Permanent and temporary combined protection system for treating collapsed cavity at top of tunnel

Abstract

The utility model discloses a permanent and temporary combined protection system for treating a cavity with collapsed top of a tunnel, and aims to solve the problems that the cavity with collapsed top is easy to cause safety accidents in tunnel construction, and the traditional treatment method has many limitations. The core of the protection system is a protection air bag, the protection air bag is made of rubber and can be customized according to the actual situation of the collapsed cavity, the collapsed cavity can be filled with the protection air bag in a conformal mode to form temporary supporting after inflation, and permanent supporting can be achieved after concrete is injected in the inflation state. The protective air bag is provided with an inflation inlet, an exhaust port and a tubular exhaust channel and is matched with the valve assembly, the air pressure monitoring device, the grouting pipe and the auxiliary fixing assembly to work cooperatively. During construction, a collapsed cavity is pre-reinforced and scanned to obtain data to manufacture the air bag, and the air bag is converted into permanent support through temporary support after installation. The system can effectively prevent rockfall, guarantees construction safety, adapts to complex collapsed cavities, is low in cost, convenient to construct and short in construction period, has remarkable advantages compared with a traditional method, and provides a more reliable solution for tunnel construction.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, specifically to a permanent-temporary combined protection system for treating collapsed cavities at the top of tunnels. Background Technology

[0002] In the field of tunnel engineering, the tunnel roof often forms collapsed cavities due to changes in geological conditions and disturbance of the surrounding rock during construction. The existence of these cavities may lead to rockfalls, collapses, or even roof falls, causing damage to the tunnel structure and resulting in construction accidents, which seriously threaten the stability of the tunnel and construction safety.

[0003] Currently, traditional methods for treating tunnel collapse cavities generally employ techniques such as concrete backfilling and steel frame support. While these methods can provide temporary or permanent support to some extent, they have certain limitations. Concrete backfilling, due to the high density of concrete or mortar, increases the local bearing capacity of the lining beneath the collapse cavity, easily leading to deformation of the initial tunnel support. Steel frame support, due to the weight of the steel frame itself and the complexity of its installation, easily increases construction difficulty and cost. Furthermore, these methods are difficult to adapt to the irregular internal shape of the collapse cavity, thus failing to effectively prevent subsequent deformation and collapse.

[0004] Despite existing improvements to address the aforementioned issues, current technologies still cannot fully meet the demands for rapid, economical, and effective treatment of collapsed cavities in tunnel construction. Therefore, developing a treatment method capable of adapting to the complex shapes of tunnel collapsed cavities and providing rapid and stable support is of great significance for ensuring tunnel construction safety, improving construction efficiency, and reducing project costs. Utility Model Content

[0005] The purpose of this utility model is to provide a permanent and temporary combined protection system for treating tunnel roof collapses, so as to overcome the limitations of traditional tunnel collapse treatment methods, achieve rapid, economical and effective treatment of tunnel roof collapses, thereby ensuring construction safety, improving construction efficiency, reducing construction costs and ensuring support effect.

[0006] The technical solution adopted in this utility model is as follows:

[0007] This utility model discloses a permanent-temporary combined protection system for treating tunnel roof collapse, including a protective airbag, which is configured to conformally fill the entire space of the tunnel roof collapse after inflation to form temporary support; the protective airbag is also configured to inject concrete into its interior while it is inflated, so that the protective airbag can be converted from temporary support to permanent support.

[0008] In this invention, during tunnel construction, the inflatable protective airbags fit snugly against the entire space of the collapsed cavity, effectively preventing falling rocks from injuring construction personnel and equipment, and ensuring construction safety. After being converted from temporary to permanent support, they can continuously support the collapsed cavity, enhancing the stability of the surrounding rock and ensuring the safe and reliable operation of the tunnel. Compared to traditional treatment methods such as concrete backfilling and steel frame support, the protective airbags of this invention have low manufacturing costs, a simple and convenient construction process, and can quickly complete the support conversion, reducing construction time and lowering labor and equipment rental costs, thereby significantly reducing construction costs. When a collapsed cavity is discovered, excavation can be stopped quickly, and temporary support can be rapidly installed and inflated. After the relevant equipment has passed, it can be efficiently converted to permanent support. The construction process is simple and efficient, greatly improving construction efficiency and accelerating the progress of tunnel construction. Moreover, the protective airbags use a slow inflation and expansion method, causing minimal disturbance to the surrounding rock, maintaining the original state and stability of the surrounding rock, reducing the safety risks caused by construction disturbance, and maintaining the overall stability of the tunnel. In addition, when faced with irregularly shaped collapsed cavities, protective airbags can be filled in a conformal manner, closely fitting the inner walls of various complex shapes, improving the adaptability and effectiveness of the support, and ensuring good support results.

[0009] According to the permanent combined protection system disclosed in this utility model, the protective airbag includes a top part, a bottom part, and a side part that connects the top part and the bottom part and forms a circle on the side. The bottom part is provided with an inflation port and an exhaust port.

[0010] In this invention, the top, bottom, and side portions of the protective airbag work together to form its basic external structure. This structural design ensures that after inflation, the airbag better adapts to the complex shape of the collapsed cavity at the top of the tunnel, achieving conformal filling of the overall space of the collapsed cavity. The inflation port and exhaust port on the bottom portion are key channels for the airbag to inflate and form temporary support, as well as for the subsequent injection of concrete to convert it into permanent support. By controlling the gas inlet and outlet and the concrete injection through these two openings, the protective airbag can play a supporting role at different stages.

[0011] According to the permanent and temporary combined protection system disclosed in this utility model, a tubular exhaust channel is provided inside the protective airbag. One end of the tubular exhaust channel extends into the top of the airbag, and the other end is connected to the exhaust port. The tubular exhaust channel is designed to effectively exhaust air and balance the air pressure inside and outside the airbag during the concrete injection process.

[0012] In this invention, the tubular exhaust channel within the protective airbag plays a crucial role throughout the entire support conversion process. As concrete is injected into the airbag, the internal space is gradually occupied, requiring gas to be released to balance the pressure. One end of this exhaust channel extends into the top of the airbag, effectively guiding the gas accumulated at the top to escape, while the other end connects to the exhaust port, providing a path for the gas to exit. This ensures smooth concrete injection and prevents problems such as airbag deformation or obstructed concrete injection due to pressure imbalance.

[0013] According to the permanent and temporary combined protection system disclosed in this utility model, the main body of the tubular exhaust channel is composed of a water-permeable spring steel pipe, wrapped with a rubber shell, and the rubber shell is connected to the inner wall of the protective airbag.

[0014] In this invention, the tubular exhaust channel is primarily constructed using a permeable spring steel pipe encased in a rubber shell. This material combination design offers multiple advantages. The permeable spring steel pipe ensures the structural strength of the exhaust channel, withstands the internal pressure of the air bladder, and prevents deformation due to excessive pressure during concrete injection, thus ensuring normal exhaust function. The outer rubber shell enhances the connection stability between the exhaust channel and the inner wall of the protective air bladder, while also preventing damage to the inner wall of the air bladder from the permeable spring steel pipe. Furthermore, the sealing properties of the rubber shell contribute to better exhaust and pressure balancing.

[0015] The permanent and temporary combined protection system disclosed in this utility model also includes a valve assembly, which includes an inflation valve and an exhaust valve. The inflation valve and the exhaust valve are respectively installed at the inflation port and the exhaust port of the protective airbag to control the entry and exit of gas in the airbag.

[0016] In this invention, the inflation valve and exhaust valve in the valve assembly are respectively installed at the inflation port and exhaust port of the protective airbag, precisely controlling the entry and exit of gas within the airbag. The inflation valve plays a crucial role in the temporary support stage of tunnel collapse treatment. It connects to the inflation equipment, inflating the airbag to fill the collapsed cavity and providing temporary stable support for tunnel construction. The exhaust valve works in conjunction with the inflation valve when converting from temporary to permanent support. First, the exhaust valve is opened to release air, making room for concrete injection. Simultaneously, during concrete injection, the exhaust valve releases the gas from the airbag, ensuring that concrete smoothly fills the internal space of the airbag, thus achieving the support conversion.

[0017] The permanent and temporary combined protection system disclosed in this utility model also includes an air pressure monitoring device, which is installed at the top inside the protective airbag to monitor the air pressure inside the airbag in real time to ensure the stability of the airbag pressure.

[0018] In this invention, an air pressure monitoring device is installed at the top inside the protective airbag to monitor the internal air pressure in real time, which is a crucial element in ensuring the stable operation of the entire protective system. During airbag inflation and concrete injection, the air pressure constantly changes. Excessively high or low air pressure can affect the support effect of the airbag and even lead to safety issues. The air pressure monitoring device provides real-time feedback on the air pressure inside the airbag, allowing construction personnel to adjust the inflation or concrete injection speed based on this information, ensuring the airbag pressure remains stable within a safe and effective range, thus guaranteeing construction safety and the stability of the support structure.

[0019] According to the permanent-temporary combined protection system disclosed in this utility model, a grouting pipe is also provided. The grouting pipe is set between the outer side of the protective airbag and the inner wall of the collapsed cavity. One end is installed between the outer side of the airbag and the inner wall of the collapsed cavity, and the other end extends to the outside of the collapsed cavity. When the protective airbag is converted from temporary support to permanent support, grout is injected into the gap between the airbag and the inner wall of the collapsed cavity through the grouting pipe to enhance the stability of the support structure.

[0020] In this invention, a grouting pipe is positioned between the outer side of the protective airbag and the inner wall of the collapsed cavity. One end of the pipe is installed between the outer side of the airbag and the inner wall of the collapsed cavity, while the other end extends to the outside of the collapsed cavity, providing crucial protection for enhancing the stability of the support structure. When the protective airbag is converted from temporary support to permanent support, grout is injected through the grouting pipe into the gap between the airbag and the inner wall of the collapsed cavity, filling any voids that may exist between them. This ensures a tight bond between the airbag and the inner wall of the collapsed cavity, forming a unified support structure. This effectively improves the stability of the support structure and further guarantees the safety of tunnel construction and subsequent operation.

[0021] The permanent and temporary combined protection system disclosed in this utility model also includes an auxiliary fixing component. The auxiliary fixing component includes several flexible cables and anchors. One end of the flexible cable is connected to the surface of the protective airbag, and the other end is connected to the anchor installed on the inner wall of the collapsed cavity at the top of the tunnel, so as to make the protective airbag fit tightly against the inner wall of the collapsed cavity and prevent it from shifting or deforming.

[0022] In this invention, the flexible cable and anchor in the auxiliary fixing component work together to stabilize the protective airbag. One end of the flexible cable is connected to the surface of the protective airbag, and the other end is connected to the anchor installed on the inner wall of the collapsed cavity at the top of the tunnel. During the inflation of the airbag to fill the collapsed cavity, the flexible cable can effectively limit the displacement of the airbag, ensuring that the protective airbag fits tightly against the inner wall of the collapsed cavity. This prevents the airbag from shifting or deforming due to external forces during construction, ensuring that the airbag can always provide stable and reliable support for the collapsed cavity, thus improving the reliability and safety of the protection system.

[0023] According to the permanent and temporary combined protection system disclosed in this utility model, the external shape and size of the protective airbag can be customized according to the actual internal conditions of the collapsed cavity at the top of the tunnel in different projects. It is made of rubber and can fit tightly against the inner wall of the collapsed cavity after being inflated.

[0024] In this invention, the external shape and dimensions of the protective airbag can be customized according to the actual internal conditions of the collapsed cavity at the top of the tunnel in different projects, and it is made of rubber, which is a key characteristic that enables it to effectively adapt to the collapsed cavity and play a supporting role. Rubber material has good flexibility and elasticity, and after inflation, it can closely conform to the inner wall of the collapsed cavity, filling the irregular spaces of the cavity and providing uniform support. Customizing the shape and dimensions of the airbag according to the actual shape of the collapsed cavity can further optimize the support effect of the airbag, making the fit between the airbag and the collapsed cavity higher, and enhancing the stability and effectiveness of the support.

[0025] The permanent-temporary combined protection system disclosed in this utility model also includes a shotcrete device for pre-reinforcing the collapsed cavity and a scanning device for acquiring three-dimensional data of the collapsed cavity. The data acquired by the scanning device is used to manufacture a protective airbag adapted to the collapsed cavity.

[0026] In this invention, the shotcrete equipment for pre-reinforcing the collapsed cavity and the scanning equipment for acquiring three-dimensional data of the collapsed cavity are important auxiliary equipment in the entire protective system construction process. After discovering the collapsed cavity, the shotcrete equipment pre-reinforces the surrounding rock inside the cavity to prevent further expansion and create safe conditions for subsequent construction. The scanning equipment acquires three-dimensional data of the collapsed cavity, which is used to manufacture protective airbags adapted to the collapsed cavity, ensuring that the airbags can accurately fit the cavity, improving the support effect of the protective airbags, thereby ensuring tunnel construction safety and improving construction efficiency.

[0027] The beneficial effects of this utility model are as follows:

[0028] 1) Traditional methods are difficult to adapt to the irregular internal shape of collapsed cavities and cannot effectively prevent subsequent deformation and collapse. The protective airbag of this utility model can be customized according to the three-dimensional data of the collapsed cavity. After inflation, it can conformally fill the entire collapsed cavity area, closely fit the inner wall of the collapsed cavity, effectively prevent rocks from falling on the collapsed cavity, and after construction, it can be converted from temporary support to permanent support, ultimately achieving the stability of the surrounding rock in the collapsed cavity area, with better support effect.

[0029] 2) Concrete backfilling increases the local bearing capacity of the lining beneath the collapsed cavity, leading to deformation of the initial tunnel support; the steel frame support is heavy and complex to install, increasing construction difficulty and cost. The airbags of this invention are low-cost to manufacture, easy to inflate, and allow for a simple and rapid construction process. When encountering a collapsed cavity during tunnel excavation, TBM excavation can be quickly stopped, and after simple preparation, the airbags can be installed and inflated to form temporary support. After the TBM passes through, it can be converted into permanent support, significantly shortening the construction period, improving construction efficiency, and reducing construction costs.

[0030] 3) Traditional treatment methods may cause significant disturbance to the surrounding rock during implementation. The airbag of this invention fills the interior of the collapsed cavity by slowly inflating, causing minimal disturbance to the surrounding rock. This ensures the stability of the surrounding rock when the open-face TBM is excavating in the lower part of the collapsed cavity, effectively guaranteeing construction safety and reducing the risk of construction accidents.

[0031] 4) This invention features a grouting pipe pre-installed between the airbag and the inner wall of the collapsed cavity. The internal conditions of the collapsed cavity are complex, and the airbag alone may not be sufficient to completely seal it. Injecting materials such as foamed concrete through the grouting pipe fills the gaps, making the collapsed cavity a unified whole and enhancing the stability of the support structure. Traditional methods lack similar dual safeguards and are insufficiently stable when dealing with complex collapsed cavities.

[0032] The present invention discloses in detail below, with reference to the embodiments shown in the accompanying drawings and the reference numerals, a permanent and temporary combined protection system for treating collapsed cavities at the top of tunnels. Attached Figure Description

[0033] Figure 1 A schematic diagram of the tunnel structure after applying the airbag support method of this utility model;

[0034] Figure 2 for Figure 1 Sectional view of AA.

[0035] Figure Labels

[0036] 1-Collapsed cavity, 2-Open TBM, 3-Protective airbag, 4-Air pressure monitoring device, 5-Inflation valve, 6-Exhaust valve, 7-Grouting pipe, 8-Tube exhaust channel, 9-Water-permeable spring steel pipe. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0038] In the field of tunnel construction, the safety hazards caused by roof collapse have always been a difficult problem in engineering. The permanent and temporary combined protection system for treating roof collapse in tunnels disclosed in this utility model provides an effective solution to this problem.

[0039] like Figure 1 and Figure 2 As shown, this utility model discloses a permanent-temporary combined protection system for treating tunnel roof collapse cavities, including a protective airbag 3, which is configured to conformally fill the overall space of the tunnel roof collapse cavity 1 after inflation to form temporary support; the protective airbag 3 is also configured to inject concrete into its interior in the inflated state of the temporary support, so that the protective airbag 3 can be converted from temporary support to permanent support.

[0040] In this invention, the protective airbag 3 offers significant advantages during tunnel construction. After inflation, it fits tightly against the collapsed cavity 1, preventing falling rocks from injuring personnel and ensuring construction safety. When converted to permanent support, it continuously supports the collapsed cavity 1, enhancing the stability of the surrounding rock and ensuring the safety of tunnel construction and operation. Compared to traditional methods of concrete backfilling and steel frame support, the protective airbag 3 has lower manufacturing costs, is simpler to construct, and can quickly complete the support conversion, reducing construction time and costs. Upon discovery of the collapsed cavity 1, excavation can be quickly stopped, and the airbag can be rapidly installed and inflated to form temporary support, which can then be efficiently converted to permanent support, significantly improving construction efficiency and accelerating tunnel project progress. Simultaneously, the slow inflation of the protective airbag 3 causes minimal disturbance to the surrounding rock, maintaining its stability and reducing safety risks. Furthermore, it can conformally fill irregular collapsed cavities 1, fitting tightly against the inner wall, improving the adaptability and effectiveness of the support and ensuring good support performance.

[0041] like Figure 1 and Figure 2As shown, during tunnel excavation, once a collapsed cavity 1 is discovered at the top of the tunnel, the construction team immediately stops the open-face TBM2 excavation. Subsequently, the team quickly treats the interior of cavity 1, first clearing loose rocks and other debris, and then using shotcrete equipment to seal the surrounding rock. During shotcreting, the concrete mix ratio is precisely adjusted according to the geological conditions of the surrounding rock in cavity 1 to ensure appropriate thickness and strength. The nozzle is always perpendicular to the inner wall of cavity 1, spraying from bottom to top. This not only effectively prevents further expansion of cavity 1 but also creates a stable environment for subsequent operations, ensuring the safe entry of construction personnel and minimizing disturbance to the surrounding rock. Compared to the potentially significant disturbance caused by traditional concrete backfilling, this method is more conducive to maintaining the stability of the surrounding rock, laying a good foundation for subsequent support work.

[0042] After the interior of the collapsed cavity 1 has basically stabilized, the construction personnel set up a 3D laser scanner inside the cavity 1 to perform a comprehensive scan and obtain its 3D structural data. Using this data, a model of the collapsed cavity 1 was created, accurately and intuitively obtaining its shape and dimensions. This operation is crucial, providing key information for the subsequent fabrication of precisely fitted protective airbags 3. This allows the airbags 3 to better conform to the collapsed cavity 1, enhancing the support effect and overcoming the shortcomings of traditional methods that are difficult to adapt to the irregular shape of the collapsed cavity 1.

[0043] like Figure 2 As shown, based on the collapsed cavity 1 model, rubber material was selected to fabricate the protective airbag 3 in the factory. The thickness of the rubber airbag was strictly controlled to 8mm, and its external shape and dimensions were customized strictly according to the actual internal conditions of the collapsed cavity 1. Rubber material is low in cost and the manufacturing process is relatively simple, which greatly reduces the manufacturing cost compared with traditional support methods such as steel frame support. During the fabrication of the protective airbag 3, two openings were set at the bottom of the protective airbag 3, serving as an inflation port and an exhaust port respectively. This design facilitates the control of gas entry and exit within the airbag, enabling rapid inflation to form temporary support, and subsequent injection of concrete to convert it into permanent support. The operation is simple and quick, effectively shortening the construction period.

[0044] like Figure 2 As shown, a long tubular exhaust channel 8 is installed at the top inside the protective airbag 3. The main body of the tubular exhaust channel 8 is a water-permeable spring steel pipe 9 with an inner diameter of 200mm, and is wrapped with a rubber shell, which is firmly connected to the inner wall of the protective airbag 3. This design ensures effective venting and balance of air pressure inside and outside the airbag during concrete injection, preventing the airbag from deforming due to air pressure issues, ensuring smooth support transition, improving the reliability of the support, and avoiding problems that may occur in similar stages with traditional methods, such as concrete injection obstruction or airbag rupture, thereby ensuring construction safety and support effectiveness.

[0045] like Figure 2As shown, the air pressure monitoring device 4 is installed and fixed in the top area inside the airbag 3. A valve assembly consisting of a suitable inflation valve 5 and an exhaust valve 6 is installed at the inflation port and exhaust port of the protective airbag 3, respectively. The air pressure monitoring device 4 monitors the internal air pressure of the airbag in real time, ensuring stable airbag pressure. Construction personnel can adjust the inflation or concrete injection speed based on the air pressure data to avoid safety hazards and ensure construction safety. The valve assembly precisely controls the inflow and outflow of gas inside the airbag, enabling the airbag to quickly reach the appropriate pressure to form stable temporary support, thus improving construction efficiency.

[0046] like Figure 1 and Figure 2 As shown, the pre-fabricated and assembled protective airbag 3 is transported to the tunnel construction site and placed inside the collapsed cavity 1. When placing the protective airbag 3, 3-5 grouting pipes 7 are pre-installed between the top of the protective airbag 3 and the inner wall of the collapsed cavity 1. Before inflating the protective airbag 3, the exhaust valve 6 is closed, and the inflation valve 5 is connected to the inflation equipment for inflation. During inflation, the air pressure inside the airbag is monitored in real time by the air pressure monitoring device 4. Construction personnel adjust the inflation speed according to the air pressure data to ensure inflation to a suitable pressure level. After the protective airbag 3 is inflated to the appropriate level, it is fixed in place using an auxiliary fixing assembly. One end of the flexible cable in the auxiliary fixing assembly is connected to the surface of the protective airbag 3, and the other end is connected to the anchor installed on the inner wall of the collapsed cavity 1 at the top of the tunnel, ensuring that the protective airbag 3 fits tightly against the inner wall of the collapsed cavity 1, preventing displacement or deformation.

[0047] like Figure 1 and Figure 2 As shown, at this time, the gas filled in the protective airbag 3 serves as a temporary treatment device, effectively preventing falling rocks from the upper part of the collapsed cavity 1 and ensuring the stability of the surrounding rock when the open-face TBM2 is excavating under the collapsed cavity 1, thus guaranteeing construction safety. Furthermore, the protective airbag 3 slowly inflates and fills the interior of the collapsed cavity 1, causing minimal disturbance to the surrounding rock and helping to maintain its stability. This offers significant advantages over traditional methods such as concrete backfilling. This completes the temporary construction method for treating tunnel collapses. The entire process is simple to operate, allows for rapid erection of temporary supports, shortens construction time, improves construction efficiency, and reduces construction costs.

[0048] like Figure 2As shown, after the open-type TBM2 smoothly passes through the collapsed cavity area, the protective airbag 3 is converted from a temporary treatment device to a permanent cavity treatment device. Under the monitoring of the air pressure monitoring device 4, the construction personnel open the exhaust valve 6 of the protective airbag 3 to slowly release air, while simultaneously injecting foam concrete into the protective airbag 3 through the inflation valve 5. The foam concrete flows in from the top opening of the tubular exhaust channel 8, flows through the interior of the tubular exhaust channel 8, and stops injecting and closes both valves once the foam concrete can flow out evenly from the exhaust valve 6. During this process, the tubular exhaust channel 8 and the exhaust valve 6 work together to ensure that the gas inside the protective airbag 3 is discharged smoothly, balance the air pressure inside and outside the airbag, and allow the foam concrete to fill the internal space of the airbag evenly, ensuring the smooth conversion to permanent support and improving the support quality.

[0049] like Figure 2 As shown, foamed concrete is then injected into the gap between the protective airbag 3 and the collapsed cavity 1 through the grouting pipe 7 pre-installed at the top. During the grouting process, the bottom outer side of the protective airbag 3 is closely observed, and injection is stopped when foamed concrete is seen seeping out. Grouting through the grouting pipe 7 fills the gap between the protective airbag 3 and the inner wall of the collapsed cavity 1, making the collapsed cavity a whole, enhancing the stability of the support structure, effectively preventing subsequent deformation and collapse of the collapsed cavity 1, and ensuring the safety and reliability of the tunnel structure during construction and subsequent operation. The grouting pipe 7 acts as a double insurance, compensating for the potential lack of airtightness that might exist with only the protective airbag 3, improving the overall support effect, and further ensuring construction safety and the long-term stability of the tunnel.

[0050] Throughout the construction process, the shotcrete equipment used for pre-reinforcing the collapsed cavity 1 and the scanning equipment used to acquire three-dimensional data of the collapsed cavity 1 played crucial roles. The shotcrete equipment pre-reinforced the surrounding rock of the collapsed cavity 1 in the early stages, ensuring construction safety; the data acquired by the scanning equipment provided key support for the fabrication of the suitable protective airbags 3, ensuring that the protection system could effectively cope with collapsed cavities 1 of different shapes. The close coordination of all aspects of this permanent and temporary combined protection system not only ensured construction safety, improved construction efficiency, and reduced construction costs, but also ensured the support effect, achieving effective treatment of the collapsed cavity 1 at the top of the tunnel.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A combined permanent and temporary protection system for treating collapsed cavities at the top of tunnels, characterized in that, The protective airbag (3) is made of rubber material and is configured to conformally fill the entire space of the collapsed cavity (1) at the top of the tunnel after inflation to form a temporary support; the protective airbag (3) is also configured to inject concrete into it in the inflated state of the temporary support so that the protective airbag (3) can be converted from a temporary support to a permanent support. The protective airbag (3) includes a top part, a bottom part, and a side part that connects the top part and the bottom part and forms a circle on the side. The bottom part is provided with an inflation port and an exhaust port. It also includes a valve assembly, which includes an inflation valve (5) and an exhaust valve (6). The inflation valve (5) and the exhaust valve (6) are respectively installed at the inflation port and the exhaust port of the protective airbag (3) to control the gas in and out of the airbag. The protective airbag (3) is provided with a tubular exhaust channel (8). One end of the tubular exhaust channel (8) extends into the top of the airbag, and the other end is connected to the exhaust port. The tubular exhaust channel (8) is configured to exhaust air and balance the air pressure inside and outside the airbag during the concrete injection process. The protective airbag (3) can be inflated through the inflation valve to the inflation port so that the protective airbag can be used as a temporary treatment device; the protective airbag can also be injected with foam concrete through the inflation valve and the inflation port, and when the foam concrete flows out evenly from the exhaust valve through the tubular exhaust channel, the injection of foam concrete is stopped and the inflation valve and exhaust valve are closed so that the protective airbag can be converted from a temporary treatment device into a permanent landslide treatment device.

2. The permanent-temporary combined protection system according to claim 1, characterized in that, The tubular exhaust channel (8) is mainly composed of a water-permeable spring steel pipe (9) and wrapped with a rubber shell. The rubber shell is connected to the inner wall of the protective airbag (3).

3. The permanent-temporary combined protection system according to claim 2, characterized in that, It also includes an air pressure monitoring device (4), which is installed on the top of the protective airbag (3) to monitor the air pressure inside the airbag in real time to ensure that the airbag pressure is stable.

4. The permanent-temporary combined protection system according to claim 3, characterized in that, A grouting pipe (7) is also provided. The grouting pipe (7) is set between the outer side of the protective airbag (3) and the inner wall of the collapsed cavity (1). One end is installed between the outer side of the protective airbag (3) and the inner wall of the collapsed cavity (1), and the other end extends to the outside of the collapsed cavity (1). When the protective airbag (3) is converted from temporary support to permanent support, grout is injected into the gap between the airbag and the inner wall of the collapsed cavity (1) through the grouting pipe (7) to enhance the stability of the support structure.

5. The permanent-temporary combined protection system according to claim 4, characterized in that, It also includes an auxiliary fixing component, which includes several flexible cables and anchors. One end of the flexible cable is connected to the surface of the protective airbag (3), and the other end is connected to the anchor installed on the inner wall of the collapsed cavity (1) at the top of the tunnel, so as to make the protective airbag (3) fit tightly against the inner wall of the collapsed cavity (1) and prevent it from shifting or deforming.

6. The permanent-temporary combined protection system according to any one of claims 1-5, characterized in that, The external shape and size of the protective airbag (3) can be customized according to the actual internal conditions of the collapsed cavity (1) at the top of the tunnel in different projects. It is made of rubber and can fit tightly against the inner wall of the collapsed cavity (1) after being inflated.

7. The permanent-temporary combined protection system according to claim 6, characterized in that, It also includes a shotcrete equipment for pre-reinforcing the collapsed cavity (1) and a scanning device for acquiring three-dimensional data of the collapsed cavity (1), the data acquired by the scanning device being used to make a protective airbag (3) adapted to the collapsed cavity (1).

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