A ductile curing liquid, a preparation method and application thereof

Abstract

This invention discloses a toughening curing liquid, its preparation method, and its application. The toughening curing liquid comprises the following raw material components by weight: 70-80 parts of silicate cement, 20-30 parts of admixture, 15-25 parts of organic monomer, 1-2 parts of crosslinking agent, 0.1-2 parts of initiator, 5-10 parts of expanding agent, 0.01-0.1 parts of fiber, and 70-100 parts of water. The admixture is one or two of fly ash or coal gasification slag powder with a particle size <45μm. The organic monomer is acrylamide monomer, and the crosslinking agent is N,N-methylenebisacrylamide. The initiator is ammonium persulfate or potassium persulfate. The expanding agent is calcium oxide-calcium sulfoaluminate expanding agent, and the fiber includes polypropylene fibers with a diameter of 18-48μm and a length of 4-6mm. Toughening liquid is used to prepare tough cement soil for underground continuous wall curtains. It can resist mining stress disturbance. When mining stress is transmitted to the continuous wall, the tough structure formed in the wall will undergo elastic deformation, avoiding cracks, splits or deformation damage to the wall.

Description

Technical Field

[0001] This invention belongs to the field of anti-seepage engineering technology, specifically relating to a toughening curing liquid, its preparation method, and its application. Background Technology

[0002] The TRD method, also known as the equal-thickness cement-soil underground continuous wall curtain method, involves inserting a cutting box equipped with a cutting chain and cutter head, meeting the design depth, into the ground. While longitudinally cutting and laterally advancing to form a trench, cement grout is injected into the foundation to achieve thorough mixing with the original foundation, forming an equal-thickness continuous wall-type seepage-proof curtain underground. The curtain constructed using this method can be called an equal-thickness cement-soil in-situ water-stopping curtain. Currently, equal-thickness cement-soil in-situ curtains are mainly used as water-stopping curtains or to form water-stopping and soil-retaining structures with inserted steel sections. They are widely used in traditional projects such as building foundation engineering, underground passages, shield tunnel shafts, large landfills, subway cross-working shafts, foundation retaining walls, water-stopping walls, and soil-retaining and seepage-proofing for deep-sea and large reservoirs and river embankments. The applicable strata are mainly Quaternary loose layers such as silty clay, clay, silt, and sand, all of which have good water-stopping and seepage-proofing effects.

[0003] However, existing uniform-thickness cement-soil underground continuous walls are all rigid walls with weak resistance to deformation. In the later stages, the walls are prone to deformation and damage due to mining activities, resulting in a large number of cracks. High-pressure water erosion outside the wall can cause the water-cutting curtain to fail, further increasing the mine's water inflow and potentially leading to mine flooding accidents. When existing uniform-thickness cement-soil underground continuous walls are used as water-cutting curtains, they face the risk of erosion from both dynamic and static water. Changing water bodies outside the wall will carry away calcium hydroxide, an important hydration product of cement. As calcium hydroxide dissolves and is lost, the wall will develop cracks, voids, and other undesirable structures, thereby reducing the wall's durability. In severe cases, water may seep into parts of the wall, causing the continuous wall to lose its water-cutting function. Summary of the Invention

[0004] In view of the defects and shortcomings of the existing technology, the purpose of this invention is to provide a tough curing liquid, a preparation method and its application, so as to solve the technical problems of weak deformation capacity and easy deformation and loss of water-proof function of continuous wall anti-seepage curtains in the existing technology.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A toughening curing liquid comprises the following raw material components: by weight, 70-80 parts of silicate cement, 20-30 parts of admixture, 15-25 parts of organic monomer, 1-2 parts of crosslinking agent, 0.1-2 parts of initiator, 5-10 parts of expansion agent, 0.01-0.1 parts of fiber, and 70-100 parts of water.

[0007] The present invention also has the following technical features:

[0008] Specifically, the admixture is one or two of fly ash or coal gasification slag powder with a particle size of <45μm.

[0009] Furthermore, the organic monomer is an acrylamide monomer, the crosslinking agent is N,N-methylenebisacrylamide, and the initiator is ammonium persulfate or potassium persulfate.

[0010] Furthermore, the expanding agent is a calcium oxide-calcium sulfoaluminate expanding agent, and the fiber comprises polypropylene fibers with a diameter of 18-48 μm and a length of 4-6 mm.

[0011] This invention also discloses a method for preparing a toughening curing liquid, the method comprising the following steps:

[0012] Step 1: Weigh the organic monomer, crosslinking agent and initiator, and mix them at a rate of 50 r / min to 100 r / min to obtain a mixed powder;

[0013] Step 2: Weigh out ordinary silicate cement, admixture, expansion agent and polypropylene fiber and pour them into the mixer. Mix at a mixing speed of 50 r / min to 100 r / min for 1 to 3 minutes. Then weigh out a certain amount of water and pour it into the mixer. Mix at a mixing speed of 100 r / min to 200 r / min for 1 to 3 minutes to obtain the mixed slurry.

[0014] Step 3: Add the mixed powder from Step 1 to the mixed slurry from Step 2, and stir at a stirring rate of 100 r / min to 200 r / min for 3 to 5 minutes to obtain a toughened curing liquid;

[0015] The composition, by weight, consists of 70-80 parts silicate cement, 20-30 parts admixture, 15-25 parts organic monomer, 1-2 parts crosslinking agent, 0.1-2 parts initiator, 5-10 parts expansion agent, 0.01-0.1 parts fiber, and 70-100 parts water.

[0016] Furthermore, the toughening curing liquid and the in-situ soil and rock, and by mass percentage, the toughening curing liquid accounts for 20% to 30% of the mass of the in-situ soil and rock.

[0017] Furthermore, the tough cement soil comprises the following raw material components: 25% toughening curing liquid and 100% in-situ soil by mass percentage.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] (1) The toughening curing liquid provided by this invention contains admixtures and an expanding agent. The added admixtures can react with the cement hydration product calcium hydroxide after cement curing to generate a new gel. The newly generated gel fills the structural pores, which can effectively improve the cement's impermeability and enhance the wall's resistance to dynamic / static water erosion. The added expanding agent can ensure a tighter bond between the wall's micro-expansion and the surrounding soil and rock. On the other hand, it can have a synergistic activation effect with cement and admixtures, causing the entire system to generate more hydration products, thereby making the internal structure more compact.

[0020] (2) The toughening curing liquid provided by this invention incorporates fibers, which further ensure the crack resistance of the wall. Polypropylene fibers have a low elastic modulus and good ductility, which can inhibit early cracking of cement-soil walls, reduce initial shrinkage deformation, and improve the toughness of cement. Furthermore, the polypropylene fibers and the polyacrylamide gel generated by in-situ polymerization of acrylamide have hydrogen bonding, which will make the wall structure more tightly interlocked. This will generate chemical forces between the cured liquid-bonded stone and the soil and rock in addition to consolidation and interlocking, greatly improving the stress disturbance resistance and crack resistance of the continuous wall.

[0021] (3) The tough cement soil underground continuous wall curtain formed by uniformly mixing and solidifying the tough curing liquid provided by the present invention with the in-situ soil and rock can resist the disturbance of mining stress. When the mining stress is transmitted to the continuous wall, the tough structure formed in the wall will undergo elastic deformation, absorb the energy of the stress tip and thus block its expansion, thereby avoiding the wall from cracking, splitting or deforming. The polyacrylamide gel in the tough structure also has a certain water absorption and expansion property. When the wall cracks due to various reasons, the polyacrylamide gel will absorb water from the outside of the wall and expand to fill the crack, so that the wall structure is restored to integrity and avoids further water damage threat. Attached Figure Description

[0022] Figure 1 The results of the compressive strength test of the tough cement-soil sample prepared in Example 1 are shown.

[0023] Figure 2 The microstructure of the tough cement-soil sample prepared in Example 1 is shown.

[0024] Figure 3 The results of the compressive strength test of the tough cement-soil sample prepared in Example 2 are shown.

[0025] Figure 4 The microstructure of the tough cement-soil sample prepared in Example 2;

[0026] Figure 5 The results of the compressive strength test of the tough cement-soil sample prepared in Comparative Example 1 are shown.

[0027] Figure 6The microstructure of the tough cement-soil sample prepared in Comparative Example 2 is shown.

[0028] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, any other embodiments obtained by those skilled in the art are within the scope of protection of the present invention.

[0030] The technical terms used in this application are explained as follows:

[0031] In-situ soil and rock: The soil and rock within the length, width, and height range of the cement-soil continuous wall, which is determined according to the site conditions and hydrogeological conditions.

[0032] The technical concept of this application is as follows: Since the main factor determining the final performance of a cement-soil continuous wall is the type and dosage of the curing liquid, and the pores and fissures inherent in the in-situ soil and rock are released after the soil and rock are cut and mixed by the cutting box, the amount of curing liquid that can be injected can be determined according to the density and volume of the soil and rock and the construction cost. Therefore, the main factor determining the performance of the continuous wall is still the type of curing liquid. Currently, the curing liquids on the market are mainly cement-based and geopolymer-based materials, and the toughness improvement is only achieved by adding some fibers. However, the addition of fibers cannot eliminate the stress disturbance generated by coal mining. When the mining stress propagates to the continuous wall, cracks begin to appear at some poor structural points because the wall is a rigid structure. Eventually, these cracks will penetrate and form water-conducting channels, causing the continuous wall to lose its water-blocking function. Acrylamide composite silicate cement is used to undergo an in-situ polymerization reaction in the soil and rock, forming a tough network structure that is evenly distributed within it, thus giving the continuous wall toughness. The use of polypropylene fibers works synergistically with polyacrylamide gel, and the fibers further interweave and bridge irregularly in the three-dimensional network, making the entire structure have a stronger stress relief effect. When mining stress propagates to the continuous wall, the tough structure inside the wall will undergo elastic deformation, absorbing the energy of the stress tip and thus inhibiting its propagation, thereby preventing the wall from cracking, splitting or being destroyed, keeping the wall structure intact and avoiding the threat of water damage.

[0033] The toughening curing liquid provided by this invention can be evenly distributed within the soil and rock mass under thorough stirring in the cutting box. After curing, it forms a tough continuous wall with the soil and rock mass, which can resist mining-induced stress disturbance. When mining-induced stress propagates to the continuous wall, the tough structure within the wall will undergo elastic deformation, absorbing the energy at the stress tip and thus hindering its propagation, thereby preventing cracks, splits, or deformation damage to the wall. In addition, the polyacrylamide gel in the tough structure also has a certain water absorption and swelling property. When cracks appear in the wall due to various reasons, the polyacrylamide gel will absorb water from the outside of the wall and swell to fill the cracks, restoring the integrity of the wall structure and avoiding further water damage threats.

[0034] The toughening curing liquid of the present invention comprises the following raw material components: by weight, 70-80 parts of silicate cement, 20-30 parts of admixture, 15-25 parts of organic monomer, 1-2 parts of crosslinking agent, 0.1-2 parts of initiator, 5-10 parts of expansion agent, 0.01-0.1 parts of fiber, and 70-100 parts of water.

[0035] The preparation method of the toughening curing liquid of the present invention includes the following steps:

[0036] Step 1: Weigh the organic monomer, crosslinking agent and initiator, and mix them at a rate of 50 r / min to 100 r / min to obtain a mixed powder;

[0037] Step 2: Weigh out ordinary silicate cement, admixture, expansion agent and polypropylene fiber and pour them into the mixer. Mix at a mixing speed of 50 r / min to 100 r / min for 1 to 3 minutes. Then weigh out a certain amount of water and pour it into the mixer. Mix at a mixing speed of 100 r / min to 200 r / min for 1 to 3 minutes to obtain the mixed slurry.

[0038] Step 3: Add the mixed powder from Step 1 to the mixed slurry from Step 2, and stir at a stirring rate of 100 r / min to 200 r / min for 3 to 5 minutes to obtain a toughened curing liquid;

[0039] The composition, by weight, consists of 70-80 parts silicate cement, 20-30 parts admixture, 15-25 parts organic monomer, 1-2 parts crosslinking agent, 0.1-2 parts initiator, 5-10 parts expansion agent, 0.01-0.1 parts fiber, and 70-100 parts water.

[0040] It should be noted that the raw materials used in this invention are all conventional raw materials and are commercially available.

[0041] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0042] Example 1

[0043] This embodiment provides a toughening curing liquid, comprising the following raw material components: by weight, 80 parts cement, 20 parts fly ash, 25 parts organic monomer, 2 parts crosslinking agent, 1 part initiator, 10 parts expansion agent, 0.05 parts fiber, and 100 parts water.

[0044] The toughening curing liquid is prepared by the following method:

[0045] Step 1: Weigh the organic monomer, crosslinking agent and initiator, and mix them at a rate of 50 r / min for 1 min to obtain a mixed powder;

[0046] Step 2: Weigh out silicate cement, admixture, expansion agent and polypropylene fiber and pour them into the mixer. Stir at 50 r / min for 1 min. Then weigh out a certain amount of water and pour it into the mixer. Stir at 100 r / min for 2 min to obtain the mixed slurry.

[0047] Step 3: Add the mixed powder from Step 1 to the mixed slurry from Step 2, and stir at a stirring rate of 200 r / min for 3 min to obtain a toughened curing liquid.

[0048] The prepared toughening liquid is mixed and stirred evenly with in-situ soil and rock to obtain tough cement-soil, specifically including the following steps:

[0049] Start the vertical cutting drive wheel and cut vertically with the chain cutter at a speed of 0.02 m / min. At the same time, inject tap water to maintain the soil specific gravity between 1.8 and 2.0. When the chain cutter cuts to 10 cm from the bottom of the box, start the horizontal cutting drive wheel and cut horizontally at a speed of 0.02 m / min while injecting tap water to maintain the soil specific gravity between 1.8 and 2.0. When cutting to the other side of the box, retract the cutter at a speed of 0.1 m / min. When it reaches the side of the box again, add a solidifying liquid with a rock and soil mass fraction of 25% and cut horizontally at a speed of 0.05 m / min and stir. After the cutting and stirring are completed, take cement-soil slurry from different depths inside the box for solidification and performance testing.

[0050] The performance test results of the solidified cement-soil sample were as follows: setting time 21 h 34 min, 28-day compressive strength 6.1 MPa, and 28-day permeability coefficient 0.0075 × 10⁻⁶. -7 cm / s, and the toughness index at 28d is 116.2%.

[0051] Figure 1 The compressive strength test of the cement-soil sample prepared in this embodiment shows that the compressive failure deformation rate of the underground continuous wall curtain exceeds 50%, which indicates that the underground continuous wall curtain has excellent toughness. Figure 2The image shows the microstructure of the tough cement soil as captured by a scanning electron microscope. It can be seen that the tough cement soil has a relatively dense structure with a network of polyacrylamide gel evenly distributed within it.

[0052] Example 2

[0053] The operation method and steps in this embodiment are the same as in Embodiment 1, except that the proportion of raw material components is 70 parts cement, 30 parts coal gasification slag powder, 15 parts organic monomer, 1 part crosslinking agent, 0.5 parts initiator, 5 parts expansion agent, 0.03 parts fiber, and 100 parts water.

[0054] The prepared toughening liquid was mixed and stirred evenly with the in-situ soil to obtain tough cement soil. The cement soil slurry was cured according to the method in Example 1 and its performance was tested.

[0055] The performance test results are as follows: setting time 23h30min, 28d compressive strength 3.2MPa, 28d permeability coefficient 0.091×10-7cm / s, and 28d toughness index 54.6%.

[0056] Figure 3 The compressive strength test results of the specimens prepared in this embodiment show that the compressive failure deformation rate of the specimens exceeds 40%, which indicates that the continuous wall has good toughness.

[0057] Figure 4 The image shows the microstructure of the sample obtained in this embodiment, captured by a scanning electron microscope. As can be seen from the image, the cement-soil sample has a relatively compact structure with a network of polyacrylamide gel evenly distributed within it.

[0058] Comparative Example 1

[0059] The preparation method in this comparative example is the same as that in Example 1, except that the proportions of the raw material components are: 80 parts cement, 20 parts fly ash, 25 parts polyacrylamide, 10 parts expansion agent, 0.05 parts fiber, and 100 parts water.

[0060] The prepared curing liquid was mixed and stirred evenly with the in-situ soil to obtain tough cement soil. The cement soil slurry was cured according to the method in Example 1 and its performance was tested.

[0061] The performance test results are as follows:

[0062] The performance of the cement-soil sample after solidification was as follows: setting time 24h16min, 28d compressive strength 5.2MPa, 28d permeability coefficient 0.067×10-7cm / s, and 28d toughness index 2.1%.

[0063] Figure 5The figure shows the compressive strength test results of the specimens prepared in this comparative example. As can be seen from the figure, the specimens prepared in this comparative example were fractured when the compressive failure deformation rate reached 1.8%, which indicates that the continuous wall prepared in this comparative example does not have toughness.

[0064] Figure 6 The image shows the microstructure of the sample prepared in this comparative example, obtained by scanning electron microscopy. As can be seen from the image, there is a lot of fly ash distributed in the structure of the cement-soil sample, and film-like polyacrylamide gel is visible. No network-like polyacrylamide gel was found.

[0065] As can be seen from Example 1, Example 2, and Comparative Example 1:

[0066] The toughening curing liquid provided by this invention can improve the toughness of underground continuous wall curtains, making their compressive failure deformation rate exceed 40%, and their permeability coefficient reaches and exceeds 1×10⁻⁶. -8 On the order of cm / s.

[0067] This is because the addition of acrylamide monomers, initiators, crosslinking agents, admixtures, expanding agents, and fibers to the toughening curing liquid optimizes the pore structure of the wall, making its internal structure more compact. The added admixtures can react with calcium hydroxide, a cement hydration product, in the later stages to generate new gels that fill any cracks, voids, or other defects in the wall structure, thus making the wall more compact and improving its performance. The added expanding agent produces a micro-expansion effect after the slurry cures, making the wall bond more tightly to the surrounding soil and rock. The added polypropylene fibers ensure the wall's crack resistance and improve the overall toughness of the continuous wall. During the hardening of the cement-soil and the in-situ polymerization of acrylamide, the polypropylene fibers interweave, creating a bridging effect between the hardened curing liquid and the soil and rock mass beyond mere consolidation. The interweaving and pulling of the fibers further strengthens the underground continuous wall structure. The crack resistance and toughness of the continuous wall curtain structure are further improved. The polyacrylamide gel generated by the in-situ polymerization of polypropylene fibers and acrylamide has hydrogen bonding, which will make the wall structure more tightly interlocked and greatly improve the stress disturbance resistance and crack resistance of the continuous wall. Under the action of the initiator, the acrylamide monomer gradually polymerizes into linear polyacrylamide, and then further crosslinks into a three-dimensional network structure of polyacrylamide gel under the action of the crosslinking agent. The polyacrylamide gel generated by in-situ polymerization intersperses in the cement and soil and tightly wraps them. Its unique three-dimensional network structure provides space for the material to deform under stress, thus endowing the material with excellent toughness.

[0068] The organic monomer added in Comparative Example 1 is polyacrylamide, a commercially available linear polymer commonly used as a suspending agent, thickener, and flocculant. Directly adding polyacrylamide does not result in in-situ polymerization; its function is often to cause flocculation and further thicken the material. Because there is no cross-linking bridging effect from a cross-linking agent, a three-dimensional network structure cannot be formed, thus failing to impart excellent toughness to the material. This is evident from the toughness index and compressive strength deformation rate of the examples and comparative examples. The compressive strength deformation rate of the samples in the examples is greater than 40%, while the compressive strength deformation rate of the sample in Comparative Example 1 is only 1.8%. This indicates that the sample with directly added polyacrylamide lacks toughness. Furthermore, scanning electron microscopy images show that network-like polyacrylamide gels can be observed in the electron microscope images of the examples, while the electron microscope images of the comparative example only show film-like polyacrylamide gels, without any network-like polyacrylamide gels.

[0069] This invention also protects the application of toughening curing liquid in the preparation of tough cementitious soil for underground continuous wall curtain systems.

[0070] The application specifically includes the following steps:

[0071] Step 1: Determine the construction technology and parameters based on the site conditions and hydrogeological conditions. Construction methods include one-step construction, two-step construction, and three-step construction. Construction parameters include the location of the cutoff curtain, the thickness of the cutoff curtain, and the design depth of the cutoff curtain. The cutoff curtain line is determined based on the location of the cutoff curtain and the terrain. The design depth of the cutoff curtain must ensure that the bottom of the cutoff curtain is set in the impermeable rock mass.

[0072] Step two: Based on the control lines of the curtain wall's plane position, first use an excavator to excavate a 1-1.2m wide, uniformly thick cement-soil underground continuous wall construction guide trench, approximately 2m deep. Excess soil from the excavation trench should be disposed of promptly to ensure the normal construction of the uniformly thick cement-soil underground continuous wall and to meet the requirements for civilized construction.

[0073] Step 3: Use an excavator to dig a pre-embedded pit approximately 3m deep, 2m long, and 1m wide, and then lower the pre-embedded boxes into the pit section by section. After all the cutting boxes have been driven in, effective measures should be taken to backfill the pre-embedded pit.

[0074] Step four: Set up a total station on one side of the construction site and adjust the position of the piling machine. The piling machine should be stable and level. Place positioning lines on the piling machine's forward movement area in the continuous wall construction method using cement-soil of uniform thickness to control the main unit's movement.

[0075] Step 5: Use a crawler crane to lift the cutting box section by section into the pre-embedded pit and fix it with a support platform. The main unit of the continuous wall system for the same thickness of concrete underground soil is moved to the pre-embedded pit position and connected to the cutting box. The main unit then returns to the predetermined construction position to perform the self-driving excavation process for the cutting box.

[0076] Step six: After the cutting box is driven into the designed depth, install the inclinometer. The multi-segment inclinometer installed inside the cutting box can manage the vertical accuracy of the wall, usually ensuring an accuracy within 1 / 250.

[0077] Step 7: After the inclinometer is installed, connect the main unit to the cutting box, inject excavation fluid into the bottom of the cutting box for cutting, and use no less than 50 kg of bentonite per unit soil volume. Control the excavation speed at 1-2 m / h. The second step is back cutting, with the excavation speed controlled at 6-12 m / h. Inject 20%-30% of the self-developed toughening curing liquid, and control the wall mixing speed at 3-5 m / h to force the wall to mix with the in-situ soil and form a continuous underground wall of uniform thickness.

[0078] By adding the toughening curing liquid provided by this invention to a traditional rigid diaphragm wall curtain, the rigid diaphragm wall curtain can be transformed into a tough diaphragm wall curtain, improving its impermeability, disturbance resistance, and crack resistance. The toughening curing liquid, under thorough mixing in the cutting box, is evenly distributed within the rock and soil mass. After curing, it forms a tough diaphragm wall with the rock and soil mass, resisting surface disturbance and underground mining stress. When mining stress propagates to the diaphragm wall, the tough structure within the wall will undergo elastic deformation, absorbing the energy at the stress tip and thus hindering its propagation, thereby preventing cracks, splits, or deformation damage to the wall. Furthermore, the polyacrylamide gel in the tough structure also has a certain water absorption and swelling property. When cracks appear in the wall due to various reasons, the polyacrylamide gel will absorb water from the outside of the wall and swell to fill the cracks, restoring the wall structure to its integrity, avoiding further water damage threats, and ensuring the quality of the cutoff curtain and the safety of subsequent coal mine mining operations.

[0079] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0080] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. The application of a toughening curing liquid in the preparation of tough cement-soil for underground continuous wall curtain systems, characterized in that, The toughening curing liquid comprises, by weight, the following raw material components: 70-80 parts silicate cement, 20-30 parts admixture, 15-25 parts organic monomer, 1-2 parts crosslinking agent, 0.1-2 parts initiator, 5-10 parts expansion agent, 0.01-0.1 parts fiber, and 70-100 parts water. The admixture is one or two of fly ash or coal gasification slag powder with a particle size of <45μm. The organic monomer is an acrylamide monomer, the crosslinking agent is N,N-methylenebisacrylamide, and the initiator is ammonium persulfate or potassium persulfate. The expanding agent is calcium oxide-calcium sulfoaluminate expanding agent, and the fiber includes polypropylene fiber with a diameter of 18~48μm and a length of 4~6mm; The preparation of the toughening curing liquid includes the following steps: Step 1: Weigh the organic monomer, crosslinking agent and initiator, and mix them at a rate of 50 r / min to 100 r / min to obtain a mixed powder; Step 2: Weigh out silicate cement, admixture, expansion agent and polypropylene fiber and pour them into the mixer. Mix at a mixing speed of 50 r / min to 100 r / min for 1 to 3 minutes. Then weigh out a certain amount of water and pour it into the mixer. Mix at a mixing speed of 100 r / min to 200 r / min for 1 to 3 minutes to obtain the mixed slurry. Step 3: Add the mixed powder from Step 1 to the mixed slurry from Step 2, and stir at a stirring rate of 100r / min to 200r / min for 3 to 5 minutes to obtain a toughened curing liquid.

2. The application as described in claim 1, characterized in that, The tough cement soil comprises the following raw material components: toughening curing liquid and in-situ soil and rock, and by mass percentage, the toughening curing liquid accounts for 20% to 30% of the mass of the in-situ soil and rock.

3. The application as described in claim 1, characterized in that, The toughening curing liquid comprises the following raw material components by weight: 80 parts silicate cement, 20 parts fly ash, 25 parts organic monomer, 2 parts crosslinking agent, 1 part initiator, 7 parts expansion agent, 0.05 parts fiber, and 100 parts water; the fiber is a polypropylene fiber with a diameter of 30 μm and a length of 5 mm.

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