A shotcrete slipform mechanism for TBM primary lining support

Abstract

The present invention discloses a shotcrete slipform mechanism for TBM primary lining support, which belongs to the field of additive manufacturing. It includes a shotcrete module, a variable curvature sliding template module and a smoothing module installed on a supporting steel frame. The smoothing module includes two smoothing roller structures. The variable curvature sliding template module is installed in the middle area of ​​the supporting steel frame and is located between a pair of smoothing roller structures. The variable curvature sliding template module uses a tensioning cylinder and an adjusting cylinder to control the piston rod stroke to adjust the template curvature to adapt to the tunnel section. The shotcrete module is installed between the variable curvature sliding template module and the first smoothing roller structure. The angle between the first smoothing roller structure and the supporting steel frame is greater than the angle between the second smoothing roller structure and the supporting steel frame. The nozzle in the shotcrete module is tilted toward the second smoothing roller structure. The present invention can provide a continuous and smooth surface support while spraying concrete, thereby reducing the rebound rate of the shotcrete.

Description

Technical Field

[0001] The present invention belongs to the field of additive manufacturing, and in particular relates to a shotcrete slipform mechanism for TBM primary lining support. Background Art

[0002] To efficiently construct tunnels capable of withstanding long-term loads and external forces such as earthquakes, tunnel boring machines (TBMs) are becoming the most widely used excavation equipment. The construction process is broadly divided into four steps: excavation, mucking, support, and advancement. Lining is a permanent support structure constructed along the tunnel perimeter using materials such as reinforced concrete to prevent deformation or collapse of the surrounding rock during underground construction. The structural stability and mechanical durability of the lining are prerequisites for the efficient construction of tunnels capable of withstanding long-term loads and external forces such as earthquakes. Different lining methods are used depending on the surrounding rock conditions, generally classified as primary lining and secondary lining. Tunnel excavation disrupts the initial stress balance of the stratum, causing stress release in the surrounding rock and deformation in the cavern. Excessive deformation can lead to loosening of the surrounding rock or even collapse. To control stress release and deformation in the surrounding rock, enhance structural safety, and facilitate construction, a structural layer with lower rigidity, known as the primary lining, is constructed immediately after tunnel excavation. This layer serves as part of the permanent load-bearing structure. Commonly used primary lining support methods include timber, steel, grid, anchor, and shotcrete. Shotcrete technology, one of the three pillars of the New Austrian Tunneling Method (NATM), is widely used in underground and tunnel projects due to its simple process, timely support, and low cost. Shotcrete can be used as permanent or temporary support in tunnel projects, and can also be combined with various anchors, steel fibers, steel arches, and steel mesh to form a combined support structure. Currently, shotcrete technology is widely used in the construction of various types of tunnels, underground structures, mine tunnels, and high-rise building foundations.

[0003] The principle of shotcrete is to load pre-prepared fresh concrete into a spraying mechanism. High-pressure gas is used to deliver the fresh concrete to the nozzle, where it is sprayed at extremely high speed onto the tunnel's surrounding rock surface. During this process, concrete particles collide with the tunnel's inner surface under high impact, causing some material to fail to adhere and rebound to the ground and the surrounding environment. The rebound rate of shotcrete can typically reach 10% to 30%, sometimes even reaching 40%. On the one hand, severe rebound not only leads to material waste and changes in the concrete material ratio, but also increases cleaning and material costs, significantly limiting the development of the shotcrete process. On the other hand, severe rebound can easily lead to problems such as uneven shotcrete layer thickness and concrete collapse, compromising the overall structural performance of the initial shotcrete lining and affecting the efficiency of repeated construction. The rebound rate is primarily related to the shotcrete construction process, such as the concrete's incident angle and spraying distance. An ideal spraying angle and distance significantly minimize rebound. However, at present, the primary TBM lining support construction form is mostly manually operated wet spraying machines or spraying trolleys. The technical level and daily status of the construction workers are also important reasons for the different rebound rates of shotcrete.

[0004] To address these issues, various improvement methods have been proposed. For example, improving the material formulation to enhance concrete adhesion and strength, and adjusting spraying parameters such as spraying pressure and nozzle angle to reduce concrete rebound, have been proposed. However, improving the material formulation requires high construction conditions and increases material costs, while adjusting spraying parameters requires high technical skills and is difficult to train. This significantly restricts the application and promotion of shotcrete technology in TBM primary lining support. Summary of the Invention

[0005] In response to the above problems, the present invention proposes a shotcrete slipform mechanism for TBM primary lining support, so as to provide a continuous and smooth surface support while spraying concrete, thereby reducing the rebound rate of the shotcrete process.

[0006] The technical solutions of the present invention are as follows:

[0007] A shotcrete slipform mechanism for TBM primary lining support comprises a shotcrete module, a variable curvature sliding template module and a smoothing module mounted on a supporting steel frame, wherein the smoothing module comprises a first smoothing roller structure and a second smoothing roller structure mounted on the upper and lower sides of the supporting steel frame respectively; the variable curvature sliding template module is mounted in the middle area of ​​the supporting steel frame and is located between a pair of smoothing roller structures; the variable curvature sliding template module adopts a tensioning cylinder and an adjusting cylinder to control the piston rod stroke in a linked manner to adjust the template curvature to adapt it to the tunnel section; the shotcrete module is mounted between the variable curvature sliding template module and the first smoothing roller structure, the angle between the first smoothing roller structure and the supporting steel frame is greater than the angle between the second smoothing roller structure and the supporting steel frame, and the nozzle in the shotcrete module is inclined toward the second smoothing roller structure.

[0008] As a preferred embodiment of the present invention, in the smoothing module, the first smoothing roller structure and the second smoothing roller structure both include a roller bracket and a smoothing roller, the smoothing roller is fixed across the width direction of the supporting steel frame by the roller bracket, and a pair of smoothing rollers are arranged in parallel.

[0009] As a preference of the present invention, the roller bracket in the second leveling roller structure is a right-angle structure.

[0010] As a preferred embodiment of the present invention, the variable curvature sliding template module includes a tensioning template, a pair of limiting rollers located on the upper and lower sides of the tensioning template, at least two adjustment components and a tensioning component located between the pair of limiting rollers; the tensioning component is used to control the deformation of the rear side of the tensioning template, and the adjustment component is used to control the deformation of the front side of the tensioning template; the tensioning template is composed of an inner sliding template and an outer tensioning belt.

[0011] As a preferred embodiment of the present invention, the tensioning assembly and the adjusting assembly are both based on the piston rod stroke of the oil cylinder to control the deformation of the tensioning template;

[0012] The adjustment assembly includes a pair of adjustment cylinders, a pair of connecting spokes, two pairs of triangular spoke plates, and two pairs of adjustment rollers. A pair of adjustment cylinders is fixed on both sides of the supporting steel frame. The piston rods of the adjustment cylinders are connected to the eccentric position of the connecting spokes. A triangular spoke plate is connected to each end of the connecting spoke. A pair of adjustment rollers is connected between a pair of triangular spoke plates at the same height.

[0013] The tensioning assembly includes a pair of tensioning cylinders and a tensioning roller; the pair of tensioning cylinders are fixed at the center positions on both sides of the supporting steel frame, and the two ends of the tensioning roller are respectively connected to the piston rods of the pair of tensioning cylinders.

[0014] As a preference of the present invention, the extension amounts of all the adjusting cylinders in the two adjusting assemblies are the same, and the extension amounts of a pair of tensioning cylinders in the tensioning assembly are the same.

[0015] As a preferred embodiment of the present invention, the injection module includes a linear guide rail and a nozzle mounted on the guide rail, and the nozzle can slide along the guide rail.

[0016] As a preferred embodiment of the present invention, a baffle is provided behind the nozzle to prevent concrete from rebounding to the linear guide rail.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention integrates the sliding formwork mechanism and the nozzle design. The cavity between the sliding formwork and the tunnel wall stores rebound concrete, and the tensioning belt is used to buffer the concrete impact, significantly reducing the rebound rate of the shotcrete. The sliding formwork provides continuous and smooth surface support during the spraying process, so that the rebound concrete is confined in the cavity and directly participates in the initial lining formation, reducing material waste. The leveling roller (arranged in both directions up and down) can dynamically trim the surface morphology of the sprayed layer, avoiding local defects during demoulding and ensuring the integrity of the lining structure.

[0019] (2) This invention uses a tensioning cylinder and an adjustment cylinder for linkage control. By controlling the piston rod stroke, the curvature of the sliding template is adjusted, allowing for rapid adaptation to the geometric requirements of different tunnel sections (e.g., horseshoe-shaped, rectangular), without the need for template replacement, significantly reducing construction preparation time. This design is compatible with the dynamic cross-section changes required during TBM construction and is particularly suitable for rapid cross-section switching under complex geological conditions.

[0020] (3) The sliding formwork mechanism of the present invention replaces the traditional formwork with a tensioning belt to directly contact the concrete, which concentrates the wear on the belt surface that is easy to replace, significantly extending the service life of the sliding formwork. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the construction of a shotcrete slipform mechanism used for TBM primary lining support in a tunnel;

[0022] Figure 2 This is a schematic diagram of the overall structure of the shotcrete slipform mechanism used for TBM primary lining support;

[0023] Figure 3 It is a schematic diagram of the overall structure from another perspective;

[0024] Figure 4 It is a schematic diagram of the injection module structure;

[0025] Figure 5 This is a structural diagram of the variable curvature sliding formwork module mounted on a supporting steel frame;

[0026] Figure 6 This is a structural diagram of the variable curvature sliding formwork module mounted on the supporting steel frame after the sliding formwork and tensioning belt are hidden;

[0027] Figure 7 It is a structural diagram of the leveling module mounted on the supporting steel frame;

[0028] Figure 8 It is a schematic diagram of the two-dimensional equivalent model of the variable curvature sliding template module;

[0029] In the figure: 1-tunnel, 2-engineering vehicle, 3-mechanical arm, 4-support steel frame, 5-injection module, 6-variable curvature sliding template module, 7-leveling module, 501-linear guide rail, 502-guide rail pulley, 503-nozzle support plate, 504-nozzle bracket, 505-drive motor, 506-pitch cylinder, 507-baffle, 508-nozzle, 601-tensioning cylinder, 602-adjusting cylinder, 603-connecting spoke, 604-triangular spoke plate, 605-tensioning roller, 606-adjusting roller, 607-limiting roller, 608-limiting plate, 609-sliding template, 610-tensioning belt, 701-upper leveling roller, 702-upper roller bracket, 703-lower leveling roller, 704-lower roller bracket. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0032] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] The accompanying drawings show various structural schematic diagrams of the embodiments disclosed in the present invention. These drawings are not drawn to scale, and some details are exaggerated and may be omitted for the purpose of clarity.

[0034] like Figure 1 The figure shows a schematic diagram of a shotcrete slipform mechanism used for TBM primary lining support during tunnel construction. The slipform mechanism is mounted on an engineering vehicle via a robotic arm. Engineering vehicle 2 travels axially along tunnel 1. Robotic arm 3 is connected to engineering vehicle 2 via circumferential threaded holes on engineering vehicle 2. Support steel frame 4 is threadedly connected to the end of robotic arm 3 via circumferential threaded holes on the flange at the end of robotic arm 3. Spraying module 5 is threadedly connected to support steel frame 4 via threaded holes at the upper end of support steel frame 4. Variable curvature sliding formwork module 6 and smoothing module 7 are both threadedly connected to support steel frame 4 via threaded holes on both sides of support steel frame 4. The shotcrete slipform mechanism used for TBM primary lining support provides a continuous, smooth surface support while spraying concrete. Concrete that rebounds during the spraying process is stored in a chamber formed between the sliding formwork and the tunnel wall. Under the constraints of the sliding formwork, the desired primary lining shape is formed, solving the problem of high rebound rate in the shotcrete process.

[0035] Figure 2 and Figure 3 They are schematic diagrams of the overall structure from different perspectives. The shotcrete slipform mechanism includes a spraying module 5 installed on the supporting steel frame 4, a variable curvature sliding template module 6 and a smoothing module 7. The smoothing module 7 is composed of a first smoothing roller structure and a second smoothing roller structure respectively installed on the upper and lower sides of the supporting steel frame; the variable curvature sliding template module 6 is installed in the middle area of ​​the supporting steel frame, located between a pair of smoothing roller structures, and the variable curvature sliding template module 6 adopts a tensioning cylinder and an adjusting cylinder to control the piston rod stroke to adjust the template curvature to adapt it to the tunnel section; the spraying module 5 is installed between the variable curvature sliding template module 6 and the first smoothing roller structure, the angle between the first smoothing roller structure and the supporting steel frame 4 is greater than the angle between the second smoothing roller structure and the supporting steel frame 4, and the nozzle in the spraying module 5 is inclined toward the direction of the second smoothing roller structure.

[0036] like Figure 4 As shown, the spray module 5 includes at least one linear guide rail 501 and a spray head 508 mounted on the guide rail, and the spray head can slide along the guide rail.

[0037] In one embodiment of the present invention, the spray module 5 further includes a guide pulley 502, a nozzle support plate 503, a nozzle bracket 504, a drive motor 505, a pitch cylinder 506, and a baffle 507. The guide pulley 502 is nested in a groove defined in the linear guide 501. The nozzle support plate 503 is positioned on the linear guide 501 via the guide pulley 502. The nozzle bracket 504 is connected to the nozzle support plate 503 via threaded holes circumferentially defined in the nozzle support plate 503. The drive motor 505 is threadedly connected to the nozzle support plate 503 to control the movement of the nozzle 508 on the linear guide 501. The pitch cylinder 506 is hingedly connected to the nozzle bracket 504. The baffles 507 are symmetrically positioned on either side of the nozzle 508 and connected to the nozzle bracket 504 via a pin. The baffles 507 prevent concrete from rebounding into the linear guide 501, thereby ensuring the proper operation of the spray module 5. The nozzle 508 is hinged to the piston rod of the pitch cylinder 506 and the nozzle bracket 504 respectively. The parameters such as the pitch angle of the nozzle can be optimized according to the existing technology, and other nozzle structures can also be replaced as long as the function of spraying concrete can be met.

[0038] like Figure 5 and Figure 6 As shown, the variable curvature sliding template module 6 includes a tensioning template, a pair of limiting rollers 607 located on the upper and lower sides of the tensioning template, at least two adjustment assemblies located between the limiting rollers 607, and a tensioning assembly. The tensioning assembly is used to control the deformation of the rear side of the tensioning template, and the adjustment assembly is used to control the deformation of the front side of the tensioning template. In the present invention, both the tensioning assembly and the adjustment assembly control the deformation of the tensioning template based on the piston rod stroke of the oil cylinder. The tensioning template consists of an inner sliding template and an outer tensioning belt. The sliding template provides strong support, while the tensioning belt reduces wear on the sliding template.

[0039] In a specific embodiment of the present invention, the adjustment assembly includes a pair of adjustment cylinders 602, a pair of connecting spokes 603, two pairs of triangular spokes 604 and two pairs of adjustment rollers 606; a pair of adjustment cylinders 602 are fixed on both sides of the supporting steel frame, and the piston rods of the adjustment cylinders 602 are connected to the eccentric position of the connecting spokes 603, and a triangular spoke 604 is connected to each end of the connecting spoke 603, and a pair of adjustment rollers 606 are connected between a pair of triangular spokes 604 of the same height; specifically, the piston rod of the adjustment cylinder 602 is hinged to a slightly eccentric position in the middle of the connecting spoke 603, and the two sides of the connecting spoke 603 are respectively hinged to one corner of the triangular spoke 604, and the remaining two corners of each triangular spoke 604 are respectively hinged with an adjustment roller 606.

[0040] The tensioning assembly includes a pair of tensioning cylinders 601 and a tensioning roller 605; the pair of tensioning cylinders 601 are fixed at the center position on both sides of the supporting steel frame, and the two ends of the tensioning roller 605 are respectively connected to the piston rods of a pair of tensioning cylinders, for example, the piston rod of the tensioning cylinder 601 is hinged to the tensioning roller 605.

[0041] The tensioning belt 610 can also be internally provided with a supporting sliding formwork 609. This belt is positioned outside the roller assembly formed by the tensioning roller 605, the adjusting roller 606, and the limiting roller 607. The sliding formwork 609 is in line contact with the tensioning roller 605, the adjusting roller 606, and the limiting roller 607. The tensioning belt 610 is applied to the surface of the sliding formwork 609 by its own tensioning force. By placing the tensioning belt outside the sliding formwork, the present invention limits wear to the concrete and the tensioning belt, without damaging the sliding formwork itself. Even after extended service life, maintenance of the sliding formwork requires only the replacement of the tensioning belt, reducing both the time and cost of maintenance. Furthermore, the limiting rollers 607 are secured by limiting plates 608, which are symmetrically positioned on either side of the sliding formwork 609. The limiting plates 608 are hingedly connected to the limiting rollers 607, primarily serving to limit lateral slippage of the sliding formwork 609.

[0042] The present invention can adjust the curvature of the sliding template to adapt to the curvature requirements of different tunnel sections simply by extending or retracting the tensioning cylinder and the regulating cylinder piston rod to adjust the positions of different rollers, ensuring that the shape of the cavity formed between the sliding template and the tunnel wall meets the design requirements of the surface morphology and dimensions of the initial tunnel lining. This reduces the frequency of template replacement due to different cross-sectional shapes during TBM tunnel excavation, greatly improving construction efficiency.

[0043] The core advantage of the present invention is that the shotcrete sliding formwork mechanism used for TBM primary lining support can be adaptively adjusted according to the curvature of different tunnel sections, thereby achieving high-quality shotcrete primary lining operations. Therefore, accurately solving the relationship between the expansion and contraction amount of the tensioning cylinder 601 and the adjusting cylinder 602 and the curvature of the sliding template 609 is a prerequisite for ensuring its function. The present invention simplifies the variable curvature sliding template module 6, and projects and transforms its complex three-dimensional geometric structure to form a two-dimensional equivalent model that is easy to analyze. In order to intuitively understand and analyze the influence of the expansion and contraction amount of the tensioning cylinder 601 and the adjusting cylinder 602 on the curvature of the sliding template 609, the actual position of the tensioning cylinder 601 and the adjusting cylinder 602 are virtually extended axially to the point on the surface of the tensioning belt 610 to replace the actual cylinder position, and only the key structural nodes are retained, including the position points of the limiting rollers 607 at both ends of the sliding template 609, the virtual extension point of the adjusting cylinder 602, and the semicircular curve of the tunnel 1 section. The simplified two-dimensional equivalent model is as follows Figure 8 shown.

[0044] like Figure 8 Part (a) is a diagram showing the actual position of the cylinder, where the adjustment cylinder 602 is virtually extended axially to a point on the surface of the tensioning belt 610; Figure 8 Part (b) is a simplified diagram of the kinematic relationship formed by retaining only the key structural nodes, including the positions of the limiting rollers 607 at both ends of the sliding template 609, the virtual extension point of the regulating cylinder 602, and the semicircular curve of the cross section of tunnel 1; Figure 8 Part (c) is a simplified schematic diagram of the sliding mechanism motion relationship.

[0045] Known parameters include: a - roller radius; b - the distance between the adjustment roller 606 and the center of the tunnel 1 when the sliding template 609 is flat; x1 - the horizontal wheelbase of the limiting rollers 607 on both sides; x2 - the horizontal wheelbase between the limiting roller 607 and the adjusting cylinder 602 on the same side; x5 - the distance between the tensioning roller 605 and the sliding template 609 when the sliding template 609 is flat; r - the radius of the tunnel 1; z - the total length of the tensioning belt 610; z3 - the wheelbase between the limiting roller 607 and the tensioning roller 605 when the sliding template 609 is flat; - When the sliding template 609 is flat, the line connecting the limiting roller 607 and the center of the tunnel 1 forms an acute angle with the sliding template 609; - When the sliding template 609 is flat, adjust the obtuse angle between the line connecting the roller 606 and the center of the tunnel 1 and the sliding template 609; - When the sliding template 609 is a plane, the line connecting the adjusting roller 606 and the center of the tunnel 1 forms an obtuse angle with the axis of the adjusting roller 606.

[0046] The parameters to be solved are as follows: z1 - the arc length of the sliding template between a pair of limiting rollers 607 after the sliding template 609 adapts to the curvature of the tunnel section; z2 - the wheelbase between the limiting roller 607 and the tensioning roller 605 after the sliding template 609 adapts to the curvature of the tunnel section; x3 - the extension amount of the adjusting cylinder 602; x4 - the extension amount of the tensioning cylinder 601.

[0047] According to the geometric relationship presented by the simplified two-dimensional equivalent model, the following two sets of equations can be established, which can be solved simultaneously to obtain the extension amount x3 of the regulating cylinder 602 and the extension amount x4 of the tensioning cylinder 601:

[0048]

[0049]

[0050] According to the first equation, the extension amount of the regulating cylinder 602 x3 is obtained:

[0051]

[0052] According to the second set of equations, the extension of the tensioning cylinder 601 x4 is obtained:

[0053]

[0054] like Figure 7 As shown, in the smoothing module 7, the first smoothing roller structure and the second smoothing roller structure each include a pair of roller brackets and a smoothing roller. The smoothing rollers are fixed across the width direction of the supporting steel frame 4 through the roller brackets, and the pair of smoothing rollers are arranged in parallel.

[0055] In a specific implementation of the present invention, according to Figure 7 As shown, the smoothing module 7 primarily comprises an upper smoothing roller 701, an upper roller bracket 702, a lower smoothing roller 703, and a lower roller bracket 704. The upper smoothing roller 701 is hinged to the upper roller bracket 702, which is in turn threadedly connected to the upper end of the support steel frame 4. The lower smoothing roller 703 is hinged to the lower roller bracket 704, which is in turn threadedly connected to the lower end of the support steel frame 4. Both the upper roller bracket 702 and the lower roller bracket 704 are adjustable in their inclination angles to accommodate surface smoothing tasks for various tunnel initial lining applications. Preferably, the lower roller bracket 704 is a right-angle structure, with the angle between the upper roller bracket 702 and the support steel frame 4 significantly greater than the angle between the lower roller bracket 704 and the support steel frame 4, to facilitate installation of the spraying module 5.

[0056] By installing smoothing rollers above and below the variable-curvature sliding formwork module 6, the present invention can smooth the surface topography of the initial shotcrete lining, regardless of whether the initial shotcrete lining is applied counterclockwise or clockwise along the tunnel circumference. This reduces the potential for localized defects on the initial lining surface during demolding from the sliding formwork. Furthermore, the present invention provides a sound hardware foundation for planning process parameters for initial shotcrete lining in tunnels, significantly aiding in the construction of actual tunnel shotcrete linings.

[0057] The initial lining construction method of the above-mentioned shotcrete slipform structure is as follows:

[0058] When it is necessary to carry out the initial shotcrete lining construction on tunnel 1, the engineering vehicle 2 drives to the section of tunnel 1 that needs initial support, and the robotic arm 3 drives the supporting steel frame 4 to drive the sliding formwork mechanism toward the tunnel wall. By adjusting the tensioning cylinder 601 and the adjusting cylinder 602 on the variable curvature sliding formwork module 6 to extend or retract the piston rod to adjust the positions of different rollers, the curvature of the sliding formwork 609 is matched with the curvature of the tunnel 1 section, ensuring that a fan-shaped annular chamber is formed between the sliding formwork 609 and the tunnel 1.

[0059] The sliding formwork mechanism always maintains a certain distance from the tunnel 1 wall; this distance is the designed thickness of the tunnel's initial lining. The integrated robotic arm 5, drive motor 505, and pitch cylinder 506 adjust the nozzle 508 in translation and pitch, ensuring it sprays at the optimal angle and covers the entire sliding formwork 609 area. Fresh concrete is delivered to the nozzle 508 and, under the action of high-pressure gas, is sprayed onto the tunnel 1 wall. A baffle 507 blocks any concrete that may rebound, ensuring the proper functioning of the spraying module 5. Concrete that rebounds during the spraying process is stored in the chamber formed between the sliding formwork 609 and the tunnel 1, thereby reducing the rebound rate of the sprayed concrete. The sliding formwork mechanism provides a continuous, smooth surface support while spraying the concrete. The newly sprayed concrete continuously fills the previously preliminarily hardened concrete, forming the desired initial lining shape within the constraints of the sliding formwork 609.

[0060] After completing the spraying operation in one area, the robot arm 3 drives the sliding formwork mechanism to move circumferentially along the cross-section of the tunnel 1 to proceed with the spraying operation in the next area. During the movement of the sliding formwork mechanism, whether the initial concrete lining is being sprayed counterclockwise or clockwise along the tunnel circumference, the upper leveling roller 701 and the lower leveling roller 703 are both capable of, and at least one of them is capable of, leveling the already demolded sprayed concrete primary lining, thereby reducing localized defects that may occur on the primary lining surface during demolding by the sliding formwork mechanism.

[0061] The above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and many variations are possible. All variations that can be directly derived or imagined by a person skilled in the art from the disclosure of the present invention should be considered to be within the scope of protection of the present invention.

Claims

1. A shotcrete slipform mechanism for TBM primary lining support, characterized in that: The invention comprises a spray module (5), a variable curvature sliding template module (6) and a smoothing module (7) installed on a supporting steel frame (4), wherein the smoothing module (7) is composed of a first smoothing roller structure and a second smoothing roller structure respectively installed on the upper and lower sides of the supporting steel frame; the variable curvature sliding template module (6) is installed in the middle area of ​​the supporting steel frame and is located between a pair of smoothing roller structures; the variable curvature sliding template module (6) adopts a tensioning oil cylinder and an adjusting oil cylinder to control the piston rod stroke to adjust the template curvature so that it adapts to the tunnel section; the tunnel section, the variable curvature sliding template module and the second smoothing roller structure form a fan annular chamber; the spray module (5) is installed on the variable curvature sliding template module Between the curvature sliding template module (6) and the first leveling roller structure, the angle between the first leveling roller structure and the supporting steel frame (4) is greater than the angle between the second leveling roller structure and the supporting steel frame (4), and the nozzle in the injection module (5) is inclined toward the second leveling roller structure. When the injection module (5) injects fresh concrete toward the second leveling roller structure, the concrete rebounds through the tunnel section and is stored in the fan-shaped annular chamber, forming the required primary lining shape under the constraint of the chamber shape; during the movement of the sliding template mechanism, the first leveling roller structure and / or the second leveling roller structure in the leveling module (7) perform a leveling operation on the demoulded primary lining.

2. The shotcrete slipform mechanism for TBM primary lining support according to claim 1, characterized in that: In the smoothing module (7), the first smoothing roller structure and the second smoothing roller structure both include a roller bracket and a smoothing roller, the smoothing rollers are fixed across the width direction of the supporting steel frame (4) via the roller bracket, and a pair of smoothing rollers are arranged in parallel.

3. The shotcrete slipform mechanism for TBM primary lining support according to claim 2, characterized in that: The roller bracket in the second leveling roller structure is a right-angle structure.

4. The shotcrete slipform mechanism for TBM primary lining support according to claim 1, characterized in that: The variable curvature sliding template module (6) comprises a tensioning template, a pair of limiting rollers (607) located on the upper and lower sides of the tensioning template, at least two adjustment components and a tensioning component located between the pair of limiting rollers (607); the tensioning component is used to control the deformation of the rear side of the tensioning template, and the adjustment component is used to control the deformation of the front side of the tensioning template; the tensioning template is composed of an inner sliding template and an outer tensioning belt.

5. The shotcrete slipform mechanism for TBM primary lining support according to claim 4, characterized in that: The tensioning assembly and the adjusting assembly are both based on the piston rod stroke of the oil cylinder to control the deformation of the tensioning template; The adjustment assembly comprises a pair of adjustment cylinders (602), a pair of connecting spokes (603), two pairs of triangular spoke plates (604) and two pairs of adjustment rollers (606); the pair of adjustment cylinders (602) are fixed on both sides of the supporting steel frame, the piston rods of the adjustment cylinders (602) are connected to the eccentric position of the connecting spokes (603), the two ends of the connecting spokes (603) are each connected to a triangular spoke plate (604), and a pair of adjustment rollers (606) are connected between a pair of triangular spoke plates (604) of the same height; The tensioning assembly comprises a pair of tensioning oil cylinders (601) and a tensioning roller (605); the pair of tensioning oil cylinders (601) are fixed at the center positions on both sides of the supporting steel frame, and the two ends of the tensioning roller (605) are respectively connected to the piston rods of the pair of tensioning oil cylinders.

6. The shotcrete slipform mechanism for TBM primary lining support according to claim 5, characterized in that: The extension amounts of all the adjusting cylinders (602) in the two adjusting assemblies are the same, and the extension amounts of a pair of tensioning cylinders (601) in the tensioning assembly are the same. The relationship between the extension amount and the template curvature is: ； ； Where a is the radius of the adjustment roller; b is the distance between the adjustment roller and the tunnel center when the sliding template is flat; x1 is the horizontal wheelbase of the limit rollers on both sides; x3 is the extension of the adjustment cylinder; x4 is the extension of the tensioning cylinder; r is the radius of the tunnel; z is the total length of the tensioning belt; β is the obtuse angle between the line connecting the adjustment roller and the tunnel center and the sliding template when the sliding template is flat.

7. The shotcrete slipform mechanism for TBM primary lining support according to claim 1, characterized in that: The spray module (5) comprises a linear guide rail (501) and a spray head (508) mounted on the guide rail, wherein the spray head is capable of sliding along the guide rail.

8. The shotcrete slipform mechanism for TBM primary lining support according to claim 7, characterized in that: A baffle (507) is provided behind the nozzle (508) to prevent concrete from rebounding to the linear guide rail.

9. A primary lining construction method based on the shotcrete slipform mechanism according to claim 1, characterized in that: include: The engineering vehicle equipped with the mechanical arm drives to the tunnel section where the primary support is required, and the mechanical arm drives the variable curvature sliding template module (6) in the sliding template mechanism toward the tunnel wall, and controls the piston rod stroke by the tensioning cylinder and the regulating cylinder to adjust the template curvature so that it adapts to the tunnel section; The distance between the variable curvature sliding template module (6) and the tunnel section is controlled so that a fan-shaped annular chamber is formed between the variable curvature sliding template module (6), the tunnel section, and the second leveling roller structure. The nozzle in the injection module (5) is tilted toward the second leveling roller structure and injects fresh concrete. The concrete rebounds from the tunnel section and is stored in the fan-shaped annular chamber, and the desired primary lining shape is formed under the constraint of the chamber shape. After completing the spraying operation in one area, the robot arm drives the sliding formwork mechanism to move circumferentially along the tunnel section to carry out the spraying operation in the next area. During the movement of the sliding formwork mechanism, the first leveling roller structure and / or the second leveling roller structure in the leveling module (7) perform a leveling operation on the demoulded primary lining.

10. The primary lining construction method of the shotcrete slipform mechanism according to claim 9, characterized in that: When the robotic arm drives the sliding formwork mechanism to move circumferentially along the tunnel section, the first leveling roller structure and the second leveling roller structure can both face upward or downward, and the directions of the two leveling roller structures change alternately in a complete circumferential movement.

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