical concept, the inventor further made the following designs:

[0019] (1) First, since the present invention aims to make the solidifying material enter the soft soil under the action of pure osmosis, all components of the present invention are water-soluble and can form large and small ionic groups in the aqueous solution. These ionic groups will penetrate from the high concentration area to the low concentration area under the action of osmotic pressure, and then achieve radial or longitudinal penetration in the soft soil step by step to achieve the solidification of the soft soil.

[0020] (2) Secondly, in order to better achieve the effective migration of the curing agent components under pure osmotic pressure, the present invention designs a sufficient amount of organic salt in the material formula to increase the osmotic pressure of the entire material, so that the main components in the material can enter the soft soil under the action of the osmotic pressure difference and react with the water in the soft soil to solidify the soft soil.

[0021] (3) At the same time, in order to achieve effective solidification of water in soft soil, the present invention designs a sufficient amount of surfactant in the material formula to release the water molecules tightly bound to the soft soil particles, and then react with the curing agent to solidify. Specifically: because the surface of soft soil particles usually carries an electric charge, a double electric layer is formed around them, the inner layer is a tightly adsorbed ion layer, and the outer layer is a diffused counter ion layer. The counter ions in the outer layer interact with water molecules to form hydrated ions, so that these water molecules are firmly adsorbed on the surface of the particles and are difficult to react with the curing agent. The present invention designs a surfactant in the material formula. The surfactant has a hydrophilic group and a hydrophobic group. The hydrophilic group electrostatically adsorbs the surface of the charged soil particles, so that the water molecules electrostatically adsorbed on the soil particles are released; at the same time, the hydrophilic group adsorbed on the surface of the soil particles will cause the hydrophobic group to be arranged toward the water phase or other soil particles, so that the surface of the soil particles is hydrophobic, which further reduces the soil particles' ability to bind water, thereby releasing the water molecules to react with the curing agent.

[0022] (4) The present invention designs a curing agent in the material formula, and the curing agent undergoes a curing reaction in the soil to form a hard solid structure, thereby enhancing the soil structural strength.

[0023] (5) It should be noted that since the present invention aims to achieve the entry of solidifying materials into soft soil under pure penetration, the present invention cannot contain water-insoluble cement in its formulation, nor can it use a system that will solidify rapidly, such as a two-liquid slurry (calcium chloride and sodium silicate). Therefore, how to make soft soil reach solidification strength under the condition of ion penetration is one of the core issues to be solved by the present invention.

[0024] In order to solve this problem, the inventor creatively designed a curing agent containing silicate, aluminate, organosilicon and activator. The activator activates the mineral activity in the soft soil, so that the minerals in the soft soil interact with the effective components of the added curing agent, thereby forming a stable curing product and enhancing the strength of the soft soil after curing.

[0025] Furthermore, the present invention selects different stimulants for stimulating the activity of the soft soil according to different characteristics of the soft soil.

[0026] For soft soil rich in alkaline earth metal minerals, i.e., soft soil rich in calcite CaCO3, dolomite CaMg(CO3)2 and other minerals, the activator is selected from at least one of ethylenediaminetetraacetic acid (EDTA), disodium salt form of ethylenediaminetetraacetic acid (EDTA-Na2), gluconic acid or citric acid. After the infiltration and curing material enters the soft soil, the electron donor atoms (such as oxygen and nitrogen) in the activator will react with the metal ions (such as Ca 2+ Mg 2+ ) to form a chelate with a ring structure. This chelate is more stable in solution, reducing the free energy of metal ions, thereby increasing the solubility of alkaline earth metal ions in soft soil. At the same time, chelate is an unstable substance that can slowly release alkaline earth metal ions, which allows alkaline earth metal ions to undergo hydration reactions with silicate and aluminate, forming hydrated silica-aluminate gel around soil particles. The chelate that releases alkaline earth metal ions continues to chelate alkaline earth metal ions from soft soil. As the hydration reaction proceeds, this cycle is repeated, and a gel skeleton is formed around the soft soil particles, improving the overall strength of the soft soil.

[0027] For soft soils that do not contain alkaline earth metal minerals, clay minerals (such as kaolin Al2(Si2O5)(OH)4, montmorillonite (Al2O3)·(SiO2)·(nH2O), illite KAl2[(SiAl)4O 10 ]·(OH)2·nH2O, etc.), the activator is selected from at least one of sodium hydroxide and potassium hydroxide. Under high pH environment, some structures of these minerals (kaolinite, montmorillonite, illite) disintegrate, releasing silicate and aluminate. At this time, the ratio of silicate to aluminate is not enough to polymerize and form a high-strength solid. The additional silicon source and aluminum source introduced into the curing agent make the Si / Al element ratio reach between 1.0 and 3.5. Under the action of the activator, silicate and aluminate form a long-chain or three-dimensional mesh aluminosilicate skeleton structure, and gradually remove water during the polycondensation process. The gel phase gradually consolidates and hardens to form a hard solid structure, which enhances the structural strength of the soil.

[0028] (6) The permeable solidifying material of the present invention gradually penetrates radially or longitudinally into the soft soil after entering the soft soil. When the permeable solidifying material enters the soft soil, the water is released from the surface of the soft soil, and the curing agent reacts and solidifies in the ionic environment of the soil solution to form a solidified product. The formation of the solidified product will hinder the further penetration of the permeable solidifying material of the present invention to a certain extent.

[0029] In order to solve this problem, the curing agent of the present invention contains a certain amount of water-soluble silicone in addition to water-soluble silicates and aluminates. The silicone can be hydrolyzed to generate active silanol groups (Si-OH). These groups interact with the silicon-oxygen network in the cured product to form Si-O-Si bonds. The silicone molecule structure contains hydrophobic groups R (such as methyl, octyl or fluoroalkyl). The addition of these components will introduce hydrophobicity into the cured product, so that the surface of the cured product in the soft soil is covered with non-polar groups, which is not easy to form hydrogen bonds or strong electrostatic interactions with water molecules and ionic groups, thereby providing a penetration channel for subsequent penetration curing materials to avoid being intercepted by the cured product generated on the surface of the soft soil.

[0030] The presence of organosilicon not only provides a permeation channel for subsequent infiltration and curing materials, but also promotes the formation of cured products and enhances the strength of cured products. 2+ Mg 2+ In addition to the methyl silicate gel (etc.) that forms an organic network with better curing effect, silicone can hydrolyze to generate active silanol groups (Si-OH). These groups interact with the silicon-oxygen network in the cured product to form a larger Si-O-Si bond network, thereby promoting the overall strength of the cured product.

[0031] (7) In addition, the surfactant selected in the present invention is a surfactant containing a non-polar group. After releasing water from the surface of the soft soil, the non-polar group will combine with the surface of the soil particles to form a non-polar protective film, so that the effective ingredients (curing agent) in the permeable curing material of the present invention are not retained by the soil particles and can migrate smoothly to the deep layer of the soft soil under the action of the osmotic pressure difference.

[0032] At the same time, the present invention selects to add organic salts containing non-polar groups. The non-polar groups in the organic salts, the non-polar groups in the surfactants and the organosilicon will form hydrophobic groups and be tightly combined in the aqueous solution. This combination process will also cause other components in the solution, such as silicate, aluminate, activator, etc., to form relatively stable ion aggregates. A series of ion aggregates will migrate to the deep layer of the soft soil as a whole under the action of the osmotic pressure difference.

[0033] Through the above design, the permeable solidification material of the present invention can continuously and stably penetrate into the soft soil radially and longitudinally, thereby achieving effective solidification of each stratum of the soft soil material.

[0034] Preferably, the organic salt of the present invention is selected from at least one of sodium methylenebisnaphthalene sulfonate, sodium methylenebismethylnaphthalene sulfonate, sodium naphthalene disulfonate, sodium naphthalene sulfonate or sodium dodecylbenzene sulfonate.

[0035] First, the above organic salts all contain highly hydrophilic sodium sulfonate groups (SO3Na), which enables the organic salts to dissolve in water to form solutions; moreover, after dissolving in water, the above organic salts will dissociate into Na + , naphthalenesulfonate and other ions increase the total ion concentration of the solution, which helps to promote the migration of the effective ingredients in the entire penetrating curing agent to the low concentration area; in addition, the above-mentioned organic salt contains one or more naphthalene rings or benzene rings, which makes the molecule have a higher planarity, which helps the molecule to form a stable and uniform solution dispersion in the medium. More importantly, the naphthalene ring or benzene ring itself has certain non-polar characteristics, especially the π electron system, which provides these two groups with greater non-polarity, which enables these two groups to form a stable non-polar aggregation with the non-polar groups in the surfactant, and then on the one hand, it can better form a hydrophobic film on the surface of soil particles, and on the other hand, the ionic groups in the subsequently injected penetrating curing agent material can also better migrate to the deep soft soil together.

[0036] Preferably, the surfactant of the present invention is selected from one of amphoteric surfactants, cationic surfactants, and anionic surfactants according to soil characteristics; further preferably, the amphoteric surfactant of the present invention is selected from at least one of cocamidopropyl betaine, cocamidoethyl betaine, lauramide propyl betaine, and triethanolamine. The cationic surfactant of the present invention is selected from at least one of hexadecyltrimethylammonium bromide, dodecylbenzyldimethylammonium chloride, and tetraethylammonium bromide. The anionic surfactant of the present invention is selected from at least one of naphthalene-based water reducer, polycarboxylate water reducer, sodium lignin sulfonate, sodium lauryl sulfate, sodium petroleum sulfonate, sodium alkylbenzene sulfonate, and sodium sulfate of fatty alcohol polyoxyethylene ether.

[0037] The amphoteric surfactant is selected so that it can exhibit ionic properties under different pH conditions. The ionic properties can neutralize the charge on the surface of soil particles, destroy the double electrical layer structure, and release the moisture bound to the double electrical layer. At the same time, the above-mentioned surfactant is also water-soluble, and the hydrophilic groups contained therein can bind to water molecules through hydrogen bonds or electrostatic effects, further releasing water molecules from the surface of soft soil. Furthermore, after the moisture on the surface of soil particles is released, the hydrophobic groups in the above-mentioned surfactant are more inclined to adsorb to the surface of soil particles, and interact hydrophobically with the particles, thereby forming a hydrophobic film on the surface of soil particles, and the hydrophobic groups in the organic salts will further bind to the hydrophobic film to prevent the subsequent penetration and solidification materials from being intercepted by the surface of soil particles.

[0038] Specifically, cationic surfactants can be selected in alkaline soils with negative charges on the soil surface, and anionic surfactants can be selected in acidic soils with positive charges on the soil surface.

[0039] Further preferably, the curing agent comprises the following components in parts by weight: 5-35 parts of silicate; 5-35 parts of aluminate; 5-35 parts of organosilicon; and 5-15 parts of activator.

[0040] By rationally setting the ratio of silicate, aluminate, organosilicon and activator, it is ensured that the solidified product can be effectively formed and the strength of the formed solidified product can meet the actual construction requirements.

[0041] Specifically, water-soluble silicates, commonly used are sodium silicate and potassium silicate; water-soluble aluminates, commonly used are sodium metaaluminate, potassium metaaluminate, potassium aluminate; organic silicon, commonly used is at least one of sodium methyl silicate, potassium methyl silicate, tridecafluorooctyl triethoxysilane or n-octyl triethoxysilane; which dissociates in water to form K + / Na + , silicate, aluminate, etc. On the one hand, it promotes the improvement of the ion concentration of the overall infiltration and curing material, and on the other hand, it can provide the silicate and aluminate required for the curing reaction.

[0042] In practical applications, considering the cost, it is further preferred that the silicate is sodium silicate; the aluminate is sodium metaaluminate, and the organosilicon is sodium methyl silicate. Among them, the sodium silicate is provided by a sodium silicate solution with a solid content of 25% to 30%; the sodium methyl silicate is provided by a sodium methyl silicate solution with a solid content of 30% to 99%, and the aluminate is provided by a sodium metaaluminate solid.

[0043] The infiltration solidification material of the present invention preferably comprises the following components in parts by weight: 10-15 parts of organic salt; 10-15 parts of surfactant; and 40-80 parts of curing agent.

[0044] The curing agent preferably includes the following components in parts by weight: 15-25 parts of silicate; 15-25 parts of aluminate; 25-35 parts of organosilicon; and 8-12 parts of activator.

[0045] The present invention also provides a method for preparing the above-mentioned permeable solidification material, comprising the following steps: weighing the raw materials of each component in proportion and fully mixing the raw materials of each component, thereby preparing the soft soil permeable solidification material; or weighing the raw materials of each component in proportion and fully dissolving the raw materials of each component to form a saturated aqueous solution, thereby preparing the soft soil permeable solidification material.

[0046] Specifically, the solvent water in the aqueous solution of the present invention may be a water solution in which some components are provided by the aqueous solution, such as sodium silicate and sodium methyl silicate, or may be formed by dissolving solid powder in water.

[0047] The present invention also provides a method for using the soft soil permeable solidification material, comprising the following steps: loading the soft soil permeable solidification material into a liquid storage device, and injecting the permeable solidification material in the liquid storage device into the soft soil through an injection pipe having one end connected to the liquid storage device and the other end inserted into the soft soil;

[0048] Soft soil permeable solidification material is injected under pressure P 注 Injected into soft soil under the action of 注 Satisfaction: P 注 -P 水 =0.01MPa~0.05MPa; where P 水 The water head pressure at the liquid outlet of the injection pipe;

[0049] When the soft soil to be solidified is soft soil without alkaline earth metal elements, the activator of the permeable solidification material is selected from at least one of sodium hydroxide or potassium hydroxide; when the soft soil to be solidified is soft soil rich in alkaline earth metal elements, the activator of the permeable solidification material is selected from at least one of EDTA, EDTA-Na2, gluconic acid or citric acid.

[0050] The present invention only needs to provide a driving pressure for the liquid of the penetrating solidifying material to enter the soft soil. The pressure is only 0.01-0.05 MPa higher than the water head pressure, and will not interfere with the soft soil foundation. It can be well applied to the repair of subway tunnels in operation.

[0051] Preferably, in actual use, the injection pressure can be generated only by the water level difference between the liquid storage device and the soft soil surface; it can also be provided by a hydraulic pump.

[0052] More preferably, the injection pipe is inserted into the soft soil to a depth of 0.1m to 5m; the liquid outlet of the injection pipe is arranged at the end of the injection pipe away from the liquid storage device, or the liquid outlet of the injection pipe is arranged on the side wall of the injection pipe.

[0053] In actual use, considering that the penetration radius of the permeable solidifying material may not meet the actual needs, the present invention is designed to drill a deep hole in the soft soil, insert the injection pipe into the deep hole, and evenly open multiple liquid outlets on the side wall of the injection pipe, so that the permeable solidifying material penetrates from multiple directions in the radial and longitudinal directions to ensure the solidification of the entire soft soil layer. The injection pressure needs to be designed to exceed the maximum head pressure of the multiple liquid outlets of the entire injection pipe by 0.01MPa~0.05MPa.

[0054] When the soft soil permeable solidification material of the present invention is used, the amount of the saturated aqueous solution is adjusted according to the expected volume of the reinforced soft soil and the water content of the soft soil. Preferably, the amount of the saturated aqueous solution formed by the soft soil permeable solidification material of the present invention is greater than the water content in the soft soil to be solidified, so as to ensure that the soft soil can be effectively solidified.

[0055] The beneficial effects of the present invention are:

[0056] (1) The present invention creatively proposes the technical concept of "using infiltration to allow soft soil solidification materials to enter the soft soil and achieve undisturbed solidification", and further designs a fully water-soluble infiltration solidification material component, and designs that the three main components of organic salt, surfactant and curing agent are combined in a specific proportion to form an infiltration solidification material; realizes the process of effective ingredients migrating to the deep layer of the soft soil under the action of high osmotic pressure, the surfactant releasing the water that is effectively combined with the soft soil, and the curing agent combining and solidifying in the soft soil, thereby achieving the purpose of undisturbed soft soil solidification by infiltration.

[0057] (2) In order to ensure that the permeable solidifying material can continue to penetrate deep into the soft soil, the present invention also specifically selects a surfactant with a hydrophobic group, an organic salt with a hydrophobic group, and an organosilicon containing a hydrophobic group. The hydrophobic group of the surfactant is combined with the hydrophobic group of the organic salt to form a hydrophobic layer on the soil surface to provide a permeation channel for the subsequent permeable solidifying material; the organosilicon forms a hydrophobic layer on the surface of the cured silicate gel to provide a permeation channel for the subsequent permeable solidifying material. This ensures that the permeable solidifying material can continue to stably penetrate into the deep soft soil layer and promotes the effective fixation of the soft soil.

[0058] (3) In order to ensure that the curing strength of soft soil meets the standard without the addition of cement or other cementitious materials, the present invention designs a curing agent comprising silicate, aluminate, organosilicon and an activator. The activator activates the active ingredients in the soft soil minerals to participate in the reaction, and together with the silicate and aluminate in the infiltration curing material, a curing product with a stable structure and meeting the strength standard is generated, thereby ensuring the effective curing effect on the soft soil and improving the strength of the soft soil after curing.

[0059] (4) The present invention uses different types of activators under different soft soil compositions to achieve targeted activation of active components in minerals to participate in the solidification reaction under different soft soil compositions, thereby achieving effective solidification of the soft soil.

[0060] (5) The present invention achieves true undisturbed solidification by applying a pressure greater than the water head pressure of the liquid outlet by 0.01-0.05 MPa to add the permeable solidification material to the soft soil.

[0061] (6) When the soft soil permeable solidification material of the present invention is used, it only needs to be equipped with simple equipment such as a liquid storage device and an injection pipe. It has low requirements on equipment and has great prospects for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 Schematic diagram of the experimental apparatus used in Experimental Example 1;

[0063] Figure 2 It is a schematic diagram of the state of the unconfined compression test of the consolidated soil of the experimental group 2 of the experimental example 1;

[0064] Figure 3 Schematic diagram of the failure state of the stabilized soil in Experimental Group 2 of Experimental Example 1. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the present invention is further described below in conjunction with specific embodiments. For those without specific conditions in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are followed. The exemplary embodiments can be implemented in various forms and should not be construed as being limited to the examples described herein; on the contrary, these embodiments are provided so that the present invention will be more comprehensive and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art.

[0066] Example 1-Example 12

[0067] Embodiments 1 to 12 each provide a soft soil permeation solidification material, the material comprising an organic salt, a surfactant and a curing agent, wherein the curing agent comprises a silicate, an aluminate, an organosilicon and an activator. The silicate is provided by a sodium silicate solution with a solid content of 30%, and the organosilicon is provided by a sodium methyl silicate solution with a solid content of 45%.

[0068] The specific selection and dosage of each component of Example 1 to Example 12 are shown in Table 1. The amount of sodium silicate in Table 1 specifically refers to dry sodium silicate, and the amount of sodium methyl silicate specifically refers to dry sodium methyl silicate.

[0069] Table 1 Proportions of soft soil permeation solidification materials in various embodiments

[0070]

[0071] The soft soil permeable solidification materials of Examples 1 to 12 are prepared by first weighing each component in proportion, then adding the solid to the sodium silicate solution and the organosilicon solution, stirring, and then adding water appropriately, and continuing to stir until the solid powder is completely dissolved to obtain a saturated aqueous solution, thereby preparing the soft soil permeable solidification material.

[0072] Comparative Example 1-Comparative Example 6

[0073] Comparative Examples 1 to 6 each provide a soft soil permeation solidification material, and the components thereof are shown in Table 2; in Table 2, sodium silicate is provided by a sodium silicate solution having a solid content of 30%, and sodium methyl silicate is provided by a sodium methyl silicate solution having a solid content of 45%. The amount of sodium silicate in Table 2 specifically refers to the amount of dry sodium silicate; the amount of sodium methyl silicate in Table 2 specifically refers to the amount of dry sodium methyl silicate.

[0074] Table 2 Proportions of soft soil permeability solidification materials in each comparative example

[0075]

[0076] The soft soil permeation solidification materials of Comparative Examples 1 to 6 are prepared by first weighing each component in proportion, then adding the solid to the sodium silicate solution and the organosilicon solution, stirring, and then adding water appropriately, and continuing to stir until the solid powder is completely dissolved to obtain a saturated aqueous solution, thereby preparing the soft soil permeation solidification material.

[0077] Experimental Example 1:

[0078] Soft soil sample 1 and soft soil sample 2 were taken for penetration reinforcement experiment respectively, and element analysis was performed on the dry soil samples. The molar ratio of soil sample 1 satisfied: (Ca+Mg) / (Si+Al)=0.01, and the molar ratio of soil sample 2 satisfied: (Ca+Mg) / (Si+Al)=2.13.

[0079] Use Figure 1 The experimental device shown was used to conduct a permeation reinforcement experiment. The soil sample was prepared and the performance was measured according to GB / T 50123. A soft soil sample with a moisture content of 35% was placed in an unconfined compression mold. 100 ml of the configured permeation solidification material of each embodiment and comparative example was placed in an infusion bag. The permeation solidification material was transported to the soft soil through an infusion tube. The needle at one end of the infusion tube away from the infusion bag was inserted into the soft soil sample with an insertion depth of 3 cm. The height of the infusion bag from the soft soil surface was 1 m. The flow rate was adjusted to control the liquid injection rate. The permeation was completed within 72 hours.

[0080] Take surface soil samples and bottom soil samples, measure the sinking depth of the soil samples after 72 hours, evaluate the material penetration rate and solidification time, seal and cure for 7 days after liquid penetration is completed, measure the unconfined compressive strength of the soil samples, and evaluate the reinforcement status of the soft soil.

[0081] The measurement results are shown in Table 3:

[0082] Table 3 Performance test data of soil samples after solidification in each experimental group

[0083]

[0084] Experimental groups 1-12 are performance tests of the solidified soil after the permeable solidification material of the present invention is used according to the method of use of the present invention, experimental groups 13-14 are performance tests of the solidified soil after the permeable solidification material of the present invention is not used according to the method of use of the present invention, but is used on an unsuitable soil sample, and experimental groups 15-21 are performance tests of the solidified soil after the permeable solidification material of Examples 1-6 is used; it can be concluded from the data in Table 3 that:

[0085] (1) The 72-hour sinking depths of the surface and bottom layers of the solidified soil samples obtained by using the permeable solidification material of the present invention according to the method of use of the present invention are significantly higher than those of the comparative examples, indicating that the permeable solidification material of the present invention has been able to penetrate into the bottom layer of the soil sample after 72 hours of use and has preliminarily solidified the soil sample. However, the permeable solidification materials of comparative examples 1-6 cannot effectively penetrate into the soft soil or cannot effectively undergo a solidification reaction after penetration, so that the strength of the soft soil cannot be improved after use.

[0086] (2) After the infiltration solidification material of the present invention is used according to the method of use of the present invention, the strength of the soil sample is significantly improved after curing for 7 days. Under certain ratios, the strength of the soil sample can exceed 1MPa after curing for 7 days, which can well meet the actual construction requirements. Figure 2 The schematic diagram of the state of the unconfined compression test of the stabilized soil of experimental group 2 shows that it is still intact when the pressure is greater than 1MPa; it is destroyed when the pressure is greater than 1.065MPa, showing the following Figure 3 Schematic diagram of the failure state of stabilized soil shown in.

[0087] (3) By comparing the data of experimental group 2 and experimental group 13, and the data of experimental group 10 and experimental group 14, it can be seen that the same permeable solidification material has quite different curing results after being used on soil samples with different properties. This indicates that when the permeable solidification material of the present invention is used in soil samples with different properties, the choice of activator is different. It is necessary to select an activator of appropriate properties according to the properties of the soil sample, thereby promoting the occurrence of a suitable reaction.

[0088] In summary, the present invention provides a permeable solidifying material and a corresponding method of using the permeable solidifying material. The permeable solidifying material of the present invention can achieve undisturbed solidification of soil samples, and has a good application prospect in urban tunnel repair.

[0089] The present invention is not limited to the above-mentioned embodiments, and anyone should be aware that any structural changes made under the enlightenment of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention.

Claims

1. A soft soil penetration and solidification material, It is characterized in that The invention comprises the following components in parts by weight: 5-20 parts of organic salt; 5-20 parts of surfactant; 15-80 parts of curing agent; All components of the soft soil permeable solidification material are water-soluble materials; The organic salt is an organic salt containing a non-polar group; the surfactant is a surfactant containing a non-polar group, and the curing agent includes silicate, aluminate, organosilicon and activator; The curing agent comprises the following components in parts by weight: 5-35 parts of silicate; 5-35 parts of aluminate; 5-35 parts of organosilicon; 5-15 parts of activator; When the soft soil to be solidified is soft soil that does not contain alkaline earth metal elements, the activator is selected from at least one of sodium hydroxide and potassium hydroxide; When the soft soil to be solidified is soft soil rich in alkaline earth metal elements, the activator is selected from EDTA, EDTA-Na 2 , at least one of gluconic acid or citric acid; The organic salt is selected from at least one of sodium methylenebisnaphthalene sulfonate, sodium methylenebismethylnaphthalene sulfonate, sodium naphthalene disulfonate, sodium naphthalene sulfonate or sodium dodecylbenzene sulfonate; The surfactant is selected from one of an amphoteric surfactant, a cationic surfactant or an anionic surfactant; The silicate is at least one of sodium silicate or potassium silicate; the aluminate is at least one of sodium metaaluminate or potassium aluminate; the organosilicon is at least one of sodium methyl silicate, potassium methyl silicate, tridecafluorooctyltriethoxysilane or n-octyltriethoxysilane.

2. The soft soil permeation solidification material according to claim 1, It is characterized in that The amphoteric surfactant is selected from at least one of cocamidopropyl betaine, cocamidoethyl betaine, lauramidopropyl betaine and triethanolamine; The cationic surfactant is at least one selected from hexadecyltrimethylammonium bromide, dodecylbenzyldimethylammonium chloride and tetraethylammonium bromide; The anionic surfactant is selected from at least one of naphthalene water reducer, polycarboxylate water reducer, sodium lignin sulfonate, sodium lauryl sulfate, sodium petroleum sulfonate, sodium alkylbenzene sulfonate and sodium fatty alcohol polyoxyethylene ether sulfate.

3. A method for preparing the soft soil permeable solidification material according to any one of claims 1 or 2, It is characterized in that The steps include: Weighing the raw materials of each component in proportion and fully mixing the raw materials of each component, so as to prepare the soft soil permeable solidification material; Alternatively, the soft soil permeable solidification material is prepared by weighing the raw materials of each component in proportion and fully dissolving the raw materials of each component to form an aqueous solution.

4. A method for using the soft soil permeation solidification material according to any one of claims 1 or 2, It is characterized in that The method comprises the following steps: loading the soft soil permeable solidifying material into a liquid storage device, and injecting the soft soil permeable solidifying material in the liquid storage device into the soft soil through an injection pipe at one end of the injection pipe being connected to the liquid storage device and at the other end of the injection pipe being inserted into the soft soil; The soft soil permeable solidification material is injected at a pressure P 注 Injected into soft soil under the action of 注 Satisfaction: P 注 -P 水 =0.01MPa~0.05MPa; where P 水 It is the water head pressure at the liquid outlet of the injection pipe.

5. The method for using the soft soil permeation solidification material according to claim 4, It is characterized in that The injection pipe is inserted into the soft soil to a depth of 0.1m to 5m; The liquid outlet of the injection pipe is arranged at the end of the injection pipe away from one end of the liquid storage device, or the liquid outlet of the injection pipe is arranged on the side wall of the injection pipe.

6. The method for using the soft soil permeation solidification material according to claim 5, It is characterized in that The injection pressure is generated by the water level difference between the liquid storage device and the liquid outlet of the injection pipe; or the injection pressure is provided by a hydraulic pump.

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