Tunnel primary formwork building concrete air bag formwork and construction method thereof

Abstract

The invention provides a tunnel primary formwork building concrete air bag formwork and a construction method thereof. The tunnel primary formwork building concrete air bag formwork comprises a supporting frame and an air bag supporting assembly. The air bag supporting assembly comprises an air bag template, and the air bag template is connected with the supporting frame; the supporting frame comprises a fixed arch-shaped frame, a plurality of fixed hooks are arranged on the side face of the fixed arch-shaped frame, the air bag formwork comprises a second air bag, the second air bag is an inner soft bag, the second air bag is sleeved with a third air bag, the third air bag is an outer hard bag, and the outer surface of the second air bag and the outer surface of the third air bag are provided with a first pouring hole and a second pouring hole respectively. And the two pouring holes are communicated with each other. According to the air bag formwork composed of the second air bag and the third air bag, compared with a traditional formwork, the air bag formwork is convenient to carry and move after being deflated and only needs to be inflated during use, traditional concrete spraying is replaced with a quick-hardening concrete pouring mode, and the construction efficiency is greatly improved. And the problem of high resilience in the concrete spraying process is solved fundamentally.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular to a tunnel initial formwork concrete airbag formwork and a construction method thereof. Background Art

[0002] At present, in the process of tunnel construction at home and abroad, during the initial stage of construction, the traditional construction method is to inject the spraying material into the concrete spraying machine (hereinafter referred to as the spraying machine), and then spray the spraying material onto the surrounding rock surface through the spraying pipe and high-pressure air. The spraying needs to be layered, and the thickness of the single layer is 1 / 4 of the spraying material. , if the initial support thickness is When the spraying is needed, the Secondly, the wet spraying concrete method is commonly used in the above-mentioned initial support construction process. This method has the following shortcomings: The first concrete wet spraying has a large rebound rate, and the average rebound rate is According to the above construction specifications, the rebounded concrete cannot be collected for secondary use. Therefore, a higher rebound rate will cause a waste of raw materials, and a large rebound rate will cause a large amount of dust to be generated at the construction site. The workers will easily develop lung-related diseases if they inhale the dust for a long time. At this stage, various construction units have invested a lot of manpower and material resources to control the rebound rate from the direction of technical improvement and strengthening management, but they can still only control the rebound rate within The normal dosage of shotcrete per meter of the upper arch tunnel is , the concrete loss caused by rebound per kilometer of tunnel reaches ; Second, when constructing tunnels under adverse geological conditions such as high geothermal heat, water-rich environment, high altitude and low temperature, the rebound rate of shotcrete is greater due to the influence of low temperature, low air pressure and other regional environments. In the plain area, the concrete spraying work that can be completed in 3 hours will take more than 1 hour in the harsh environment. hours to complete, exacerbating the over-consumption of shotcrete, increasing construction costs, causing serious economic losses and environmental pollution; Initial support is usually not done by pouring concrete. Although pouring concrete can fully avoid the occurrence of high rebound rate and effectively reduce losses compared to spraying, traditional concrete solidifies slowly and the waiting time for initial setting is long during pouring. Therefore, the initial support of tunnel concrete is mostly carried out by spraying concrete, and pouring is rarely considered. Therefore, a tunnel initial formwork concrete airbag formwork and a construction method thereof are proposed to solve the above-mentioned problems. Summary of the Invention

[0003] The main purpose of the present invention is to provide a tunnel initial formwork concrete airbag formwork and a construction method thereof, so as to solve the problem of high rebound rate of existing concrete during spraying operation.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a tunnel initial formwork concrete airbag formwork: comprising a support frame, an airbag support assembly; The airbag support assembly includes an airbag template, which is connected to the support frame.

[0005] In the preferred embodiment, the support frame includes a fixed arch frame, and a plurality of fixed hooks are provided on the side of the fixed arch frame. The airbag template includes a second airbag, which is an inner soft bag and a third airbag is provided on the outside, which is an outer hard bag. The outer surface of the second airbag and the outer surface of the third airbag are respectively provided with a first casting hole and a second casting hole, and the first casting hole and the second casting hole are connected to each other. A small oscillator is provided on the inner wall of the second airbag, and the third airbag is connected to the fixed hook by a binding rope.

[0006] In the preferred solution, the support frame includes two movable support frames, a connecting frame is provided on the top of the movable support frame, a vertical plate is provided between the connecting frame and the movable support frame, a connecting arch frame connected to the connecting frame is provided on the outer sleeve of the movable support frame, a workbench is provided between the two connecting arch frames, and the movable support frame is an N-shaped frame, which includes two vertical rods and a horizontal rod, wherein a side plate is provided on the side of one vertical rod facing the other vertical rod, and an installation horizontal plate is provided between the two horizontal rods, and the installation horizontal plate is located between the two vertical plates.

[0007] In the preferred solution, the airbag support assembly also includes a telescopic rotating arm mechanism, an airbag winding mechanism and a support assembly. The telescopic rotating arm mechanism includes a coaxial dual-axis motor, which is arranged at the top of the mounting horizontal plate and is located between the two vertical plates. The two output shafts of the coaxial dual-axis motor are both provided with a transmission shaft that passes through the vertical plate and extends to the outside of the vertical plate. The transmission shaft is connected to the vertical plate through a bearing. A first telescopic rod is provided at the opposite ends of the two transmission shafts. The two first telescopic rods are respectively arranged on the opposite sides of the two vertical plates. The output ends of the two first telescopic rods are connected to each other through a connecting horizontal plate, and a mounting hole is provided on the upper surface of the connecting horizontal plate.

[0008] In the preferred embodiment, the airbag winding mechanism includes a winding roller and a guide roller, both of which are arranged between two side plates, and the guide roller is located below the winding roller. A winding motor is provided on the side of a side plate facing away from the winding roller, and the output shaft of the winding motor is connected to the winding roller.

[0009] In a preferred embodiment, the airbag template includes a first airbag, one end of which is wrapped around the outside of the winding roller, and the other end extends to the top of the connecting horizontal plate and is connected to the connecting horizontal plate. The guide roller is arranged on the extension path of the first airbag and is tightly fitted with the first airbag. The guide roller is used to guide and support the first airbag.

[0010] In the preferred solution, a spray hole is provided on the side of the first airbag facing away from the support frame. The spray hole is located above the mounting hole and is interconnected with the mounting hole. The concrete nozzle is provided on the lower surface of the connecting horizontal plate and extends to the inside of the spray hole after passing through the mounting hole. The concrete nozzle is interconnected with the spraying machine through a conveying pipe. Side holes are provided on both sides of the first airbag. The two side holes are respectively interconnected with the air intake pipe and the air exhaust pipe. The other end of the air intake pipe is connected to the inflation pump, and the other end of the air exhaust pipe is connected to the air exhaust pump.

[0011] In a preferred embodiment, the support assembly includes two groups of second telescopic rods, and a group of second telescopic rods is provided on opposite sides of the two connecting arch frames. A group of second telescopic rods includes at least N second telescopic rods, N is a positive integer, and the N second telescopic rods are symmetrically distributed with the vertical plate as the center line. The output end of the second telescopic rod is provided with an arc-shaped movable bracket, and the arc-shaped movable bracket includes an arc-shaped plate provided at the output end of the second telescopic rod, and an open groove is provided on the side of the arc-shaped plate facing away from the second telescopic rod, and a rotating roller is provided between the two side walls of the open groove, and the rotating roller is in contact with the surface of the first airbag facing the support frame.

[0012] In a preferred solution, the coaxial dual-axis motor, the first telescopic rod, the winding motor, the air pump, the air pump and the second telescopic rod are controlled in a linkage manner.

[0013] A method for constructing a tunnel initial support concrete airbag formwork comprises: performing tunnel initial support shotcrete construction on the excavated tunnel cavity in a plurality of tunnel segments from back to front along the longitudinal extension direction of the constructed tunnel; the construction method for the tunnel initial support shotcrete is consistent for the plurality of tunnel segments; and the tunnel initial support shotcrete construction for any tunnel segment comprises the following steps: S1. After the support frame is installed in the area inside the tunnel where concrete is to be sprayed, the second and third airbags are moved into the interior of the support frame and connected to each other via binding ropes and fixing hooks to secure the third airbag to the support frame. The airbags are then inflated using an air pump until both the second and third airbags are fully filled. After S2, the second airbag, and the third airbag are all inflated, both sides are sealed with a tunnel plug plate, and rapid-hardening concrete is poured between the third airbag and the rock base through the first pouring hole and the second pouring hole. The concrete is vibrated by a small vibrator. After the vibration operation is completed, wait for the concrete to initially set, then deflate the second and third airbags and demould. S3. Repeat the above process until all tunnel segments in the constructed tunnel are poured with concrete.

[0014] The present invention provides a tunnel initial formwork concrete airbag formwork and a construction method thereof. By adopting the above scheme, the following beneficial effects are achieved: 1. The present invention utilizes an airbag formwork composed of a second airbag and a third airbag. Compared to conventional formwork, this airbag formwork is easier to carry and move after being deflated, and only requires inflation for use. During tunnel construction, this formwork replaces conventional shotcrete with rapid-hardening concrete, thereby fundamentally resolving the high rebound rate problem during concrete spraying. 2. A support frame, an airbag support assembly, and a support assembly are provided. The mobile support member cooperates with the airbag support assembly so that during the concrete spraying operation in the initial tunnel support process, the first airbag is inflated to a full state. Then, the filling constraint of the airbag template limits the concrete spraying area between the first airbag and the tunnel base surface, thereby preventing the concrete from splashing and rebounding due to the impact force of the spraying. 3. Through the setting of the airbag support component and the supporting component, under the action of the first telescopic rod and the second telescopic rod, the airbag mold can be used to constrain the concrete spraying operations during tunnel construction, whether it is leveling or secondary lining, and can be adjusted according to actual construction needs during the constraint process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 A schematic structural diagram of a tunnel initial formwork concrete airbag formwork provided by an embodiment of the present invention; Figure 2 for Figure 1 A structural diagram from another perspective; Figure 3 for Figure 2 Structural cross-sectional view; Figure 4 for Figure 3 A structural diagram from another perspective; Figure 5 A schematic structural diagram of a support frame according to an embodiment of the present invention; Figure 6 for Figure 5 A structural diagram from another perspective; Figure 7 Schematic diagram of the structure of the telescopic rotating arm mechanism in an embodiment of the present invention; Figure 8This is a schematic structural diagram of an airbag template in an embodiment of the present invention; Figure 9 Schematic diagram of the structure of the arc-shaped movable bracket in an embodiment of the present invention; Figure 10 This is a schematic diagram of the airbag template in use according to an embodiment of the present invention; Figure 11 for Figure 10 A structural diagram from another perspective; Figure 12 Schematic diagram of the structure of an embodiment of the present invention; Figure 13 for Figure 12 Schematic diagram of the enlarged structure at point A in the middle.

[0016] In the accompanying drawings, the components represented by the reference numerals are as follows: 1. Support frame; 101. Mobile support frame; 102. Connecting frame; 103. Mounting cross plate; 104. Connecting arch frame; 105. Work table; 106. Vertical plate; 107. Side plate; 108. Fixed arch frame; 109. Fixed hook; 2. Telescopic rotating arm mechanism; 21. Coaxial dual-axis motor; 22. Drive shaft; 23. First telescopic rod; 24. Connecting cross plate; 25. Mounting hole; 3. Winding motor; 4. Winding roller; 5. Guide roller ; 6. Airbag template; 61. First airbag; 62. Side hole; 63. Injection hole; 64. Second airbag; 65. Third airbag; 66. First pouring hole; 67. Second pouring hole; 68. Small oscillator; 7. Delivery pipe; 8. Air inlet pipe; 9. Concrete nozzle; 10. Second telescopic rod; 11. Arc-shaped movable bracket; 111. Arc-shaped plate; 112. Open groove; 113. Rotating roller; 12. Exhaust pipe; 13. Binding rope; 14. Tunnel. DETAILED DESCRIPTION

[0017] Example 1: like Figure 12 and 13 As shown, a tunnel initial support concrete airbag formwork includes a support frame 1 and an airbag support assembly; The airbag support assembly includes an airbag template 6, which is connected to the support frame 1; The support frame 1 includes a fixed arch frame 108, and a plurality of fixing hooks 109 are provided on the side of the fixed arch frame 108. The airbag template 6 includes a second airbag 64, which is an inner soft bag and is covered with a third airbag 65 on the outside. The third airbag 65 is an outer hard bag. The outer surface of the second airbag 64 and the outer surface of the third airbag 65 are respectively provided with a first pouring hole 66 and a second pouring hole 67. The first pouring hole 66 and the second pouring hole 67 are connected to each other. A small oscillator 68 is provided on the inner wall of the second airbag 64. The third airbag 65 is connected to the fixing hook 109 by a binding rope 13. Based on the above, in this embodiment, an integrated second airbag 64 and a third airbag 65 are provided so that the two cooperate with each other to form a movable template. Compared with the traditional template, the template is easy to move and use, and only needs to be inflated during use. It is easy to use and highly flexible. In addition, by pouring concrete between the template and the rock base surface instead of the method of spraying concrete in the preliminary support process, the rebound problem in the spraying concrete process is completely solved. The concrete poured in the above process is preferably fast-hardening concrete.

[0018] A method for constructing an airbag formwork for initial tunnel support concrete: along the longitudinal extension direction of the constructed tunnel 14, the excavated tunnel hole is divided into multiple tunnel sections 14 from the back to the front for initial tunnel support spraying concrete construction. The construction method of the initial tunnel support spraying concrete for the multiple tunnel sections 14 is the same. When performing the initial tunnel support spraying concrete construction on any tunnel section 14, the following steps are included: S1. After the support frame 1 is installed in the area to be sprayed concrete inside the tunnel 14, the second airbag 64 and the third airbag 65 are moved into the interior of the support frame 1 and connected to each other via the binding rope 13 and the fixing hook 109. The binding rope 13 is preferably made of steel wire to connect and fix the third airbag 65 to the support frame 1. The binding rope 13 is inflated by an air pump so that the second airbag 64 and the third airbag 65 are both inflated. After S2, the second airbag 64 and the third airbag 65 are all in a filled state, both sides are sealed by the tunnel plugging head, and concrete is poured between the third airbag 65 and the rock base through the first pouring hole 66 and the second pouring hole 67. The concrete is vibrated by the small vibrator 68. After the vibration operation is completed, wait for the concrete to initially set, then deflate the second airbag 64 and the third airbag 65 and demould. S3. Repeat the above process until all tunnel segments in the constructed tunnel 14 are poured with concrete.

[0019] Example 2: like Figure 1 、 2 , 3, 4, 10 and 11, a tunnel initial support concrete airbag formwork: including a support frame 1, an airbag support assembly; The airbag support assembly includes an airbag template 6, which is connected to the support frame 1; like Figure 5 and 6As shown, the support frame 1 includes two mobile support frames 101, a connecting frame 102 is provided on the top of the mobile support frame 101, a vertical plate 106 is provided between the connecting frame 102 and the mobile support frame 101, and a connecting arch frame 104 connected to the connecting frame 102 is provided on the outside of the mobile support frame 101. A workbench 105 is provided between the two connecting arch frames 104. The mobile support frame 101 is an N-shaped frame, which includes two vertical rods and a horizontal rod, wherein a side plate 107 is provided on the side of one vertical rod facing the other vertical rod, and a mounting horizontal plate 103 is provided between the two horizontal rods, and the mounting horizontal plate 103 is located between the two vertical plates 106; Based on the above, the mobile support frame 101, the connecting frame 102, and the connecting arch frame 104 cooperate with each other to form the main body of the support frame, which plays the role of overall support. The installation of the horizontal plate 103 and the workbench 105 not only plays the role of connecting the main bodies of the support frames on both sides, but also the installation of the horizontal plate 103 can provide a carrier for the installation of the coaxial dual-axis motor 21. The workbench 105 is convenient for staff to stand on its surface to debug or maintain the equipment. The setting of the vertical plate 106 supports the drive shaft 22, and the side plate 107 supports the winding roller 4 and the guide roller 5.

[0020] like Figure 1 、 2 , 3, 4 and 7, the airbag support assembly also includes a telescopic rotating arm mechanism 2, an airbag winding mechanism and a support assembly. The telescopic rotating arm mechanism 2 includes a coaxial dual-axis motor 21. The coaxial dual-axis motor 21 preferably uses a Siemens 6SL3120-2TE13-0AD0 dual-axis servo motor, and preferably uses a Siemens original matching SINAMICS series driver (actuator) in conjunction with the dual-axis servo motor. The coaxial dual-axis motor 21 is arranged on the top of the mounting horizontal plate 103 and is located between the two vertical plates 106. A transmission shaft 22 that passes through the vertical plate 106 and extends to the outside of the vertical plate 106 is provided at both output shafts of the coaxial dual-axis motor 21. The transmission shaft 22 is connected to the vertical plate 106 through a bearing. An angle sensor is provided at the connection between the transmission shaft 22 and the vertical plate 106 to monitor the rotation angle of the first telescopic rod 23. A first telescopic rod 23 is provided at the opposite end of the two transmission shafts 22. The Tuoda TD-80 industrial-grade electric telescopic rod is preferably used, and the Tuoanda TD-1248 wired controller (actuator) is preferably used in conjunction with the first telescopic rod 23. A pull-wire displacement sensor is provided at the connection between the cylinder body and the piston rod of the first telescopic rod 23 to monitor the extended length of the first telescopic rod 23. The two first telescopic rods 23 are respectively provided on the opposite sides of the two vertical plates 106. The output ends of the two first telescopic rods 23 are connected to each other through a connecting cross plate 24. The upper surface of the connecting cross plate 24 is provided with a mounting hole 25. Based on the above, the coaxial dual-axis motor 21 simultaneously drives the two first telescopic rods 23 to rotate through the transmission shaft 22. The rotation direction and speed of the two first telescopic rods 23 are completely consistent. The connecting cross plate 24 is connected to the airbag template 6, and the setting of the mounting hole 25 enables the concrete sprinkler 9 to be inserted therein.

[0021] like Figure 1 、 2 As shown in , 3 and 4 , the airbag winding mechanism includes a winding roller 4 and a guide roller 5. The winding roller 4 and the guide roller 5 are both arranged between the two side plates 107, and the guide roller 5 is located below the winding roller 4. A winding motor 3 is provided on the side of one side plate 107 away from the winding roller 4. The winding motor 3 preferably uses a Panasonic MSMD042G1U servo motor, and preferably uses a Panasonic MADHT1505E driver (actuator) for use with the winding motor 3. The output shaft of the winding motor 3 is connected to the winding roller 4. An absolute encoder is provided at the output shaft of the winding motor 3 to calculate the deployed length of the first airbag 61 according to the number of rotations of the winding roller 4. like Figure 3 and 8 As shown, an airbag template 6 is wrapped around the outside of the winding roller 4. The airbag template 6 includes a first airbag 61. A pressure sensor is provided inside the first airbag 61 to monitor the internal pressure of the first airbag 61 after inflation (usually maintained at 0.2-0.3 MPa, which can be adjusted according to actual construction needs). One end of the first airbag 61 is wrapped around the outside of the winding roller 4, and the other end extends above the connecting cross plate 24 and is connected to the connecting cross plate 24. The guide roller 5 is provided on the extension path of the first airbag 61 and is in close contact with the first airbag 61. The guide roller 5 is used to guide and support the first airbag 61. A spray hole 63 is provided on the side of the first airbag 61 facing away from the support frame 1. The spray hole 63 is located above the mounting hole 25 and is interconnected with the mounting hole 25. The concrete nozzle 9 is provided on the lower surface of the connecting horizontal plate 24 and extends into the interior of the spray hole 63 after passing through the mounting hole 25. Side holes 62 are provided on both sides of the first airbag 61. The two side holes 62 are respectively interconnected with the air intake pipe 8 and the air extraction pipe 12. The other end of the air intake pipe 8 is connected to the inflation pump, and the other end of the air extraction pipe 12 is connected to the air extraction pump. Based on the above, the winding motor 3 is powered on to drive the winding roller 4 to rotate, thereby realizing the winding or unwinding operation of the first airbag 61. If the winding roller 4 rotates counterclockwise to wind the first airbag 61, then it is unwinding when it rotates clockwise, and vice versa. The guide roller 5 plays a role in guiding the unwinding and winding directions of the first airbag 61. like Figure 8As shown, the airbag template 6 is provided with an injection hole 63 on the side away from the telescopic rotating arm mechanism 2, and a concrete nozzle 9 is provided inside the injection hole 63. The concrete nozzle 9 is interconnected with the spraying machine through a delivery pipe 7. A concrete pressure sensor is provided near the delivery pipe 7 near the concrete nozzle 9 to monitor the pressure of the concrete sprayed. The airbag template 6 is interconnected with the air pump through an air inlet pipe 8. The air pump preferably uses a Kaishan KSDY-12 / 10 electric mobile screw air compressor, and preferably uses an INVT CHF1000 series inverter (actuator) in conjunction with the air pump, and is interconnected with the exhaust pump through an exhaust pipe 12. The exhaust pump preferably uses a German Busch R5-300 rotary vane vacuum pump, and preferably uses an ULVAC-R20 series vacuum controller (actuator) in conjunction with the exhaust pump. Based on the above, the setting of the side hole 62 enables the first airbag 61 to be inflated through the air pump and the air inlet pipe 8, so that the first airbag 61 is transformed from a deflated state to a filled state. The filled first airbag 61 plays a role in restricting the sprayed concrete, so that the concrete is confined between the first airbag 61 and the tunnel base surface, avoiding high rebound of the concrete during the spraying process. The exhaust pipe 12 and the exhaust pump on the other side cooperate with each other to extract the gas inside the first airbag 61 in the filled state and restore the first airbag 61 to a deflated state. The setting of the injection hole 63 corresponding to the mounting hole 25 ensures that the concrete nozzle 9 can spray concrete from the injection hole 63, and the sprayed concrete fills the space between the tunnel base surface and the first airbag 61.

[0022] like Figure 1 、 2 , 3 and 4, the support assembly includes two groups of second telescopic rods 10, preferably the Gewa electric cylinder GWD-100 industrial telescopic rod, and preferably the Xinjie DS50 series servo driver (actuator) is used in conjunction with the second telescopic rod 10. The connection between the cylinder body and the piston rod of the second telescopic rod 10 is used to monitor the extended length of the second telescopic rod 10. A group of second telescopic rods 10 is provided on opposite sides of the two connecting arch frames 104. A group of second telescopic rods 10 includes at least 2N second telescopic rods 10, where N is a positive integer. The 2N second telescopic rods 10 are symmetrically distributed with the vertical plate 106 as the midline, and an arc-shaped movable bracket 11 is provided at the output end of the second telescopic rod 10; like Figure 9 As shown, the arc-shaped movable bracket 11 includes an arc-shaped plate 111 provided at the output end of the second telescopic rod 10. An open groove 112 is provided on the side of the arc-shaped plate 111 facing away from the second telescopic rod 10. A rotating roller 113 is provided between the two side walls of the open groove 112. The rotating roller 113 contacts the surface of the first airbag 61 facing the support frame 1. Based on the above, the support assembly plays a role in supporting the first airbag 61. By driving the second telescopic rod 10, the arc-shaped movable bracket 11 can move along the direction of the second telescopic rod 10. When the arc-shaped movable bracket 11 contacts the first airbag 61, it can support the first airbag 61 to ensure that the shape of the first airbag 61 is fixed. When the arc-shaped movable bracket 11 returns to the extended state, it facilitates the unwinding operation of the first airbag 61.

[0023] The coaxial dual-axis motor 21, the first telescopic rod 23, the winding motor 3, the air pump, the air pump and the second telescopic rod 10 are linked and controlled. The linked control is achieved by the cooperation between the main controller and multiple actuators. The specific usage is as follows: The main controller preferably uses a Siemens S7-1200 series PLC controller, which is set on the upper surface of the mounting horizontal plate 103 to receive sensor signals and output control instructions according to a preset program. The controller is the core device of the linkage control.

[0024] A method for constructing a tunnel initial support concrete airbag formwork comprises: performing tunnel initial support shotcrete construction on a tunnel cavity formed by excavation in a plurality of tunnel sections 14 from back to front along the longitudinal extension direction of the constructed tunnel 14; the construction method for the tunnel initial support shotcrete of the plurality of tunnel sections 14 is the same; and the tunnel initial support shotcrete construction for any tunnel section 14 comprises the following steps: S1. The support frame 1 moves to the area inside the tunnel 14 where concrete is to be sprayed. At this time, the airbag template 6 is in a retracted state, and the first telescopic rod 23 is not extended and is in a horizontal state. At this time, the first airbag 61 is in an uninflated state; S2. Shotcrete construction for initial tunnel support. The process is as follows: Before the initial shotcrete leveling, S21 and Tunnel 14 were pre-treated. This involved removing gangue and dangerous rocks, and then removing impurities such as dust, dirt, wood chips, and oil from the base surface to provide conditions for the subsequent installation of support structures. S22. After the pretreatment is completed, the base surface is pretreated by spraying concrete. The pretreatment process is as follows: S221, by driving the first telescopic rod 23, the output end of the first telescopic rod 23 is extended, and after the extension, the distance between the first airbag 61 and the base surface is , the thickness of the first airbag 61 after inflation is , ; S222: After the first telescopic rod 23 is extended to the preset position, it drives the coaxial dual-shaft motor 21, the winding motor 3, the air pump, and the sprayer. The coaxial dual-shaft motor 21 drives the first telescopic rod 23 to rotate around the transmission shaft 22 via the transmission shaft 22. The winding motor 3 drives the winding roller 4 to rotate and unwind the first airbag 61 in the wound state. The sprayer delivers the concrete to the concrete nozzle 9 through the delivery pipe 7 for spraying. Based on the above, while the first airbag 61 is unwinding, the first telescopic rod 23 drives the first airbag 61 to unfold along a fixed path. During the unfolding process, the air pump quickly inflates the first airbag 61, so that the unfolded part of the first airbag 61 is inflated to a full state. After inflation, the spraying machine works to spray concrete through the concrete nozzle 9, and the sprayed concrete adheres to the rock base surface. That is, during the unwinding process, air is inflated in time and the concrete spraying operation is carried out synchronously, so that the concrete spraying operation is carried out during the gradual unfolding of the first airbag 61. The above process is repeated until the construction of the area is completed and a concrete base surface is formed. During the construction process, the second telescopic rod 10 works to drive the arc-shaped movable support 11 to move in a direction close to the first airbag 61, so that the arc-shaped movable support 11 contacts the first airbag 61 to support the first airbag 61. After the construction is completed, the air pump stops working, and the unfolded first airbag 61 is now in a fully inflated state. S3. After the initial spraying of concrete is completed, wait for the concrete to initially set. minutes, after the initial setting, at the final setting Hours before, the support frame 1 is moved away from the area, and the first telescopic rod 23, the winding roller 4 and the second telescopic rod 10 are driven to reset and the air pump is started at the same time, so that the deployed first air bag 61 is transformed from a filled state to a deflated state and rewound around the outside of the winding roller 4, completing the storage operation, and installing the arch frame and the steel mesh. After the installation is completed, the support frame 1 is moved back to the construction area; After the arch frame and the steel mesh are installed, the construction process of S221 is repeated so that the output end of the first telescopic rod 23 is extended. At this time, the distance between the first airbag 61 and the concrete base surface after the extension is , the thickness of the first airbag 61 after inflation is , After the first telescopic rod 23 is extended to the preset position, the first airbag 61 deployment step in the construction process S222 is repeated, so that the first airbag 61 is fully deployed and kept in a filled state. At this time, tunnel plugging plates are installed on both sides of the deployed first airbag 61, and concrete is poured between the first airbag 61 and the concrete base surface through the concrete sprayer 9 to complete the concrete pouring operation in the secondary lining process; S5. Initial shotcrete construction of the next tunnel segment. According to the method in S1-S4, initial tunnel support shotcrete construction is carried out on the next tunnel segment until the tunnel support shotcrete construction process of all tunnel segments in the constructed tunnel 14 is completed.

[0025] The linkage process in the above construction process is as follows: 1. Deployment and inflation stage (corresponding to construction step S222): Objective: The first airbag 61 is unfolded from the rolled-up state to an arc adapted to the tunnel base surface and inflated to a full state, while the second telescopic rod 10 provides support synchronously.

[0026] Linkage logic: After the proximity sensor detects that the support frame 1 is in place, it sends a "position signal" to the PLC controller (hereinafter referred to as PLC), and the PLC starts the process; The PLC instructs the first telescopic rod 23 to extend, and the wire displacement sensor provides real-time feedback on the extension length. When the preset L1 (the distance between the airbag and the base surface) is reached, the first telescopic rod stops extending; The PLC synchronously instructs the reeling motor 3 to rotate forward (unwind), and the absolute encoder provides real-time feedback on the airbag deployment length. At the same time, it instructs the coaxial dual-axis motor 21 to rotate the transmission shaft 22, and the angle sensor provides feedback on the rotation angle to ensure that the airbag deployment path is consistent with the curvature of the tunnel arch (e.g., 90° at the arch top and 30° at the side wall). After unwinding begins, the PLC instructs the air pump to start, and the pressure sensor monitors the airbag pressure in real time: when the pressure is lower than 0.2MPa, the pump controller increases the air flow rate; when it reaches 0.25MPa, the flow rate is maintained stable; When the airbag deployment length reaches the construction length of the segment (the encoder feedback value meets the standard), the PLC instructs the reeling motor 3 to stop unwinding and the coaxial dual-axis motor 21 to stop rotating; at the same time, the second telescopic rod (10) is instructed to extend, and its displacement sensor feedbacks the extension length until the rotating roller 113 of the arc-shaped movable bracket 11 is in contact with the first airbag 61 (the displacement sensor feedback is "in place" when in contact), and then stops extending.

[0027] 2. Concrete spraying stage (corresponding to construction steps S222 and S4): Objective: The concrete nozzle 9 sprays accurately, the first airbag 61 remains filled, and the support is stable.

[0028] Linkage logic: After the airbag pressure stabilizes, the PLC instructs the shotcrete machine to start, and the concrete pressure sensor monitors the injection pressure: if the pressure is greater than 0.5MPa, the PLC instructs the shotcrete machine to reduce the output; if it is less than 0.3MPa, the output is increased; During the injection process, the pressure sensor continuously monitors the airbag pressure: if the pressure drops (<0.2MPa) due to the impact of concrete, the PLC instructs the air pump to replenish the pressure; The displacement sensor of the second telescopic rod 10 provides real-time feedback on the support status: if the airbag expands outward due to the injection pressure, causing the support distance to increase, the PLC instructs the second telescopic rod 10 to extend synchronously to maintain the support force.

[0029] 3. Winding and resetting stage (corresponding to construction step S3): Objective: The first airbag 61 is deflated and retracted, and all components are restored to their initial states.

[0030] Linkage logic: After the concrete has initially set (the "rewinding command" is manually triggered through the HMI), the PLC instructs the shotcrete machine to stop working; Instruct the second telescopic rod 10 to retract (stop after the displacement sensor feedback indicates that it is fully retracted); The vacuum pump is started and the pressure sensor monitors the airbag pressure: when the pressure drops below 0.05MPa (the airbag is deflated), the vacuum pump stops; The PLC instructs the winding motor 3 to rotate in the reverse direction (winding), and at the same time instructs the first telescopic rod 23 to retract (the displacement sensor feedback indicates that it is fully retracted) and the coaxial dual-axis motor 21 to reverse direction (the angle sensor feedback indicates that it is reset to the horizontal state); The absolute encoder monitors that the airbag is wound up (the number of turns is reset to zero), the PLC instructs the winding motor 3 to stop, and all components are reset.

[0031] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A tunnel initial formwork concrete airbag formwork, characterized by: It includes a support frame (1) and an airbag support assembly; The airbag support assembly comprises an airbag template (6), which is connected to the support frame (1).

2. The airbag formwork for tunnel initial formwork according to claim 1, characterized in that: The support frame (1) includes a fixed arch frame (108), and a plurality of fixed hooks (109) are provided on the side of the fixed arch frame (108). The airbag template (6) includes a second airbag (64), the second airbag (64) is an inner soft bag, and a third airbag (65) is provided on the outside, and the third airbag (65) is an outer hard bag. The outer surface of the second airbag (64) and the outer surface of the third airbag (65) are respectively provided with a first pouring hole (66) and a second pouring hole (67), and the first pouring hole (66) and the second pouring hole (67) are connected to each other. A small oscillator (68) is provided on the inner wall of the second airbag (64), and the third airbag (65) is connected to the fixed hook (109) through a binding rope (13).

3. The airbag formwork for tunnel initial formwork according to claim 1, characterized in that: The support frame (1) comprises two movable support frames (101), a connecting frame (102) is provided on the top of the movable support frame (101), a vertical plate (106) is provided between the connecting frame (102) and the movable support frame (101), a connecting arch frame (104) connected to the connecting frame (102) is sleeved on the outside of the movable support frame (101), a workbench (105) is provided between the two connecting arch frames (104), the movable support frame (101) is an N-shaped frame, the N-shaped frame comprises two vertical rods and a horizontal rod, a side plate (107) is provided on the side of one vertical rod facing the other vertical rod, a mounting horizontal plate (103) is provided between the two horizontal rods, and the mounting horizontal plate (103) is located between the two vertical plates (106).

4. The airbag formwork for tunnel initial formwork concrete according to claim 3, characterized in that: The airbag support assembly further comprises a telescopic rotating arm mechanism (2), an airbag retracting mechanism and a supporting assembly. The telescopic rotating arm mechanism (2) comprises a coaxial dual-axis motor (21). The coaxial dual-axis motor (21) is arranged at the top of the mounting horizontal plate (103) and is located between the two vertical plates (106). The two output shafts of the coaxial dual-axis motor (21) are both provided with a transmission shaft (22) that passes through the vertical plate (106) and extends to the outside of the vertical plate (106). The transmission shaft (22) is connected to the vertical plate (106) through a bearing. The two transmission shafts (22) are both provided with a first telescopic rod (23) at opposite ends. The two first telescopic rods (23) are respectively provided on opposite sides of the two vertical plates (106). The output ends of the two first telescopic rods (23) are connected to each other through a connecting horizontal plate (24). The upper surface of the connecting horizontal plate (24) is provided with a mounting hole (25).

5. The airbag formwork for tunnel initial formwork according to claim 4, characterized in that: The airbag reeling mechanism comprises a reeling roller (4) and a guide roller (5), both of which are arranged between two side plates (107), and the guide roller (5) is located below the reeling roller (4). A reeling motor (3) is arranged on the side of one side plate (107) facing away from the reeling roller (4), and the output shaft of the reeling motor (3) is connected to the reeling roller (4).

6. The airbag formwork for tunnel initial formwork according to claim 5, characterized in that: The airbag template (6) includes a first airbag (61), one end of which is wound around the outside of the winding roller (4), and the other end of which extends to the top of the connecting transverse plate (24) and is connected to the connecting transverse plate (24). The guide roller (5) is arranged on the extension path of the first airbag (61) and is tightly fitted with the first airbag (61). The guide roller (5) is used to guide and support the first airbag (61).

7. The airbag formwork for tunnel initial formwork according to claim 6, characterized in that: A spray hole (63) is provided on a side of the first air bag (61) facing away from the support frame (1), the spray hole (63) is located above the mounting hole (25) and is communicated with the mounting hole (25), a concrete spray head (9) is provided on the lower surface of the connecting horizontal plate (24) and extends to the inside of the spray hole (63) after passing through the mounting hole (25), the concrete spray head (9) is communicated with the spraying machine through the delivery pipe (7), side holes (62) are provided on both sides of the first air bag (61), the two side holes (62) are communicated with the air inlet pipe (8) and the air extraction pipe (12) respectively, the other end of the air inlet pipe (8) is connected to the air pump, and the other end of the air extraction pipe (12) is connected to the air extraction pump.

8. The airbag formwork for tunnel initial formwork according to claim 7, characterized in that: The support assembly includes two groups of second telescopic rods (10), and a group of second telescopic rods (10) is provided on opposite sides of the two connecting arch frames (104). The group of second telescopic rods (10) includes at least 2N second telescopic rods (10), N is a positive integer, and the 2N second telescopic rods (10) are symmetrically distributed with the vertical plate (106) as the center line. The output end of the second telescopic rod (10) is provided with an arc-shaped movable bracket (11), and the arc-shaped movable bracket (111) includes an arc-shaped plate (111) provided at the output end of the second telescopic rod (10). An open groove (112) is provided on the side of the arc-shaped plate (111) facing away from the second telescopic rod (10), and a rotating roller (113) is provided between the two side walls of the open groove (112). The rotating roller (113) contacts the surface of the first airbag (61) facing the support frame (1).

9. The airbag formwork for tunnel initial formwork according to claim 7, characterized in that: The coaxial dual-axis motor (21), the first telescopic rod (23), the winding motor (3), the air pump, the air pump, and the second telescopic rod (10) are controlled in a linked manner.

10. A method for constructing a tunnel initial formwork using an airbag concrete formwork, characterized by: Along the longitudinal extension direction of the constructed tunnel (14), the tunnel hole formed by the excavation is divided into multiple tunnel (14) segments from the back to the front for the construction of the tunnel initial support shotcrete construction. The construction method of the tunnel initial support shotcrete of the multiple tunnel (14) segments is the same. When the tunnel initial support shotcrete construction is carried out on any tunnel (14) segment, the following steps are included: S1. After the support frame (1) is installed in the area to be sprayed with concrete inside the tunnel (14), the second airbag (64) and the third airbag (65) are moved to the inside of the support frame (1) and connected to each other through the binding rope (13) and the fixing hook (109) to achieve the connection and fixation of the third airbag (65) with the support frame (1), and the airbag is inflated by the air pump so that the second airbag (64) and the third airbag (65) are both filled; After S2, the second airbag (64) and the third airbag (65) are all in a filled state, both sides thereof are blocked by a tunnel plugging plate, and rapid hardening concrete is poured between the third airbag (65) and the rock base through the first pouring hole (66) and the second pouring hole (67), and the concrete is vibrated by a small vibrator (68). After the vibrating operation is completed, the concrete is initially set, and the second airbag (64) and the third airbag (65) are deflated and then demoulded; S3. Repeat the above process until all tunnel segments in the constructed tunnel (14) are poured with concrete.

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