Spraying concrete slip form mechanism for TBM primary lining support

Abstract

The invention discloses a sprayed concrete slip form mechanism for TBM primary lining support, and belongs to the field of additive manufacturing. Comprising a spraying module, a variable-curvature sliding formwork module and a leveling module which are installed on a supporting steel frame, and the leveling module comprises two leveling roller structures; the variable-curvature sliding formwork module is installed in the middle area of the supporting steel frame and located between the leveling roller structures, and the variable-curvature sliding formwork module controls the stroke of a piston rod through linkage of a tensioning oil cylinder and an adjusting oil cylinder so as to adjust the curvature of a formwork, so that the formwork can be matched with the tunnel section. The spraying module is installed between the variable-curvature sliding formwork module and the first leveling roller structure, the included angle between the first leveling roller structure and the supporting steel frame is larger than the included angle between the second leveling roller structure and the supporting steel frame, and a spraying head in the spraying module inclines towards the second leveling roller structure. According to the invention, a continuous and smooth surface support can be provided while the concrete is sprayed, and the rebound rate of the sprayed concrete is reduced.

Description

Technical Field

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

[0002] In order to efficiently construct tunnels that can withstand external forces such as long-term loads and seismic impacts, tunnel boring machines (TBMs) are gradually becoming the most widely used excavation equipment. The construction process generally consists of four parts: excavation, mucking, support, and propulsion. Among them, lining is a permanent support structure built along the perimeter of the tunnel with materials such as reinforced concrete to prevent the surrounding rock from deforming or collapsing during underground construction. The structural stability and mechanical durability of the lining are the prerequisites for efficiently constructing tunnels that can withstand external forces such as long-term loads and seismic impacts. During the support process, different lining support methods will be determined according to the conditions of the surrounding rock, which are usually divided into primary lining and secondary lining. Tunnel excavation destroys the initial stress balance of the stratum, resulting in the release of surrounding rock stress and chamber deformation. Excessive deformation will lead to loosening or even collapse of the surrounding rock. To control the appropriate release of surrounding rock stress and deformation, increase structural safety, and facilitate construction, a structural layer with a relatively small stiffness that is constructed immediately after tunnel excavation and serves as part of the long-term load-bearing structure is called the primary lining. Currently, common primary lining support forms include wooden support, steel support, grid support, bolt support, and shotcrete support, etc. Shotcrete technology is one of the three major pillars of the New Austrian Tunneling Method. It has been widely used in underground and tunnel engineering due to its simple process, timely support, and low cost. Shotcrete can be used as a permanent or temporary support for tunnel engineering, or it can be combined with various forms of bolts, steel fibers, steel arches, steel meshes, etc. to form a combined support structure. Currently, shotcrete technology is widely used in the construction of various tunnels, underground buildings, mine roadways, and high-rise building foundations, etc.

[0003] The principle of the shotcrete process is to load the freshly mixed concrete prepared in advance into the spraying mechanism, and use high-pressure gas to send the freshly mixed concrete to the nozzle, and spray it onto the surface of the tunnel surrounding rock at an extremely high speed. During this process, due to the collision of concrete particles with the inner surface of the tunnel under high impact force, some materials fail to adhere to the inner surface of the tunnel and rebound to the ground and the surrounding environment. The rebound rate of shotcrete can usually reach 10% to 30%, and sometimes even 40%. On the one hand, serious rebound not only causes material waste and changes in the proportion of concrete materials, but also increases the cost of cleaning and materials, greatly restricting the development of the shotcrete process. On the other hand, serious rebound is likely to cause problems such as uneven thickness of the shotcrete layer and collapse and fall of the concrete, which not only affects the overall structural performance of the primary lining of the shotcrete, but also affects the efficiency of repeated construction. The rebound rate is mainly related to the construction process of shotcrete, such as the incident angle of the concrete and the spraying distance. More ideal spraying angles and distances will greatly reduce the rebound amount. However, at present, the construction form of the primary lining support of TBM is mostly manual operation of wet shotcreting machines or shotcreting trolleys, and the technical level and daily state of the construction personnel are also important reasons for the uneven rebound rate of shotcrete.

[0004] To address these problems, various improvement methods have been proposed. For example, by improving the material formula to enhance the adhesion and strength of the concrete; adjusting the spraying parameters, such as spraying pressure and nozzle angle, to reduce the concrete rebound amount. Among these improvement methods, improving the material formula has high requirements for construction conditions and also increases the material cost; adjusting the spraying parameters has high requirements for the technical level of construction personnel and is difficult to train. This obviously restricts the application and promotion of the shotcrete process in the primary lining support of TBM. Summary of the Invention

[0005] In view of the above problems, the present invention proposes a shotcrete slip form mechanism for the primary lining support of TBM to provide a continuous and smooth surface support while spraying shotcrete and reduce the rebound rate of the shotcrete process.

[0006] The technical solution of the present invention is 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 installed on a supporting steel frame, wherein the smoothing module 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 is installed in the middle area of the supporting steel frame and is located between a pair of smoothing roller structures, and the variable curvature sliding template module adopts a tensioning cylinder and an adjusting cylinder to control the piston rod stroke to adjust the template curvature so that it adapts 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, 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 preferred embodiment 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 are 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, and a pair of adjustment rollers are 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 preferred embodiment 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] Preferably, the spraying module includes a linear guide rail and a spray head mounted on the guide rail, and the spray head can slide along the guide rail.

[0016] Preferably, a baffle is provided behind the spray head to prevent the concrete from rebounding onto the linear guide rail.

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

[0018] (1) The slip form mechanism and the spray head of the present invention are integrally designed. The rebound concrete is stored in the chamber between the sliding formwork and the tunnel wall, and the tensioned belt is combined to buffer the impact of the concrete, significantly reducing the rebound rate of the sprayed concrete. Among them, the sliding formwork provides continuous and smooth surface support during the spraying process, so that the rebound concrete is constrained in the chamber and directly participates in the formation of the primary lining, reducing material waste. The leveling rollers (arranged bidirectionally up and down) can dynamically trim the surface topography of the sprayed layer, avoid local defects during demoulding, and ensure the integrity of the lining structure.

[0019] (2) The present invention adopts the linkage control of the tensioning oil cylinder and the adjusting oil cylinder, and adjusts the curvature of the sliding formwork by controlling the stroke of the piston rod, quickly adapting to the geometric requirements of different tunnel cross-sections (such as horseshoe shape, rectangle), without replacing the formwork, and greatly shortening the construction preparation time. This design is compatible with the dynamic cross-section change requirements in TBM construction, and is especially suitable for rapid cross-section switching under complex geological conditions.

[0020] (3) The slip form mechanism of the present invention replaces the traditional formwork with a tensioned belt to directly contact the concrete, concentrating the wear on the surface of the easily replaceable belt, and significantly extending the service life of the sliding formwork. Description of the Drawings

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

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

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

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

[0025] Figure 5 is a schematic diagram of the structure of the variable curvature sliding formwork module mounted on the support steel frame;

[0026] Figure 6 is a schematic diagram of the structure of the variable curvature sliding formwork module mounted on the support steel frame after hiding the sliding formwork and the tensioned belt;

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

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

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

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, or it may be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in combination with 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 some details may be omitted for the purpose of clear expression.

[0034] like Figure 1 The figure shows a schematic diagram of the construction of a shotcrete slipform mechanism for TBM primary lining support in a tunnel. The slipform mechanism is installed on an engineering vehicle through a mechanical arm. The engineering vehicle 2 travels along the axial direction of the tunnel 1. The mechanical arm 3 is connected to the engineering vehicle 2 through the circumferential threaded hole opened on the engineering vehicle 2. The support steel frame 4 is threadedly connected to the end of the mechanical arm 3 through the circumferential threaded hole on the flange at the end of the mechanical arm 3. The injection module 5 is threadedly connected to the support steel frame 4 through the threaded hole opened at the upper end of the support steel frame 4. The variable curvature sliding template module 6 and the smoothing module 7 are threadedly connected to the support steel frame 4 through the threaded holes opened on both sides of the support steel frame 4. The shotcrete slipform mechanism for TBM primary lining support can provide a continuous and smooth surface support while spraying concrete. The rebounded concrete during the spraying process will be stored in the chamber formed between the sliding template and the tunnel wall. The required initial lining shape is formed under the constraint of the sliding template, which solves the problem of high rebound rate of 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 a 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, 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 at least includes a 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 a specific implementation of the present invention, the spraying module 5 further includes a guide rail pulley 502, a nozzle support plate 503, a nozzle bracket 504, a driving motor 505, a pitching oil cylinder 506, and a baffle 507. The guide rail pulley 502 is nested in the groove opened on the linear guide rail 501. The nozzle support plate 503 is arranged on the linear guide rail 501 through the guide rail pulley 502. The nozzle bracket 504 is connected to the nozzle support plate 503 through the threaded holes circumferentially opened on the nozzle support plate 503. The driving motor 505 is threadedly connected to the nozzle support plate 503 to control the movement of the nozzle 508 on the linear guide rail 501. The pitching oil cylinder 506 is hinged to the nozzle bracket 504. The baffles 507 are symmetrically arranged on both sides of the nozzle 508 and are connected to the nozzle bracket 504 through pin shafts. The baffles 507 can prevent the concrete from rebounding into the linear guide rail 501, thereby ensuring the normal operation of the spraying module 5. The nozzle 508 is respectively hinged to the piston rod of the pitching oil cylinder 506 and the nozzle bracket 504. Parameters such as the pitching 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 satisfied.

[0038] As Figure 5 and Figure 6 shown, the variable curvature sliding formwork module 6 includes a tensioning formwork, and a pair of limiting rollers 607 located on the upper and lower sides inside the tensioning formwork, at least two adjusting 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 formwork, and the adjusting component is used to control the deformation of the front side of the tensioning formwork. In the present invention, both the tensioning component and the adjusting component control the deformation of the tensioning formwork based on the piston rod stroke of the oil cylinder. The tensioning formwork is composed of an inner sliding formwork and an outer tensioning belt. Among them, the sliding formwork can provide strong support force, and the tensioning belt can reduce the wear of the sliding formwork.

[0039] In a specific implementation of the present invention, the adjusting component includes a pair of adjusting oil cylinders 602, a pair of connecting spokes 603, two pairs of triangular spokes 604, and two pairs of adjusting rollers 606; a pair of adjusting oil cylinders 602 are fixed on both sides of the support steel frame. The piston rod of the adjusting oil cylinder 602 is connected to the eccentric position of the connecting spoke 603. Each end of the connecting spoke 603 is connected to a triangular spoke 604. A pair of adjusting rollers 606 are connected between the pair of triangular spokes 604 at the same height; specifically, the piston rod of the adjusting oil cylinder 602 is hinged to a position slightly eccentric in the middle of the connecting spoke 603. The two sides of the connecting spoke 603 are respectively hinged to one of the corners of the triangular spoke 604. The remaining two corners of each triangular spoke 604 are respectively hinged with an adjusting 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 central positions on both sides of the supporting steel frame. Both ends of the tensioning roller 605 are respectively connected to the piston rods of the pair of tensioning cylinders. For example, the piston rod of the tensioning cylinder 601 is hinged to the tensioning roller 605.

[0041] A sliding template 609 for support can also be arranged inside the tensioning belt 610. It is sleeved outside the roller group formed by the tensioning roller 605, the adjusting roller 606 and the limiting roller 607. The contact modes between the sliding template 609 and the tensioning roller 605, the adjusting roller 606 and the limiting roller 607 are all line contacts. The tensioning belt 610 is arranged on the surface of the sliding template 609 through its own tensioning force. In the present invention, by arranging the tensioning belt outside the sliding template, the wear only occurs between the concrete and the tensioning belt, and the sliding template itself will not be damaged. After the slip form mechanism has been in service for a long time, only the tensioning belt needs to be replaced to complete the equipment maintenance, reducing the time and economic costs of maintaining the slip form mechanism. In addition, the limiting roller 607 is fixed by a limiting plate 608. The limiting plates 608 are symmetrically arranged on both sides of the sliding template 609. The limiting roller 607 is hinged on the limiting plate 608. The limiting plate 608 mainly serves to limit the lateral slip of the sliding template 609.

[0042] In the present invention, by only extending or retracting the piston rods of the tensioning cylinder and the adjusting cylinder to adjust the positions of different rollers, the curvature of the sliding template can be adjusted to meet the curvature requirements of different tunnel sections, ensuring that the shape of the chamber formed between the sliding template and the tunnel wall conforms to the design requirements of the surface topography size of the primary lining of the tunnel, reducing the frequency of replacing the template during the process of the TBM excavating the tunnel due to different cross-sectional shapes, and greatly improving the construction efficiency.

[0043] The core advantage of the present invention lies in that the shotcrete slip form mechanism for the primary lining support of the TBM can be adaptively adjusted according to the curvatures of different tunnel sections, so as to achieve high-quality shotcrete primary lining operation. Therefore, accurately solving the relationship between the telescopic amounts of the tensioning cylinder 601 and the adjusting cylinder 602 and the curvature of the sliding template 609 is the prerequisite for ensuring the realization of its function. The present invention simplifies the variable-curvature sliding template module 6, projects and transforms its complex three-dimensional geometric structure to form a two-dimensional equivalent model that is convenient for analysis. In order to intuitively understand and analyze the influence of the telescopic amounts of the tensioning cylinder 601 and the adjusting cylinder 602 on the curvature of the sliding template 609, the axial positions of the actual tensioning cylinder 601 and the adjusting cylinder 602 are virtually extended to the points on the surface of the tensioning belt 610 to replace the actual cylinder positions, and only the key structural nodes are retained, including the position points where the limiting rollers 607 at both ends of the sliding template 609 are located, the virtual extension points of the adjusting cylinder 602, and the semi-circular curve of the tunnel 1 section. The simplified two-dimensional equivalent model is as Figure 8 shown.

[0044] As shown in Figure 8 part (a) in it is a schematic diagram of replacing the actual position of the oil cylinder with the point where the adjusting oil cylinder 602 is axially and virtually extended to the surface of the tensioning belt 610; Figure 8 part (b) in it is a simplified diagram of the kinematic relationship formed by only retaining the key structural nodes, including the position points of the limit rollers 607 at both ends of the sliding formwork 609, the virtual extension point of the adjusting oil cylinder 602, and the semi-circular curve of the cross-section of the tunnel 1; Figure 8 part (c) in it is a schematic diagram of the motion relationship of the simplified slip form mechanism.

[0045] The known parameters include: a - the radius of the roller; b - the distance between the adjusting roller 606 and the center of the tunnel 1 when the sliding formwork 609 is a plane; x1 - the horizontal axis distance between the two limit rollers 607 on both sides; x2 - the horizontal axis distance between the limit roller 607 and the adjusting oil cylinder 602 on the same side; x5 - the distance between the tensioning roller 605 and the sliding formwork 609 when the sliding formwork 609 is a plane; r - the radius of the tunnel 1; z - the total length of the tensioning belt 610; z3 - the axis distance between the limit roller 607 and the tensioning roller 605 when the sliding formwork 609 is a plane; - The acute angle formed between the line connecting the limit roller 607 and the center of the tunnel 1 and the sliding formwork 609 when the sliding formwork 609 is a plane; - The obtuse angle formed between the line connecting the adjusting roller 606 and the center of the tunnel 1 and the sliding formwork 609 when the sliding formwork 609 is a plane; - The obtuse angle formed between the line connecting the adjusting roller 606 and the center of the tunnel 1 and the axis of the adjusting roller 606 when the sliding formwork 609 is a plane.

[0046] The parameters to be solved are as follows: z1 - the arc length of the sliding formwork between a pair of limit rollers 607 after the sliding formwork 609 adapts to the curvature of the tunnel cross-section; z2 - the axis distance between the limit roller 607 and the tensioning roller 605 after the sliding formwork 609 adapts to the curvature of the tunnel cross-section; x3 - the extension amount of the adjusting oil cylinder 602; x4 - the extension amount of the tensioning oil 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, and the extension amount x3 of the adjusting oil cylinder 602 and the extension amount x4 of the tensioning oil cylinder 601 can be solved by simultaneous equations respectively:

[0048]

[0049]

[0050] According to the first set of equations, the extension amount x3 of the adjusting oil cylinder 602 is solved as:

[0051]

[0052] According to Equation Set 2, the extension x4 of the tensioning oil cylinder 601 is solved as follows:

[0053]

[0054] As Figure 7 shown, in the leveling module 7, both the first leveling drum structure and the second leveling drum structure include a pair of drum brackets and a leveling drum. The leveling drum is fixedly supported across the width direction of the support steel frame 4 through the drum brackets, and a pair of leveling drums are arranged in parallel.

[0055] In a specific implementation of the present invention, according to Figure 7 the direction shown, the leveling module 7 mainly includes an upper leveling drum 701, an upper drum bracket 702, a lower leveling drum 703, and a lower drum bracket 704. The upper leveling drum 701 is hinged to the upper drum bracket 702, and the upper drum bracket 702 is connected to the upper end of the support steel frame 4 by a screw thread. The lower leveling drum 703 is hinged to the lower drum bracket 704, and the lower drum bracket 704 is connected to the lower end of the support steel frame 4 by a screw thread. The upper drum bracket 702 and the lower drum bracket 704 can both adjust the inclination angle to adapt to the surface leveling work of different tunnel primary linings. Preferably, the lower drum bracket 704 is a right-angle structure, and the angle between the upper drum bracket 702 and the support steel frame 4 is significantly greater than the angle between the lower drum bracket 704 and the support steel frame 4, which is convenient for the installation of the spraying module 5.

[0056] By arranging leveling drums above and below the variable-curvature sliding formwork module 6 in the present invention, no matter whether the concrete primary lining is sprayed counterclockwise or clockwise along the tunnel circumference, the leveling drums can level the surface topography of the sprayed concrete primary lining and reduce the possible local defects on the surface of the primary lining when the slip form mechanism is demolded. At the same time, the present invention provides a good hardware basis for planning the process parameters of the tunnel sprayed concrete primary lining and provides great help for the construction of the tunnel sprayed concrete primary lining in engineering practice.

[0057] The construction method of the primary lining of the above-mentioned sprayed concrete slip form mechanism is as follows:

[0058] When it is necessary to construct the primary lining of the tunnel 1 by spraying concrete, the engineering vehicle 2 travels to the cross-section of the tunnel 1 that needs to be initially supported. The robotic arm 3 drives the support steel frame 4 to drive the slip form mechanism towards the tunnel wall. By adjusting the extension or retraction of the pistons of the tensioning oil cylinder 601 and the adjusting oil cylinder 602 on the variable-curvature sliding formwork module 6 to adjust the positions of different drums, the curvature of the sliding form 609 is matched with the curvature of the tunnel 1 cross-section to ensure that an annular chamber is formed between the sliding form 609 and the tunnel 1.

[0059] The sliding formwork mechanism always keeps a certain distance to fit the wall of tunnel 1, and this distance is the design thickness size of the initial lining of the tunnel. The integrated mechanical arm 5, the drive motor 505 and the pitch cylinder 506 perform translation and pitch adjustment on the nozzle 508 to ensure that it is incident at the best spraying angle and the spraying range covers the entire sliding formwork 609 area. The freshly mixed concrete is transported to the nozzle 508 and sprayed onto the wall of tunnel 1 under the action of high-pressure gas. The baffle 507 blocks the concrete that may rebound to ensure the normal operation of the injection module 5. The concrete that rebounds during the injection process will be stored in the chamber formed between the sliding formwork 609 and the tunnel 1, thereby reducing the rebound rate of the sprayed concrete, and using the sliding formwork mechanism to provide a continuous and smooth surface support while spraying the concrete; the newly sprayed concrete is continuously filled onto the concrete that has been initially hardened in the previous part, and the required initial lining shape is formed under the constraint of the sliding formwork 609.

[0060] After the spraying operation of one area is completed, the robot arm 3 drives the sliding form mechanism to move along the circumference of the tunnel 1 section to carry out the spraying operation of the next area. During the movement of the sliding form mechanism, whether the initial concrete lining is sprayed counterclockwise or clockwise along the circumference of the tunnel, the upper leveling roller 701 and the lower leveling roller 703 can and at least one of them can level the demoulded sprayed concrete initial lining, thereby reducing the local defects that may be generated on the surface of the initial lining when the sliding form mechanism is demoulded.

[0061] The above examples are only 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 associated with the contents disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A shotcrete slipform mechanism for the primary lining support of a TBM, characterized in that, The invention comprises a spray module (5), a variable curvature sliding template module (6) and a smoothing module (7) mounted on a supporting steel frame (4); the smoothing module (7) is composed of a first smoothing roller structure and a second smoothing roller structure respectively mounted on the upper and lower sides of the supporting steel frame; the variable curvature sliding template module (6) 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 (6) uses a tensioning cylinder and an adjusting cylinder to control the stroke of a piston rod to adjust the template curvature so that it adapts to the tunnel section; the spray module (5) is mounted 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 spray head in the spray module (5) is inclined toward the second smoothing roller structure.

2. The shotcrete slipform mechanism for the primary lining support of a TBM according to claim 1, wherein In the smoothing module (7), the first smoothing roller structure and the second smoothing roller structure both comprise 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 primary lining support of TBM 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 at 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 the primary lining support of a TBM according to claim 4, wherein 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 respectively connected to a triangular spoke plate (604), and a pair of adjustment rollers (606) are connected between a pair of triangular spoke plates (604) at 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 of 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 the primary lining support of a TBM according to claim 5, wherein 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: ； ； Wherein, a is the radius of the adjusting roller; b is the distance between the adjusting roller and the center of the tunnel when the sliding formwork is planar; is the horizontal axis distance between the two limiting rollers; is the extension of the adjusting oil cylinder; is the extension of the tensioning oil cylinder; r is the radius of the tunnel; z is the total length of the tensioning belt; is the obtuse angle formed between the line connecting the adjusting roller and the center of the tunnel and the sliding formwork when the sliding formwork is planar.

7. The shotcrete slipform mechanism for the primary lining support of a TBM 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 the primary lining support of a TBM 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 for the shotcrete slip form 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 through the linkage between 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 first leveling drum structure; the nozzle in the injection module (5) is tilted toward the second leveling drum 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 the spraying operation in one area is completed, 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 smoothing roller structure and / or the second smoothing roller structure in the smoothing module (7) perform a smoothing operation on the demoulded primary lining.

10. The initial lining construction method of the shotcrete slip form mechanism according to claim 9, characterized in that, When the mechanical arm drives the sliding form 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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