A goaf roadway inflation model and a roadway construction method

Abstract

This invention discloses an inflatable model for a goaf roadway and a roadway construction method. The inflatable model includes: an airbag with an arched roadway shape; grouting pipes, including a main pipe and several branch pipes, with the main pipe positioned along the circumference of the arch of the airbag; several branch pipes arranged sequentially along the axial direction of the main pipe, located at the arch top of the airbag, and detachably connected to the main pipe; the branch pipes are rigid pipes, with several staggered grouting holes on their sidewalls, and plugged with plug rods; several groups of grouting pipes are arranged sequentially along the axial direction of the airbag. The roadway construction method includes the following steps: placing the inflatable model in the goaf and inflating it; pouring mortar to cover the inflatable model; injecting cement grout into the grouting pipes to push open the plug rods, with the cement grout flowing through the grouting holes into the mortar voids; and removing the airbag. This invention has the advantages of rapid construction and stable roadway formation.

Description

Technical Field

[0001] This application relates to the field of goaf tunneling technology, specifically to an air-filled goaf tunneling model and a tunneling construction method. Background Technology

[0002] After the working face is mined out, the goaf needs to be filled with backfill materials such as tailings, and roadways need to be rationally arranged within the goaf. How to safely and economically construct roadways has become one of the most critical technical challenges in the mining industry. Currently, three main construction methods are used both domestically and internationally:

[0003] The first method is to excavate a roadway in the backfill after the goaf is filled. Its advantage lies in the mature design, mining and support construction technology, but it has obvious defects: (1) Excavating a roadway in the artificial pillar of the tailings cemented backfill will damage the cemented pillar and affect its stability and integrity; (2) The roadway construction and maintenance costs are relatively high; (3) The construction period is relatively long.

[0004] The second method involves reserving the location of a roadway using a roadway model within the goaf before backfilling, followed by tailings cementing backfilling. After backfilling is completed, the roadway model is removed to form the backfilled roadway. Although this technology overcomes some of the shortcomings of traditional roadway excavation techniques, its disadvantages are prominent: (1) The construction risk is extremely high when reserving roadway space within the goaf, especially in metal mines. (2) The maintenance technology for the reserved space during backfilling is complex and costly, and the final shape and size of the roadway are difficult to meet the mining design requirements.

[0005] The third method involves injecting gas into the roadway model in stages—bottom, middle, and top—during the tailings backfilling process to form a complete roadway. While this technique addresses some of the problems of the first two methods by combining backfilling processes, it has the following shortcomings: (1) The timing of the staged gas injection depends on the precise matching of the solidification time and strength of the backfill slurry, and is greatly affected by environmental factors such as temperature and humidity; (2) The connection between demolding and support processes is demanding, and in high-altitude goaf areas, if the curing strength of the backfill is insufficient, there may be safety hazards such as surrounding rock collapse. Summary of the Invention

[0006] Therefore, it is necessary to provide an air-filled model for goaf roadways and a roadway construction method to solve the problems of complex and cumbersome construction process and insufficient roadway strength leading to easy collapse in existing goaf roadway construction methods.

[0007] To achieve the above objectives, the inventors provide an air-filled model for goaf roadways, comprising:

[0008] An airbag, the outer contour of which is an arched alleyway;

[0009] The grouting pipeline includes a main pipeline and several branch pipelines. The main pipeline is located at the airbag along the arched circumference. Several branch pipelines are arranged sequentially along the axial direction of the main pipeline and are located at the arched top of the airbag, and are detachably connected to the main pipeline. The branch pipelines are rigid pipes, and several staggered grouting holes are opened on the side walls of the branch pipelines, and the grouting holes are plugged with plug rods. Several groups of grouting pipelines are provided, and several groups of grouting pipelines are arranged sequentially along the axial direction of the airbag.

[0010] In some embodiments, the branch pipes of adjacent grouting pipes are staggered.

[0011] In some embodiments, the spacing between adjacent grouting pipes is 1m-1.5m.

[0012] In some embodiments, the main pipe and branch pipe are detachably connected by a snap-fit ​​structure or clamp.

[0013] In some embodiments, the grouting pipe has 3 to 5 branch pipes.

[0014] In some embodiments, the length of the plug rod is 30cm-50cm.

[0015] Unlike existing technologies, the inflatable goaf tunnel model described in the above technical solution features an arched tunnel shape for its airbags, making it a one-piece tunnel model. Inflating the airbags and placing them within the goaf directly creates a complete tunnel space in one step. This allows for filling and reinforcing of the entire filling area between the airbags and the goaf. After the filling solidifies, the airbags are deflated and removed. The location where the airbags were placed forms the tunnel. This eliminates the need for step-by-step model assembly, simplifying the entire installation process. Simple and quick; by setting up grouting pipes, cement grout can be injected into the grouting pipes to reinforce the filling body. The injected cement grout pushes open the plug rod, and the cement grout flows out of the grouting hole into the gap of the filling body and covers the plug rod. The cement grout and the plug rod together form a support body to reinforce the filling body. Each set of grouting pipes has multiple grouting holes in an interlaced manner, and there are also multiple sets of grouting pipes, so that a root-like support body can be formed in the filling body, which greatly enhances the strength of the filling body and ensures that the filling body is stable enough.

[0016] The inventors also provide a method for constructing tunnels, comprising the following steps:

[0017] Placement Model: Place the goaf roadway inflatable model in the goaf, wherein the goaf roadway inflatable model is any of the above-mentioned goaf roadway inflatable models, and inflate the airbag until it is full;

[0018] Grouting of the filling area: Grout is poured into the filling area between the goaf and the air-filled model of the goaf roadway until it covers the air-filled model of the goaf roadway to form a filling body;

[0019] Reinforcement of the filling body: When the mortar at the arch of the airbag has initially set to the first preset strength, cement grout is injected into the grouting pipe. The cement grout pushes open the plug rod, and the grouting hole is opened. The cement grout is injected into the voids of the mortar through the grouting hole. The cement and the plug rod together form a support body. The first preset strength is the strength of the mortar in a flowable state.

[0020] De-inflate the airbag: Once the mortar and cement grout have completely solidified, detach the branch pipe from the main pipe and remove the main pipe and the deflated airbag.

[0021] In some embodiments, in the step of "Place Model", the airbag is first filled with water to a preset height before inflating the airbag.

[0022] In some embodiments, in the step of "grouting the filling area", the mortar is a mixture of sand and cement, and the ratio of cement to mortar is 1:6.

[0023] In some embodiments, in the step of “filling area grouting”, the mortar is poured in layers at a height below the dome of the airbag.

[0024] Unlike existing technologies, the tunnel construction method described in the above technical solution, in the step of model placement, uses the aforementioned inflatable tunnel model for goaf tunnel construction. The airbags are arched, forming a single, integrated tunnel model. Inflating the airbags and placing them within the goaf directly creates a complete tunnel space in one step, making the entire model placement process simple and quick. In the step of reinforcing the filling body, since the filling body is still in a flowing state, cement grout is injected through the grouting pipe to open the plug rod. Cement grout flows out of the open grouting holes, reaching the gaps in the filling body and covering the plug rod. This allows the cement grout and plug rods to work together within the filling material to form a reinforced support structure. This support structure intertwines like tree roots within the filling material. Furthermore, the injected material is pure cement grout, which, upon solidification, has a higher hardness than mortar. The branch pipes are rigid pipes, providing sufficient support and greatly enhancing the strength of the filling material, ensuring its stability. In the step of unloading the airbag, because the airbag is an integrated structure, deflation and dismantling of the branch pipes complete the demolding process. This makes demolding simple and quick, shortening the construction period by 30%-40%, and the airbag can be reused.

[0025] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0026] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this application and other related content, and should not be considered as limitations on this application.

[0027] In the accompanying drawings of the instruction manual:

[0028] Figure 1 This is a structural diagram of the air-filled model for the goaf roadway described in the specific implementation method;

[0029] Figure 2 This is a front view of the air-filled model of the goaf roadway described in the specific implementation method;

[0030] Figure 3 This is a structural diagram of the branch pipe described in the specific implementation method;

[0031] Figure 4 This is a connection structure diagram of the main pipeline and branch pipelines described in the specific implementation method;

[0032] Figure 5 A flowchart illustrating the tunnel construction method described in the specific implementation method;

[0033] The reference numerals used in the above figures are explained as follows:

[0034] 1. Airbag;

[0035] 2. Main pipeline;

[0036] 3. Branch pipes;

[0037] 300. Grouting hole;

[0038] 301. Blocking rod;

[0039] 4. Main pipeline;

[0040] 5. Clamps;

[0041] X, the arched circumferential shape of the airbag;

[0042] Y represents the axial direction of the airbag. Detailed Implementation

[0043] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0044] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0045] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0046] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0047] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0048] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0049] As understood in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0050] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0051] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0052] After the working face is mined, it is necessary to use tailings and other filling materials to fill the goaf and arrange roadways reasonably inside the goaf. How to form roadways safely and economically has become one of the key technical problems in the mining industry. At present, there is an air-filled model, which is formed by injecting air into the roadway model in sections at the bottom, middle and top of the arch to fill and construct a complete roadway. This technology has the following shortcomings: (1) The timing of step-by-step air injection depends on the precise matching of the solidification time and strength of the filling slurry, and is greatly affected by environmental factors such as temperature and humidity; (2) The connection between demolding and support processes is high. In high goaf areas, if the curing strength of the filling body is insufficient, there may be safety hazards such as the collapse of the surrounding rock.

[0053] Therefore, the present invention provides an air-filled model for goaf roadways, which is used to assist in the construction of roadways in goaf areas. It is an integrated air-filled model, and the construction process of installing and dismantling the model is simple and quick. The construction process of grouting in the filling area is also easy to control. It can construct a filling body with support structure, and the constructed filling body is sufficiently stable.

[0054] Please see Figure 1 In a specific embodiment, the air-filled model of the goaf roadway includes an airbag 1 and grouting pipes. The outer contour of the airbag 1 is arched like a roadway. The grouting pipes include a main pipe 2 and several branch pipes 3. Please refer to [link to relevant documentation]. Figure 2The main pipe 2 is located at the airbag 1 along the arched circumferential direction X; several branch pipes 3 are sequentially arranged along the axial direction of the main pipe 2, located at the arched top of the airbag 1, and are detachably connected to the main pipe 2; please refer to Figure 3 The branch pipe 3 is a rigid pipe, and its side wall has several staggered grouting holes 300, each grouting hole 300 being plugged with a plug rod 301; the grouting pipes are arranged in several groups, and these groups are sequentially arranged along the axial direction Y of the airbag; please refer to Figure 2 The circumferential X-shape of the airbag is the direction in which the airbag bends along the arch. Please refer to [link / reference]. Figure 1 The axial direction Y of the airbag is the depth direction of the formed tunnel.

[0055] The inflatable goaf tunnel model has an airbag 1 that is an arched tunnel shape, forming a one-piece tunnel model. Inflating the airbag 1 and placing it within the goaf directly creates a complete tunnel space in one step. At this point, the entire filling area between the airbag 1 and the goaf can be filled, and the filling material can be reinforced. After the filling area solidifies, the airbag 1 can be deflated and removed. The location where the airbag 1 was placed forms the tunnel. No step-by-step assembly of the model is required; the entire installation process is simple and quick. Grouting pipes are also included. The grouting pipe can be used to inject cement grout into the filling body to reinforce it. The injected cement grout will push open the plug rod 301, and the cement grout will flow out of the grouting hole 300 into the gap of the filling body and cover the plug rod 301. The cement grout and the plug rod 301 together form a support body to reinforce the filling body. Each set of grouting pipes has multiple grouting holes 300, and there are also multiple sets of grouting pipes. This can form a root-like support body in the filling body, which greatly enhances the strength of the filling body and ensures that the filling body is stable enough.

[0056] Please see Figure 1 In some embodiments, a main pipe 4 is also included, and the main pipes 2 of several groups of grouting pipes are all connected to the main pipe 4. This arrangement allows the construction worker to inject cement grout into all grouting pipes simultaneously through the main pipe 4, making the grouting process convenient and quick.

[0057] In some embodiments, the branch pipes 3 of adjacent grouting pipes are staggered, such that all branch pipes 3 are staggered, and the injected cement grout extends in multiple different directions within the filling body, reinforcing the filling body from multiple directions and angles, thereby reinforcing the filling body to a greater extent.

[0058] In some embodiments, the spacing between adjacent grouting pipes is 1m-1.5m, such as 1m or 1.5m. This arrangement can avoid mutual interference between the branch pipes 3 and can form support structures in various areas of the filling body as much as possible, thus ensuring the strength of the filling body.

[0059] In some embodiments, the grouting pipe is provided with 3 to 5 branch pipes 3, such as 3, 4 or 5, and each branch pipe 3 is set with an equal arc distance. This arrangement can avoid mutual interference between the branch pipes 3 and can form a support body at various angles in the filling body as much as possible, thus ensuring the strength of the filling body.

[0060] In some embodiments, the length of the plug rod 301 is 30cm-50cm, such as 30cm, 40cm, or 50cm. This arrangement can form a support body with a thickness of at least 30cm in the filling body, which is sufficient to reinforce the filling body. In addition, it is preferable to use a 30cm plug rod 301. This arrangement can form a support body in the filling body that is sufficient to reinforce the filling body, and can also save grouting costs.

[0061] In some embodiments, the plug rod 301 is an anchor rod, which is made of steel and forms a steel support body in the filling body. It has sufficient rigidity and strength, and its tensile strength is higher than that of the filling body. The anchor rod can also be in close contact with the filling body to form frictional (or adhesive) resistance.

[0062] Since the pressure of the filling material on the airbag 1 is mainly concentrated at the dome of the airbag 1, the branch pipe 3 is mainly located at the dome of the airbag 1, and the grouting-formed support mainly supports the filling material above the dome of the airbag 1. In some embodiments, the main pipe 2 also extends to the side of the airbag 1, and the portion of the main pipe 2 located on the side of the airbag 1 can also be connected to the branch pipe 3, allowing grouting to be injected on the side of the airbag 1 to form a support, thus supporting the filling material located on the side of the airbag 1.

[0063] In some embodiments, the main pipe 2 and the branch pipe 3 are detachably connected by a snap-fit ​​structure or clamp 5. This arrangement allows the branch pipe 3 to be removed from the main pipe 2 after the pouring is completed, so that the branch pipe 3 and the main pipe 2 are separated. The branch pipe 3 remains in the filling body as a support to reinforce the filling body, and the airbag 1 and the main pipe 2 can be reused next time.

[0064] In some embodiments, the snap-fit ​​structure includes an installation hole opened at the main pipe 2, and the outer diameter of the branch pipe 3 is adapted to the diameter of the installation hole so that the branch pipe 3 can be directly snapped into the installation hole without cement slurry leakage, and can be pulled out directly by force when disassembly is required.

[0065] Please see Figure 4 In some embodiments, the main pipe 2 is provided with a protruding connecting pipe, and the branch pipe 3 is sleeved on the connecting pipe and fixed by a clamp 5. After the filling area solidifies, the clamp 5 can be pried open to separate the branch pipe 3 from the main pipe 2.

[0066] In some embodiments, the airbag 1 is made of rubber or nylon, which has sufficient strength to temporarily support the filling body, and is wear-resistant, has a long service life, and is not easily damaged.

[0067] In some embodiments, the bottom of the airbag 1 is provided with a buckle, which is fixed to the ground by ground nails, so that the airbag 1 can remain stationary.

[0068] In some embodiments, a monitoring mechanism is also included, which includes a pressure sensor and a strength tester. The pressure sensor is located at the grouting pipe and the air bladder 1 and is used to monitor the grouting pressure and the pressure of the filling material on the air bladder 1. The strength tester is used to test the degree of solidification of the mortar poured into the filling area and to provide a basis for judging the timing of injecting cement slurry into the grouting pipe.

[0069] Please see Figure 5 The present invention also provides a method for constructing a tunnel, comprising the following steps:

[0070] S501 Placement Model: Place the goaf roadway inflatable model in the goaf area, wherein the goaf roadway inflatable model is any one of the above-mentioned goaf roadway inflatable models, and inflate the airbag 1 until it is full.

[0071] S502 Grouting of the filling area: Grout is poured into the filling area between the goaf and the air-filled model of the goaf roadway until it covers the air-filled model of the goaf roadway to form a filling body.

[0072] S503 Reinforced Filling Body: When the mortar at the arch of airbag 1 initially sets to the first preset strength, cement grout is injected into the grouting pipe. The cement grout pushes open the plug rod 301, and the grouting hole 300 is opened. The cement grout is injected into the voids of the mortar through the grouting hole 300. The cement and the plug rod 301 together form a support body; the first preset strength is the strength of the mortar in a flowable state;

[0073] S504 De-inflate airbag 1: When the mortar and cement grout have completely solidified, remove the branch pipe 3 from the main pipe 2, and remove the main pipe 2 and the deflated airbag 1.

[0074] In the model placement process, since the above-mentioned goaf roadway inflatable model is used to construct the roadway, the airbag 1 is an arched roadway shape as a whole, which is an integrated roadway model. By inflating the airbag 1 and placing it in the goaf, the complete roadway space is reserved directly at once, and the entire model placement process is simple and quick.

[0075] In the grouting process of the filling area, the grouting of the filling area can greatly reduce the pouring cost. By reinforcing the filling body in the process, the strength of the entire filling body can be guaranteed. This reduces the pouring cost and ensures the strength of the filling body.

[0076] In the reinforcement of the filling body, since the filling body is still in a flowing state, cement grout is injected through the grouting pipe to push open the plug rod 301. The cement grout flows out of the grouting hole 300 and can flow into the gaps of the filling body and cover the plug rod 301. This allows the cement grout and the plug rod 301 to jointly form a support for the reinforcement of the filling body. The support is intertwined in the filling body like tree roots. In addition, the injected cement grout has a stronger hardness than mortar after solidification. The branch pipe 3 is a rigid pipe, which also provides sufficient support, greatly enhancing the strength of the filling body and ensuring that the filling body is sufficiently stable.

[0077] In step 1, since airbag 1 is an integral structure, the demolding process can be completed by deflating the airbag and disassembling the branch pipe 3. The demolding process is simple and quick, shortening the construction period by 30%-40%, and it can also be reused.

[0078] In some embodiments, in the step of "placing the model", before inflating the airbag 1, water is first added to the airbag 1 to a preset height. The preset height can be two-thirds of the height of the airbag 1. This construction method can prevent the airbag 1 from floating during the subsequent mortar pouring process. By injecting water, the weight of the entire airbag 1 can be temporarily increased to ensure that the airbag 1 remains in place and does not affect the construction of the tunnel.

[0079] In some embodiments, in the step of "grouting the filling area", the mortar is poured in layers at a height below the arch of the airbag 1. This construction can accelerate the solidification speed of the part of the filling body located below the arch of the airbag 1, and also make the part of the filling body located below the arch of the airbag 1 have stronger strength, so that there is no need to pour additional support.

[0080] In some embodiments, in the step of "grouting the filling area", the mortar is a mixture of sand and cement, and the ratio of cement to mortar is 1:6. This ratio can greatly reduce the pouring cost. By reinforcing the filling body through this step, the strength of the entire filling body can be guaranteed. This means that the pouring cost is reduced while the strength of the filling body is guaranteed.

[0081] In some embodiments, in the step of "reinforcing the filler", the cement slurry is given an accelerator. By adding the accelerator, the setting speed of the cement slurry can be accelerated from 14 days to only 3 days, which greatly improves the construction efficiency.

[0082] In some embodiments, in the step of "reinforcing the filler", the first preset strength is 20%, at which time the filler is in a semi-solid, flowing state, and the cement slurry can be squeezed into the various gaps of the filler and intersect with the filler.

[0083] In some embodiments, during the grouting of the filling area, the mortar is poured at least one meter above the air-filled model of the goaf roadway.

[0084] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. An air-filled model for a goaf roadway, characterized in that, include: An airbag, the outer contour of which is an arched alleyway; The grouting pipeline includes a main pipeline and several branch pipelines. The main pipeline is located at the airbag along the arched circumference. Several branch pipelines are arranged sequentially along the axial direction of the main pipeline and are located at the arched top of the airbag, and are detachably connected to the main pipeline. The branch pipelines are rigid pipes, and several staggered grouting holes are opened on the side walls of the branch pipelines, and the grouting holes are plugged with plug rods. Several groups of grouting pipelines are provided, and several groups of grouting pipelines are arranged sequentially along the axial direction of the airbag.

2. The air-filled model for goaf roadways according to claim 1, characterized in that, The branch pipes of adjacent grouting pipes are staggered.

3. The air-filled model for goaf roadways according to claim 1, characterized in that, The spacing between adjacent grouting pipes is 1m-1.5m.

4. The air-filled model for goaf roadways according to claim 1, characterized in that, The main pipeline and branch pipelines are detachably connected by a snap-fit ​​structure or clamp.

5. The air-filled model for goaf roadways according to claim 1, characterized in that, The grouting pipeline has 3 to 5 branch pipelines.

6. The air-filled model for goaf roadways according to claim 1, characterized in that, The length of the plug rod is 30cm-50cm.

7. A method for constructing a tunnel, characterized in that, Includes the following steps: Placement Model: Place the goaf roadway inflatable model in the goaf, wherein the goaf roadway inflatable model is the goaf roadway inflatable model according to any one of claims 1-6, and inflate the airbag until it is full; Grouting of the filling area: Grout is poured into the filling area between the goaf and the air-filled model of the goaf roadway until it covers the air-filled model of the goaf roadway to form a filling body; Reinforcement of the filling body: When the mortar at the arch of the airbag has initially set to the first preset strength, cement grout is injected into the grouting pipe. The cement grout pushes open the plug rod, and the grouting hole is opened. The cement grout is injected into the voids of the mortar through the grouting hole. The cement and the plug rod together form a support body. The first preset strength is the strength of the mortar in a flowable state. De-inflate the airbag: Once the mortar and cement grout have completely solidified, detach the branch pipe from the main pipe and remove the main pipe and the deflated airbag.

8. The tunnel construction method according to claim 7, characterized in that, In the step "Place Model", before inflating the airbag, fill the airbag with water to the preset height.

9. The tunnel construction method according to claim 7, characterized in that, In the step of "grouting the filling area", the mortar is a mixture of sand and cement, and the ratio of cement to mortar is 1:

6.

10. The tunnel construction method according to claim 7, characterized in that, In the step "filling area grouting", the mortar is poured in layers at a height below the dome of the airbag.

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