Tunnel initial support shotcrete flatness adjusting device and construction method

Abstract

The application relates to the technical field of tunnel construction, and discloses a tunnel initial support shotcrete flatness adjusting device and a construction method, the device comprises a circular arch beam track, a moving assembly sliding along the circular arch beam track, and at least two arc-shaped baffles; the space between the arc-shaped baffles and the inner wall of the tunnel serves as a shotcrete operation space; the moving assembly is respectively provided with a supporting rod capable of driving the arc-shaped baffles to move and a concrete shotcreting arm facing the shotcrete operation space. Through the cooperation of the above components, the arc-shaped baffles can alternately adhere to the inner wall of the tunnel under the action of the supporting rods, concrete is shotcreting in the shotcrete operation space, the shape of the concrete is effectively limited, the concrete is initially set and formed in the shotcrete operation space, the shotcreting concrete has excellent flatness during the overall construction, and the construction efficiency is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, specifically to a device and construction method for adjusting the flatness of shotcrete in the initial support of a tunnel. Background Technology

[0002] In tunnel engineering, after the tunnel excavation is completed, initial support work is required. Shotcrete application to the tunnel inner wall surface is a key step in ensuring the quality of this initial support work. Shotcrete application is characterized by its speed and flexibility. The main process involves spraying pre-mixed cement slurry onto the tunnel inner wall and other working surfaces using various types of concrete spraying equipment. Within minutes, the concrete sets to form a hard support layer, serving as the reference working surface for subsequent tunnel construction processes. Therefore, the smoothness of the shotcrete surface is crucial. A smooth concrete surface facilitates the application of waterproofing materials, preventing voids behind the waterproofing layer and further ensuring the quality of the secondary lining construction.

[0003] During shotcrete operations, adjusting the smoothness of the concrete surface relies primarily on the operator's proficiency in operating the spraying equipment, their experience in controlling the overall smoothness, and the subsequent calibration of measuring equipment. However, in actual construction, due to a combination of factors, including varying operator skill levels, the influence of tunnel wall soil on concrete adhesion, and different initial setting times in different areas, the smoothness of the shotcrete surface is often difficult to control precisely. This resulting localized unevenness not only affects the overall aesthetics of the tunnel but also reduces the stability and durability of the support structure, consequently impacting subsequent waterproofing and secondary lining construction.

[0004] To address the issue of precise control over the flatness of shotcrete, current technologies have focused on adjusting the concrete raw material mix ratio and adding flatness monitoring methods. However, these approaches still present challenges such as increased costs, higher technical requirements for personnel's ability to control concrete flatness, and the need for in-depth training before personnel can take up their posts. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a device for adjusting the flatness of shotcrete in the initial support of a tunnel, comprising a circular arch beam track, a movable component that can slide along the circular arch beam track, and at least two arc-shaped baffles. The curvature of the circular arch beam track and the arc-shaped baffles are approximately the same as the arc curvature of the tunnel inner wall. Detachable side baffles made of flexible material are respectively provided on the two sides of the arc-shaped baffles. The moving assembly includes a first moving assembly, a second moving assembly, a third moving assembly distributed circumferentially along the circular arch beam track, and a spraying moving assembly with a concrete spraying arm. The first moving assembly, the second moving assembly, and the third moving assembly are respectively connected to the inner wall of the arc-shaped baffle via support rods, which are used to drive the arc-shaped baffle to approach or move away from the inner wall of the tunnel or to move circumferentially along the circular arch beam track. The space between the arc-shaped baffle and the inner wall of the tunnel is the concrete spraying operation space. The concrete spraying arm faces the spraying operation space.

[0006] Furthermore, a first track is provided on the outer arc surface of the circular arch beam track, and a second track is provided on the side wall; the support rod includes a main support rod, a secondary support rod, and a side support rod; The first moving component includes a moving trolley placed in a first track and a secondary support rod mounted on the moving trolley; the second moving component includes a moving trolley placed in a second track and a side support rod mounted on the moving trolley; the third moving component includes a moving trolley placed in a first track and a main support rod mounted on the moving trolley; the spraying moving component includes a moving trolley placed in a first track and a concrete spraying arm mounted on the moving trolley.

[0007] Furthermore, there are at least two side support rods, which are respectively installed at both ends of the moving trolley of the second moving component, and the distance between the side support rods is greater than the width of the arc-shaped baffle.

[0008] Furthermore, the support rod and the inner wall of the arc-shaped baffle are slidably connected. The inner wall of the arc-shaped baffle has a main sliding groove in the middle along the arc direction to accommodate the ends of the main support rod and the auxiliary support rod. Side sliding grooves are opened on both sides along the arc direction to accommodate the ends of the side support rods respectively. At least two support grooves are opened in the middle of the main sliding groove.

[0009] Furthermore, the main support rod and the auxiliary support rod include a hydraulic press mounted on the moving trolley, a first push rod and a second push rod connected to and sleeved with the output end of the hydraulic press, the rear end of the second push rod extending along the axial direction of the first push rod can be inserted into the support groove, the hydraulic press can independently control the first push rod or the second push rod to advance or retract, the side support rod includes a fixed cylinder and a fixed rod connected to each other by springs, the fixed cylinder is connected to the moving trolley, and the fixed rod is connected to the arc-shaped baffle.

[0010] Furthermore, the first push rod end of the main support rod is provided with a pulley assembly placed in the main sliding groove, and the fixed rod end of the side support rod is provided with a pulley assembly, which can be placed in the side sliding groove.

[0011] Furthermore, the concrete spraying arm includes a rotating arm, a swing arm, and a spraying head connected in sequence. The rotating arm is mounted on a moving trolley and can rotate axially to drive the spraying head toward different spraying angles. The swing arm is hinged to the rotating arm and is used to drive the spraying head to swing around the hinge. The swing arm is provided with a connector for connecting a concrete pipe and communicating with the spraying head.

[0012] Furthermore, the arc-shaped baffle includes a main board composed of several rigid plates, side baffles connected to both sides of the main board, and a curvature adjustment device disposed on the inner wall of the main board. The curvature adjustment device can adjust and limit the curvature of the main board according to the curvature of the inner wall of the tunnel; the side baffles are made of flexible material.

[0013] Furthermore, the curvature adjustment device includes several locking holes fixed on the rigid plate and a curved rod inserted into the locking holes. The curved rod is bent according to the curvature of the tunnel inner wall before construction and cut into sections according to the size of the arc-shaped baffle.

[0014] Furthermore, the present invention also provides a construction method for adjusting the flatness of shotcrete in the initial support of a tunnel, specifically: the arc-shaped baffle includes a first arc-shaped baffle and a second arc-shaped baffle, and the construction process includes the following steps: Step S1, Pre-construction preparation; The circular arch beam track is installed parallel to the inner wall of the tunnel on the ring section to be constructed. The ring section is vertically divided into two construction areas from the top of the arch downwards. Starting from the initial working face near the ground in one construction area, the moving trolleys are installed in the first track in the order of the first moving component - the third moving component - the spraying moving component. The moving trolley of the second moving component is installed in the second track, and the concrete pipe is connected to the concrete spraying arm. Then, release material is applied to the outer walls of the first and second arc-shaped baffles, and side baffles are installed.

[0015] Step S2, first shotcrete application; Erect the first arc-shaped baffle, aligning its outer wall with the inner wall of the tunnel and its bottom with the tunnel floor, and install it onto the device. Each support rod supports the first arc-shaped baffle. The second push rods of the main support rod and the auxiliary support rod extend out and are inserted into the support grooves of the first arc-shaped baffle. Move the concrete spraying arm to the upper part of the first arc-shaped baffle and face the spraying work space. Start spraying until the concrete fills the spraying work space. Step S3: Install the second arc-shaped baffle; After completing step S2, the spraying moving component and the second moving component move along their respective tracks to the next construction work surface, connect the second arc-shaped baffle to the end of the side support rod, align the outer wall of the second arc-shaped baffle with the inner wall of the tunnel, and connect the bottom with the top of the first arc-shaped baffle; move the concrete spraying arm to the upper part of the second arc-shaped baffle and face the spraying work space, and start spraying until the concrete fills the spraying work space; at the same time, the first arc-shaped baffle remains fixed under the support of the support rods of the first and third moving components, waiting for the concrete between it and the inner wall of the tunnel to initially set; Step S4: Adjust the position of the arc-shaped baffle; After the initial setting of the concrete sprayed in step S2 and the completion of the spraying construction in step S3, the first push rods on the main support rod and the secondary support rod are retracted respectively, the first arc-shaped baffle is lifted, and the third moving component is driven to move to the next construction work surface. At the same time, the second push rod on the secondary support rod retracts, causing the first moving component to disengage from the first arc-shaped baffle, and the spraying moving component is moved to the next construction work surface in sync. Step S5: Alternate spraying application; After the first arc-shaped baffle is in place, the first push rod on the third moving component is pushed forward to fit against the inner wall of the tunnel, and the bottom of the first arc-shaped baffle is connected to the top of the second arc-shaped baffle; the first moving component is moved to the second arc-shaped baffle, and the auxiliary support rod is pushed forward to support the second arc-shaped baffle; the second moving component is moved along the second track to the first arc-shaped baffle, so that the side support rod supports the first arc-shaped baffle; then the second push rod on the main support rod retracts and disengages from the support groove, and the third moving component is moved to the second arc-shaped baffle; the spraying construction is started; steps S4 and S5 are repeated, and the first arc-shaped baffle and the second arc-shaped baffle are moved alternately to the subsequent construction work surface until the construction reaches the tunnel arch position; Step S6: Continue construction until completion; After the arch construction is completed, the positions of the spraying moving component and the first moving component are interchanged, and each moving component is moved to the near-ground initial working surface of the other side of the construction area. Steps S2 to S5 are repeated until the tunnel arch is closed on that side. Then the circular arch beam track is moved along the tunnel depth direction to the next construction segment, and all steps are repeated until the construction is completed.

[0016] The present invention has the following beneficial effects: The shotcrete flatness adjustment device of the present invention features precise mechanized operation. Through the coordinated operation of the arc-shaped baffle and the moving components, and the precise and stable support provided by the support rod to the arc-shaped baffle, a smooth and uniform concrete spraying operation space is created between the arc-shaped baffle and the inner wall of the tunnel by utilizing the smoothness of the outer wall of the arc-shaped baffle. When construction is carried out in the spraying operation space, the shape of the sprayed concrete can be effectively defined and initially set within the spraying operation space. There is no need to monitor or adjust the flatness of the concrete in real time during the spraying process, reducing the reliance on manual experience during shotcrete construction, thereby solving the problem of uneven shotcrete caused by differences in personnel skill levels. Furthermore, this invention utilizes multiple moving components in conjunction with a circular arch beam track to enable multiple arc-shaped baffles to move alternately along the circular arch beam track, thereby reaching different construction work areas inside the tunnel wall. This allows for step-by-step construction and alternating operations during concrete spraying, significantly improving construction efficiency and standardization while enhancing the smoothness of the sprayed concrete. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a tunnel initial support shotcrete flatness adjustment device according to the present invention. Figure 2 This is a partial structural schematic diagram of a tunnel initial support shotcrete flatness adjustment device according to the present invention. Figure 3 This is a schematic diagram of the arc-shaped baffle in the first embodiment of the tunnel initial support shotcrete flatness adjustment device of the present invention. Figure 4 This is a schematic diagram of the support rod structure of a tunnel initial support shotcrete flatness adjustment device according to the present invention. Figure 5 This is a schematic diagram of the concrete spraying arm of a tunnel initial support shotcrete flatness adjustment device according to the present invention. Figure 6 This is a front view of the positions of each component in step S3 of the tunnel initial support shotcrete flatness adjustment construction method of the present invention. Figure 7 This is a front view of the positions of each component in step S4 of the tunnel initial support shotcrete flatness adjustment construction method of the present invention. Figure 8 This is a schematic diagram of the arc-shaped baffle in the second embodiment of the tunnel initial support shotcrete flatness adjustment device of the present invention.

[0018] In the attached diagram: 1. Arch beam track; 11. First track; 12. Second track; 2. Moving assembly; 21. First moving assembly; 22. Second moving assembly; 23. Third moving assembly; 24. Spraying moving assembly; 3. Arc-shaped baffle; 31. Side baffle; 32. Main sliding groove; 33. Side sliding groove; 34. Support groove; 35. Rigid plate; 36. Lock hole; 37. Curved rod; 4. Support rod; 41. Main support rod; 42. Secondary support rod; 43. Side support rod; 44. Spring; 45. First push rod; 46. Second push rod; 47. Fixed cylinder; 48. Fixed rod; 49. Pulley block; 5. Concrete spraying arm; 51. Rotating arm; 52. Swing arm; 53. Spraying head; 54. Connector; 6. Hydraulic press. Detailed Implementation

[0019] The technical solution of the present invention will now be described with reference to the accompanying drawings. However, the described embodiments are only some embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," and "outer," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. For example, in the embodiments, "inner" refers to the direction toward the center of the circular arch beam track, and "outer" refers to the direction toward the inner wall of the tunnel. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0021] In the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with terms such as "first," "second," etc., may explicitly or implicitly include one or more of that feature. In this invention, unless otherwise stated, "several" or "a plurality of" means two or more.

[0022] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set", "install", "connect", and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to an electrical connection or a mechanical connection; they can refer to an indirect connection through an intermediate medium, or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in conjunction with the specific circumstances.

[0023] The accompanying drawings show various structural schematic diagrams according to embodiments disclosed in the present invention. These drawings are not drawn to scale, and some details may be enlarged or omitted for illustrative purposes.

[0024] like Figure 1 , 2 The diagram shows the overall structure of a shotcrete smoothness adjustment device for initial tunnel support according to the present invention. The shotcrete smoothness adjustment device includes a circular arch beam track 1 that can be installed inside the tunnel and whose curvature is approximately the same as the arc curvature of the tunnel inner wall; multiple movable components 2 that can slide along the circular arch beam track 1; and at least two arc-shaped baffles 3. The curvature of the arc-shaped baffles 3 is approximately the same as the arc curvature of the tunnel inner wall. The arc-shaped baffles 3, when... Figure 1 , 2 In the standing state shown, there are detachable side baffles 31 made of flexible material on each of its two sides. The flexible material is a rubber strip that matches the shape of the side. The width of the side baffle 31 is consistent with the design thickness of the concrete to be sprayed. By utilizing the adaptive deformation capability of the rubber strip, it can be ensured that the side baffle 31 fits the inner wall of the tunnel more closely. Furthermore, the moving assembly 2 includes a first moving assembly 21, a second moving assembly 22, a third moving assembly 23 with a retractable support rod 4, and a spraying moving assembly 24 with a concrete spraying arm 5. The moving assembly 2 also includes a moving trolley that can slide on the arch beam track 1. The arch beam track 1 is provided with at least two track grooves. The moving trolley of the second moving assembly 22 is placed in different track grooves from the moving trolleys of other moving assemblies 2, so that the sliding process of the second moving assembly 22 and other moving assemblies on the arch beam track 1 does not interfere with each other. The support rod 4 is connected to the inner wall of the arc-shaped baffle 3 and is used to drive the arc-shaped baffle 3 to approach or move away from the inner wall of the tunnel, or to move circumferentially along the arch beam track 1. When the arc-shaped baffle 3 approaches the inner wall of the tunnel under the advancement of the support rod 4, the space between it and the inner wall of the tunnel serves as the concrete spraying operation space, while the side baffle 31 ensures the relative enclosure of the spraying operation space.

[0025] Specifically, the operation of the moving component 2 is as follows: a first track 11 is provided on the outer arc surface of the arch beam track 1, and a second track 12 is provided on the side wall of the arch beam track 1. The support rod 4 includes a main support rod 41, a secondary support rod 42, and a side support rod 43. The first moving component 21 includes a moving trolley placed in the first track 11 and a secondary support rod 42 mounted on the moving trolley. The third moving component 23 includes a moving trolley placed in the first track 11 and a main support rod 41 mounted on the moving trolley. The spraying moving component 24 includes a moving trolley placed in the first track 11 and a concrete spraying arm 5 mounted on the moving trolley and facing the spraying work space. The second moving component 22 includes a moving trolley placed in the second track 12 and a side support rod 43 mounted on the moving trolley. In this embodiment, both the first and second tracks on the arch beam track are equipped with racks. The moving trolley is equipped with gears that match the racks, and a motor drives the gears. Sliding is achieved through the meshing of the gears and racks. The sliding speed can be manually controlled to ensure the smooth movement of the moving component 2.

[0026] The concrete spraying arm 5 can slide along the circular arch beam track 1 to various working surfaces inside the tunnel for concrete spraying construction, driven by the spraying moving component 24. The spraying working space formed between the arc baffle 3 and the tunnel wall effectively confines the concrete sprayed by the concrete spraying arm 5 within the spraying working space. The outer wall of the arc baffle 3 can ensure the flatness of the sprayed concrete, while the thickness of the sprayed concrete within the spraying working space is determined by the width of the side baffle 31 of the arc baffle 3.

[0027] At least two arc-shaped baffles 3 installed in the device can be used alternately as concrete molds to assist in adjusting the flatness of the concrete spraying process. Specifically, one arc-shaped baffle 3 acts as a concrete mold, limiting the concrete spraying range and maintaining the flatness of the concrete surface during the spraying process; the other arc-shaped baffle 3 acts as a curing mold, temporarily fixing the concrete after the concrete construction in the corresponding spraying work space is completed until the initial setting of the concrete is achieved. The support rod 4 installed on the moving component 2 not only supports the arc-shaped baffle 3 as a spraying mold or a curing mold, but its telescopic function also allows the arc-shaped baffle 3 to be alternately slid to the next construction position via the moving component 2.

[0028] Furthermore, a moving device is also provided at the bottom of the arch beam track 1 to drive the arch beam track 1 to move inside the tunnel.

[0029] In this embodiment, there are at least two side support rods 43, which are respectively installed at both ends of the moving trolley of the second moving component 22. The distance between the side support rods 43 is greater than the horizontal width of the arc-shaped baffle 3 after it is erected, that is, the chord length direction of the arc of the arc-shaped baffle 3, so that other arc-shaped baffles 3 can move alternately in the device under the drive of the support rods 4.

[0030] like Figure 3 As shown, the support rod 4 and the inner wall of the arc-shaped baffle 3 are slidably connected. The inner wall of the arc-shaped baffle 3 has a main sliding groove 32 along an arc-shaped direction at its center to accommodate the ends of the main support rod 41 and the auxiliary support rod 42. Side sliding grooves 33 along an arc-shaped direction on both sides are provided to accommodate the ends of the side support rods 43. At least two support grooves 34 are provided in the center of the main sliding groove 32. The transverse cross-section of the main sliding groove 32 and the side sliding grooves 33 is T-shaped.

[0031] like Figure 4 As shown, the main support rod 41 and the auxiliary support rod 42 include a hydraulic press 6 mounted on the moving trolley and a first push rod 45 and a second push rod 46 connected to and sleeved with the output end of the hydraulic press 6. After the second push rod 46 extends axially along the first push rod 45, its end can be inserted into the support groove 34. The hydraulic press 6 can independently control the advancement or retraction of the first push rod 45 or the second push rod 46. The side support rod 43 includes a fixed cylinder 47 and a fixed rod 48 connected to each other. The fixed cylinder 47 is connected to the moving trolley, and the fixed rod 48 is connected to the arc-shaped baffle 3. Since the side support rod 43 mainly moves along the side sliding groove 33 during the specific implementation process, in order to further improve the smoothness of movement and avoid damage to the components caused by the rigid contact between the side support rod 43 and the arc-shaped baffle 3 due to the resistance in the movement of the side support rod 43, the fixed rod 48 and the fixed cylinder 47 are connected by a spring 44 as a buffer.

[0032] Furthermore, the first push rod 45 end of the main support rod 41 is provided with a pulley group 49, and the fixed rod 48 end of the side support rod 43 is provided with a pulley group 49. The pulley groups 49 are respectively placed in the main sliding groove 32 and the side sliding groove 33. Since the cross-section of the main sliding groove 32 and the side sliding groove 33 is T-shaped, the arc-shaped baffle 3 can be clamped and thus stabilized on the main support rod 41 or the side support rod 43. It can also be driven by the main support rod 41 to approach or move away from the inner wall of the tunnel.

[0033] like Figure 5As shown, the concrete spraying arm 5 includes a rotating arm 51, a swing arm 52, and a spraying head 53 connected in sequence. The rotating arm 51 is mounted on a mobile trolley and can rotate axially to drive the spraying head 53 to different spraying angles. The swing arm 52 is hinged to the rotating arm 51, allowing the spraying head 53 to swing around the hinge point, facilitating adjustment of the spraying head 53's position according to the location of the construction site. The swing arm 52 is equipped with a connector 54 for connecting a concrete pipe and communicating with the spraying head 53. During the concrete spraying process, to avoid uneven filling due to differences in concrete fluidity, the spraying head 53 is also equipped with a flow regulating device, which can adjust the spraying pressure and flow rate according to the concrete consistency, ensuring uniform concrete distribution within the spraying work space and effectively reducing material waste.

[0034] like Figure 6 , 7 The diagram illustrates the specific implementation process of the shotcrete flatness adjustment device of the present invention. In this embodiment, according to... Figure 6 , 7 As shown in the frontal view, the shotcrete project is vertically divided into left and right construction areas from the top of the arch beam track 1. For ease of description, the arc-shaped baffle 3 of this invention includes a first arc-shaped baffle and a second arc-shaped baffle with identical structures. The construction process mainly includes the following steps: Step S1, Pre-construction preparation; Before concrete spraying, assemble the device and install the circular arch beam track 1 in the ring section of the tunnel to be sprayed with concrete, with the outer arc surface of the track parallel to the arc surface of the inner wall of the tunnel. In this embodiment, construction begins in the left construction area. Starting from the ground, install each moving trolley in the first track 11 in the order of the first moving component 21-the third moving component 23-spraying moving component 24, and install the moving trolley of the second moving component 22 in the second track 12. Install the support rod 4 or concrete spraying arm 5 on each moving component, and connect the concrete pipe to the connection port on the concrete spraying arm 5. Since the side baffle 31 of the arc baffle 3 is detachable, the side baffle 31 can be installed on the first arc baffle and the second arc baffle according to the concrete spraying thickness required by the actual construction, and the outer walls of the first arc baffle and the second arc baffle are coated with release material.

[0035] Specifically, for the installation of the side baffle 31, only the side baffles 31 on both sides of the arc baffle 3 need to be installed during the shotcrete construction of the first ring section of the tunnel. During the construction of each subsequent ring section of the tunnel, only the side baffle 31 on one side in the tunnel depth direction needs to be installed, and the other side uses the already constructed concrete as the side boundary of the arc baffle 3.

[0036] Step S2, first shotcrete application; The first arc-shaped baffle is erected vertically, with its straight edges facing up and down as the bottom and top of the baffle, respectively. The outer wall is aligned with the inner wall of the tunnel, and the bottom is aligned with the tunnel floor. The concrete spraying arm 5 is moved to the upper part of the first arc-shaped baffle and faces the spraying work space between the baffle and the inner wall of the tunnel. Each support rod supports the first arc-shaped baffle. The second push rods 46 of the main support rod 41 and the auxiliary support rod 42 are extended and inserted into the support grooves 34 of the first arc-shaped baffle. After the device is ready, the concrete spraying arm 5 is started to spray concrete into the spraying work space outside the first arc-shaped baffle until the space is completely filled. During the spraying process, in order to spray concrete onto the construction surface more evenly, the rotating arm 51 on the concrete spraying arm 5 can be started to rotate, driving the spraying head 53 to different angles of the spraying work space, avoiding concrete accumulation and uneven spraying caused by spraying concrete at the same angle.

[0037] Step S3: Install the second arc-shaped baffle; After completing step S2, operate the spraying moving component 24 and the second moving component 22 to move along their respective tracks to the next construction work surface, connect the second arc-shaped baffle to the end of the side support rod 43, align the outer wall of the second arc-shaped baffle with the inner wall of the tunnel, and connect the bottom with the top of the first arc-shaped baffle; move the concrete spraying arm 5 to the upper part of the second arc-shaped baffle and towards the spraying work space between the second arc-shaped baffle and the inner wall of the tunnel. At this point, all components in this step are located as follows: Figure 6 The construction status position is shown, and then the concrete spraying operation at the current position is started until the concrete fills the spraying operation space in this step; During the shotcrete process in this step, the first arc-shaped baffle in step S2 is kept fixed under the support of the support rods of the first moving component 21 and the third moving component 23, waiting for the concrete between the first arc-shaped baffle and the tunnel inner wall to initially set. Step S4: Adjust the position of the arc-shaped baffle 3; After step S3 spraying is completed and the concrete sprayed in step S2 has initially set, the first push rod 45 on the main support rod 41 and the secondary support rod 42 retracts. Driven by the pulley block 49 on the main support rod 41, the first arc-shaped baffle is lifted towards the inside of the tunnel, and each component is positioned as follows: Figure 7 The adjustment status position is shown; Next, the third moving component 23 is activated. With the second push rod 46 on the main support rod 41 and the support groove 34 on the first arc-shaped baffle engaging with each other, the third moving component 23 drives the first arc-shaped baffle to move along the first track 11 to the next construction work surface. At the same time, the second push rod 46 on the auxiliary support rod 42 retracts, causing the first moving component 21 to disengage from the first arc-shaped baffle, and the spraying moving component 24 is operated simultaneously to move to the next construction work surface. Step S5: Alternate spraying application; After step S4, once the first arc-shaped baffle reaches the working surface, the first push rod 45 on the third moving component 23 is operated to push the first arc-shaped baffle towards the tunnel wall, connecting the bottom of the first arc-shaped baffle with the top of the second arc-shaped baffle. Next, the first moving component 21 is moved to the second arc-shaped baffle, and the auxiliary support rod 42 is pushed to support the second arc-shaped baffle. Then, the second moving component 22 is moved along the second track 12 to the first arc-shaped baffle, and the side support rod 43 supports the first arc-shaped baffle. Then, the second push rod 46 on the main support rod 41 of the third moving component 23 retracts and disengages from the support groove 34, and the third moving component 23 is moved to the second arc-shaped baffle. Subsequently, the concrete spraying arm 5 is activated to spray concrete into the spraying working space between the first arc-shaped baffle and the tunnel wall until the concrete fills the spraying working space. Then repeat steps S4 and S5, alternately moving the first and second arc-shaped baffles to the subsequent construction work surface until the construction reaches the arch position.

[0038] Step S6: Continue construction until completion; After the arch construction is completed, as each moving component moves past the tunnel arch, the spraying moving component 24 will be located close to the ground. At this time, the construction direction needs to be adjusted, and each moving component is moved to the other side of the construction area. The positions of the spraying moving component 24 and the first moving component 21 are removed and interchanged. Steps S2 to S5 are repeated until the spraying concrete construction in the right construction area is completed. Then, the entire concrete spraying construction of the tunnel ring where the circular arch beam track 1 is currently located is completed. After that, the circular arch beam track 1 is moved along the tunnel depth direction to the next construction ring, and all steps are repeated until the construction is completed.

[0039] In actual construction, in order to reduce manual intervention and improve automation, the mobile component 2, support rod 4 and concrete spraying arm 5 are all equipped with remote control systems. Operators can monitor and adjust the pushing and retracting actions of the support rod 4 and the sliding position on the mobile trolley in real time through the control panel.

[0040] In another embodiment of the invention, in order to better adapt to different tunnel inner wall curvatures, such as Figure 8As shown, the arc-shaped baffle 3 includes a main board composed of several rigid plates 35 spliced ​​together, side baffles 31 connected to both sides of the main board, and a curvature adjustment device disposed on the inner wall of the main board. The rigid plates 35 are flexibly spliced ​​together, which facilitates the adjustment of the shape of the main board according to different curvatures of the tunnel inner wall. Since the side baffles 31 are made of flexible material and have grooves at the splicing points with the main board, it is also convenient to tightly connect the main board and adapt to the different curvatures of the tunnel inner wall to fit the tunnel inner wall. The curvature adjustment device can adjust and limit the curvature of the main board according to the curvature of the tunnel inner wall.

[0041] Furthermore, the curvature adjustment device includes several locking holes 36 fixed on the rigid plate 35 and curved rods 37 inserted into the locking holes 36. The curved rods 37 are bent according to the curvature of the tunnel inner wall before construction and cut into sections according to the size of the arc-shaped baffle 3. During the actual construction process, the curved rods 37 corresponding to the construction location are selected according to the construction progress, and the curved rods 37 are inserted into the locking holes 36 on the main plate, so that the curvature of the main plate matches the actual arc of the current construction location on the tunnel inner wall. As the arc-shaped baffle 3 moves alternately, different curved rods 37 are inserted to achieve curvature matching between the arc-shaped baffle 3 and each construction location.

[0042] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for adjusting the flatness of shotcrete in the initial support of a tunnel, characterized in that, It includes a circular arch beam track, a movable component that can slide along the circular arch beam track, and at least two arc-shaped baffles, each of which has a detachable side baffle made of flexible material on its two sides; The moving assembly includes a first moving assembly, a second moving assembly, a third moving assembly distributed circumferentially along the circular arch beam track, and a spraying moving assembly with a concrete spraying arm; wherein the first moving assembly, the second moving assembly, and the third moving assembly are respectively connected to the inner wall of the arc-shaped baffle via support rods, for driving the arc-shaped baffle to approach or move away from the inner wall of the tunnel or to move circumferentially along the circular arch beam track, and the space between the arc-shaped baffle and the inner wall of the tunnel is the concrete spraying operation space; the concrete spraying arm faces the spraying operation space.

2. The tunnel initial support shotcrete flatness adjustment device according to claim 1, characterized in that, The outer arc surface of the circular arch beam track is provided with a first track, and the side wall is provided with a second track; the support rod includes a main support rod, a secondary support rod and a side support rod; The first moving component includes a moving trolley placed within a first track and a secondary support rod mounted on the moving trolley; The second moving component includes a moving trolley placed within a second track and a side support rod mounted on the moving trolley; The third moving component includes a moving trolley placed within the first track and a main support rod mounted on the moving trolley; The spraying moving assembly includes a moving trolley placed within a first track and a concrete spraying arm mounted on the moving trolley.

3. The tunnel initial support shotcrete flatness adjustment device according to claim 2, characterized in that, There are at least two side support rods, which are respectively installed at both ends of the moving trolley of the second moving component, and the distance between the side support rods is greater than the width of the arc-shaped baffle.

4. The tunnel initial support shotcrete smoothness adjustment device according to claim 3, characterized in that, The support rod and the inner wall of the arc-shaped baffle are slidably connected. The inner wall of the arc-shaped baffle has a main sliding groove in the middle along the arc direction. The main sliding groove is used to accommodate the ends of the main support rod and the auxiliary support rod. The two sides of the arc-shaped baffle have side sliding grooves in the arc direction. The side sliding grooves are used to accommodate the ends of the side support rods respectively. At least two support grooves are provided in the middle of the main sliding groove.

5. The tunnel initial support shotcrete flatness adjustment device according to claim 4, characterized in that, The main support rod and the auxiliary support rod include a hydraulic press mounted on a moving trolley, a first push rod and a second push rod connected to the output end of the hydraulic press, the second push rod being sleeved inside the first push rod and extending axially along the first push rod so that its rear end can be inserted into the support groove, the hydraulic press being able to independently control the first push rod or the second push rod to advance or retract, the side support rod including a fixed cylinder and a fixed rod connected to each other by springs, the fixed cylinder being connected to the moving trolley, and the fixed rod being connected to an arc-shaped baffle.

6. The tunnel initial support shotcrete smoothness adjustment device according to claim 5, characterized in that, The first push rod end of the main support rod is provided with a pulley group, which can be placed in the main sliding groove. The fixed rod end of the side support rod is provided with a pulley group, which can be placed in the side sliding groove.

7. The tunnel initial support shotcrete flatness adjustment device according to claim 6, characterized in that, The concrete spraying arm includes a rotating arm, a swing arm, and a spraying head connected in sequence. The rotating arm is mounted on a mobile trolley and can rotate axially. The swing arm is hinged to the rotating arm and is provided with a connector for connecting a concrete pipe and communicating with the spraying head.

8. The tunnel initial support shotcrete smoothness adjustment device according to claim 7, characterized in that, The arc-shaped baffle includes a main board made of several rigid plates, side baffles connected to both sides of the main board, and a curvature adjustment device disposed on the inner wall of the main board.

9. The tunnel initial support shotcrete smoothness adjustment device according to claim 8, characterized in that, The curvature adjustment device includes a plurality of locking holes fixed on the rigid plate and a crank rod inserted into the locking holes.

10. A construction method for adjusting the smoothness of shotcrete in the initial support of a tunnel according to claim 7 or 9, characterized in that, The arc-shaped baffle includes a first arc-shaped baffle and a second arc-shaped baffle. The construction process includes the following steps: Step S1, Pre-construction preparation; The circular arch beam track is installed parallel to the inner wall of the tunnel on the ring section to be constructed. The ring section is vertically divided into two construction areas from the top of the arch downwards. Starting from the initial working face near the ground in one construction area, the moving trolleys are installed in the first track in the order of the first moving component - the third moving component - the spraying moving component. The moving trolley of the second moving component is installed in the second track, and the concrete pipe is connected to the concrete spraying arm. Then, release material is applied to the outer walls of the first and second arc-shaped baffles, and side baffles are installed. Step S2, initial shotcrete application; Erect the first arc-shaped baffle, aligning its outer wall with the inner wall of the tunnel and its bottom with the tunnel floor, and install it onto the device. Each support rod supports the first arc-shaped baffle. The second push rods of the main support rod and the auxiliary support rod extend out and are inserted into the support grooves of the first arc-shaped baffle. Move the concrete spraying arm to the upper part of the first arc-shaped baffle and face the spraying work space. Start spraying until the concrete fills the spraying work space. Step S3: Install the second arc-shaped baffle; After completing step S2, the spraying moving component and the second moving component move along their respective tracks to the next construction work surface, connect the second arc-shaped baffle to the end of the side support rod, align the outer wall of the second arc-shaped baffle with the inner wall of the tunnel, and connect the bottom with the top of the first arc-shaped baffle; move the concrete spraying arm to the upper part of the second arc-shaped baffle and face the spraying work space, and start spraying until the concrete fills the spraying work space; at the same time, the first arc-shaped baffle remains fixed under the support of the support rods of the first and third moving components, waiting for the concrete between it and the inner wall of the tunnel to initially set; Step S4: Adjust the position of the arc-shaped baffle; After the initial setting of the concrete sprayed in step S2 and the completion of the spraying construction in step S3, the first push rods on the main support rod and the secondary support rod are retracted respectively, the first arc-shaped baffle is lifted, and the third moving component is driven to move to the next construction work surface. At the same time, the second push rod on the secondary support rod retracts, causing the first moving component to disengage from the first arc-shaped baffle, and the spraying moving component is moved to the next construction work surface in sync. Step S5: Alternate spraying application; After the first arc-shaped baffle is in place, the first push rod on the third moving component is pushed forward to fit against the inner wall of the tunnel, and the bottom of the first arc-shaped baffle is connected to the top of the second arc-shaped baffle; the first moving component is moved to the second arc-shaped baffle, and the auxiliary support rod is pushed forward to support the second arc-shaped baffle; the second moving component is moved along the second track to the first arc-shaped baffle, so that the side support rod supports the first arc-shaped baffle; then the second push rod on the main support rod retracts and disengages from the support groove, and the third moving component is moved to the second arc-shaped baffle; the spraying construction is started; steps S4 and S5 are repeated, and the first arc-shaped baffle and the second arc-shaped baffle are moved alternately to the subsequent construction work surface until the construction reaches the tunnel arch position; Step S6: Continue construction until completion; After the arch construction is completed, the positions of the spraying moving component and the first moving component are interchanged, and each moving component is moved to the near-ground initial working surface of the other side of the construction area. Steps S2 to S5 are repeated until the tunnel arch is closed on that side. Then the circular arch beam track is moved along the tunnel depth direction to the next construction segment, and all steps are repeated until the construction is completed.

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