Expanding soil nailing system and construction method thereof

Abstract

This application relates to an expansive soil nailing support system and its construction method. The expansive soil nailing support system includes soil nails, each comprising internal reinforcement, concrete, and a sintered layer. The internal reinforcement is inserted into the soil, with grouting holes between the reinforcement and the soil. The concrete is located in the grouting holes, and a protrusion is provided on the side of the concrete facing the soil. The sintered layer is located on the surface of the protrusion. The sintered layer increases the strength of the soil nail at that point, enabling it to withstand greater shear forces. Thus, the combined effect of the protrusion and the sintered layer significantly enhances the shear resistance of the soil nail, thereby enabling the expansive soil nailing support system to exert a stronger restraining effect on the soil, reducing the risk of slippage in the corresponding parts of the soil, and improving the stability of the soil.

Description

Technical Field

[0001] This application relates to the field of soil reinforcement technology, and in particular to expansive soil nailing support systems and their construction methods. Background Technology

[0002] When using soil nailing technology to reinforce soil and rock, holes are typically drilled at corresponding locations in the soil, steel bars are inserted into the holes, and then cement mortar is poured into the holes. After the cement mortar hardens, it forms a soil nail containing concrete and steel bars. However, this type of soil nail has low pull-out resistance, especially in soft soil, where it is easily pulled out as a whole. The bonding effect of this type of soil nail on the soil is often limited, resulting in low soil stability. Furthermore, this type of soil nail has low shear resistance. When using this type of soil nail to reinforce soil at slopes, the presence of a sliding layer in the soil at the slope can exert a large shear force on the soil nail, easily leading to brittle fracture of the soil nail. This also results in low soil stability and may even lead to landslides or other dangerous situations.

[0003] In addition, since soil nails are buried in the soil, their condition cannot be directly observed. To understand whether soil nails have broken or not, a pull-out test is usually conducted on the corresponding soil nails using a sampling method. This method is often destructive to the soil nails. Summary of the Invention

[0004] Therefore, it is necessary to provide an expansive soil nailing system and its construction method that can improve soil stability, addressing the problem that traditional soil nailing technology has a low soil reinforcement capacity, resulting in low soil stability.

[0005] This application provides an expandable soil nailing support system, including soil nails, wherein the soil nails include:

[0006] An inner reinforcement bar is inserted into the soil, and there are grouting holes between the inner reinforcement bar and the soil.

[0007] Concrete is located in the grouting hole, and the side of the concrete facing the soil has a protrusion;

[0008] A sintered layer is located on the surface of the protrusion.

[0009] In one embodiment, the sintered layer is formed by the polymerization reaction of aluminosilicate components in the slurry.

[0010] In one embodiment, the surface of the soil facing the sintered layer has a lithified layer formed by soil particles in the soil under thermal induction.

[0011] In one embodiment, the concrete includes a first section of concrete, a second section of concrete, and a third section of concrete distributed sequentially along the length of the inner reinforcement. The first section of concrete is closer to the opening of the grouting hole than the third section of concrete. The stiffness of the first section of concrete is greater than that of the second section of concrete, and the stiffness of the second section of concrete is greater than that of the third section of concrete.

[0012] In one embodiment, the expansive soil nailing support system further includes magnetic wires located in the soil, the magnetic wires being situated outside the concrete, and the shape of the magnetic wires being adaptable to changes in the shape of the concrete.

[0013] This application also provides a construction method for the aforementioned expansive soil nailing support system, the construction method comprising the following steps:

[0014] The inner reinforcement and the outer tube are inserted into the soil, with the inner reinforcement located inside the outer tube, and a heating layer is provided at a designated location on the outer tube.

[0015] Grout is injected into the grouting cavity between the inner reinforcement and the outer tube; the heating layer generates heat energy; the designated part of the outer tube softens under the induction of the heat energy, and the grout corresponding to the designated part of the outer tube expands outward under static pressure, and the surface of the outwardly expanding grout is induced by the heat energy to form the sintered layer. After the injected grout solidifies, it forms the concrete located in the grouting hole, and the outwardly expanding grout solidifies to form the protrusion.

[0016] In one embodiment, the concrete includes a first section of concrete, a second section of concrete, and a third section of concrete; the grout includes a first type of grout, a second type of grout, and a third type of grout; and the step of injecting the grout into the grouting cavity includes the following steps:

[0017] The third type of grout, the second type of grout, and the first type of grout are sequentially injected into the grouting cavity through the opening of the grouting hole;

[0018] After the first type of grout cures, it forms the first section of concrete; after the second type of grout cures, it forms the second section of concrete; and after the third type of grout cures, it forms the third section of concrete. The stiffness of the first section of concrete is greater than that of the second section of concrete, and the stiffness of the second section of concrete is greater than that of the third section of concrete.

[0019] In one embodiment, the first slurry is ordinary cement mortar, the third slurry is ECC material, and the second slurry is a mixture of cement-based material and ECC material.

[0020] In one embodiment, the step of inserting the inner reinforcement and outer tube into the soil includes the following steps:

[0021] An outer tube is provided, and magnetic wire is wound around the outer wall of the outer tube;

[0022] Insert the outer tube into the soil;

[0023] During the outward expansion of the slurry, the shape of the magnetic lines changes with the shape of the outwardly expanding slurry. The construction method further includes the following steps:

[0024] The magnetic lines inserted into the soil along with the outer tube are scanned using a magnetizer to obtain the current magnetic flux density curve of the magnetic lines. The current magnetic flux density curve is compared with the set standard density curve to determine whether the shape of the outwardly expanding slurry meets the set requirements. If the set requirements are not met, slurry is injected into the set part of the outer tube until the shape of the outwardly expanding slurry meets the set requirements.

[0025] In one embodiment, the construction method further includes the following steps:

[0026] Insert the hollow detection conduit into the soil, positioning it beside the outer tube;

[0027] The step of scanning the magnetic lines that have been inserted into the soil along with the outer tube using a magnetizer includes the following steps:

[0028] The sensor of the magnetizer moves along the hollow detection conduit while scanning the magnetic lines.

[0029] The aforementioned expansive soil nailing support system and its construction method, by setting protrusions on the concrete side, increase the contact area between the soil nail and the soil. The protrusions and the soil form a larger mutual resisting force along the length of the soil nail, improving the pull-out resistance of the soil nail. This allows the soil nail to form a stronger bond with the soil along its length, enhancing the stability of the soil. Furthermore, the protrusions increase the volume of the soil nail at that location, thereby enhancing its shear resistance. Simultaneously, the surface of the protrusions has a sintered layer, which increases the strength of the soil nail at that location, enabling it to withstand greater shear forces. Thus, the combined effect of the protrusions and the sintered layer significantly enhances the shear resistance of the soil nail, resulting in a stronger confinement effect on the soil, reducing the risk of slippage in the corresponding parts of the soil, and further improving the stability of the soil. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of an expansion soil nailing support system in one embodiment of this application.

[0031] Figure 2 This is a schematic diagram of the structure of the combined rod in an embodiment of this application when it is filled with grout.

[0032] Figure 3 This is a schematic diagram of the soil nail structure in one embodiment of this application.

[0033] Figure 4 This is a longitudinal sectional view of a composite member in one embodiment of this application.

[0034] Figure 5 This is a structural schematic diagram of the combined rod in one embodiment of this application.

[0035] Figure 6 This is a schematic diagram of the structure of the third type of slurry, the second type of slurry, and the first type of slurry being poured into the outer tube in one embodiment of this application.

[0036] Figure 7 This is a schematic diagram illustrating the detection of soil nails using a magnetizer in one embodiment of this application.

[0037] Figure 8 This is a schematic diagram of the current magnetic flux density curve in one embodiment of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Soil nail; 11. Internal reinforcement; 12. Concrete; 121. Protrusion; 13. Sintered layer; 14. Outer tube; 15. Heating layer; 2. Soil; 21. Lithified layer; 22. Surface soil; 23. Middle soil; 24. Deep soil; 25. Slope; 26. Sliding layer; 3. Magnetic lines; 31. Magnetic field lines; 32. Current magnetic flux density curve; 4. Grout; 41. First type of grout; 42. Second type of grout; 43. Third type of grout; 5. Magnetizer; 6. Composite rod. Detailed Implementation

[0040] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0041] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0042] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0046] like Figure 1 and Figure 3 As shown, an embodiment of the present application provides an expansion soil nailing support system including a soil nail 1, the soil nail 1 including an inner reinforcement 11, concrete 12, and a sintered layer 13; the inner reinforcement 11 is inserted into the soil 2, and there is a grouting hole between the inner reinforcement 11 and the soil 2; the concrete 12 is located in the grouting hole, and a protrusion 121 is provided on the side of the concrete 12 facing the soil 2; the sintered layer 13 is located on the surface of the protrusion 121. The protrusion 121 on the concrete 12 increases the contact area between the soil nail 1 and the soil 2, and the protrusion 121 and the soil 2 can form a large mutual blocking force along the length of the soil nail 1, which improves the pull-out resistance of the soil nail 1. This allows the soil nail 1 to form a stronger connection with the soil 2 along its length, thus improving the stability of the soil 2. Furthermore, the protrusion 121 increases the volume of the soil nail 1 at that location, thereby enhancing its shear resistance. At the same time, the surface of the protrusion 121 has a sintered layer 13, which increases the strength of the soil nail 1 at that location, allowing it to withstand greater shear forces. Thus, the combined effect of the protrusion 121 and the sintered layer 13 significantly enhances the shear resistance of the soil nail 1, thereby enabling the expansive soil nail support system to exert a stronger restraining effect on the soil 2, reducing the risk of slippage in the corresponding parts of the soil 2, and further improving the stability of the soil 2.

[0047] like Figure 2 and Figure 3 As shown, a construction method for an expansive soil nailing support system provided in one embodiment of this application includes the following steps:

[0048] The inner reinforcement 11 and the outer tube 14 are inserted into the soil 2, with the inner reinforcement 11 located inside the outer tube 14, and a heating layer 15 is provided at a designated location on the outer tube 14. Grout 4 is injected into the grouting cavity between the inner reinforcement 11 and the outer tube 14. The heating layer 15 generates heat energy. The designated location on the outer tube 14 softens under the induction of heat energy. The grout 4 corresponding to the designated location on the outer tube 14 expands outward under static pressure. The surface of the outwardly expanding grout 4 is induced by heat energy to form a sintered layer 13. After the injected grout 4 solidifies, it forms concrete 12 located in the grouting hole. After the outwardly expanding grout 4 solidifies, it forms a protrusion 121, thereby obtaining a soil nail 1 with a protrusion 121 and a sintered layer 13. Furthermore, based on the interlocking relationship between the protrusion 121 and the soil 2, a greater mutual resisting force can be formed between the soil 2 and the protrusion 121 along the length direction of the soil nail 1, improving the pull-out resistance of the soil nail 1 and enabling the soil nail 1 to form a stronger connection with the soil 2 along its length direction, thus improving the stability of the soil 2. The protrusion 121 also increases the volume of the soil nail 1 at that location, improving its shear resistance. Simultaneously, a sintered layer 13 is formed on the surface of the protrusion 121, and this sintered layer 13 is formed by the thermal induction of the slurry 4. This sintered layer 13 has superior strength compared to concrete 12, thereby significantly improving the strength of the soil nail 1 at that location, enabling the soil nail 1 to... By withstanding greater shear forces, the combined effect of the protrusion 121 and the sintered layer 13 significantly improves the shear resistance of the soil nail 1, enabling the expansion soil nail support system to provide greater restraint for the soil 2, reducing the risk of slippage at corresponding parts of the soil 2, and further improving the stability of the soil 2. In addition, based on the above steps, this construction method, especially by utilizing the heating layer 15 to generate heat at a designated location on the outer pipe 14, obtains both the protrusion 121 and the sintered layer 13, thereby further improving the stability of the soil 2. In other words, this construction method achieves a significant improvement in the stability of the soil 2 in a simple way.

[0049] like Figure 3 As shown, in some embodiments, the soil nail 1 includes an outer tube 14, an inner rib 11 located inside the outer tube 14, and the inner rib 11 located at the center of the outer tube 14. For example... Figure 1 As shown, in some embodiments, the expansive soil nailing support system includes multiple soil nails 1 inserted into the soil 2, and the specific number of soil nails 1 can be determined according to requirements.

[0050] In some embodiments, the slurry 4 contains aluminosilicate components, and the aluminosilicate components located on the outwardly expanding surface of the slurry 4 undergo a polymerization reaction under thermal induction to form a sintered layer 13. That is, the sintered layer 13 is formed by the polymerization reaction of the aluminosilicate components in the slurry 4. This sintered layer 13 has high strength and is not easily eroded or damaged, resulting in a longer lifespan for the expandable soil nailing support system, and thus enabling the soil 2 to remain stable for a longer period of time.

[0051] like Figure 2 and Figure 3 As shown, in some embodiments, the heat released by the heating layer 15 acts on the surface of the slurry 4 and also burns the soil 2 at that location, causing the soil particles of the soil 2 to bond together and form a lithification effect, thereby forming a lithification layer 21. That is, the lithification layer 21 is formed by the soil particles in the soil 2 under the induction of heat energy, thus giving the surface of the soil 2 facing the sintering layer 13 a lithification layer 21. This lithification layer 21 has higher hardness and strength than the surrounding ordinary soil. Based on this lithification layer 21, the soil 2 can exert a greater force on the protrusion 121 along the length direction of the soil nail 1. That is, a greater mutual blocking force along the length direction of the soil nail 1 can be formed between the soil 2 and the protrusion 121, improving the pull-out resistance of the soil nail 1 and improving the binding effect on the soil 2, making the soil 2 more stable. In some embodiments, the outwardly expanding slurry 4 exerts a compressive effect on the soil 2, causing the compressed soil particles to aggregate and, combined with thermal energy, form a denser lithified layer 21 with higher hardness and strength. In some embodiments, the outwardly expanding slurry 4 is subjected to a reverse compressive effect from the soil 2, which enhances the strength of the formed sintered layer 13.

[0052] In some embodiments, the concrete 12 includes a first section, a second section, and a third section of concrete distributed sequentially along the length of the inner reinforcement 11. The first section of concrete is closer to the opening of the grouting hole than the third section of concrete, meaning the third section of concrete is located deeper in the soil 2. The stiffness of the first section of concrete is greater than that of the second section, and the stiffness of the second section is greater than that of the third section. In other words, the stiffness of the concrete 12 varies along its length; the section further from the opening has lower stiffness and better elastic deformation capacity. Furthermore, the deeper the concrete 12 is located in the soil 2, the greater the torque generated by the shear force of the soil 2. This reduces the risk of brittle fracture of the concrete 12.

[0053] like Figure 6 As shown, in some embodiments, the grout 4 includes a first grout 41, a second grout 42, and a third grout 43, and the step of injecting the grout 4 into the grouting cavity includes the following steps:

[0054] The third type of grout 43, the second type of grout 42, and the first type of grout 41 are sequentially injected into the grouting cavity through the opening of the grouting hole. After the first type of grout 41 cures, it forms the first section of concrete; after the second type of grout 42 cures, it forms the second section of concrete; and after the third type of grout 43 cures, it forms the third section of concrete. The stiffness of the first section of concrete is greater than that of the second section of concrete, and the stiffness of the second section of concrete is greater than that of the third section of concrete. That is, by injecting different types of grout 4, concrete 12 with a gradient change in stiffness is formed in each section. In some embodiments, the first type of grout 41 is ordinary cement mortar, the third type of grout 43 is ECC material, which is short for engineering cement-based reinforced composite material; the second type of grout 42 is a mixture of cement-based material and ECC material. Thus, the third concrete segment formed by the curing of ECC material has high ductility, and the second concrete segment formed by the curing of the second type of grout 42 will also have a certain degree of ductility. Based on the multi-crack micro-crack characteristics of ECC material, soil nail 1 can overcome the shear force it is subjected to, thereby reducing the risk of brittle fracture of soil nail 1.

[0055] like Figure 2 and Figure 3 As shown, in some embodiments, the expansive soil nailing system further includes magnetic wires 3 located in the soil 2, with the magnetic wires 3 situated outside the concrete 12, and the shape of the magnetic wires 3 adapting to the shape of the concrete 12. Thus, when needed, such as Figure 3 and Figure 8 As shown, the shape of the magnetic line 3 is determined by measuring the current magnetic flux density curve 32, which in turn determines the shape of the concrete 12 located in the soil 2. When the deviation between the current magnetic flux density curve 32 of the magnetic line 3 and the set standard magnetic flux density curve exceeds the set range, it is determined that the concrete 12 has undergone a failure change exceeding the set requirements, and corresponding maintenance measures can be taken. Moreover, this detection method will not cause additional damage to the soil nail 1.

[0056] like Figure 2 and Figure 3 As shown, in some embodiments, the step of inserting the inner reinforcement 11 and the outer tube 14 into the soil 2 includes the following steps:

[0057] An outer tube 14 is provided, and a magnetic wire 3 is wound around the outer wall of the outer tube 14; the outer tube 14 is inserted into the soil 2, and the magnetic wire 3 is inserted into the soil 2 along with the outer tube 14, thereby also realizing the implantation of the magnetic wire 3 into the soil 2.

[0058] During the outward expansion of the slurry 4, the shape of the magnetic wire 3 changes with the shape of the outwardly expanding slurry 4. In some embodiments, the construction method further includes the following steps:

[0059] like Figure 3 , Figure 7and Figure 8 As shown, the magnetizer 5 is used to scan the magnetic line 3 that has been inserted into the soil 2 along with the outer tube 14 to obtain the current magnetic flux density curve 32 of the magnetic line 3; the current magnetic flux density curve 32 is compared with the set standard density curve to determine whether the shape of the outwardly expanding grout 4 meets the set requirements. If it does not meet the set requirements, the grout 4 is injected into the set part of the outer tube 14 until the shape of the outwardly expanding grout 4 meets the set requirements. In this way, after the grout 4 is cured, a protrusion 121 and concrete 12 that meet the set requirements will be formed.

[0060] In some embodiments, the construction method further includes the following steps:

[0061] Insert the hollow detection conduit into the soil 2, and position the hollow detection conduit next to the outer tube 14.

[0062] In some embodiments, the step of scanning the magnetic lines 3 that have been inserted into the soil 2 with the outer tube 14 using the magnetizer 5 includes the following steps:

[0063] The sensor of magnetizer 5 moves along the hollow detection tube while scanning the magnetic lines 3.

[0064] In some embodiments, the magnetizer 5 is a portable magnetizer, and the sensor of the magnetizer 5 is a magnetic sensor, and the magnetic wire 3 is a magnetite nanowire. For example... Figure 3 and Figure 7 As shown, the magnetizer 5 can capture the magnetic field lines 31 radiated by the magnetic lines 3 of the soil nail 1.

[0065] In some embodiments, the expansive soil nailing support system and its construction method are used to reinforce the soil and rock, i.e., the soil 2 is soil and rock; and based on the design of the magnetic wire 3, the morphology of the concrete 12 can be monitored throughout the entire life cycle of the expansive soil nailing support system. The construction method utilizes the physical and chemical coupling expansion effect to enhance the anchoring performance of the expansive soil nailing support system, and non-destructive testing is achieved by analyzing the magnetic induction spectrum of the magnetic nanowire. In addition, the design of the soil nail 1 with a gradient change in stiffness enables it to meet the required strength while having the required deformation capacity.

[0066] In some embodiments, the inner reinforcement 11 is made of steel reinforcement; a thermite reaction layer is coated on a designated portion of the inner wall of the outer tube 14, which constitutes the heating layer 15; and the composition of the thermite reaction layer includes nano-aluminum powder, iron oxide, and silica buffer. During construction, the heating layer 15 undergoes an aluminite reaction, thereby releasing high temperatures, i.e., releasing high heat energy, which can induce the polymerization reaction of the aluminosilicate components in the slurry 4, thereby obtaining the sintered layer 13, and can induce the soil particles of the surrounding soil 2 to produce a lithification effect, thereby obtaining the lithified layer 21. In some embodiments, the outer tube 14 is made of basalt fiber tube.

[0067] like Figure 1 As shown, in some embodiments, the soil 2 is the soil 2 at the slope. Different depths of this soil 2 have different structural characteristics. Based on the structural characteristics of the soil 2 at different depths, the soil 2 can be divided from shallow to deep into surface soil 22, middle soil 23, and deep soil 24. That is, the soil 2 includes surface soil 22, middle soil 23, and deep soil 24 distributed sequentially from shallow to deep. The surface of the surface soil 22 forms the slope surface 25. There is a sliding layer 26 between the surface soil 22 and the middle soil 23, and there is also a sliding layer 26 between the middle soil 23 and the deep soil 24. The sliding layer 26 is mostly soft soil, which has a greater potential risk of sliding, thus easily causing landslides and other similar situations. Figure 2 , Figure 3 and Figure 6 As shown, the expansive soil nailing support system and its construction method are used to reinforce the soil 2. After the outer pipe 14 is inserted into the soil 2, the two spaced heating layers 15 on the inner wall of the outer pipe 14 correspond to the two sliding layers 26 of the soil 2. During the injection of grout 4 into the grouting cavity, static pressure grouting is used, and the third type of grout 43 corresponds to the deep soil 24, the second type of grout 42 corresponds to the middle soil 23, and the first type of grout 41 corresponds to the surface soil 22. The two heating layers 15 undergo an aluminothermic reaction, causing the corresponding two parts of the outer pipe 14 to soften. The second type of grout 42 expands radially outward from the corresponding two parts of the outer pipe 14 based on the static pressure driving action, eventually forming two ellipsoidal protrusions 121. A sintered layer 13 is formed on the surface of each of the two protrusions 121, and a lithified layer 21 is formed at the location corresponding to each sintered layer 13 in the soil 2. Ultimately, the two protrusions 121 correspond to the two sliding layers 26 of the soil 2, respectively. Based on the two protrusions 121, two sintered layers 13, and two lithified layers 21, the risk of sliding of the two sliding layers 26 is reduced, as is the risk of brittle fracture of the soil nail 1. This solves the problems of rapid attenuation of the anchoring force of the soil nail 1 at the sliding layer 26 and easy shearing of the concrete 12 at the sliding layer 26. This construction method improves the anchoring force of the soil nail 1, increasing the pull-out resistance of a single soil nail 1 by 150% compared to conventional soil nails. Furthermore, based on the design of magnetic wires 3, intelligent monitoring is achieved, solving the technical pain point of difficulty in non-destructive testing of the quality of concealed works, and enabling non-contact, non-destructive, and rapid testing of construction quality and subsequent use status. In some embodiments, after the shape of the outwardly expanding grout 4 reaches the set requirements, the first type of grout 41 is injected into the grouting cavity. The stiffness of the soil nail 1 changes in a gradient manner, solving the problem of stress concentration at the sliding layer 26. This expansive soil nailing support system and its construction method are suitable for precise prevention and control of complex soft strata and strata prone to landslides.

[0068] In some embodiments, the construction method includes the following steps:

[0069] Geophysical exploration and drilling methods were used to determine the depth of the sliding layer 26 of the soil 2 at the slope, and the surface soil 22, middle soil 23 and deep soil 24 of the soil 2 at the slope were divided. The initial water content and permeability of the soil 2 at the slope were measured, and the thickness of the aluminothermic reaction layer and the concentration of the second slurry 42 were determined based on the measurement results, thereby completing the site investigation and parameter calibration.

[0070] In some embodiments, the construction method includes the following steps:

[0071] Outer tube processing: Select basalt fiber tubes with a diameter of 80mm-120mm, and coat a 3mm-5mm thick aluminothermic reaction layer on a designated part of the inner wall of the basalt fiber tube.

[0072] Magnetic wire layout: A bidirectional spiral cross-winding process is used to wind magnetite nanowires on the outer wall of the outer tube 14, and a weak magnetic pulse is used to initially activate the magnetic wires 3.

[0073] Inner rib assembly: Insert the inner rib 11 with positioning bracket into the outer tube 14, ensuring the inner rib 11 is centered within the outer tube 14. Seal isolation rings are installed at both ends of the outer tube 14. These sealing isolation rings reduce the amount of heat energy released from the heating layer 15 that diffuses outward from the non-reactive area, thus obtaining a combined rod 6 comprising the outer tube 14, heating layer 15, magnetic wire 3, and inner rib 11. (See...) Figure 4 and Figure 5 As shown.

[0074] In some embodiments, the step of inserting the inner reinforcement 11 and the outer tube 14 into the soil 2 includes the following steps:

[0075] The combined rod 6 is inserted into the soil 2, thereby enabling the inner reinforcement 11 and the outer tube 14 to be inserted into the soil 2 simultaneously, and also enabling the magnetic wire 3 to be implanted into the soil 2 simultaneously.

[0076] In some embodiments, the outer tube processing step, the magnetic wire laying step, and the inner rib assembly step are all completed in advance in the factory, realizing the factory prefabrication of the composite rod 6.

[0077] In some embodiments, the construction method includes the following steps:

[0078] Using a down-the-hole hammer or auger drill, holes are drilled at the designed angle on the slope surface 25 of the soil 2 at the slope to obtain installation holes; prefabricated composite rods 6 are pushed into the installation holes, with hollow inspection guides tied to the sides of the composite rods 6, and the hollow inspection guides are parallel to the outer pipe 14; a third type of grout 43 is injected into the bottom of the grouting cavity, with the grouting pressure controlled at 0.3MPa-0.5MPa, and the third type of grout 43 corresponds to the deep soil 24; a second type of grout 42 is injected into the grouting cavity, the second type of grout 42 containing... It contains 2% potassium nitrate, which can act as an initiator of the aluminothermic reaction and reduce the ignition energy of the aluminothermic reaction layer. The second type of grout 42 corresponds to the central soil 23. The first type of grout 41 is injected into the grouting cavity. The electrical contacts in the aluminothermic reaction layer are connected, and the aluminothermic reaction layer undergoes an oxidation-reduction reaction after being heated, and the aluminothermic reaction layer violently releases heat energy. The part of the outer pipe 14 coated with the aluminothermic reaction layer softens instantaneously when heated, and the second type of grout 42 expands radially outward from this point along the outer pipe 14, squeezing the surrounding soil 2. Under high temperature and pressure, the aluminosilicate components in the outward-expanding slurry undergo a polymerization reaction to form a sintered layer 13, and the sliding layer 26 and the corresponding soil particles are forcibly solidified to form a lithified layer 21. The sensor of the magnetizer 5 is sent into the hollow detection conduit. The sensor moves along the hollow detection conduit and scans the magnetic line 3 at close range, collecting the magnetic field vector data excited by the magnetic line 3 in real time, and obtaining the current magnetic flux density curve 32 of the magnetic line 3. The current magnetic flux density curve 32 is compared with the set standard magnetic flux density curve. If the current magnetic flux density curve 32 shows a significant depression or oscillation relative to the standard magnetic flux density curve at the depth of the corresponding sliding layer 26, it is determined that the shape of the slurry 4 at that point does not meet the set requirements, and this point is a defect reaction zone. The defect reaction zone may have uneven outward expansion of the slurry 4 or damage to the outer tube 14. For the defect reaction zone, ultrafine cement slurry is injected again into the defect reaction zone through the pressure compensation pipe reserved in the combined rod 6 until the detected current magnetic flux density curve 32 meets the set requirements. In addition, a significant dip or oscillation indicates that the amplitude of the current magnetic flux density curve 32 at a specific depth decreases by more than 15% of the preset standard value.

[0079] In addition, the chemical formula for the aluminothermic reaction is as follows:

[0080]

[0081] In some embodiments, the ECC material contains 1.5%-2.5% by weight of polyethylene fiber or polyvinyl alcohol fiber.

[0082] In some embodiments, there is a gradually changing intersoluble zone with a length of 0.5m-1.0m between the third type of grout 43 injected into the grouting cavity and the second type of grout 42. The gradually changing intersoluble zone is formed by the mutual fusion of the second type of grout 42 and the third type of grout 43. After the gradually changing intersoluble zone is cured, it will form concrete 12 with a stiffness that changes continuously along the axial direction of the soil nail 1.

[0083] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An expansive soil nailing system comprising a soil nail, characterized in that, The soil nails include: An inner reinforcement bar is inserted into the soil, and there are grouting holes between the inner reinforcement bar and the soil. Concrete is located in the grouting hole, and the side of the concrete facing the soil has a protrusion; A sintered layer is located on the surface of the protrusion; the sintered layer is formed by the polymerization reaction of the aluminosilicate component in the grout injected through the grouting hole.

2. The expandable soil nailing support system according to claim 1, characterized in that, The surface of the soil facing the sintered layer has a lithified layer, which is formed by soil particles in the soil under thermal induction.

3. The expandable soil nailing support system according to claim 1, characterized in that, The concrete includes a first section of concrete, a second section of concrete, and a third section of concrete distributed sequentially along the length of the inner reinforcement. The first section of concrete is closer to the opening of the grouting hole than the third section of concrete. The stiffness of the first section of concrete is greater than that of the second section of concrete, and the stiffness of the second section of concrete is greater than that of the third section of concrete.

4. The expansive soil nailing support system according to claim 1, characterized in that, The expansive soil nailing support system also includes magnetic lines located in the soil, the magnetic lines being located on the outside of the concrete, and the shape of the magnetic lines being able to change with the shape of the concrete.

5. A construction method for an expansive soil nailing support system as described in claim 1, characterized in that, The construction method includes the following steps: The inner reinforcement and the outer tube are inserted into the soil, with the inner reinforcement located inside the outer tube, and a heating layer is provided at a designated location on the outer tube. Grout is injected into the grouting cavity between the inner reinforcement and the outer tube; the heating layer generates heat energy; the designated part of the outer tube softens under the induction of the heat energy, and the grout corresponding to the designated part of the outer tube expands outward under static pressure, and the surface of the outwardly expanding grout is induced by the heat energy to form the sintered layer. After the injected grout solidifies, it forms the concrete located in the grouting hole, and the outwardly expanding grout solidifies to form the protrusion.

6. The construction method according to claim 5, characterized in that, The concrete includes a first section of concrete, a second section of concrete, and a third section of concrete. The grout includes a first type of grout, a second type of grout, and a third type of grout. The step of injecting the grout into the grouting cavity includes the following steps: The third type of grout, the second type of grout, and the first type of grout are sequentially injected into the grouting cavity through the opening of the grouting hole; After the first type of grout cures, it forms the first section of concrete; after the second type of grout cures, it forms the second section of concrete; and after the third type of grout cures, it forms the third section of concrete. The stiffness of the first section of concrete is greater than that of the second section of concrete, and the stiffness of the second section of concrete is greater than that of the third section of concrete.

7. The construction method according to claim 6, characterized in that, The first type of slurry is ordinary cement mortar, the third type of slurry uses ECC material, and the second type of slurry is a mixture of cement-based material and ECC material.

8. The construction method according to claim 5, characterized in that, The step of inserting the inner reinforcement and outer tube into the soil includes the following steps: An outer tube is provided, and magnetic wire is wound around the outer wall of the outer tube; Insert the outer tube into the soil; During the outward expansion of the slurry, the shape of the magnetic lines changes with the shape of the outwardly expanding slurry. The construction method further includes the following steps: The magnetic lines inserted into the soil along with the outer tube are scanned using a magnetizer to obtain the current magnetic flux density curve of the magnetic lines. The current magnetic flux density curve is compared with the set standard density curve to determine whether the shape of the outwardly expanding slurry meets the set requirements. If the set requirements are not met, slurry is injected into the set part of the outer tube until the shape of the outwardly expanding slurry meets the set requirements.

9. The construction method according to claim 8, characterized in that, The construction method also includes the following steps: Insert the hollow detection conduit into the soil, positioning it beside the outer tube; The step of scanning the magnetic lines that have been inserted into the soil along with the outer tube using a magnetizer includes the following steps: The sensor of the magnetizer moves along the hollow detection conduit while scanning the magnetic lines.

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