Grouting reinforcement composite material for riverbed sand layer and preparation method and application thereof

Abstract

The application belongs to the technical field of horizontal directional drilling, and particularly relates to a grouting reinforcement composite material for riverbed sand soil layers, a preparation method and application; the grouting reinforcement composite material for riverbed sand soil layers provided by the application strengthens the solidification of the sand soil layer by utilizing the mechanism of isocyanate and polyol solidification and the mechanism of cement and water solidification, forms a stable borehole, is beneficial to horizontal directional drilling construction, and further improves the solidification strength of the sand soil layer by adding nano silicon oxide, polyvinyl alcohol, fly ash and ethyl acetate, so as to solve the technical problem that the effect of cement and other solidifying agents in grouting reinforcement of riverbed sand soil layers is not good and it is difficult to form a stable borehole in the riverbed sand soil layer.

Description

Technical Field

[0001] This application belongs to the field of horizontal directional drilling technology, and particularly relates to grouting reinforcement composite materials for riverbed sand layers, their preparation methods, and applications. Background Technology

[0002] Traditional construction methods often require excavation from above the construction area, followed by backfilling, which is time-consuming and labor-intensive. In contrast, horizontal directional drilling (WD) involves laying pipelines from below the construction area, reducing the amount of work and minimizing the impact on surrounding buildings. Therefore, WD is widely used in water supply, power supply, and communication industries.

[0003] During the construction of water supply, power supply and communication projects, it is often necessary to cross obstacles such as rivers. The construction area is located below a riverbed sand layer, which is a product of water transport and deposition. It mainly consists of non-cohesive silty soil rock layers and silty fine sand. It is easy to dilute and disperse, and has poor cementation. When encountering quicksand layers during horizontal directional drilling, collapse and hole failure often occur, resulting in over-diameter leakage or even failure to form a hole.

[0004] Currently, to stabilize soil layers, cement and other curing agents are often used for grouting to solidify the borehole. This allows the cement grout to penetrate into a certain area around the borehole, filling the loose soil layer and solidifying it. This can strengthen the borehole wall and achieve the goal of controlling borehole stability. However, cement has poor permeability. While it works well in strata with large fractures and coarse sand layers, it is not effective in silty rock layers and riverbed sand layers composed of silty fine sand. At the same time, riverbed sand layers have a high water content, and the cement has a long curing time and is easily diluted by water, reducing the curing effect. Therefore, it is difficult to form stable boreholes in riverbed sand layers. Summary of the Invention

[0005] In view of this, this application provides a grouting reinforcement composite material for riverbed sand layers, its preparation method and application, to solve the technical problem that the existing technology of grouting reinforcement of riverbed sand layers with cement and other curing agents is not effective and it is difficult to form stable boreholes in riverbed sand layers.

[0006] The first aspect of this application provides a grouting reinforcement composite material for riverbed sand layers, comprising an organic active grouting reinforcement component and an inorganic active grouting reinforcement component.

[0007] The organic active grouting reinforcement components include: isocyanate, polyol, catalyst, retarder, and organic solvent;

[0008] The inorganic active grouting reinforcement components include cement and water.

[0009] Preferably, the organic active grouting reinforcement component further includes: nano-silica.

[0010] Preferably, the inorganic active grouting reinforcement component further includes: polyvinyl alcohol.

[0011] Preferably, the organic solvent in the organic active grouting reinforcement component is selected from ethyl acetate.

[0012] Preferably, the inorganic active grouting reinforcement component further includes fly ash.

[0013] Preferably, the organic active grouting reinforcement component further includes an emulsifier.

[0014] Preferably, the isocyanate is selected from at least one of diphenylmethane diisocyanate and toluene diisocyanate;

[0015] The polyol is selected from polyether polyol 330N.

[0016] Preferably, the catalyst is selected from at least one of 1,4-butanediol, triethylamine, triethanolamine, triethylenediamine, stannous octoate, and dibutyltin dilaurate;

[0017] The retarder is selected from at least one of phosphoric acid, benzoyl chloride, p-toluenesulfonyl chloride, and citric acid;

[0018] The emulsifier is selected from Tween-80.

[0019] Preferably, based on mass fraction, the grouting reinforcement composite material of the riverbed sand layer contains,

[0020] The organic active grouting reinforcement component includes: 1-5 parts by weight of isocyanate, 1-5 parts by weight of polyol, 0.1-1 parts by weight of organic solvent, 0.1-1 parts by weight of emulsifier, 0.1-1 parts by weight of catalyst, and 0.05-1 parts by weight of nano-silica.

[0021] The inorganic active grouting reinforcement component includes: 5-20 parts by weight of cement, 5-20 parts by weight of water, 0.5-2 parts by weight of fly ash, and 0.1-1 parts by weight of polyvinyl alcohol.

[0022] The second aspect of this application provides a method for preparing a grouting reinforcement composite material for riverbed sand layers, which can prepare the grouting reinforcement composite material for riverbed sand layers described in the first aspect, including the following steps:

[0023] Isocyanate, polyol, catalyst, retarder and nano-silica are dissolved in an organic solvent to obtain an organic active grouting reinforcement component;

[0024] Cement, fly ash, and polyvinyl alcohol are dissolved in an aqueous solvent to obtain an inorganic active grouting reinforcement component.

[0025] The third aspect of this application provides an application of a composite material for grouting reinforcement of riverbed sand layers, which is the same as the application of the composite material for grouting reinforcement of riverbed sand layers described in the first aspect. The application includes the following steps:

[0026] Step S1: Apply pressure to inject the organic active grouting reinforcement component and the inorganic active grouting reinforcement component into the borehole through the organic active grouting pipe and the inorganic active grouting pipe respectively, filling the sand layer around the borehole wall to obtain the borehole to be solidified;

[0027] Step S2, curing, allows the organic and inorganic active grouting reinforcement components in the sand layer surrounding the borehole wall to react and solidify, resulting in a stable borehole.

[0028] Preferably, in step S1, the applied pressure is 0.5-1.5 MPa, and the flow rates of the organic active grouting reinforcement component and the inorganic active grouting reinforcement component are 10-30 L / min;

[0029] In step S2, the curing time is 12 to 24 hours.

[0030] In summary, this application provides a grouting reinforcement composite material for riverbed sand layers, its preparation method, and its application. The grouting reinforcement composite material for riverbed sand layers comprises an organic active grouting reinforcement component consisting of isocyanate, polyol, catalyst, retarder, nano-silica, and organic solvents, and an inorganic active grouting reinforcement component consisting of cement and water. The isocyanate and polyol in the organic active grouting reinforcement component can penetrate deep into the riverbed sand layer and rapidly react to form a cross-linked network structure, improving the strength of the sand layer and allowing it to solidify deep into the sand layer. The cement grout, composed of cement and water... The material can also form a cementitious substance to solidify the shallow layer of sand, improving the structural strength and durability of the sand layer. Therefore, when using the grouting reinforcement composite material provided in this application to solidify the riverbed sand layer, the mechanism of better permeability and rapid solidification of isocyanate and polyol can quickly form a preliminary reinforced borehole that is strengthened to a deep layer. Then, the sand layer around the borehole can be further reinforced by traditional cement grout, thereby forming a high-strength, stable borehole that is not easy to collapse. This solves the technical problem that the existing technology of cement and other curing agents is not effective in reinforcing the riverbed sand layer and it is difficult to form a stable borehole in the riverbed sand layer. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a scanning electron microscope (SEM) image of a riverbed sand layer sample after the grouting-reinforced composite material described in Example 5 of this application has been solidified.

[0033] Figure 2 This is a scanning electron microscope (SEM) image of a riverbed sand layer sample after the grouting-reinforced composite material described in Example 6 of this application has been solidified.

[0034] Figure 3 This is a scanning electron microscope image of a riverbed sand layer sample after the grouting reinforcement composite material described in Example 3 of this application has been solidified. Detailed Implementation

[0035] This application provides a grouting reinforcement composite material for riverbed sand layers, its preparation method, and its application, which solves the technical problem that the existing technology of grouting reinforcement of riverbed sand layers with cement and other curing agents is not effective and it is difficult to form stable boreholes in riverbed sand layers.

[0036] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] In view of the defects existing in the current process of cement grouting reinforcement of riverbed sand layers, this application provides a grouting reinforcement composite material for riverbed sand layers. The grouting reinforcement composite material consists of an organic active grouting reinforcement component and an inorganic active grouting reinforcement component. The inorganic active grouting reinforcement component includes traditional cement and water, and the organic active grouting reinforcement component includes isocyanate and polyol. Compared with the poor permeability and long curing time of cement, isocyanate and polyol have good permeability in sand layers and can quickly penetrate into the deep layers of sand layers around the borehole wall. Moreover, isocyanate and polyol have a fast reaction rate, which can quickly solidify the sand layer around the borehole wall. Afterwards, water around the sand layer is not easy to penetrate, so the cement is not easily washed away and diluted during the curing process, resulting in a good curing effect and further strengthening the solidification of the sand layer around the borehole wall. This application utilizes the curing mechanism of isocyanate and polyol and the curing mechanism of cement to work together to form a stable borehole, thereby overcoming the defects existing in the process of cement grouting reinforcement of riverbed sand layers.

[0038] As a preferred option, to further improve the curing effect, this application also improves the organic active grouting reinforcement component by adding nano-silica. Nano-silica further promotes the penetration effect of the organic active grouting reinforcement component and can also react with inorganic active grouting reinforcement components such as cement to improve the curing strength of the sand layer around the borehole wall.

[0039] As a preferred option, to further improve the curing effect, this application also improves the inorganic active grouting reinforcement component by adding polyvinyl alcohol. Polyvinyl alcohol can increase the permeability of the inorganic active grouting reinforcement component, allowing the inorganic active grouting reinforcement component such as cement to penetrate into the sand layer more easily and solidify the deeper sand layer.

[0040] As a preferred option, to further improve the curing effect, this application also improved the organic solvent in the organic active grouting reinforcement component, and selected ethyl acetate as the solvent. In addition to improving the fluidity of the organic active grouting reinforcement component, the ethyl acetate solvent also participates in the reaction of isocyanate and polyol in the organic active grouting reinforcement component, promoting its coagulation and curing, resulting in higher curing strength of the sand layer.

[0041] Meanwhile, the inorganic active grouting component in the grouting reinforcement composite material provided in this application also contains fly ash to improve the effect of cement solidification of sandy soil layers, while the organic active grouting component also contains emulsifiers to improve the dispersion and mixing effect of the inorganic active grouting component and the organic active grouting component.

[0042] Example 1

[0043] Example 1 of this application provides a method for preparing a grouting reinforcement composite material, the method including preparing an inorganic active grouting component and preparing an organic active grouting component.

[0044] The preparation of inorganic active grouting components includes: mixing cement and water, stirring at a speed of 100 r / min to ensure uniform mixing of cement and water, then adding fly ash while stirring continuously, adjusting the fluidity and strength of the formula appropriately, then adding polyvinyl alcohol to improve the permeability of the grout, and stirring continuously to obtain the inorganic active grouting components, and then storing them in a container.

[0045] The preparation of the organic active grouting component includes: thoroughly mixing diphenylmethane diisocyanate (MDI) and polyether polyol to form a polymer slurry; then adding 20% ​​ethyl acetate solvent to the polymer slurry while continuously stirring to fully dissolve the MDI and polyether polyol; next, adding 1% emulsifier Tween-80, 1.5% catalyst 1,4-butanediol, and 2% retarder phosphoric acid, and stirring the prepared polymer slurry with a glass rod for about 20 seconds; the organic active grouting component is then obtained and stored in a container.

[0046] In this embodiment, the dosage ratio of each component of the grouting reinforcement composite material is as follows: 2.5g of diphenylmethane diisocyanate (MDI), 2.5g of polyether polyol, 0.1g of nano-silica, 0.5g of ethyl acetate, 0.25g of emulsifier, 0.25g of catalyst, 10g of cement, 10g of water, 1g of fly ash, and 0.2g of polyvinyl alcohol (PVA).

[0047] Example 2

[0048] Example 2 of this application provides a method for preparing a grouting reinforcement composite material. The difference between the preparation method and Example 1 is that the proportions of each component in the grouting reinforcement composite material are as follows: 3g of diphenylmethane diisocyanate (MDI), 3.5g of polyether polyol, 0.25g of nano-silica, 0.7g of ethyl acetate, 0.4g of emulsifier, 0.45g of catalyst, 12g of cement, 12g of water, 2g of fly ash, and 0.4g of polyvinyl alcohol (PVA).

[0049] Example 3

[0050] Example 3 of this application provides a method for preparing a grouting reinforcement composite material. The difference between the preparation method and Example 1 is that the proportions of each component in the grouting reinforcement composite material are as follows: 4.5g of diphenylmethane diisocyanate (MDI), 4g of polyether polyol, 0.5g of nano-silica, 0.9g of ethyl acetate, 0.45g of emulsifier, 0.45g of catalyst, 15g of cement, 15g of water, 3g of fly ash, and 0.6g of polyvinyl alcohol (PVA).

[0051] Example 4

[0052] Example 3 of this application provides a method for preparing a grouting reinforcement composite material. As a comparison with Example 1, the difference between the preparation method and Example 1 is that nano-silica, fly ash and polyvinyl alcohol are not used. The dosage ratio of each component of the grouting reinforcement composite material is as follows: 4.5g of diphenylmethane diisocyanate (MDI), 4g of polyether polyol, 0.7g of ethyl acetate, 0.4g of emulsifier, 0.45g of catalyst, 15g of cement and 15g of water.

[0053] Example 5

[0054] Example 5 of this application provides a method for preparing a grouting reinforcement composite material. As a comparison with Example 1, the difference between the preparation method and Example 1 is that nano-silica and polyvinyl alcohol are not used. The dosage ratio of each component of the grouting reinforcement composite material is as follows: 4.5g of diphenylmethane diisocyanate (MDI), 4g of polyether polyol, 0.7g of ethyl acetate, 0.4g of emulsifier, 0.45g of catalyst, 15g of cement, 15g of water, and 3g of fly ash.

[0055] Example 6

[0056] Example 6 of this application provides a method for preparing a grouting reinforcement composite material. As a comparison with Example 1, the difference between the preparation method and Example 1 is that nano-silica is not used. The dosage ratio of each component of the grouting reinforcement composite material is as follows: 4.5g of diphenylmethane diisocyanate (MDI), 4g of polyether polyol, 0.7g of ethyl acetate, 0.4g of emulsifier, 0.45g of catalyst, 15g of cement, 15g of water, 3g of fly ash, and 0.6g of polyvinyl alcohol (PVA).

[0057] Experimental Example 1

[0058] Experimental Example 1 of this application tests the performance of the grouting reinforcement composite material provided in Examples 1-6. The sample used for performance testing is 100 portions of riverbed sand.

[0059] The testing process included: first, making molds by cutting PVC pipes, uniformly shaping the riverbed sand layer molds into cylinders with a diameter of 5cm and a height of 10cm, coating the inner wall of the molds with sesame oil for easy sampling, and then injecting 100 portions of riverbed sand into the PVC pipe molds to form riverbed sand layer samples; after the samples were prepared, the demolded samples were injected into the grouting reinforcement composite materials provided in Examples 1-6 using Y-shaped pipes, and placed in a constant temperature and humidity curing chamber, cured under curing conditions of 90-100% humidity and 20±2℃. At 6h, 24h, and 72h curing periods, their unconfined compressive strength was tested to measure the curing effect. After the curing period, the unconfined compressive strength test was conducted. The riverbed sand layer sample was placed in the center of the pressure plate of the pressure testing machine, aligned with the upper and lower pressure plates, and the pressure testing machine was started to make the end face of the specimen in close contact with the upper and lower pressure plates, and the load was applied at a speed of 0.7mm / min until failure; the test results are shown in Table 1.

[0060] As can be seen from the test results shown in Table 1, compared with the sand layer after curing of the grouting reinforced composite material provided in Examples 1-3, the compressive strength of the sand layer after curing of the grouting reinforced composite material provided in Example 6 is 3.74-5.12 MPa, which is lower than the curing strength of the sand layer provided in Examples 1-3. This indicates that the nano-silica provided in this application can improve the curing strength of the sand layer around the borehole wall by reacting with inorganic active grouting reinforced components such as cement.

[0061]

[0062] Table 1

[0063] As can be seen from the test results shown in Table 1, compared with the sand layer after curing of the grouting reinforced composite material provided in Examples 1-3, the compressive strength of the sand layer after curing of the grouting reinforced composite material provided in Example 6 is 3.74-5.12 MPa, which is lower than the curing strength of the sand layer provided in Examples 1-3. This indicates that the nano-silica provided in this application can improve the curing strength of the sand layer around the borehole wall by reacting with inorganic active grouting reinforced components such as cement.

[0064] Furthermore, the compressive strength of the cured sand layer of the grouting reinforcement composite material provided in Example 5 is 3.57 to 5.02 MPa, which is lower than the cured strength of the sand layer provided in Example 6. This indicates that the nano-silica and polyvinyl alcohol provided in this application can improve the cured strength of the sand layer around the borehole wall by reacting with inorganic active grouting reinforcement components such as cement.

[0065] The compressive strength of the cured sand layer after grouting reinforcement composite material provided in Example 4 was 3.45 to 4.97 MPa, which was lower than the cured strength of the sand layer provided in Example 5. This shows that the fly ash provided in this application can improve the cured strength of the sand layer around the borehole wall by reacting with inorganic active grouting reinforcement components such as cement.

[0066] Comparing Examples 5 and 6, it can be seen that the pores in the cured sand layer without the addition of nano-silica and polyvinyl alcohol grouting reinforcement composite material are deeper, while the pores in the cured sand layer with the addition of polyvinyl alcohol grouting reinforcement composite material are shallower. This indicates that polyvinyl alcohol promotes the permeability of the grouting reinforcement composite material. Further comparing Examples 6 and 3, it can be seen that the pores in the cured sand layer with the addition of both nano-silica and polyvinyl alcohol grouting reinforcement composite material are very shallow, indicating that the grouting reinforcement composite material has good permeability and improves the curing effect.

[0067] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A composite material for grouting reinforcement of riverbed sand layers, characterized in that, Includes organic active grouting reinforcement components and inorganic active grouting reinforcement components; The organic active grouting reinforcement components include: isocyanate, polyol, catalyst, retarder, organic solvent, nano-silica, and emulsifier; the organic solvent is selected from ethyl acetate. The inorganic active grouting reinforcement components include: polyvinyl alcohol, fly ash, cement, and water; Its preparation method includes the following steps: Isocyanate, polyol, catalyst, retarder and nano-silica are dissolved in an organic solvent to obtain an organic active grouting reinforcement component; Cement, fly ash, and polyvinyl alcohol are dissolved in an aqueous solvent to obtain an inorganic active grouting reinforcement component; Calculated by mass parts, in the grouting reinforcement composite material of the riverbed sand layer, The organic active grouting reinforcement component includes: 1-5 parts by weight of isocyanate, 1-5 parts by weight of polyol, 0.1-1 parts by weight of organic solvent, 0.1-1 parts by weight of emulsifier, 0.1-1 parts by weight of catalyst, and 0.05-1 parts by weight of nano-silica; The inorganic active grouting reinforcement component includes: 5-20 parts by weight of cement, 5-20 parts by weight of water, 0.5-2 parts by weight of fly ash, and 0.1-1 parts by weight of polyvinyl alcohol.

2. The composite material for grouting reinforcement of riverbed sand layers according to claim 1, characterized in that, The isocyanate is selected from at least one of diphenylmethane diisocyanate and toluene diisocyanate; The polyol is selected from polyether polyol 330N; the catalyst is selected from at least one of 1,4-butanediol, triethylamine, triethanolamine, triethylenediamine, stannous octoate, and dibutyltin dilaurate; the retarder is selected from at least one of phosphoric acid, benzoyl chloride, p-toluenesulfonyl chloride, and citric acid; and the emulsifier is selected from Tween-80.

3. The application of the composite material for grouting reinforcement of riverbed sand layers as described in any one of claims 1-2, characterized in that, The application includes the following steps: Step S1: Apply pressure to inject the organic active grouting reinforcement component and the inorganic active grouting reinforcement component into the borehole through the organic active grouting pipe and the inorganic active grouting pipe respectively, filling the sand layer around the borehole wall to obtain the borehole to be solidified; Step S2, after curing, allows the organic and inorganic active grouting reinforcement components in the sand layer surrounding the borehole wall to react and solidify, resulting in a stable borehole.

Images