A support-free roadway lining vertical formwork

Abstract

The utility model discloses a kind of roadway lining supportless formwork, belong to roadway engineering technical field.The supportless formwork includes formwork, back arris, opposite pull bolt, gable card and nut.The anchoring end of opposite pull bolt is fixedly connected on roadway initial support structure, tension end passes through formwork, back arris and gable card in turn, nut is screwed on tension end terminal and tightens gable card.The back arris is preferably composed of two steel pipes side by side, and the two side flanges of the gable card are bridged and pressed against the outer surface of the back arris.The initial support structure can be welded with U-shaped steel arch or welded with pressure plate by resin anchor rod.The utility model applies pre-tightening torque by nut, forms self-balancing stress system without floor support, and transfers concrete side pressure to roadway surrounding rock.It realizes the parallel operation of tunneling and lining, significantly improves construction efficiency, reduces comprehensive cost, and improves the safety of operation.

Description

Technical Field

[0001] This utility model relates to the field of tunnel engineering technology, and in particular to a supportless vertical formwork for tunnel lining. Background Technology

[0002] In the construction of tunnel lining in underground engineering projects such as mines and tunnels, a reliable formwork support system is required for concrete pouring and forming.

[0003] However, existing tunnel lining construction methods, regardless of the type of standardized formwork used, typically rely on full-span scaffolding for their lateral pressure support systems. This involves erecting dense steel pipe or structural steel supports on the excavated tunnel floor, and then fixing the formwork to these supports. While this traditional method provides the necessary support strength, it also presents significant drawbacks: Extensive scaffolding occupies valuable working space within the tunnels. Tunnels are typically narrow, and the scaffolding severely divides and compresses the internal space, obstructing the flow of personnel, materials, and machinery. Due to space constraints, the critical processes of tunneling and lining cannot be carried out in parallel or at different depths on the same working face; tunneling or subsequent work must wait until the lining work in the previous section is completed before proceeding, significantly slowing down the overall construction progress. The erection, dismantling, and transportation of full-span scaffolding requires substantial manpower and resources, involving complex procedures, high labor intensity, and significant safety risks associated with working at heights, directly increasing overall construction costs.

[0004] Therefore, this utility model proposes a supportless vertical formwork for tunnel lining to address the shortcomings of existing technologies. Utility Model Content

[0005] In view of the problems in the existing technology of formwork without support for roadway lining, such as the reliance on full-span scaffolding for formwork support, resulting in serious occupation of roadway space and the inability to carry out excavation and lining operations in parallel, this utility model aims to provide a roadway lining formwork without support with an improved structure that can effectively solve the above problems.

[0006] This utility model provides a supportless vertical formwork for tunnel lining, including: template, back rib, tie bolt, U-shaped clamp, and nut.

[0007] The tie bolt is a connector that transmits the lateral pressure of the concrete. Its inner end is the anchoring end and its outer end is the tensioning end. The anchoring end is fixedly connected to the initial support structure on the side of the roadway surrounding rock by welding, using the roadway surrounding rock or the initial support structure as the load-bearing foundation.

[0008] The template is pre-drilled with holes for the tie bolts to pass through, and is assembled to form the outline of the roadway lining; the back rib is composed of two steel pipes arranged side by side, abutting against the outer surface of the template away from the roadway surrounding rock, and is used to disperse lateral pressure; the mountain-shaped clip is fitted onto the tensioning end of the tie bolt, and its two side flanges cross over and press against the outer surface of the back rib.

[0009] The nut is threadedly connected to the tension end of the tie bolt and presses the mountain-shaped clamp. The nut applies a preload torque, so that the template, back rib, mountain-shaped clamp and tie bolt form a tight self-balancing cantilever force system.

[0010] Preferably, the back rib is composed of two steel pipes arranged side by side, with a gap between the two steel pipes for the tie bolt to pass through; the two flanges of the mountain-shaped clamp press against the outer walls of the two steel pipes respectively, thereby achieving uniform force transmission.

[0011] Preferably, the initial support structure is a U-shaped steel arch frame, and the anchoring ends of the tie bolts are directly fixed to the web or flange of the U-shaped steel arch frame by welding to achieve a rigid connection.

[0012] Preferably, the initial support structure uses resin anchors embedded in the surrounding rock of the roadway, in conjunction with a pressure-bearing steel plate. The pressure-bearing steel plate is located between the resin anchor and the tie bolt, with one side welded to the inner end of the resin anchor and the opposite side welded to the anchoring end of the tie bolt, thus forming a combined anchoring chain.

[0013] Preferably, the template has pre-drilled mounting holes for the tie bolts to pass through. The diameter of the mounting holes is designed to be larger than the diameter of the tie bolt rod, so as to facilitate rapid on-site assembly and accommodate manufacturing or installation errors.

[0014] Preferably, the mountain-shaped clip is a butterfly clip structure made of cast steel or high-strength stamped steel plate. This structure can convert the point load when the nut is tightened into a line load applied to the back rib, preventing local deformation caused by stress concentration.

[0015] Preferably, the tie bolt has external threads along its entire length or at both ends, and the nut is tightened in conjunction with these external threads to form a non-loosening redundant structure that can withstand the pre-tightening torque applied during construction.

[0016] This utility model has the following beneficial effects: 1. In this utility model, by fixing the anchor end of the tie bolt to the initial support structure of the roadway, and using the surrounding rock of the roadway or the U-shaped steel arch as the load-bearing foundation of the template support, the problem that the roadway lining must rely on full-span scaffolding for support in the prior art is solved, and the technical effect of completely releasing the internal space of the roadway and facilitating the passage of people and vehicles and logistics transportation is achieved.

[0017] 2. In this utility model, by constructing a cantilevered force-bearing system that does not require a ground support, the support process of the lining formwork is completely separated from the tunnel excavation process. This solves the problem of mutual interference and inability to perform parallel operations between the excavation and lining processes in the prior art, and achieves the technical effect of significantly improving construction efficiency, shortening the construction period, and reducing the overall construction cost. Attached Figure Description

[0018] Figure 1 This is a three-dimensional schematic diagram of a supportless vertical formwork for tunnel lining proposed in this utility model. Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0019] Legend: 1. Template; 2. Backing rib; 3. Tie bolt; 4. U-shaped steel arch; 5. Resin anchor; 6. Pressure-bearing steel plate; 7. Mountain-shaped clamp; 8. Nut. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0021] Example: Please refer to Figures 1 to 2 This utility model provides a supportless formwork for roadway lining, which aims to solve the structural defects of existing roadway lining construction, which usually uses full-span scaffolding as a support system, resulting in serious occupation of the internal space of the roadway, inability to achieve parallel operation of excavation and lining, low construction efficiency, high overall cost and insufficient operational safety.

[0022] like Figure 1 and Figure 2As shown, the supportless vertical formwork for the tunnel lining mainly includes formwork 1, back ribs 2, tie bolts 3, U-shaped clips 7, and nuts 8. The components are mechanically connected to form a complete stress and forming system. Formwork 1 serves as the forming interface for concrete pouring. It is composed of several unit plates spliced ​​together to form the design outline of the tunnel lining. Formwork 1 is used to bear the lateral pressure generated during concrete pouring and to define the final shape of the concrete. Back ribs 2 are set on the outer surface of formwork 1 away from the surrounding rock of the tunnel. They are used to reinforce formwork 1 and distribute concentrated loads to prevent local deformation of formwork 1. Tie bolts 3 serve as the core tie members connecting formwork 1 and the initial support structure of the tunnel. They are installed through formwork 1, back ribs 2, and U-shaped clips 7 to convert the lateral pressure of the concrete into tensile force and transmit it to the surrounding rock side of the tunnel.

[0023] Specifically, the tie bolt 3 is a long rod-shaped structure with an anchoring end located on the side of the roadway surrounding rock and a tensioning end extending into the interior space of the roadway. The anchoring end is fixedly connected to the initial support structure on the side of the roadway surrounding rock, using the existing support system of the roadway as the load-bearing foundation. The tensioning end passes sequentially through the installation hole reserved in the template 1, the back rib 2, and the mountain-shaped clip 7 in a direction away from the roadway surrounding rock. The mountain-shaped clip 7 is sleeved on the tensioning end rod of the tie bolt 3, and its two flanges cross and press against the back rib. On the outer surface of template 2, nut 8 is threadedly connected to the tensioning end of tie bolt 3 and tightened into the groove of mountain-shaped clip 7. By applying torque to tighten nut 8, a tight rigid connection is formed between template 1, back rib 2, mountain-shaped clip 7 and tie bolt 3, thereby constructing a self-balancing cantilever force system that does not require ground support. This system can effectively resist the lateral thrust during concrete pouring, ensuring the lining thickness and appearance quality, while freeing up the working space inside template 1.

[0024] To solve the above-mentioned technical problems, the supportless vertical formwork for the tunnel lining also includes a back rib 2 composed of two parallel steel pipes and a mountain-shaped clamp 7 with a specific geometric shape. Furthermore, the back rib 2 and the mountain-shaped clamp 7 form a tight structural fit and force transmission connection with the aforementioned template 1 and tie bolts 3.

[0025] Please refer to the following carefully. Figure 1 and Figure 2 The back rib 2 has a double-pipe combination form consisting of two standard steel pipes arranged in parallel, and a gap channel extending through the length of the back rib 2 is formed between the adjacent side walls of the two steel pipes. The back rib 2 is attached to the side surface of the template 1 away from the surrounding rock of the roadway, and makes line contact or surface contact with the surface of the template 1 through the pipe wall of the steel pipe. Its function is to enhance the overall rigidity of the template 1 and disperse the lateral pressure of the concrete in the longitudinal or transverse direction, and prevent the template 1 from bulging locally.

[0026] Meanwhile, the mountain-shaped clamp 7 is correspondingly provided with an arched central section and flanges extending from the central section to both sides. A through hole is provided at the top center of the central section for the tie bolt 3 to pass through. In the assembled state, the tensioning end of the tie bolt 3 passes through the gap channel of the back rib 2 and continues through the through hole of the mountain-shaped clamp 7, allowing the mountain-shaped clamp 7 to movably fit onto the tie bolt 3. The two flanges of the mountain-shaped clamp 7 span the gap channel and press against the outer cylindrical surfaces of the two steel pipes of the back rib 2. This double-point bridging fit structure ensures that the enormous axial clamping force generated when the nut 8 is tightened can be vertically transmitted through the two flanges of the mountain-shaped clamp 7 to the two steel pipes of the back rib 2, and then the steel pipes evenly press the template 1, forming a stable triangular mechanical transmission structure, greatly improving the overall stability and vibration resistance of the support system.

[0027] Based on the above embodiments, the present invention may further include the following preferred technical solutions: As a preferred implementation method to adapt to different roadway support conditions, in order to make firm anchoring by utilizing the existing initial support system of the roadway, when the initial support structure of the roadway adopts a U-shaped steel arch frame 4 laid along the roadway outline, the anchoring end of the tie bolt 3 is directly fixed to the web or flange of the U-shaped steel arch frame 4 by welding. The rigid force transmission is achieved through welding connection, ensuring that the pull-out force during concrete pouring is directly transmitted to the U-shaped steel arch frame 4 and ultimately borne by the surrounding rock of the roadway.

[0028] As another preferred implementation method for roadways without U-shaped steel support, in order to achieve formwork erection without supports under the condition of only surrounding rock anchor bolt support, the initial support structure uses resin anchor bolts 5 embedded in the surrounding rock of the roadway, and is used in conjunction with pressure-bearing steel plates 6. The pressure-bearing steel plates 6 are constructed as rectangular plates and are set between the resin anchor bolts 5 and the tie bolts 3. The surface of the pressure-bearing steel plates 6 near the surrounding rock is welded and fixed to the exposed end of the resin anchor bolts 5, and the opposite surface of the pressure-bearing steel plates 6 away from the surrounding rock is welded and fixed to the anchoring end of the tie bolts 3, thereby constructing a combined anchoring chain composed of resin anchor bolts 5, pressure-bearing steel plates 6 and tie bolts 3 connected in sequence.

[0029] To facilitate rapid on-site assembly and accommodate manufacturing or installation errors, the template 1 is pre-drilled with mounting holes for the tie bolts 3 to pass through. The diameter of the mounting holes is designed to be larger than the diameter of the tie bolt 3, so that the tie bolt 3 has a certain radial adjustment margin when passing through the template 1, avoiding installation difficulties caused by slight deviations in the hole position.

[0030] To ensure that the mechanical transmission components have sufficient structural strength and rigidity, the mountain-shaped clip 7 is preferably made of cast steel or high-strength stamped steel plate, also known as a butterfly clip. Its geometry is configured to convert the point load applied by the nut 8 into a line load applied to the back rib 2 when the nut 8 is tightened, so as to prevent the back rib 2 from deforming due to stress concentration.

[0031] To ensure the tightness and anti-loosening capability of the connection, the tie bolt 3 has external threads on its entire length or both ends. The nut 8 is tightened with the external threads to form an anti-loosening redundant structure. This structure can withstand the pre-tightening torque applied in stages from the arch foot to the arch top by a torque wrench used during construction, ensuring the stability of the prestress state of the formwork 1 system before pouring.

[0032] Working principle: First, determine the specific anchoring connection mode based on the actual support conditions of the roadway. If the initial support of the roadway is equipped with a U-shaped steel arch 4, the construction personnel will directly weld and fix the anchoring end of the tie bolt 3 to the web or flange of the U-shaped steel arch 4, and use the U-shaped steel arch 4 as the main load-bearing foundation.

[0033] If the initial support of the roadway does not include a U-shaped steel arch frame 4, it is necessary to drill holes in the surrounding rock of the roadway and install resin anchor rods 5. First, weld one side of the pressure-bearing steel plate 6 to the inner end of the resin anchor rod 5, and then weld the anchoring end of the tie bolt 3 to the other side of the pressure-bearing steel plate 6 to complete the connection of the internal anchoring end, thus constructing a combined anchoring structure consisting of resin anchor rod 5, pressure-bearing steel plate 6 and tie bolt 3.

[0034] After the anchoring end connection is completed, the tensioning end of the tie bolt 3 is passed outward through the pre-drilled template 1. On the outside of the template 1 away from the surrounding rock, the back rib 2 composed of two steel pipes arranged side by side and the butterfly clip as the mountain-shaped clip 7 are installed in sequence. The two flanges of the mountain-shaped clip 7 are connected and pressed against the outer wall of the two steel pipes of the back rib 2.

[0035] Finally, screw the nut 8 onto the end of the tie bolt 3 to form a non-loosening redundant structure. When tightening, use a torque wrench to apply torque symmetrically twice in the order from the arch foot to the arch top, forcing the template 1 system to obtain prestress and eliminating assembly gaps, so that the template 1 and the back rib 2 fit tightly together.

[0036] During the concrete pouring process, the lateral pressure of the concrete borne by the formwork 1 is evenly transmitted to the tie bolts 3 through the back ribs 2. Then, the tie bolts 3, with the help of the U-shaped steel arch frame 4 or the combination structure of resin anchor rods 5 and bearing steel plates 6, transfer the load to the surrounding rock of the roadway or the initial support structure, forming a stable support system without scaffolding. This connection method eliminates the need for traditional full-span scaffolding, realizes the open use of the roadway space, and allows the tunneling and lining processes to be carried out in parallel. This not only ensures the quality of lining formation but also improves construction efficiency and reduces overall costs.

[0037] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A formwork system for tunnel lining without support, characterized in that, Includes template (1), back rib (2), tie bolt (3), mountain-shaped clip (7), and nut (8); The tie bolt (3) is a connector that transmits the lateral pressure of concrete. Its inner end is the anchoring end and its outer end is the tensioning end. The anchoring end is fixedly connected to the initial support structure on the side of the roadway surrounding rock. The tensioning end passes through the template (1), the back rib (2) and the mountain-shaped clip (7) in sequence along the direction away from the roadway surrounding rock. The template (1) is pre-drilled with holes for the tie bolts (3) to pass through, and is assembled to form the outline of the roadway lining; the back rib (2) abuts against the outer surface of the template (1) away from the surrounding rock, and is used to disperse the pressure borne by the template (1); the mountain-shaped clip (7) is sleeved on the tensioning end of the tie bolts (3), and the two flanges of the mountain-shaped clip (7) cross and press against the outer surface of the back rib (2); The nut (8) is threaded to the tension end of the tie bolt (3) and presses the mountain-shaped clip (7). By tightening the nut (8), the template (1) system is given prestress, thereby forming a supportless force-bearing system that transmits the lateral pressure borne by the template (1) to the tie bolt (3) through the back rib (2), and then to the surrounding rock side of the roadway by the tie bolt (3).

2. The formwork for roadway lining without support as described in claim 1, characterized in that, The back rib (2) is composed of two steel pipes arranged side by side, with a gap formed between the two steel pipes for the tie bolt (3) to pass through; the two flanges of the mountain-shaped clip (7) press against the outer wall of the two steel pipes respectively.

3. The formwork for roadway lining without support as described in claim 1, characterized in that, The initial support structure is a U-shaped steel arch frame (4); the anchoring end of the tie bolt (3) is directly welded and fixed to the web or flange of the U-shaped steel arch frame (4).

4. The formwork for roadway lining without support as described in claim 1, characterized in that, The initial support structure uses resin anchors (5) implanted in the surrounding rock of the roadway, and is used in conjunction with pressure-bearing steel plates (6).

5. The formwork for roadway lining without support as described in claim 4, characterized in that, The pressure-bearing steel plate (6) is located between the resin anchor rod (5) and the tie bolt (3); one side of the pressure-bearing steel plate (6) is welded to the inner end of the resin anchor rod (5), and the other side of the pressure-bearing steel plate (6) is welded and fixed to the anchoring end of the tie bolt (3).

6. The formwork for roadway lining without support as described in claim 1, characterized in that, The mountain-shaped clip (7) has a butterfly clip structure, with a raised arch in the middle for the tie bolt (3) to pass through, and the nut (8) abuts against the groove of the raised arch.

7. The formwork for roadway lining without support as described in claim 1, characterized in that, The nut (8) and the tie bolt (3) form a loosening-resistant redundant structure, and the nut (8) is constructed to withstand the torque applied by the torque wrench in sequence from the arch foot to the arch top.

8. The formwork for roadway lining without support as described in claim 1, characterized in that, The outer side of the template (1) is locked by the back rib (2), the mountain-shaped clip (7) and the nut (8), which enables the open use of the tunnel space and the parallel operation of excavation and lining when pouring concrete.

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