Disposal unit and construction method suitable for tunnel vault collapse cavity of TBM (Tunnel Boring Machine)

Abstract

The invention discloses a disposal unit and a construction method suitable for a tunnel vault collapse cavity of a TBM (tunnel boring machine), and belongs to the technical field of underground engineering tunnel construction.The disposal unit comprises six types of assembly air bags, namely an I-type air bag, an II-type air bag, an III-type air bag, an IV-type air bag, a V-type air bag and a VI-type air bag; the six air bags are connected through air valve connectors and air valve connectors, the front side and the rear side of the I-type air bag are respectively provided with an air valve connector and an inflation inlet, and the front side and the rear side of the VI-type air bag are respectively provided with an electromagnetic controllable exhaust valve and an air valve connector. By adopting the disposal unit with the structure and cooperating with a corresponding construction method, the safe state of tunnel construction can be quickly recovered, the construction process is accelerated, and permanent support for ensuring the safety of the tunnel operation process can be formed through later retreatment.

Description

Technical Field

[0001] The present invention relates to the technical field of underground engineering tunnel construction, and in particular to a disposal unit and a construction method suitable for a TBM tunnel vault collapse cavity. Background Art

[0002] With the development of urbanization and the increasing demand for infrastructure construction, the development of tunnels and underground spaces is increasing. However, during the tunnel excavation process, due to the complex and changeable geological conditions, such as unstable rock formations and abundant groundwater, the tunnel surrounding rock instability problem is often encountered, resulting in the collapse of the top of the tunnel during the construction process. The collapse of the unstable cavity and the large rockfall pose a great safety threat to the tunnel under construction and operation.

[0003] Regarding the treatment method of tunnel vault collapse cavity, the filling of inflatable airbags stands out due to its low production cost. However, the airbags used for filling tunnel vault collapse cavity in the existing inventions can be divided into two types: complete airbags that fill the entire cavity and beaded airbags that are manufactured in the form of small components and can be arranged and stacked.

[0004] The first method: using a complete airbag for pre-support, and then grouting the bottom of the working entrance, grouting the space between the airbag and the inner wall of the collapsed cavity, and grouting the cavity filled inside the airbag, and filling the collapsed cavity with foam concrete, as shown in the invention patent "A method for treating collapsed tunnels with airbag grouting" with announcement number CN117780392B. The disadvantage of this method is that the grouting process is too complicated, and the foam concrete has a certain strength growth period after grouting. However, this method cannot grout different areas at the same time, so grouting construction is required in different areas, which greatly prolongs the construction process.

[0005] The second method is to stack and fill air bags in the form of small components that can be connected to each other in the form of beads, and then fill them with air to squeeze the surrounding rock of the collapsed cavity, so as to avoid the collapse of the collapsed cavity and the unstable falling of the arch, such as the invention patent with announcement number CN110847935B "A rapid construction method for tunnels passing through large karst cave cavities". The defect of this method is that it only relies on the pressure of air bags to squeeze the surrounding rock for support. During the long-term operation of the tunnel, there may be a risk of air leakage and deflation of the air bags, and it cannot be used as a permanent support form. Therefore, there is an urgent need for a method for handling the collapsed cavity of the tunnel vault that can not only temporarily support the collapsed cavity to ensure the rapid restoration of the safe state of tunnel construction and speed up the construction process, but also form a permanent support to ensure the safety of the tunnel operation process through later reprocessing. Summary of the invention

[0006] The purpose of the present invention is to provide a disposal unit and construction method suitable for TBM tunnel vault collapse cavity, support the collapse cavity to provide temporary support, improve the stability of the tunnel collapse cavity, avoid secondary collapse, and ensure the rapid restoration of the safe construction environment of the tunnel below the collapse cavity. At the same time, it can be reprocessed later to become a permanent support, ensuring the safety of the lining structure of the tunnel vault below, and providing protection for the safe and stable operation of the tunnel in the later stage.

[0007] To achieve the above-mentioned purpose, the present invention provides a disposal unit and construction method suitable for a TBM tunnel vault collapse cavity, comprising six types of assembled airbags, the six types of assembled airbags being respectively Type I airbags, Type II airbags, Type III airbags, Type IV airbags, Type V airbags and Type VI airbags, the six types of airbags being connected by air valve connectors and air valve interfaces, the Type I airbag being provided with an air valve connector and an inflation port on the front and rear sides respectively, the Type VI airbag being provided with an electromagnetically controllable exhaust valve and an air valve interface on the front and rear sides respectively.

[0008] Preferably, a valve connector and a valve interface are respectively provided on the front and rear sides of the Type II airbag; a valve connector is provided on the front side of the Type III airbag, and an valve interface is provided on the left side; a valve connector is provided on the top side of the Type IV airbag, and an valve interface is provided on the front side; a valve connector is provided on the front side of the Type V airbag, and an valve interface is provided on the bottom side.

[0009] Preferably, the standard dimensions of the assembled airbag are 500mm in length, 500mm in width, 250mm in height, and 5mm in wall thickness. The material of the assembled airbag is rubber. The air valve interface includes an air valve interface shell, and several sealing rings, movable rubber gaskets and fixed rubber gaskets arranged inside the air valve interface shell. A thread is arranged on the inner side of one end of the air valve interface shell, and a sealing ring, a movable rubber gasket, a sealing ring, a fixed rubber gasket, and a sealing ring are arranged in sequence from the thread to the inner side of the other end of the air valve interface shell.

[0010] Preferably, the air valve joint includes an air valve joint shell, a rotatable threaded sleeve, and a check valve head, a check valve spring, and a spring fixing ring arranged inside the air valve joint shell. The rotatable threaded sleeve is arranged on the outside of one side of the air valve joint shell, and the outside of the spiral threaded sleeve is provided with a thread matching the thread on the inner side of the air valve interface shell. The spring fixing ring, the check valve spring, the spring fixing ring, and the check valve head are arranged in sequence from the inside of one side of the air valve joint shell on which the rotatable threaded sleeve is arranged toward the inside of the other side of the air valve joint shell.

[0011] Preferably, an exhaust valve spring, a movable valve stem, a magnetic pole, a coil core, and a power supply and switch control cabin are sequentially arranged on one side of the interior of the electromagnetically controlled exhaust valve and on the other side of the interior of the electromagnetically controlled exhaust valve. An air inlet is arranged at the bottom end of the electromagnetically controlled exhaust valve, and an exhaust hole is arranged at the top end of the electromagnetically controlled exhaust valve. The air inlet and the exhaust holes are connected to the interior of the electromagnetically controlled exhaust valve.

[0012] The present invention also provides a construction method applicable to a TBM tunnel vault collapse cavity, using the above-mentioned treatment unit applicable to a TBM tunnel vault collapse cavity, comprising the following steps:

[0013] S1, enter from the working entrance, clean the collapsed cavity and support and reinforce the large unstable rock and soil with high risk of collapse;

[0014] S2, scanning the collapsed cavity by a three-dimensional laser scanner to determine the volume of the collapsed cavity, and estimating the required number of assembled airbags and the arrangement and connection methods of various types of airbags to obtain an estimated result;

[0015] S3, using the estimated results to conduct trial assembly and trial charging operations in an open space, and then using a 3D laser scanner to scan the results after the trial assembly to determine the accuracy of the estimated results and the ideal installation and connection sequence;

[0016] S4, partitioning the assembled airbag during the trial assembly process to obtain a partition result;

[0017] S5, installing the assembled airbag disassembled after trial assembly and trial filling in the collapsed cavity according to the ideal installation connection sequence and the partition result, monitoring and adjusting the position during inflation, and detecting the working air pressure state of the assembled airbag in real time;

[0018] S6, after the installation and layout of the assembled airbags, a temporary support is formed;

[0019] S7, according to the zoning results, the foam concrete is injected into the assembled airbag and solidified for a certain period of time, and the temporary support can be turned into permanent support. When the foam concrete is injected into a certain partition, the electromagnetically controllable exhaust valve switch in the partition is opened to exhaust the air;

[0020] S8, close the working entrance and exit, carry out the initial concrete spraying, install the steel mesh, erect the steel arch frame and then spray concrete to form the TBM tunnel lining structure.

[0021] Preferably, in S2, a false roof is set at the tunnel vault as a subsequent construction work platform, and holes are reserved as working entrances and exits, and the size of the working entrances and exits is set to a diameter of 0.8m.

[0022] Preferably, in S4, the assembled airbag is divided into at least three zones. The specific zoning is based on the shape of the collapsed cavity and is divided according to the number of airbags in two adjacent layers. When the number of airbags in two adjacent layers is different, the zones should be divided. Each zone is provided with an inflation port and an electromagnetically controllable exhaust valve.

[0023] Preferably, in S7, the preparation process of foamed concrete is: mixing cement, anti-cracking fiber, redispersible latex powder and water to prepare an intermediate slurry, the basic mix ratio of which is cement: lime: foaming agent: fiber: water = 1:1:0.5:0.05:0.5, and then adding a coagulant, a foaming agent and a foam stabilizer to the intermediate slurry and mixing to obtain foamed concrete.

[0024] Preferably, in S7, the injection pressure of the foamed concrete is 0.005-0.15 MPa.

[0025] Therefore, the present invention adopts a disposal unit and construction method of the above-mentioned structure suitable for the TBM tunnel vault collapse cavity, which can not only ensure the rapid restoration of the safe state of tunnel construction and speed up the construction process, but also form permanent support to ensure the safety of the tunnel operation process through later processing.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the longitudinal section of the collapsed cavity when the treatment unit and construction method for the collapsed cavity of the TBM tunnel vault play a supporting role;

[0028] Figure 2 A schematic cross-sectional view of a collapsed cavity when a treatment unit and a construction method for a collapsed cavity of a TBM tunnel vault are used to support the collapsed cavity;

[0029] Figure 3 It is a schematic diagram of a horizontal section of a collapsed cavity when a treatment unit and a construction method for a collapsed cavity of a TBM tunnel vault are exerting a supporting effect;

[0030] Figure 4 It is a schematic diagram of a type I airbag structure of a disposal unit and construction method suitable for a TBM tunnel vault collapse cavity according to the present invention;

[0031] Figure 5 It is a schematic diagram of a type II airbag structure of a disposal unit and construction method suitable for a TBM tunnel vault collapse cavity according to the present invention;

[0032] Figure 6 It is a schematic diagram of the structure of a type III airbag suitable for a disposal unit and a construction method of a TBM tunnel vault collapse cavity according to the present invention;

[0033] Figure 7 It is a schematic diagram of a type IV airbag structure of a disposal unit and construction method suitable for a TBM tunnel vault collapse cavity according to the present invention;

[0034] Figure 8 A schematic diagram of a V-type airbag structure of a disposal unit and construction method suitable for a TBM tunnel vault collapse cavity according to the present invention;

[0035] Fig. 9 It is a schematic diagram of a type VI airbag structure of a disposal unit and construction method suitable for a TBM tunnel vault collapse cavity according to the present invention;

[0036] Fig.10 It is an exploded schematic diagram of a gas valve interface and a gas valve joint of a disposal unit and a construction method suitable for a TBM tunnel vault collapse cavity according to the present invention;

[0037] Fig.11 A longitudinal section schematic diagram of a gas valve interface and a gas valve joint of a disposal unit and a construction method applicable to a TBM tunnel vault collapse cavity of the present invention;

[0038] Fig.12 It is an explosion schematic diagram of an electromagnetically controllable exhaust valve of a disposal unit and construction method applicable to a TBM tunnel vault collapse cavity of the present invention;

[0039] Fig.13 The invention is a schematic longitudinal section diagram of an electromagnetically controllable exhaust valve of a disposal unit and a construction method suitable for a TBM tunnel vault collapse cavity.

[0040] Reference numerals

[0041] 1. Tunnel; 2. Surrounding rock; 3. Collapse cavity; 4. Working entrance and exit; 5. Assembled airbag; 51. Type I airbag; 52. Type II airbag; 53. Type III airbag; 54. Type IV airbag; 55. Type V airbag; 56. Type VI airbag; 6. Inflating port; 7. Valve interface; 71. Valve interface shell; 72. Fixed rubber gasket; 73. Movable rubber gasket; 74. Sealing ring; 8. Valve joint; 81. Valve joint outer shell Shell; 82, check valve head; 83, check valve spring; 84, spring fixing ring; 85, rotatable threaded sleeve; 9, electromagnetic controllable exhaust valve; 91, air inlet; 92, exhaust hole; 93, movable valve stem; 94, exhaust valve spring; 95, magnetic pole; 96, coil core; 97, power supply and switch control cabin; 10, TBM tunnel lining structure; 11, fault fracture zone; 12, temporary support structure at the bottom of the collapsed cavity. DETAILED DESCRIPTION

[0042] Example

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0047] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] The present invention provides a disposal unit and construction method suitable for a collapsed cavity of a TBM tunnel vault. The disposal unit is an assembled airbag 5, which can be connected to each other into a whole through connectors on the surface or inside the airbag to fill the collapsed cavity of the TBM tunnel vault. The assembled airbag 5 is divided into different types and can be used for filling in different areas. The deformability of the airbag ensures that the airbag and the collapsed cavity 3 are densely filled. At the same time, by scanning the volume shape of the collapsed cavity 3, the assembly form of the assembled airbag 5 is designed to be suitable for filling collapsed cavities 3 of different shapes.

[0049] like Figures 4 to 9As shown, there are six types of assembled airbags, which are Type I airbag 51, Type II airbag 52, Type III airbag 53, Type IV airbag 54, Type V airbag 55 and Type VI airbag 56. The six airbags are connected by an air valve connector 8 and an air valve interface 7. The front and rear sides of the Type I airbag 51 are respectively provided with an air valve connector 8 and an inflation port 6, and the front and rear sides of the Type VI airbag 56 are respectively provided with an electromagnetically controllable exhaust valve 9 and an air valve interface 7.

[0050] The front and rear sides of the type II airbag 52 are respectively provided with an air valve connector 8 and an air valve interface 7; the front side of the type III airbag 53 is provided with an air valve connector 8, and the left side is provided with an air valve interface 7; the top side of the type IV airbag 54 is provided with an air valve connector 8, and the front side is provided with an air valve interface 7; the front side of the type V airbag 55 is provided with an air valve connector 8, and the bottom side is provided with an air valve interface 7.

[0051] The standard size of the assembly airbag is 500mm long, 500mm wide, 250mm high, and 5mm thick. The main material of the assembly airbag is rubber, which is made of synthetic rubber, natural rubber and fiber reinforcement layer after vulcanization. It has good anti-expansion strength, elasticity and flexibility, and can be used in construction under various working conditions.

[0052] like Fig.10 , Fig.11 As shown, the air valve interface 7 includes an air valve interface shell 71, and a plurality of sealing rings 74, movable rubber gaskets 73 and fixed rubber gaskets 72 arranged inside the air valve interface shell 71. A thread is arranged on the inner side of one end of the air valve interface shell 71, and a sealing ring 74, a movable rubber gasket 73, a sealing ring 74, a fixed rubber gasket 72 and a sealing ring 74 are arranged in sequence from the thread to the inner side of the other end of the air valve interface shell 71.

[0053] The gas valve joint 8 comprises a gas valve joint housing 81, a rotatable threaded sleeve 85, and a check valve head 82, a check valve spring 83, and a spring fixing ring 84 arranged inside the gas valve joint housing 81. The rotatable threaded sleeve 85 is arranged outside one side of the gas valve joint housing 81, and the outside of the spiral threaded sleeve is provided with a thread matching with the thread inside the gas valve interface housing 71. The inside of the gas valve joint housing 81 on one side of which the rotatable threaded sleeve 85 is provided is provided with a spring fixing ring 84, a check valve spring 83, a spring fixing ring 84, and a check valve head 82 in sequence toward the inside of the other side of the gas valve joint housing 81. During operation, all check valve heads 82 have the same opening direction to prevent gas backflow and prevent the failure of the entire support system due to damage to a single airbag.

[0054] like Fig.12 , Fig.13As shown, an exhaust valve spring 94, a movable valve stem 93, a magnetic pole 95, a coil core 96 and a power supply and switch control cabin 97 are sequentially arranged on one side of the interior of the electromagnetically controlled exhaust valve 9 and on the other side of the interior of the electromagnetically controlled exhaust valve 9. An air inlet 91 is arranged at the bottom end of the electromagnetically controlled exhaust valve 9, and an exhaust hole 92 is arranged at the top end of the electromagnetically controlled exhaust valve 9. The air inlet 91 and the exhaust hole 92 are connected to the interior of the electromagnetically controlled exhaust valve 9.

[0055] When the foam concrete is pumped in from the air filling port 6, the electromagnetically controllable exhaust valve 9 at the top is opened, and after the power supply and switch control cabin 97 is powered on by remote control, the iron core coil generates repulsion, the exhaust valve spring 94 at the other end is compressed, and the movable valve stem 93 with the magnetic pole 95 is pushed open to form a gas channel, and the compressed gas enters from the air inlet 91 and is discharged from the exhaust hole 92. While the foam concrete is pumped in, the gas in the air bag is discharged. When the power supply and switch control cabin 97 are powered off, the repulsion in the iron core coil disappears, the exhaust valve spring 94 at the other end is extended, and the movable valve stem 93 moves under the elastic force of the exhaust valve spring 94 to close the air inlet 91 and the exhaust hole 92.

[0056] like Figures 1 to 3 As shown, a construction method suitable for a TBM tunnel vault collapse cavity, using the above-mentioned treatment unit suitable for a TBM tunnel vault collapse cavity, includes the following steps:

[0057] S1, enter from the working entrance 4, clean the collapsed cavity 3 and support and reinforce the large unstable rock and soil with high risk of collapse;

[0058] In S1, during the cleaning of the collapsed cavity 3, small pieces are chiseled out locally and the slag is transported out of the hole. This step can prevent the safety threat to the construction workers and the obstruction to the construction process caused by the local pieces falling during the construction process.

[0059] S2, scanning the collapsed cavity 3 by a three-dimensional laser scanner to determine the volume of the collapsed cavity 3, and estimating the required number of assembled airbags 5 and the arrangement and connection methods of various types of airbags to obtain an estimated result;

[0060] In S2, a false roof is set at the arch of the tunnel 1 as a subsequent construction work platform, and a hole is reserved as a working entrance and exit 4, and the size of the working entrance and exit 4 is set to a diameter of 0.8m.

[0061] S3, using the estimated results to conduct trial assembly and trial charging operations in an open space, and then using a 3D laser scanner to scan the results after the trial assembly to determine the accuracy of the estimated results and the ideal installation and connection sequence;

[0062] In S3, the assembly process of the assembled airbag 5 is specifically as follows:

[0063] First, multiple standard assembled airbags 5 are connected to each other into a strip structure through multiple combined components. Each assembled airbag 5 is provided with a check valve to block gas backflow and prevent the problem of some airbags being damaged during operation and causing the entire support system to fail.

[0064] An air pressure sensor can be set in each airbag to detect whether the air pressure is within the normal working pressure. The air pressure sensor transmits signals wirelessly. The battery supply time span does not need to be too long. It depends on the construction period of Tunnel 1. Generally, the supply is sufficient for about two months.

[0065] This step can ensure that the airbag assembly and the collapsed cavity 3 are close in shape and fit closely together. At the same time, during the trial filling, it can preliminarily detect whether the assembled airbag 5 has any damage or leakage problems. After the trial assembly result is relatively ideal, it is disassembled and transported into the working entrance in sequence according to the predetermined splicing sequence of the trial assembly operation, so as to be prepared for splicing and inflation in the collapsed cavity 3.

[0066] S4, partitioning the assembled airbag 5 during the trial assembly process to obtain a partitioning result;

[0067] In S4, the assembled airbag 5 is divided into at least three zones. The specific zoning is based on the shape of the collapsed cavity 3 and the zones are divided according to the number of airbags in two adjacent layers. When the number of airbags in two adjacent layers is different, the zones should be divided. Each zone is provided with an inflation port 6 and an electromagnetically controllable exhaust valve 9. When the assembled airbag 5 in a zone is damaged, the assembled airbag 5 is disassembled according to the zone and the damaged assembled airbag 5 is replaced without disassembling the entire support system for replacement.

[0068] S5, installing the assembled airbag 5 disassembled after trial assembly and trial filling in the collapsed cavity 3 according to the ideal installation connection sequence and the partition result, monitoring and adjusting the position during inflation, and detecting the working air pressure state of the assembled airbag 5 in real time;

[0069] The normal working pressure of the assembled airbag 5 is set to 0.005-0.15 MPa. When the working state is normal, temporary support of the collapsed cavity 3 can be achieved, so as to quickly restore the safe construction state and save the construction progress delayed by the collapse accident of the arch of the tunnel 1.

[0070] S6, after the assembled airbag 5 is installed and arranged, a temporary support is formed;

[0071] S7, according to the zoning result, the foamed concrete is injected into the assembled airbag 5 and solidified for a certain period of time, and the temporary support can be turned into permanent support. When the foamed concrete is injected into a certain partition, the electromagnetically controllable exhaust valve 9 in the partition is opened to exhaust the air.

[0072] During grouting, the electromagnetically controllable exhaust valve 9 can be opened by a remote control device to exhaust the air in the airbag during grouting. The assembled airbag 5 is deflated while grouting; the battery supply time in the electromagnetically controllable exhaust valve 9 depends on the temporary construction time, and generally the supply is sufficient for about two months.

[0073] In S7, foamed concrete has the characteristics of good fluidity, self-compacting, light weight and high strength, which not only further increases the strength of the airbag and the ability to resist risks, but also brings little additional load to the temporary support structure 12 at the bottom of the collapsed cavity and the TBM tunnel lining structure 10. The preparation process of foamed concrete is: mix cement, anti-cracking fiber, redispersible latex powder and water to prepare an intermediate slurry, and its basic mix ratio is cement: lime: foaming agent: fiber: water = 1:1:0.5:0.05:0.5, and then add accelerator, foaming agent and foam stabilizer to the intermediate slurry and mix well to obtain foamed concrete. The injection pressure of the foamed concrete is 0.005-0.15MPa. The dry weight of the foamed concrete after curing is generally 8×10 3 ~12×10 3 kN / m 3 , the compression strength needs to reach 0.4~0.6MPa to achieve the purpose of light weight and high strength.

[0074] S8, closing the working entrance and exit 4, and carrying out a series of construction processes including initial concrete spraying, installation of steel mesh, erection of steel arch frame, and re-concrete spraying to form a TBM tunnel lining structure 10.

[0075] The specific implementation process is:

[0076] During the excavation of tunnel 1 by TBM, a fault fracture zone 11 is encountered in the surrounding rock 2. When excavating to this point, the weak rock and soil in the fault fracture zone 11 at the arch of tunnel 1 collapses, forming a collapsed cavity 3 at the arch of tunnel 1. When the tail part of the TBM shield passes by Figure 1 In the section A shown, the TBM stops excavating, and the construction personnel enter the collapsed cavity 3 to construct the temporary support structure 12 at the bottom of the collapsed cavity, which serves as a working platform for subsequent construction. A working entrance and exit 4 is reserved. Then the side wall within the limited height range of the collapsed cavity 3 is processed, and the small unstable rock and soil body is chiseled out and the slag is transported out of the cave from the working entrance.

[0077] After the preliminary processing of the collapsed cavity 3 is completed, a three-dimensional laser scanner is used to determine the volume and shape of the collapsed cavity 3, and the volume and shape of the airbag assembly and the required number and assembly form of the assembled airbags 5 are determined based on the scanning results.

[0078] Then the assembled airbag 5 is installed and arranged. The assembled airbag 5 is transported into the collapsed cavity 3 from the working entrance 4 and arranged toward the top of the collapsed cavity 3 from the working platform used as the temporary supporting structure 12 at the bottom of the collapsed cavity.

[0079] In the specific layout process, the type I airbag 51 is located on the side wall of the collapsed cavity 3, and the airbag inflation and grouting start from here; the type II airbag 52 is located in the middle of the entire support system when it is in working state, and is mainly used for longitudinal linear connection with other airbags. It is the assembled airbag 5 with the highest demand; the type III airbag 53 is located on the side wall of the collapsed cavity 3 when it is in working state, and is mainly used for transverse row connection with other airbags; the type IV airbag 54 is located on the side wall of the collapsed cavity 3 when it is in working state, and is mainly used for vertical connection with the upper airbag; the type V airbag 55 is located on the side wall of the collapsed cavity 3 when it is in working state, and is mainly used for vertical connection with the lower airbag; the type VI airbag 56 is located on the side wall of the collapsed cavity 3 when it is in working state, and is mainly used to discharge the gas in the airbag during grouting.

[0080] First, the assembled airbag 5 is trial-assembled and trial-charged outdoors according to the installation form determined by the scanning results, and the appearance of the result after the trial assembly is scanned to ensure that it is close to the shape of the collapsed cavity 3 and the two fit closely. During the trial charging, it is possible to preliminarily detect whether the assembled airbag 5 produced has any damage or leakage problems. After the trial assembly results are relatively ideal, it is disassembled and transported into the working entrance in the predetermined splicing sequence of the trial assembly operation, so as to be used for splicing and inflation in the collapsed cavity 3. The volume of the assembled airbag 5 after installation is equal to that of the collapsed cavity 3.

[0081] When making the connection, the air valve interface 7 of the assembled air bag 5 is connected end to end with the air valve connector 8, and the air valve interface housing 71 in the air valve interface 7 is screwed together with the rotatable threaded sleeve 85 in the air valve connector 8 to connect them. After the connection, the fixed rubber gasket 72, the movable rubber gasket 73 and the sealing ring 74 produce a sealing effect under the contact and extrusion of the air valve interface housing 71 and the air valve connector housing 81 to prevent air leakage at the connection;

[0082] At the same time, in the trial assembly stage, the assembled airbag 5 is divided into multiple zones vertically, each zone has a separate inflation port 6 and an electromagnetically controllable exhaust valve 9, and is independent of other zones; when the assembled airbag 5 in a certain zone is damaged, the assembled airbag 5 is disassembled according to the zone and the damaged assembled airbag 5 is replaced without disassembling the entire support system and then replacing it; it is recommended that the support system be divided into at least 4 to 5 zones, and the specific zones can be divided according to the shape of the collapsed cavity 3 and the number of assembled airbags 5. When the number of assembled airbags 5 in two adjacent layers is different, zoning should be carried out.

[0083] The assembled airbag 5 is transported in from the working entrance, and assembled in the collapsed cavity 3 according to the above trial assembly results. The position is adjusted while inflating to ensure that each assembled airbag 5 is in the predetermined working position. During the inflation work, air is pumped in from the inflation port 6. The higher inflation port 6 can be inflated by connecting the inflation pump through the reserved long conduit. During inflation, check whether there is leakage or damage in the airbag. After installation, check whether the assembled airbag 5 is in the normal working pressure state. The normal working pressure value of the assembled airbag 5 is set to 0.005-0.15MPa.

[0084] The spring fixing ring 84 connects the air valve joint housing 81, the check valve head 82 and the check valve spring 83 to form a check valve. When the assembled airbag 5 is inflated, the check valve spring 83 is compressed, the check valve head 82 moves inward, the check valve channel opens, and the gas begins to enter; when the assembled airbag 5 finishes inflating, the check valve spring 83 extends, the check valve head 82 moves outward, and the check valve channel closes to prevent gas backflow and prevent a single assembled airbag 5 from being damaged and causing the entire support system to fail.

[0085] If the gap between the airbag and the inner wall of the collapsed cavity 3 cannot be filled with a standard size assembled airbag 5, when the gap width is greater than 3 / 5 of the width of the airbag, a standard size assembled airbag 5 is filled here; when the gap width is less than 3 / 5 of the gap, the gap position is filled regardless of the filling standard. Then, according to the ideal installation and connection sequence determined in the trial assembly stage, the collapsed cavity 3 is inflated and the position is monitored and adjusted at all times, and the assembled airbags 5 are detected in real time to see if they are all in a normal working pressure state.

[0086] In normal working state, the assembled airbag 5 should fill the entire collapse cavity 3 and play a supporting role to prevent unstable blocks of surrounding rock 2 on the collapse cavity 3 from falling during the construction of the tunnel 1 and affecting the construction safety in the tunnel 1, quickly restore the safe construction environment, and save the construction progress delayed by the collapse accident.

[0087] If you want to replace the collapsed cavity 3 with a more stable permanent support form, you can exhaust the assembled airbag 5 and withdraw the deflated assembled airbag 5 from the working entrance and exit 4, and then perform a more stable permanent support on the assembled airbag 5 to ensure the safety of the TBM tunnel lining structure 10 during the later operation process.

[0088] After being poured with foamed concrete, the assembled airbag 5 can become a permanent support after a period of time to resist the impact of the collapse cavity 3 or falling blocks on the lower TBM tunnel lining structure 10, so as to ensure the safety of the TBM tunnel lining structure 10 during the later operation process.

[0089] The amount of foamed concrete to be filled can be evaluated based on the strength of the TBM tunnel lining structure 10 constructed on the top of the tunnel 1. The dry weight of the foamed concrete is considered to be in the range of 8×10 3 ~12×10 3 kN / m 3 If the collapsed cavity 3 is large, because all the assembled air bags 5 in the collapsed cavity are fully pumped with foam concrete, the load on the temporary supporting structure 12 at the bottom of the lower collapsed cavity and the constructed TBM tunnel lining structure 10 is too large, it is possible to consider pumping foam concrete into only the assembled air bags 5 in the lower 2-3 partitions.

[0090] Then the working entrance and exit 4 is closed, and a series of construction processes such as initial concrete spraying, installation of steel mesh, erection of steel arch frame and re-concrete spraying are carried out to form the TBM tunnel lining structure 10.

[0091] Compared with other previous support methods, such as the method of reinforcing the free surface of the collapsed cavity 3 by hanging mesh anchor spraying or the method of directly grouting the entire collapsed cavity 3, the method of treating the collapsed cavity of the tunnel 1 of the present invention has a relatively low production cost of the assembled airbag 5, and the assembled airbag 5 is made of rubber. The filling of the assembled airbag 5 with lightweight foam concrete greatly reduces the load on the lower TBM tunnel lining structure 10; the assembled airbag 5 is suitable for filling collapsed cavities 3 of various shapes through assembly, and the assembled airbag 5 is assembled outside the construction site and inflated by an inflator, which greatly simplifies the construction process, greatly reduces the construction time, and improves the construction progress of the tunnel 1 below the collapsed cavity 3 compared with previous methods; finally, the greatest advantage of the assembled airbag 5 is that the above-mentioned temporary support can be achieved by pumping foam concrete into the assembled airbag 5, and after a period of maintenance, it becomes a permanent support structure, providing long-term protection for the safety of the tunnel lining structure during operation.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A disposal unit suitable for TBM tunnel vault collapse cavity, characterized by: The invention comprises six types of assembled airbags, which are Type I airbag, Type II airbag, Type III airbag, Type IV airbag, Type V airbag and Type VI airbag. The six airbags are connected by air valve connectors and air valve interfaces. An air valve connector and an inflation port are respectively arranged on the front and rear sides of the Type I airbag, and an electromagnetically controllable exhaust valve and an air valve interface are respectively arranged on the front and rear sides of the Type VI airbag.

2. A disposal unit suitable for TBM tunnel vault collapse cavity according to claim 1, characterized in that: The front and rear sides of the Type II airbag are respectively provided with an air valve connector and an air valve interface; the front side of the Type III airbag is provided with an air valve connector, and the left side is provided with an air valve interface; the top side of the Type IV airbag is provided with an air valve connector, and the front side is provided with an air valve interface; the front side of the Type V airbag is provided with an air valve connector, and the bottom side is provided with an air valve interface.

3. A disposal unit suitable for TBM tunnel vault collapse cavity according to claim 2, characterized in that: The standard dimensions of the assembled airbag are 500mm in length, 500mm in width, 250mm in height, and 5mm in wall thickness. The material of the assembled airbag is rubber. The air valve interface includes an air valve interface shell, and several sealing rings, movable rubber gaskets and fixed rubber gaskets arranged inside the air valve interface shell. A thread is arranged on the inner side of one end of the air valve interface shell, and a sealing ring, a movable rubber gasket, a sealing ring, a fixed rubber gasket and a sealing ring are arranged in sequence from the thread to the inner side of the other end of the air valve interface shell.

4. A disposal unit suitable for TBM tunnel vault collapse cavity according to claim 3, characterized in that: The air valve joint includes an air valve joint shell, a rotatable threaded sleeve, and a check valve head, a check valve spring, and a spring fixing ring arranged inside the air valve joint shell. The rotatable threaded sleeve is arranged on the outside of one side of the air valve joint shell, and the outside of the spiral threaded sleeve is provided with a thread matching the thread on the inner side of the air valve interface shell. The inside of one side of the air valve joint shell on which the rotatable threaded sleeve is provided is provided with a spring fixing ring, a check valve spring, a spring fixing ring, and a check valve head in sequence toward the inside of the other side of the air valve joint shell.

5. A disposal unit suitable for TBM tunnel vault collapse cavity according to claim 4, characterized in that: An exhaust valve spring, a movable valve stem, a magnetic pole, a coil core, and a power supply and switch control cabin are arranged in sequence on one side of the interior of the electromagnetically controlled exhaust valve and the other side of the interior of the electromagnetically controlled exhaust valve. An air inlet is arranged at the bottom end of the electromagnetically controlled exhaust valve, and an exhaust hole is arranged at the top end of the electromagnetically controlled exhaust valve. The air inlet and the exhaust holes are connected to the interior of the electromagnetically controlled exhaust valve.

6. A construction method suitable for TBM tunnel vault collapse cavity, characterized by: The disposal unit for TBM tunnel vault collapse cavity according to any one of claims 1 to 5 comprises the following steps: S1, enter from the working entrance, clean the collapsed cavity and support and reinforce the large unstable rock and soil with high risk of collapse; S2, scanning the collapsed cavity by a three-dimensional laser scanner to determine the volume of the collapsed cavity, and estimating the required number of assembled airbags and the arrangement and connection methods of various types of airbags to obtain an estimated result; S3, using the estimated results to conduct trial assembly and trial charging operations in an open space, and then using a 3D laser scanner to scan the results after the trial assembly to determine the accuracy of the estimated results and the ideal installation and connection sequence; S4, partitioning the assembled airbag during the trial assembly process to obtain a partition result; S5, installing the assembled airbag disassembled after trial assembly and trial filling in the collapsed cavity according to the ideal installation connection sequence and the partition result, monitoring and adjusting the position during inflation, and detecting the working air pressure state of the assembled airbag in real time; S6, after the installation and layout of the assembled airbags, a temporary support is formed; S7, according to the zoning results, the foam concrete is injected into the assembled airbag and solidified for a certain period of time, and the temporary support can be turned into permanent support. When the foam concrete is injected into a certain partition, the electromagnetically controllable exhaust valve switch in the partition is opened to exhaust the air; S8, close the working entrance and exit, carry out the initial concrete spraying, install the steel mesh, erect the steel arch frame and then spray concrete to form the TBM tunnel lining structure.

7. A construction method applicable to a TBM tunnel vault collapse cavity according to claim 6, characterized in that: In S2, a false roof is set at the tunnel vault as a subsequent construction work platform, and holes are reserved as working entrances and exits. The size of the working entrances and exits is set to a diameter of 0.8m.

8. A construction method applicable to a TBM tunnel vault collapse cavity according to claim 6, characterized in that: In S4, the assembled airbag is divided into at least three zones. The specific zoning situation takes into account the shape of the collapsed cavity and is divided according to the number of adjacent layers of airbags. When the number of adjacent layers of airbags is different, the zones should be divided; each zone is provided with an inflation port and an electromagnetically controllable exhaust valve.

9. A construction method applicable to a TBM tunnel vault collapse cavity according to claim 6, characterized in that: In S7, the preparation process of the foamed concrete is: cement, anti-cracking fiber, redispersible latex powder and water are mixed to prepare an intermediate slurry, and the basic mix ratio thereof is cement: lime: foaming agent: Fiber: Water = 1: 1:0.5:0.05:0.5, then add accelerator, foaming agent and foam stabilizer to the intermediate slurry and mix well to obtain foamed concrete.

10. A construction method applicable to a TBM tunnel vault collapse cavity according to claim 6, characterized in that: In S7, the injection pressure of the foamed concrete is 0.005-0.15 MPa.

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