box culvert guardrail

Abstract

This application discloses a self-moving box culvert guardrail, mainly solving the technical problem that the frequent disassembly and reassembly of the existing intermediate box culvert assembly area enclosure facilities affect work efficiency. It includes two crossbeams symmetrically arranged on both sides of the intermediate box culvert and fixedly connected to the rear trailer of the tunnel boring machine; an enclosure unit fixedly connected to the crossbeams and located above the intermediate box culvert; and stairs fixedly connected to the crossbeams and located on both sides of the enclosure unit for personnel passage during side rail laying. The enclosure unit includes longitudinal guardrails symmetrically arranged on both sides of the intermediate box culvert along the axial direction of the rear trailer and fixedly connected to the corresponding crossbeams; transverse guardrails perpendicular to the longitudinal guardrails and fixedly connected to the longitudinal guardrails near the intermediate box culvert assembly side; and swivel wheel sets symmetrically arranged on both sides of the bottom of the transverse guardrails. This box culvert guardrail has advantages such as convenient and reliable use and no need for manual movement.

Description

Technical Field

[0001] This application relates to the field of tunnel boring machine (TBM) construction equipment, specifically to a box culvert guardrail. Background Technology

[0002] In large-diameter shield tunnels, to facilitate the transportation of materials such as tunnel segments, the middle section of the tunnel's internal structure is often designed as a box culvert during the tunnel's structural design. This allows segment transport vehicles and material transport vehicles to simultaneously transport materials along the surface of the intermediate box culvert, which is assembled as the tunnel is excavated. This ensures that material transport can proceed concurrently with the construction of other tunnel internal structures without interference. Furthermore, after assembly, the bottom surface of the intermediate box culvert contacts the inner arc surface of the shield tunnel segments, bearing the vertical loads from top-level transportation operations. Its internal cavity can also serve as a utility tunnel or other functional area.

[0003] However, in actual construction, intermediate box culverts are continuously assembled as the tunnel boring machine (TBM) advances. These assembly areas are typically not fenced off, and due to the height of the intermediate box culverts, there is a risk of falls for personnel assembling them. To address this, some projects use fixed fences and barricades for temporary enclosure. However, their installation and securing are complex, and because the assembly position of the intermediate box culverts moves forward with the TBM's advance, these fences and barricades must be continuously removed before assembling the next section. This cumbersome operation and low construction efficiency severely impact the efficiency of intermediate box culvert assembly.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the background technology of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] In view of at least one of the above technical problems, this disclosure provides a self-moving box culvert guardrail, which mainly solves the technical problem that the existing intermediate box culvert assembly area enclosure facilities need to be frequently disassembled and reassembled, which affects the operation efficiency.

[0006] According to one aspect of this disclosure, a box culvert guardrail is provided, comprising two crossbeams symmetrically arranged on both sides of a middle box culvert and fixedly connected to a rear trailer of a tunnel boring machine; a retaining unit fixedly connected to the crossbeams and located above the middle box culvert; and stairs fixedly connected to the crossbeams and located on both sides of the retaining unit for personnel passage during side rail laying. The retaining unit comprises a longitudinal guardrail symmetrically arranged on both sides of the middle box culvert along the axial direction of the rear trailer and fixedly connected to the corresponding side crossbeams; a transverse guardrail perpendicular to the longitudinal guardrail and fixedly connected to the longitudinal guardrail near the splicing side of the middle box culvert; and swivel wheel sets symmetrically arranged on both sides of the bottom of the transverse guardrail.

[0007] In some embodiments of this disclosure, the box culvert guardrail also includes a side door that is fixed relative to the trailer attached to the tunnel boring machine and located at the crossbeam for controlling the entrance and exit of the staircase.

[0008] In some embodiments of this disclosure, the crossbeam is fixedly connected to the trailer wheel frame of the tunnel boring machine via steel sections.

[0009] In some embodiments of this disclosure, the caster assembly includes a caster body with a rotating disc and a buffer assembly fixedly connected to the rotating disc.

[0010] In some embodiments of this disclosure, the box culvert guardrail further includes a set of limiting wheels symmetrically arranged on both sides of the enclosure unit and fixedly connected to the longitudinal guardrail for corresponding travel along the side of the intermediate box culvert; the limiting wheel set includes a limiting wheel body and a buffer assembly fixedly connected to the limiting wheel body; mounting plates for fixing the limiting wheel set are provided on both sides of the longitudinal guardrail.

[0011] In some embodiments of this disclosure, the buffer assembly includes a base plate for connecting a wheel body and having a plurality of guide posts vertically arranged at the top edge; a connecting shaft perpendicular to the center of the base plate and having an external thread at the top; a pressure plate disposed above the base plate and having a plurality of guide cylinders vertically arranged at the bottom edge and coaxially fitted and matched with the guide posts; a shaft hole opened at the center of the pressure plate for the connecting shaft to pass through; a buffer spring sleeved on the connecting shaft and having its two ends abutting against the base plate and the pressure plate respectively; a limiting nut threadedly connected to the connecting shaft above the pressure plate and in contact with the pressure plate; and a connecting seat fixed above the pressure plate.

[0012] In some embodiments of this disclosure, the transverse guardrail is provided with a working door for temporary passage of personnel.

[0013] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. The retaining unit uses the trailer attached to the shield machine as the power source for movement. Through the corresponding and stable welding fixation with the trailer, the retaining unit can move forward continuously with the shield tunnel excavation process and the intermediate box culvert assembly process without human intervention, which is convenient to use.

[0014] 2. Make reasonable use of the space between the retaining unit and the tunnel wall to set up stairs, so as to facilitate construction workers to carry out side rail laying and other operations in the side rail area, which can meet various operation needs and has high flexibility.

[0015] 3. The casters at the transverse guardrails can flexibly adapt to the movement of the enclosure units on both straight and curved sections, while also providing support for the enclosure units and preventing wear caused by direct contact between the enclosure units and the surface of the intermediate box culvert. Simultaneously, the buffer components of the casters enhance their flexibility, cushioning external vertical forces and preventing direct impact on the enclosure units.

[0016] 4. By symmetrically setting limit wheel sets on both sides of the enclosure unit near the transverse guardrail, the enclosure unit can be limited in the horizontal direction, thereby avoiding the impact on the connection between the enclosure unit and the rear trailer caused by external forces, which helps to improve the service life of the box culvert guardrail and reduce the maintenance frequency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the usage state of the box culvert guardrail in one embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the universal wheel assembly in one embodiment of this application.

[0019] Figure 3 This is a schematic diagram of the limiting wheel assembly in one embodiment of this application.

[0020] In the above figures, 1 is the intermediate box culvert, 21 is the longitudinal guardrail, 22 is the transverse guardrail, 23 is the working door, 24 is the mounting plate, 3 is the crossbeam, 31 is the structural steel, 41 is the side rail, 42 is the rear trailer, 43 is the trailer wheel pair, 5 is the swivel wheel set, 51 is the wheel body, 52 is the frame, 53 is the rotating wheel, 54 is the base plate, 541 is the guide column, 55 is the connecting shaft, 56 is the spring, 57 is the pressure plate, 571 is the guide cylinder, 58 is the limit nut, 59 is the connecting seat, 6 is the staircase, 61 is the side door, 7 is the limit wheel body, and 8 is the buffer assembly. Detailed Implementation

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] To better understand the technical solution of this application, the above technical solution will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Existing intermediate box culvert protection often uses fixed fences, which need to be moved continuously as the intermediate box culvert is assembled. This moving process is complex and wastes manpower and resources. To achieve low-cost and convenient protection for intermediate box culverts, this example discloses a box culvert guardrail. See details below. Figure 1 As the tunnel boring machine continues to advance, the intermediate box culvert 1 is continuously assembled at the bottom of the tunnel along the tunnel boring machine's excavation axis. Due to the height of the intermediate box culvert, there is a risk of personnel and materials falling during material transportation. Therefore, box culvert guardrails are installed for protection.

[0024] Specifically, the box culvert guardrail disclosed in this example includes a protective unit installed on the top of the assembled box culvert. This protective unit comprises two longitudinal guardrails 21 and one transverse guardrail 22. The two longitudinal guardrails 21 are symmetrically positioned on both sides of the assembled intermediate box culvert and are symmetrical about the corresponding center plane of the intermediate box culvert, thereby preventing materials or personnel from falling from either side of the intermediate box culvert. Considering the high safety risks within the assembly area during the intermediate box culvert assembly operation, to prevent transport vehicles or workers from accidentally entering, a transverse guardrail 22 perpendicular to the longitudinal guardrails 21 is installed on the assembly side of the longitudinal guardrails 21 near the intermediate box culvert. The two ends of the transverse guardrail 22 are fixedly connected to the ends of the corresponding longitudinal guardrails 21. Thus, the two longitudinal guardrails 21 and the transverse guardrail 22 form a "U"-shaped protective area on the surface of the assembled intermediate box culvert, allowing entry only through the opening of the protective area for material transport, effectively eliminating the safety risks of falls and personnel or vehicles accidentally entering the intermediate box culvert assembly area. In addition, considering that construction workers may need to enter the intermediate box culvert assembly area for operations and measurements during actual construction, please refer to... Figure 1 In this example, a working door 23 for temporary personnel passage is installed at the horizontal guardrail.

[0025] Considering that the retaining unit needs to move forward continuously with the tunnel boring machine's (TBM) excavation and the assembly of the intermediate box culvert, and to avoid manual intervention during the forward movement and improve the usability of the box culvert guardrails, in this embodiment, the longitudinal guardrails 21 on both sides are fixedly connected to the rear trailer of the TBM. This allows the rear trailer, which moves synchronously with the TBM's excavation, to provide the power for the retaining unit's movement. For details, see... Figure 1The diagram shows a partial structural composition of the rear-mounted trailer. Symmetrical side rails 41 for the movement of the tunnel boring machine's (TBM) rear-mounted trailer are arranged on both sides of the intermediate box culvert 1. The trailer travels along the side rails 41 via trailer wheelsets 43. To effectively utilize the power of the rear-mounted trailer during its forward movement, crossbeams 3 are symmetrically arranged on both sides of the intermediate box culvert 1 to achieve uniform power transmission between the longitudinal guardrail 21 and the rear-mounted trailer. The crossbeams 3 on both sides are arranged in a direction perpendicular to the axial direction of the rear-mounted trailer. In this embodiment, the crossbeams 3 are specifically made of 175-type steel, and the corresponding ends of the crossbeams 3 are welded and fixed to the structural frame of the rear-mounted trailer, thus enabling the crossbeams 3 to move forward synchronously when the trailer moves forward. The other end of the crossbeam 3 is welded and fixed to the tail end of the longitudinal guardrail 21, thereby establishing a path for the thrust to be transmitted from the rear-mounted trailer frame through the crossbeams to the longitudinal guardrail.

[0026] However, if the enclosure unit of the box culvert guardrail is placed directly on the top surface of the intermediate box culvert, its bottom will inevitably wear against the intermediate box culvert and generate noise during the movement of the subsequent trailer, and will also create some resistance to the forward movement of the trailer. Therefore, a wheel set is installed at the bottom of the transverse guardrail. This wheel set raises the enclosure unit relative to the top surface of the intermediate box culvert by a certain height, greatly reducing friction between the enclosure unit and the intermediate box culvert during movement. However, shield tunnels are not straight; they have curved sections. Therefore, to avoid the angle between the thrust of the trailer and the rotation direction of the wheel set at the bottom of the transverse guardrail during the tunnel's turning motion, which would cause the fixed-direction running wheel set to create resistance to the forward movement of the enclosure unit along the shield curve, in this embodiment, universal wheel sets 5 are respectively installed on both sides of the bottom of the transverse guardrail 23. This allows for flexible adjustment of the rotation direction of the wheels in the universal wheel sets 5 to adapt to the direction of force applied by the trailer.

[0027] Since the longitudinal guardrails 21 on both sides have a certain length, following the approach of setting omnidirectional wheels at the bottom of the transverse guardrails in this example, it would be conventional to also set omnidirectional wheels at the bottom of the longitudinal guardrails for support. However, setting omnidirectional wheels increases the cost of the box culvert guardrails, and the omnidirectional wheels have a limited lifespan and are prone to damage, making maintenance and replacement troublesome. Therefore, in this embodiment, the longitudinal guardrails 21 are directly connected and fixed to the crossbeams 3. However, since the longitudinal guardrails have a certain length, they are quite heavy. Without the support of the wheels, this weight is entirely applied to the crossbeams 3, which greatly increases the fatigue risk of the connection between the crossbeams 3 and the rear trailer, and exacerbates the risk of breakage at the connection point. Therefore, in this embodiment, a steel section 31 is fixedly installed below the crossbeams 3 and is fixedly connected to the trailer wheelset 43 of the rear trailer. The additional load at the crossbeam is transferred through the steel section 31, thereby improving the connection strength and reliability between the crossbeams 3 and the rear trailer.

[0028] Considering that the side rails 41 on both sides of the intermediate box culvert also need to be extended during its construction, and given the height of the intermediate box culvert makes it difficult for personnel to move up and down, and the installation of guardrails further obstructs personnel movement, the following measures are proposed to facilitate the movement of workers during the side rail extension: Figure 1 In this example, staircases 6 are installed at the crossbeams 3 on both sides, and handrails are installed on one side of the staircases. This makes reasonable use of the space between the intermediate box culvert and the tunnel wall, and provides a safe passage for personnel to go up and down. However, considering that the area between the longitudinal guardrail 21 and the corresponding side rear trailer frame, i.e., at the crossbeam location, is an unclosed area, although there are stairs here, to prevent personnel or materials from accidentally falling from here, a side door 61 is installed between the longitudinal guardrail 21 and the corresponding side rear trailer frame in this example. Specifically, the side door 61 includes a door post fixedly connected to the rear trailer and installed vertically, and a door body hinged to the door post. Thus, the side door 61 enables control of the staircase entrance.

[0029] Furthermore, in this embodiment, considering that the flatness of the top surface of the intermediate box culvert cannot be strictly guaranteed due to pouring errors or surface dust and particles, and that there are splicing seams between adjacent intermediate box culverts, the retaining unit may encounter resistance to movement due to the convexity of the intermediate box culvert surface or loss of support due to the concavity of the intermediate box culvert surface when moving along the top surface of the intermediate box culvert via the caster set 5. Therefore, in this embodiment, the caster set 5 includes not only the conventional caster body with a rotating wheel, but also a buffer assembly fixedly connected to the rotating wheel. See details... Figure 2In this example, the caster wheel assembly 5 includes a wheel body 51 and a frame 52 for fixing the wheel body's axle. The top of the frame 52 is equipped with a rotating disc 53. The above-mentioned parts of the caster wheel assembly are conventional caster wheel structures, and will not be described in detail here. Furthermore, in this embodiment, the caster wheel assembly 5 also includes a base plate 54 fixedly connected to the rotating disc 53. A connecting shaft 55 is vertically fixed at the center of the base plate 54, and the top of the connecting shaft 55 has an external thread of a certain length. A spring 56 and a pressure plate 57 are sequentially fitted around the connecting shaft 55 from bottom to top. The pressure plate 57 has a shaft hole at its center for the connecting shaft 55 to pass through, and a limiting nut 58 is threadedly connected to the external thread at the top of the connecting shaft 55. By tightening the limiting nut 58, the bottom surface of the limiting nut 58 contacts the top surface of the pressure plate 57, thereby clamping and pressing the spring 56 through the limiting pressure plate 57. Additionally, a connecting seat 59 is connected to the top surface of the pressure plate 57, allowing it to be fixedly connected to the transverse guardrail. Thus, when the caster wheels pass over the relatively raised surface of the intermediate box culvert, the wheels exert an upward force on the buffer assembly through the base plate. The pressure plate, influenced by the weight of the transverse guardrail, generates a reaction force that opposes this upward force, causing the spring to compress. Furthermore, since the transverse guardrail is relatively far from both the transverse and longitudinal guardrails, the transverse guardrail acts as the force-applying end, and the connection point between the longitudinal guardrail and the transverse beam forms a fulcrum, creating a lever. By converting the vertically upward force into the elastic potential energy of the spring, the upward force is prevented from directly impacting the connection point between the longitudinal guardrail and the transverse beam, thus avoiding any impact on the connection strength between them.

[0030] Furthermore, considering that the pressure plate 57 and the base plate 54 will rotate relative to each other during spring compression and release, and that the connection shaft passing through the pressure plate alone cannot guarantee the overall structural strength and connection reliability of the buffer assembly. Therefore, see [reference needed]. Figure 2 Several guide posts 541 perpendicular to the base plate 54 are provided at the top edge of the base plate 54. In this example, one guide post is provided at each of the four corners of the base plate, for a total of four posts. Correspondingly, guide cylinders 571 are provided on the bottom surface of the pressure plate 57 at the positions of each guide post. The inner diameter of the guide cylinder 571 matches the outer diameter of the guide post 541. Thus, the coaxial nesting between the guide post and the guide cylinder serves to limit the relative position of the base plate and the pressure plate. In addition, to avoid the guide cylinder and guide post affecting the compression of the spring, in this example, the height of the guide cylinder and guide post is set to be less than the uncompressed height of the spring.

[0031] In some other embodiments, considering that the enclosure unit only connects the tail end of the longitudinal guardrail to the downstream trailer via a crossbeam, and given the length of the longitudinal guardrail, if the end of the longitudinal guardrail near the transverse guardrail is subjected to a horizontal force, based on the lever principle, there is a risk of breakage at the connection point between the longitudinal guardrail and the crossbeam. Therefore, in this embodiment, limiting wheel sets are fixedly installed on both sides of the enclosure unit, i.e., at the longitudinal guardrails on both sides, for corresponding movement along the side of the intermediate box culvert. These limiting wheel sets are located on the longitudinal guardrail side near the transverse guardrail, thereby limiting movement in the horizontal plane and preventing the enclosure unit from being affected by horizontal external forces (such as personnel leaning against it, equipment impacts, etc.) that could affect the connection strength between the longitudinal guardrail and the crossbeam or the crossbeam and the downstream trailer. For details, see [link to relevant documentation]. Figure 1 Mounting plates 24 are fixed to the outer sides of the longitudinal guardrails near the crossbeams on both sides for mounting limit wheel assemblies. The limit wheel assembly includes a limit wheel body. In this example, the limit wheel body travels along the outer side of the vertical intermediate box culvert and is relatively fixed to the longitudinal guardrail by a limiting bracket. One end of the limiting bracket is fixedly connected to the mounting plate 24, and the other end is used to fix the limit wheel body. Since the structure of the limiting bracket is diverse and relatively conventional, it will not be described in detail here. However, considering that the outer side of the intermediate box culvert may be uneven, in this example, the limit wheel body is connected to the limiting bracket through a buffer assembly. See [link to relevant documentation]. Figure 3 The limiting wheel body 7 is fixedly connected to the base plate of the buffer assembly 8, and the connecting seat of the buffer assembly 8 is fixedly connected to the limiting bracket. The buffer assembly 8 is the same as described above and will not be repeated here. This makes the wheel body of the limiting wheel body 7 parallel to the top surface of the intermediate box culvert and travel along the side of the intermediate box culvert. When encountering a protrusion, the spring in the buffer assembly provides a buffering effect, avoiding damage to the structural strength of the corresponding connection point between the longitudinal guardrail and the crossbeam under the force of the lever arm formed by the longitudinal guardrail.

[0032] To verify the actual effectiveness of the box culvert guardrail, it was applied in a large-diameter slurry shield tunnel. In actual use, the box culvert guardrail moved smoothly under the drive of a trailer without human intervention, providing excellent protection and effectively preventing the risk of personnel and materials falling from the middle box culvert. Meanwhile, the side staircases facilitate access to the side rail area for side rail laying and other operations.

[0033] Although some preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0034] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of its inventive concept. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A box culvert guardrail, characterized by, It includes two crossbeams symmetrically arranged on both sides of the intermediate box culvert and fixedly connected to the rear trailer of the tunnel boring machine; a retaining unit fixedly connected to the crossbeams and located above the intermediate box culvert; and stairs fixedly connected to the crossbeams and located on both sides of the retaining unit for personnel passage during side rail laying. The retaining unit includes longitudinal guardrails symmetrically arranged on both sides of the intermediate box culvert along the axial direction of the rear trailer and fixedly connected to the corresponding crossbeams; transverse guardrails perpendicular to the longitudinal guardrails and fixedly connected to the longitudinal guardrails near the splicing side of the intermediate box culvert; and swivel wheel sets symmetrically arranged on both sides of the bottom of the transverse guardrails.

2. The box culvert barrier of claim 1, wherein, It also includes a side door that is fixed relative to the trailer attached to the tunnel boring machine and located at the crossbeam for controlling the entrance and exit of the staircase.

3. The culvert guardrail according to claim 1, characterized in that, The crossbeam is fixedly connected to the trailer wheel frame of the trailer truck that is equipped with the tunnel boring machine by means of steel sections.

4. The box culvert barrier of claim 1, wherein, The omnidirectional wheel assembly includes an omnidirectional wheel body with a rotating disc and a buffer assembly fixedly connected to the rotating disc.

5. The box culvert barrier of claim 4, wherein, It also includes a set of limiting wheels symmetrically arranged on both sides of the enclosure unit and fixedly connected to the longitudinal guardrail for corresponding travel along the side of the intermediate box culvert; the set of limiting wheels includes a limiting wheel body and a buffer assembly fixedly connected to the limiting wheel body; mounting plates for fixing the limiting wheel set are provided on both sides of the longitudinal guardrail.

6. A box culvert guardrail according to claim 4 or 5, characterized in that The buffer assembly includes a base plate for connecting the wheel body and having several guide posts vertically arranged at the top edge; a connecting shaft perpendicular to the center of the base plate and having an external thread at the top; a pressure plate located above the base plate and having several guide cylinders vertically arranged at the bottom edge that are coaxially fitted and matched with the guide posts; a shaft hole located at the center of the pressure plate for the connecting shaft to pass through; a buffer spring sleeved on the connecting shaft and having its two ends abutting against the base plate and the pressure plate respectively; a limiting nut threadedly connected to the connecting shaft above the pressure plate and in contact with the pressure plate; and a connecting seat fixed above the pressure plate.

7. The box culvert barrier of claim 1, wherein, The horizontal guardrail is equipped with a working door for temporary passage of personnel.

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